| Mission Description |
TABLE OF CONTENTS ---------------------------------- = ROSETTA Mission Overview = ROSETTA Mission Objectives - Science Objectives = Mission Profile = Mission Phases Overview - Mission Phase Schedule - Solar Conjunctions/Oppositions - Payload Checkouts = Mission Phases Description - Launch phase (LEOP) - Commissioning phase - Cruise phase 1 - Earth swing-by 1 - Cruise phase 2 (and Deep Impact) - Mars swing-by - Cruise phase 3 - Earth swing-by 2 - Cruise phase 4 (splitted in 4-1 and 4-2) - Steins flyby - Earth swing-by 3 - Cruise phase 5 - Lutetia flyby - Rendez-Vous Manouver 1 - Cruise phase 6 - Rendez-Vous Manouver 2 - Near comet drift (NCD) phase - Approach phase - Lander delivery and relay phase - Escort phase - Near perihelion phase - Extended mission = Orbiter Experiments - ALICE - CONSERT - COSIMA - GIADA - MIDAS - MIRO - OSIRIS - ROSINA - RPC - RSI - VIRTIS - SREM = LANDER (PHILAE) - Science Objectives - Lander Experiments = Ground Segment - Rosetta Ground Segment - Rosetta Science Operations Center - Rosetta Mission Operations Center - Rosetta Lander Ground Segment - Lander Control Center - Science Operations and Navigation Center - Rosetta Scientific Data Archive = Acronyms ROSETTA Mission Overview ===================================================================== The ROSETTA mission is an interplanetary mission whose main objectives are the rendezvous and in-situ measurements of the comet 67P/Churyumov-Gerasimenko, scheduled for 2014/2015. The spacecraft carries a Rosetta Lander, named Philae, to the nucleus and deploys it onto its surface. A brief description of the mission and its objectives can be found in the Rosetta Science Management Plan RO-EST-PL-0001 and in papers GLASSMEIERETAL2007A. A detailed description of the mission analysis can be found in the Consolidated Report on Mission Analysis RO-ESC-RP-5500, the ROSETTA User Manual RO-DSS-MA-1001, and the flight Operations Plan RO-ESC-PL-5000. On its long way to the comet nucleus after a Launch by Ariane 5 P1+ in March 2004, the ROSETTA spacecraft orbits the Sun for one year until it returns to Earth for the first swing-by. The planet Mars is reached in February 2007, about 3 years after launch. In November 2007 a second Earth swing-by takes place and a third one in November 2009. Two asteroid flybys (2867 Steins and 21 Lutetia) are performed on the way to the comet. These two asteroids were selected at the Science Working Team meeting on 11th March 2004 among all the available candidate asteroids, depending on the scientific interest and the propellant required for the correction manoeuvre. Around the aphelion of its orbit, which is 5.3 AU from the Sun, the spacecraft is in a spinning hibernation mode for about 2.5 years. The comet 67P/Churyumov-Gerasimenko is reached about 10.5 years after launch, in May 2014. After a comet mapping phase the Surface Science Package, carried piggyback on the spacecraft are released for landing on the comets surface for in situ measurements. The ROSETTA mission then makes a detailed study of the comet and its environment until a Sun distance of 2 AU is reached again after comet perihelion, at the end of the year 2015. Please note: ------------ The ROSETTA spacecraft was originally designed for a mission to the comet 46 P/Wirtanen to be launched in January 2003. Due to a delay of the launch a new comet (67P/Churyumow-Gerasimenko) had been selected by the Science Working Team on 3rd-4th April 2003 RO-SWT-2004APR04. The compliance of the design was checked and where necessary adapted for this new mission. Therefore in the following all the details and characteristics for this new mission are used. ROSETTA Mission Objectives ===================================================================== The scientific objectives of the ROSETTA mission can be considered from three main viewpoints: First of all, comets and asteroids are fully-fledged members of our solar system, which means, that they are objects of intrinsic interest to planetary scientists. The level of investigations conducted on these bodies is therefore far below that achieved for the other objects of the solar system. The study of the small solar-system bodies arguably represents the last major gap in the tremendous worldwide effort that has been made to reveal our planetary neighbours to us. The most important scientific rationale for studying small solar- system bodies is the key role-play in helping us to understand the formation of the solar system. Comets and asteroids have a close genetic relationship with the planetesimals, which formed from the solar nebula 4.57 billion years ago. Most of our present understanding of these processes has been obtained by studying meteorites, which constitute a biased sample of asteroidal material, and micrometeoroids, which may represent cometary grains processed by solar radiation and atmospheric entry. There is therefore a strong scientific case of studying cometary material in situ, as it is surely more primitive than extraterrestrial samples. A third scientific aspect is the study of the physio-chemical processes, which are specific to comets and asteroids. In this respect, asteroids can provide information on impact phenomena, particularly on very large scale. However, the increase in cometary activity as these bodies approach the Sun undoubtedly represents one of the most complex and fascinating processes to be observed in the solar system. Science Objectives --------------------- The prime scientific objectives as defined in the Announcement of Opportunity RO-EST-AO-0001 by the Rosetta Science Team can be summarized as: - Global characterisation of the nucleus, determination of dynamic properties, surface morphology and composition - Chemical, mineralogical and isotropic compositions of volatiles and refractories in a cometary nucleus - Physical properties and interrelation of volatiles and refractories in a cometary nucleus - Study of the development of cometary activity and the processes in the surface layer of the nucleus and in the inner coma (dust-gas interaction) - Origin of comets, relationship between cometary and interstellar material. - Implications for the origin of the solar system - Global characterisation of the asteroid, determination of dynamic properties, surface morphology and composition. Mission Profile ===================================================================== The ROSETTA mission profile results from the orbit of the target comet 67P/Churyumov-Gerasimenko, which has a perihelion close to 1.2 AU and an aphelion of about 5.7 AU, resulting in a period of about 6.5 years. A detailed description of the Mission Profile can be found in the Consolidated Report on Mission Analysis RO-ESC-RP-5500, in the Rosetta Mission Calendar RO-ESC-PL-5026 and in the RSOC Design Specification RO-EST-PL-2010. The injection of the spacecraft by a single Ariane 5 Launch with the so-called delayed ignition of the upper stage, is not directly into the trajectory to the comet, because of the high spacecraft wet mass. Therefore the spacecraft has to be accelerated by a sequence of gravity assist manoeuvres at Mars and the Earth, in order to catch up with the comets velocity at perihelion. However, this increases the mission duration to a total of nearly 12 years. The initially large distance to the comet at the perihelion of its trajectory is slowly decreasing after the third Earth swing-by. At the intersection of both orbits, the difference in orbit inclination and the residual relative velocity are diminished by the comet orbit matching manoeuvre at around 4.0 AU Sun distance. The range of the spacecraft-to-Sun distance is between 0.88 and 5.33 AU, defined by the minimum Sun distance during the first five years of the mission with the swing-bys at Earth, and the maximum Sun distance close to the aphelion of the comets orbit. The evolution of the spacecraft distance to Earth over the mission time follows the profile of the Sun distance superimposed by an oscillation with an amplitude of 2 AU (+1,-1) and a period of about one year due to the Earths motion around the Sun. This results in a range from 0 AU (Earth Departure and Swing-by) to 6.3 AU during the superior solar conjunction close to the spacecrafts aphelion (see Solar Conjunctions section below). After the second and third Earth swing-by ROSETTA crosses the asteroid main belt, which gives the opportunity of two asteroid flybys. The asteroids 2867 Steins and 21 Lutetia, are encountered on 5 September 2008 and 10 July 2010 respectively. These two asteroids were selected at the Science Working Team meeting on 11th March 2004 among all the available candidate asteroids, depending on the scientific interests and the propellant required for the correction manoeuvre. Between the major mission events, up to the comet rendezvous manoeuvre, the spacecraft performs long interplanetary cruise phases (up to 2.5 years) with several solar conjunctions (see Solar Conjunctions section below) and the power critical aphelion passage (last cruise phase). In order to reduce the ground segment costs and the wear and tear of spacecraft equipment during these phases, the spacecraft is put in Hibernation Mode. Two types of hibernation modes are planned to be used: * Deep Space Hibernation Mode above 4.5 AU: Inertial spin mode with a spin rate of 4 deg/sec. The spacecraft is almost entirely passive, except of receivers/ decoders, power supply, heaters and two Processor Modules with one RTU. * Near Sun Hibernation Mode below 4.5 AU: 3-axes stabilised mode with the solar arrays Sun-pointing and the +X-axis Earth-pointing. Attitude control is performed with thrusters and star trackers, based on ephemerides; occasional solar array adjustments and ground contacts via the medium gain antenna (MGA). The final approach to the comet into its sphere of influence is prepared by the rendezvous manoeuvre (RVM-2), that matches the spacecraft orbit with the comet orbit. A subsequent sequence of approach manoeuvres, supported by optical navigation, takes the spacecraft closer and closer to the comet. After determination of the physical model of the comet by Doppler and optical measurements, the spacecraft is inserted into a global mapping orbit around the comet. The global mapping starts from orbital heights of 5 to 25 comet radii, depending on the actual size, shape and mass of the comet. Close observation of specific landmarks from altitudes down to one comet radius is planned. At least 80% of the illuminated surface shall be mapped. The very low velocity of the spacecraft in the comet orbit (few cm/s) requires a high performance accuracy of the propulsion system. The delivery of the Lander or Surface Science Package (SSP) is achieved from an eccentric orbit, which takes the spacecraft to a low altitude above the selected landing site. The Lander release is fully automatic according to a predefined schedule, and shall lead to touch down with minimum vertical and horizontal velocities relative to the local rotating surface. Upon the landing of the Lander, the spacecraft provides uplink and downlink data relay between the Lander and the Earth. After the Lander delivery the ROSETTA spacecraft escorts the comet until the perihelion passage and outwards again, until a Sun distance of 2 AU is reached end of the year 2015. The main scientific objective during this phase is the monitoring of the features of the active comet. Mission Phases Overview ====================================================================== This section gives an overview of the major mission phases and main events in scheduled tables. A description of the individual phases is given in the following section. More detailed information can be found in the Rosetta Mission Calendar RO-ESC-PL-5026, the Consolidated Report on Mission Analysis RO-ESC-RP-5500 and the RSOC Design Specification RO-EST-PL-2010 Mission Phase Schedule ----------------------- The following table shows a schedule of the mission phases, with start-end times (dd/mm/yyyy), duration (days) and distance to the sun (Astronomical Units). Some of the most important events within the mission phases are marked with an arrow (->). Further description of each mission phase is given below. .==================================================================== | Phase |Start Date|Main Event| End Date |Dur |SunDist(AU)| |=================|==========|==========|==========|====|===========| |LEOP |02/03/2004| |04/03/2004| 3 | | |-----------------|----------|----------|----------|----|-----------| |Commissioning1 |05/03/2004| |06/06/2004| 94 | 0.89-0.99 | | ->DSM1 | |11/05/2004| | | | | ->DSM1 Touch-up| |16/05/2004| | | | |-----------------|----------|----------|----------|----|-----------| |Cruise 1 |07/06/2004| |05/09/2004| 91 | 0.89-1.04 | |-----------------|----------|----------|----------|----|-----------| |Commissioning2 |06/09/2004| |16/10/2004| 41 | 1.04-1.09 | |-----------------|----------|----------|----------|----|-----------| |Earth Swing-by1 |17/10/2004| |04/04/2005| 170| 0.99-1.11 | | ->Earth | |04/03/2005| | | | |-----------------|----------|----------|----------|----|-----------| |Cruise 2 |05/04/2005| |28/07/2006| 480| 1.04-1.76 | | ->Deep Impact | |04/07/2005| | | | |-----------------|----------|----------|----------|----|-----------| |Mars Swing-by |29/07/2006| |28/05/2007| 304| 0.99-1.59 | | ->DSM2 | |29/09/2006| | | | | ->Mars | |25/02/2007| | | | | ->DSM3 | |29/04/2007| | | | |-----------------|----------|----------|----------|----|-----------| |Cruise 3 |29/05/2007| |12/09/2007| 107| 1.32-1.58 | |-----------------|----------|----------|----------|----|-----------| |Earth Swing-by2 |13/09/2007| |27/01/2008| 137| 0.91-1.32 | | ->Earth | |13/11/2007| | | | |-----------------|----------|----------|----------|----|-----------| |Cruise 4-1 |28/01/2008| |03/08/2008| 189| 1.02-2.03 | |-----------------|----------|----------|----------|----|-----------| |Steins Flyby |04/08/2008| |05/10/2008| 63 | 2.03-2.19 | | ->Steins | |05/09/2008| | | | |-----------------|----------|----------|----------|----|-----------| |Cruise 4-2 |06/10/2008| |13/09/2009| 343| 1.35-2.26 | | ->DSM4 | |19/03/2009| | | | |-----------------|----------|----------|----------|----|-----------| |Earth Swing-by3 |14/09/2009| |13/12/2009| 92 | 0.98-1.35 | | ->Earth | |13/11/2009| | | | |-----------------|----------|----------|----------|----|-----------| |Cruise 5 |14/12/2009| |16/05/2010| 154| 1.03-2.45 | |-----------------|----------|----------|----------|----|-----------| |Lutetia Flyby |17/05/2010| |03/09/2010| 111| 2.45-3.14 | | ->Lutetia | |10/07/2010| | | | |-----------------|----------|----------|----------|----|-----------| |Rendez-vousMan1 |04/09/2010| |13/07/2011| 313| 3.15-4.58 | | ->RVM1 | |23/01/2011| | | | |-----------------|----------|----------|----------|----|-----------| |Cruise 6 (DSHM) |14/07/2011| |22/01/2014| 917| 4.49-5.29 | |-----------------|----------|----------|----------|----|-----------| |Rendez-vousMan2 |23/01/2014| |17/08/2014| 206| 3.53-4.49 | | ->RVM2 | |23/05/2014| | | | |-----------------|----------|----------|----------|----|-----------| |Global Mapping |18/08/2014| |19/10/2014| 63 | 3.15-3.53 | |and Close | | | | | | |Observation | | | | | | |-----------------|----------|----------|----------|----|-----------| |Lander Delivery |20/10/2014| |16/11/2014| 28 | 2.97-3.15 | |->Lander Delivery| |11/11/2014| | | | |-----------------|----------|----------|----------|----|-----------| |Comet Escort |17/11/2014| |31/12/2015| 410| 1.24-2.97 | ------------------------------------------------------------------- Payload Checkouts ----------------- Payload checkouts are scenarios designed to allow Rosetta payload to make regular health checks, to activate mechanisms and to monitor trends through calibration tests. They are allocated in the mission calendar at regular 6-month periods during the first 10 years of the mission cruise phase. They are split into passive and active payload checkouts. Passive payload checkouts are entirely non-interactive. Conditions for the passive checkout are that it will: a) not require any real time monitoring, b) run entirely off of MTL, c) not require s/c specific pointing other than to maintain listed constraints, d) produce minimal science data. Active payload checkout operations are executed both interactively and non-interactively . Conditions for the active checkout are that it will: a) limit the requirement for real time monitoring, b) run mostly from MTL, c) limit the requirement for s/c specific pointing beyond maintaining listed constraints, d) produce minimal science data. There is more flexibility during active checkouts and in addition payloads use interactive passes to make any necessary memory patches and tests. .-------------------------------------------------------------------. | Name | Type | Begin | End | Mission Phase | |-----------------|--------|----------|-----------|-----------------| | P/L Checkout 0 |Passive |27/03/2005| 31/03/2005| Earth Swing-by 1| | P/L Checkout 1 |Passive |30/09/2005| 05/10/2005| Cruise 2 | | P/L Checkout 2 |Passive |03/03/2006| 08/03/2006| Cruise 2 | | P/L Checkout 3 |Passive |25/08/2006| 30/08/2006| Mars Swing-by | | P/L Checkout 4 | Active |27/11/2006| 21/12/2006| Mars Swing-by | | P/L Checkout 5 |Passive |18/05/2007| 23/05/2007| Mars Swing-by | | P/L Checkout 6 | Active |13/09/2007| 30/09/2007| Earth Swing-by 2| | P/L Checkout 7 |Passive |04/01/2008| 09/01/2008| Earth Swing-by 2| | P/L Checkout 8 | Active |19/07/2008| 24/07/2008| Cruise 4-1 | | P/L Checkout 9 |Passive |28/01/2009| 02/02/2009| Cruise 4-2 | | P/L Checkout 10 | Active |18/09/2009| 08/10/2009| Earth Swing-by 3| | P/L Checkout 12 |Passive |22/04/2010| 15/05/2010| Cruise 5 | | P/L Checkout 13 |Passive |01/12/2010| 15/12/2010| RVM1 | ------------------------------------------------------------------- Solar Conjunctions/Oppositions ------------------------------- Other mission phases, which result from the orbit geometry and interfere with the above operational phases, are the solar conjunctions. Two types of conjunctions occur throughout the mission: * Solar Oppositions: The Earth is between spacecraft and Sun, resulting in a degradation of the command link to the spacecraft. * Superior Solar Conjunctions: Sun is between spacecraft and Earth, resulting in a degradation of the command and telemetry link to/from the spacecraft. Table below shows the solar conjunction phases throughout the mission with type, begin and duration of the conjunction and correspondant mission phase. The phases are defined as the periods, during which the Sun-SpaceCraft-Earth (SSCE) angle is below 5 degrees. .-------------------------------------------------------------------. | Type |Duration| Begin | End | Mission Phase | |---------------|--------|------------|------------|----------------| | Conjunction 1 | 48d | 21/03/2006 | 07/05/2006 | Cruise 2 | | Conjunction 2 | 39d | 08/12/2008 | 15/01/2009 | Cruise 4-2 | | Conjunction 3 | 50d | 22/09/2010 | 10/11/2010 | RV Manouver 1 | | Opposition 1 | 37d | 13/04/2011 | 19/05/2011 | RV Manouver 1 | | Conjunction 4 | 64d | 15/10/2011 | 17/12/2011 | Cruise 6 | | Opposition 2 | 47d | 30/04/2012 | 15/06/2012 | Cruise 6 | | Conjunction 5 | 67d | 31/10/2012 | 05/01/2013 | Cruise 6 | | Opposition 3 | 46d | 20/05/2013 | 04/07/2013 | Cruise 6 | | Conjunction 6 | 60d | 24/11/2013 | 22/01/2014 | Cruise 6 | | Opposition 4 | 28d | 25/06/2014 | 22/07/2014 | RV Manouver 2 | | Conjunction 7 | 41d | 21/01/2015 | 02/03/2015 | Comet Escort | -------------------------------------------------------------------- Mission Phases Description ===================================================================== Launch and Early Orbit Phase (LEOP) ----------------------------- Rosetta was launched by an Ariane 5/G+ in a dedicated flight (single launch configuration) from Kourou at 07:17:51 UTC 2 March 2004. After burnout of the lower composite, the upper stage together with the spacecraft remained in an eccentric coast arc for nearly 2 hours. Then the upper stage performed delayed ignition and injected the Rosetta spacecraft into the required escape hyperbola. After spacecraft separation from the upper stage, Rosetta acquires its three axes stabilised Sun pointing attitude and deploys the solar arrays autonomously. Ground operations acquire the down-link in S-band using the ESA network and control the spacecraft to a fine- pointing attitude with the HGA pointing towards Earth using X-band telemetry. Tracking and orbit determination are performed, the departure trajectory is verified and corrected by the on-board propulsion system of the spacecraft. The launch locks of the Lander Philae are released at the end of the first ground station pass. Philae remains firmly attached to the spacecraft by the cruise latches until its release at the comet. Commissioning phase (1 and 2) ------------------- Commissioning starts three days after launch following the first trajectory correction manoeuvre. A Deep Space Manouver (DSM1) of 173 m/s is executed at perihelion. All spacecraft functions needed during the cruise to the comet, in particular for hibernation, are checked and the scientific payload is commissioned. Commissioning is done in two parts, as the New Norcia ground station must be shared with Mars Express and cannot be used by Rosetta from June to mid-September 2004. For more information refer to the following reports: RO-EST-RP-3293 Consolidated Rosetta Payload Report of the Mission Commissioning Results Review RO-EST-RP-3307 RSOC_Commissioning_Results_Report_2005Dec19.pdf RO-EST-RP-3343 Interference Scenario Report Cruise phase 1 -------------- Almost all the scientific instruments, except ALICE are switched off while ground contact is practically not available. No payload operations are done during this phase. Earth swing-by 1 ---------------- The actual Earth swing-by takes place on 4-Mar-05. The phase ends one month after the swing-by and the spacecraft is prepared for the next cruise phase to Mars. One passive Payload Checkout is scheduled end of March 2005. Immediately after this flyby an Asteroid Flyby Mode Simulation is performed using the Moon as a target. Some limited payload operations are permitted shortly before during and shortly after this Earth Flyby. Rosetta payload teams are given the opportunity to conduct scientific investigation that includes close approach of both the Earth and the Moon and the AFM simulation. Any activities that do not require the Earth-Moon system i.e. continued instrument commissioning, are considered for later in the Mission, such as during the next active checkout. The instrument objectives are listed below. ORBITER ALICE objectives are: - Flat field calibration - Extended object scattered light calibration (Moon as the target) - Absolute solar calibration - Absolute flux and wavelength calibration (wide part of the slit to take in the Moon) - Door performance test due to anomalies raised during commissioning MIRO - Asteroid Flyby Simulation test - H2O lines in Earth (high quality data obtained but analysis not complete) - Radiometric calibration of the Moon RPC - Sensor calibration - Magnetospheric physics - Verification of the science operations modes for the Mars flyby RSI - HGA to Earth around closest approach to Moon OSIRIS - Because of technical issues OSIRIS was not operated during the Earth Swing-By itself. VIRTIS - Co-alignment M/H - Aldebaran target in IR (failed, boresight did not detect the target) - Absolute calibration using the Moon - Full disc Earth imaging including exosphere over one rotation LANDER CIVA - Earth Picture with Camera #2 or 4 ROMAP with RPC MAG - magnetic axes alignment of sensors with Earth magnetic field - Checking of scaled values with known Earth values - Solar wind values comparison with other s/c Problems: RPC - Loss of LAP science data for 41.5 hours (2005-03-01 19:00 -- 2005-04-03 12:30). For more information refer to the following reports: RO-EST-RP-3318 Payload Passive Checkout 0 Report RO-EST-RP-3321 Rosetta Earth-Swingby #1 Payload Operations Report Cruise phase 2 (and Deep Impact) -------------------------------- After leaving the Earth, the spacecraft makes one revolution around the Sun, and in the second arc from perihelion to aphelion makes a swing-by of Mars. There is a solar conjunction for more than one month in April 2006 (see Solar Conjunctions section above). Two passive check-outs with non-interactive instrument operations for about 5 days are scheduled during the cruise to Mars. PC1 occurs from 5/09/2005 to 5/10/2005. PC2 takes place from 3/03/2006 to 8/03/2006. The NASA Deep Impact mission encounters comet 9P/Tempel 1 on 4 July 2005, which falls into the Cruise 2 mission phase. At around 06:00 UTC, the mother probe sends a 362 kg impactor into the nucleus with a relative speed of 10.2 km/s. Rosetta is in a privileged position for its remote sensing instruments to observe the event (80 million km distance, 90 degrees angle respect to the sun). Rosetta monitors Tempel 1 continuously (i.e. 24 hrs per day) over an extended period from 7 days before the deep impact to 11 days afterwards (27Jun-15Jul 2005). The first 2 days ALICE observe the stars for calibration. From the 28th June to the 15th July, OSIRIS, ALICE, and MIRO operate observing comet 9P/Tempel 1 continuously. VIRTIS was on only several hours around the impact. Maintenance activities were carried out for COSIMA, ROSINA, ALICE. During the Deep Impact subphase, the instruments have the following objectives: ORBITER ALICE - Baseline pre-impact spectrum. Comparison with near and long term post impact spectra. The comet is detected in all spectra. - Strong atomic lines of neutral H and O were detected throughout the observation period. - Two weak lines of neutral C detected on some dates. No change detected by ALICE in comets UV spectrum as a result of impact - except for possible enhancement in C emission. - No evidence of Ar, S, N, CO. - Water production rates. Results TBC. - Dark histograms. - Calibration star before the encounter. Spectra of calibration star is used for calibration of the Deep Impact spectra and instrument sensitivity. The data is also used to look for any flux variations due to pointing/jitter (initial results do not show any evidence of significant fluctuations in the stellar count rate). - Memory patch (time synchronisation issue). MIRO - Changes in the coma composition induced by the impact. - Upper limit on the water production rate in the pre-impact phase of the experiment. Water production rate and albeit with low signal-to-noise measured in the post impact phase. The water production rate is less than has been anticipated based on models. - Detection of carbon monoxide: the analysis is not complete but so far no CO was detected. - Estimate of Doppler velocity. OSIRIS - Accurate photometry of the unresolved nucleus (no atmosphere in between) with complete time coverage. The time resolution is better than a minute around the impact and can draw conclusion about the evolution of the impact cloud during the first hour. The long term monitoring allowed determination of the composition and evolution of the impact cloud (water production and dust/ice ratio) - UV coverage that allowed imaging of the OH emission at 308nm (estimate of the water production by the impact) - Imaging of the coma out to at least 150000km from the nucleus. The effect of the impact can be seen in the images for appromximately a week (stereo reconstruction of coma, impact cloud). VIRTIS - Coma and ejecta composition and temporal evolution. But the outburst due to the impact was not energetic enough to reach the minimum sensitivity required. Conclusions of the Deep Impact Observations: The science objectives of the Deep Impact Observations scenario are met. The brightness increase of Tempel 1 produced by the impact is lower than we had hoped for, and as a result the comet was too weak to be detected by VIRTIS. For ALICE and MIRO the signal was just above the sensitivity limit, but nevertheless important measurements could be achieved. The results of OSIRIS even exceeded the expectations, and the first scientific publications are widely cited. The data collected by the experiments on board Rosetta are unique because Tempel 1 was monitored continuously over an extended period of time (no day-and- night cycle in contrast to ground-based telescopes) and in the absence of an absorbing atmosphere. The following operations have been done during the Passive checkout 1: ORBITER ALICE - Electronic and software - Test pattern and stim test - Memory check - dark exposures There is no instrument anomalies. The door performance test showed nominal behavior. CONSERT - Consert Orbiter verification - Consert Lander verification - Consert Orbiter/Lander time synchronisation COSIMA - Self check - Target manipulator unit maintenance - Ion emitter maintenance GIADA - Run mechanisms - cover operations - Health check (all subsystems, electronics, noise and contamination monitoring, performances estimation) MIDAS - Exercising of all mechanisms (shutter, approach mechanism, linear stage, wheel, scanner) The test is successful and MIDAS is fully operable. MIRO - Regular exercise and health check of all commands in all modes - Regular dump of EEPROM memory to check for radiation damage. All objectives are met. There is no radiation damage of the EEPROM. RPC - MAG: instrument calibration. Undisturbed solar wind is measured to calibrate the offsets of the MAG instrument in quiet conditions (Hedgecock method). - LAP: instrument calibration. - MIP: Instrument checkout - IES: measurement in the undisturbed solar wind for calibration of its sensors and cross calibration with LAP. The PC operations are completed successfully with no change in instrument performance for MAG and IES. RSI Two frequency downlink drven by the USO and a ground station that can receive the X and S band signals. - Investigate the stability of the USO - Verify interaction with the ground Investigations of the USO data from PC#0 revealed that the behaviour of the USO is obviously not as good as it was during the last USO test in October. OSIRIS - Exercise the instrument mechanisms - Verify the sanity of the CCD - Verify the focus No anomaly occurs. LANDER Test of the Lander Platform overall performance Secondary battery monitoring Lander extended AFT CDMS EEPROM dump functional test for PTOLEMY CONSERT The following operations have been done during the Passive checkout 2: ORBITER ALICE - same health tests as PC1. Tests successful. CONSERT - same as PC1. Tests generally successful (see report) COSIMA - self check of all hardware sub-systems on operational voltage levels - target manipulator unit checkout - maintenance COSISCOPE checkout - emitter maintenance Tests generally successful. GIADA - Same as PC1 plus monitoring of MBS coating evolution. The cover operations went fine. There is no further contamination of the microbalances. GDS is not fully tested for light conditions. IS seems nominal. All HK values are as expected. MIDAS - same as PC1. Tests are successful. MIRO - Same as PC1. Overall success. RPC - Same as PC1. All performances checked are nominal. RSI - Same as PC1. The USO behaves very good, USO drift satisfactory. OSIRIS - Same as PC1. Generally successful. For solar elongation angles < 90 degrees OSIRIS gets substantial scattered light through the nominally closed doors. The scattered light observed during PC2 was unfortunately enough that parts of the CCD surface was saturated. This happened in spite of the large exposure time reduction that was made after PC1. VIRTIS - The check done were performed properly. LANDER Same as PC1 plus functional tests for MUPUS CONSERT For more information refer to the following reports: RO-EST-RP-3341 Deep Impact Observations, Payload Operations Report RO-EST-RP-3342 Passive Payload Checkout 1 Report RO-EST-RP-3418 Passive Payload Checkout 2 Report Mars swing-by ------------- The mission phase begins two months before DSM2 of 65 m/s, which is performed near perihelion. The actual Mars swing-by takes place on 25-Feb-07. The minimum altitude with respect to the Martian surface is 200 km. The relative approach and departure velocity is 8.8 km/s. During the swing-by a communications black-out of approximately 14 min is expected due to occultation of the spacecraft by Mars. Furthermore the spacecraft is expected to be in eclipse for about 24 min. The phase ends one month after DSM3. DSM3 of 129 m/s is scheduled near the aphelion of this arc in order to obtain the proper arrival conditions at the Earth. Two passive payload check-outs of about 5 days and an active longer one of 25 days are scheduled during the phase. PC3 starts on 25th August 2006 and ends 30th August 2006. The following operations were planed during PC3. GIADA and ROSINA did not take part in this PC. ORBITER ALICE - Electronics & software verification, test pattern and stim test, Memory Check, Aperture Door, Performance Test. All operations are executed as expected. CONSERT - Consert Orbiter verification, Consert Lander verification, Consert Orbiter/Lander time Synchronisation. COSIMA - self check of all hardware sub-systems on operational voltage levels, target manipulator unit checkout and maintenance emitter maintenance MIDAS - Regular health check and exercising of all mechanisms (shutter, approach mechanism, linear stage, wheel, scanner) MIRO - Regular exercise and health check of all commands in all modes. Regular dump of EEPROM memory to check for radiation damage. All operations are successful. RPC - MAG: Instrument calibration. Undisturbed solar wind measurement. Such data will be used to calibrate the offsets of the MAG instrument in quiet conditions (Hedgecock method). - LAP: Instrument calibration. - MIP: Instrument checkout. - IES: measurements in the undisturbed solar wind for calibration of its sensors and crosscalibration with LAP. RSI - Investigate the stability of the USO and verify interaction with the ground. The PC3 results are very promising and the behavior of the USO is as good as expected. The stability of the USO is still one order of magnitude better than anticipated before launch. OSIRIS - Instrument mechanisms, verify the sanity of the CCD, verify the focus of the instrument. VIRTIS - Both VIRTIS M and H are working as expected. - PC3 has been used to verify the upload of a new pixel map for VIRTIS-H to be used during the forthcoming PC4 (pixel map allows to drastically reduce the data volume). LANDER - Test of the Lander platform to check the overall performance and Secondary Battery Status - Lander Extended AFT with short function - tests of some units and EEPROM - checks for all ComDPU units - Secondary Battery Monitoring - CDMS EEPROM dump - Separate short functional tests for MUPUS and CONSERT The report has not yet been written. Payload checkout reports: RO-SGS-RP-0001_1_- _Rosetta_Passive_Payload_Checkout_3_Report_2007Jun27.pdf RO-EST-RP-3464_1_- _Rosetta_Report_Active_Payload_Checkout_4_2006Apr13.pdf RO-SGS-RP-0002_1_- _Rosetta_Passive_Payload_Checkout_5_Report_2007June27.pdf Cruise phase 3 -------------- No check-outs are scheduled during the short cruise to Earth. Earth swing-by 2 ---------------- Daily operations start again around two months before Rosetta reaches Earth with tracking and navigation manoeuvres. The actual Earth swing -by takes place on 13-Nov-07. The perigee altitude is 13890 km. The relative approach and departure velocity is 9.3 km/s. The phase ends one month after the LGA strobing phase. In this phase the spacecraft gets very close to the sun (min distance 0.91AU). One 15 day payload checkout and one 5 day payload checkout are also scheduled in this phase. The report has not been written. The Payload checkout reports are : RO-SGS-RP-0004_1_- _Rosetta_Report_Active_Payload_Checkout_6_2007Oct30.doc RO-SGS-RP-0005_1_a _Rosetta_Passive_Payload_Checkout_7_Report_2008Jun24.pdf. Cruise phase 4 (split into 4-1 and 4-2) -------------- In this phase the spacecraft makes one revolution around the Sun. . A solar conjunction takes place in January 2009 (see Solar Conjunctions section above), together with another two conjunctions of the Earth- spacecraft- Sun angle (Sun-Earth conjunction as seen from the spacecraft). In this phase the spacecraft gets very close to the sun (min distance 0.91AU). This Cruise phase has been splitted in two parts after the selection of the first Asteroid flyby which falls in the middle of this phase. Cruise 4-1 is before the flyby phase, and 4-2 is right after. Two passive check-outs are scheduled, one during Cruise 4-1 and the second one during Cruise 4-2. During this phase, occured Passive Checkout 9 see RO-SGS-RP-0030.pdf Active Checkout 8 see RO-SGS-RP-0019.pdf. Steins flyby ------------- Asteroid Steins was the first dedicated scientific target of the Rosetta mission. Closest approach was on 5 September 2008 at 18:38:22 UTC. Rosetta flew at 800 km from asteroid Steins. For the first time a European spacecraft flew next to an asteroid, performed an optical navigation campaign, and autonomously tracked the asteroid by means of its on board camera. The 2867 Steins E-type asteroid had been discovered on 4 November 1969 by N. Chernykh. Its dimensions have been estimated by KELLERETAL2010 to 6.67 x 5.81 x 4.47 km3, corresponding to a spherical equivalent radius of 2.65 km. Its sideral rotation period has been estimated to 6.04681 +/- 0.00002h, its pole direction in ecliptic coordinates to approximately Lambda = 250 deg and Beta = -89 deg with an error of about 5 degrees LAMYETAL2008. Its albedo has been estimated to 0.3 in the visible and 0.4 in the infrared, both by KELLERETAL2010 and LAMYETAL2008. The two asteroids Rosetta flew by are secondary science targets of the Rosetta mission, with comet 67P/Churyumov-Gerasimenko being the primary science target. Therefore, scientific measurements of Asteroid (2867) Steins had highest priority during the Steins flyby. Calibrations was performed during the flyby phase only if a calibration close in time to the actual scientific measurement was needed. The flyby geometry necessitated a flip in the spacecraft attitude before closest approach. As a compromise between the incompatible requirements to minimize the illumination of the -X and +-Y panels of the spacecraft (flip as late as possible) and to minimize the impact on the science observations (flip as early as possible), the spacecraft flip was performed between 40 and 20 minutes before closest approach. The flyby of Steins is a very fast flyby in the sense that the distance between Rosetta and the Asteroid changes by an order of magnitude within 15 minutes before and after the flyby. The heliocentric and geocentric distances of Rosetta during the Steins flyby was 2.14 AU and 2.41 AU, respectively. The one way light travel time were 20 minutes. The estimated accuracy of the determination of the position of Steins in the plane perpendicular to the flight direction during the naviga- -tion campaign was +/-2 kms for navigation with OSIRIS and +/-16 kms for navigation with the NAVCAMs (from navigation slot on Sept. 4). For the targeted passage through phase angle 0 at a distance of 1280 kms from Steins, a positional offset of 2 kms would correspond to a minimum phase angle of 0.1 degree. The following table shows an overview of the Steins Flyby scenario: ------------------------------------------------------------------ | Start Date | End Date | Operation | ------------------------------------------------------------------ | 04/08/2008 | 04/09/2008 | Navigation campaign (astrometry) using| | | | NAVCAM and OSIRIS NAC | ------------------------------------------------------------------ | 01/09/2008 | 10/09/2008 | Scientific operations targeting the | | | | asteroid | ------------------------------------------------------------------ | 07/09/2008 | 04/10/2008 | Observation of gravitational | | | | microlensing events in the galactic | | | | bulge by OSIRIS | ------------------------------------------------------------------- The following table shows the observation results per instrument: ---------------------------------------------------------------------| Instrument| Title |Success| Comments | ---------------------------------------------------------------------| ALICE 01 | Alice optics | Yes | at the beginning and | | | decontamination | | end of all scenarios | |--------------------------------------------------------------------| | ALICE 02 | Standard stellar flux | Yes | During major | | | calibration using the AL| | scenarios | | | narrow center boresight | | | |--------------------------------------------------------------------| | ALICE 03 | Standard stellar flux | Yes | During major | | | calibration using the AL| | scenarios | | | +X wide bottom boresight| | | |--------------------------------------------------------------------| | ALICE 04 | Dark exposures | Yes | Regular calibration | |--------------------------------------------------------------------| | ALICE 05 | Search for evidence of | Yes | No exosphere or coma | | | exosphere/coma around | | found | | | Steins | | | |--------------------------------------------------------------------| | ALICE 06 | Point at Steins to | Yes | First Spectrum of an | | | obtain an FUV spectrum | | asteroid below 200nm | |--------------------------------------------------------------------| | ALICE 07 | Point to the Steins RA | Yes | | | | and Dec at the mid point| | | | | of AL 06 observation | | | |--------------------------------------------------------------------| | ALICE 08 | Point to the Steins RA | Yes | | | | and Dec at the mid point| | | | | of AL 05 observation | | | |--------------------------------------------------------------------| | ALICE 09 | Standard stellar flux | Yes | During major | | | calibration using the AL| | scenarios | | | -X wide top boresight | | | |--------------------------------------------------------------------| | COSIMA 01 | Image and expose D8 | No | TMU error | | | substrate | | | |--------------------------------------------------------------------| | COSIMA 02 | Image all D8 substrates | No | Cancelled after | | | and store it | | failure of CS 01 | |--------------------------------------------------------------------| | GIADA 01 | non nominal operational | Yes | | | | configuration, i.e. only| | | | | impact sensor on and | | | | | cover closed | | | |--------------------------------------------------------------------| | LANDER 01 | Run MUPUS TEM mode | Yes | | | | during periods with | | | | | pronounced temperature | | | | | changes | | | |--------------------------------------------------------------------| | LANDER 02 | Operate ROMAP in slow | Yes | Interference from | | | mode and fast mode | | MUPUS deteceted | | | during CA +/-30min | | | |--------------------------------------------------------------------| | LANDER 03 | CASSE measurements | Yes | | | | during WOL with SW FM-2 | | | |--------------------------------------------------------------------| | LANDER 04 | Thermal test of SESAME | Yes | | | | soles | | | |--------------------------------------------------------------------| | LANDER 05 | Operation of CASSE and | Yes | | | | DIM in a dusty environ-| | | | | -ment | | | |--------------------------------------------------------------------| | MIRO 01 | Observation of Steins | Yes | | | | during approach | | | |--------------------------------------------------------------------| | MIRO 02 | Run Asteroid Mode | Yes | Poiting inaccuracy | | | sequence at closest | | during Asteroid Flyby| | | approach to Steins | | mode affects scienti-| | | | | -fic output | |--------------------------------------------------------------------| | MIRO 03 | Observation of Steins | Yes | | | | during Recession | | | |--------------------------------------------------------------------| | ROSINA 01 | Outgassing | Yes | | |--------------------------------------------------------------------| | ROSINA 02 | Single mass measurement | Yes | Contamination issue | | | sequence | | due to s/c flip. | | | | | Sw instability caused| | | | | temporary switch-off | | | | | of detector | |--------------------------------------------------------------------| | ROSINA 03 | Pressure monitoring | Yes | Contamination issue | | | | | due to s/c flip | |--------------------------------------------------------------------| | RPC 01 | Steins Fly by | Mostly| ICA did not produce | | | | | scientifically useful| | | | | data due to a comman-| | | | | -ding error. | | | | | Interference from | | | | | MUPUS detected | |--------------------------------------------------------------------| | RSI 01 | Coherent measurement | TBD | TBD | | | with Xup/Xdown or Xup/ | | | | | Sdown received by a | | | | | groundstation capable of| | | | | receiving X- and S- band| | | | | Doppler and Ranging | | | | | Signals | | | |--------------------------------------------------------------------| | SREM 01 | SREM standard | YES | No Steins specific | | | accumulation | | operations, general | | | | | particle flux | | | | | monitoring | |--------------------------------------------------------------------| | OSIRIS 01 | Vega Stare | Yes | Stellar calibrations | | | | | repeated during major| | | | | scenarios | |--------------------------------------------------------------------| | OSIRIS 02 | 16 Cyg Stare | Yes | Stellar calibrations | | | | | repeated during major| | | | | scenarios | |--------------------------------------------------------------------| | OSIRIS 03 | Steins Lightcurve at | Yes | TBD | | | CA-2 weeks | | | |--------------------------------------------------------------------| | OSIRIS 04 | Steins Lightcurve at | Mostly| WAC data compromised | | | CA-24 hours | | by overexposure | |--------------------------------------------------------------------| | OSIRIS 05 | Steins observation at CA| Mostly| NAC went into Safe | | | | | mode due to shutter | | | | | issues about 10 min | | | | | before CA | |--------------------------------------------------------------------| | OSIRIS 06 | Fast imaging sequence | Yes | observation merged | | | around the time of phase| | with OSIRIS 05 | | | angle 0 | | | |--------------------------------------------------------------------| | OSIRIS 07 | Characterization of | Yes | TBD | | | solar straylight for | | | | | same orientation as the | | | | | one the s/c had when | | | | | the OSIRIS hill sphere | | | | | dust search was | | | | | performed | | | |--------------------------------------------------------------------| | VIRTIS 01 | VIRTIS-M lightcurve of | Yes | TBD | | | Steins | | | |--------------------------------------------------------------------| | VIRTIS 02 | V-M and V-H operating; | Yes | Operations were | | |s/c stare at target Nadir| |affected by inaccuracy| | | looking; continuous | | of s/c pointing | | | acquisition in pushbroom| | | | | mode | | | |--------------------------------------------------------------------| | VIRTIS 03 | V-M and V-H continuous | Yes | TBD | | |observation of Steins for| | | | | 1 hour after VR02; V-M | | | | | in image mode (10 lines | | | | | scan) | | | |--------------------------------------------------------------------| Summary results per instrument during closest approach: ALICE: Beginning 7 minutes before CA, ALICE made a 10 minute histogram observation of the asteroid. The spectrum extracted from this histogram observation is the first of an asteroid below 200nm and has an excellent signal to noise ratio. The observed count rate from Steins was about a factor of two larger than predicted. The spectrum of Steins is similar both to the spectrum of the Earths moon obtained during ESB2, and the solar spectrum. During CA, Alice recorded the total count rate of the detector at a rate of once per second. This data will be used to derive a FUV phase curve for the asteroid; this analysis is currently under way. There are two spikes in the observed count rate, one slightly before passing through zero phase and the other centered at the time Rosetta passed through zero phase. It was initially thought that this second spike might represent an opposition surge. However, subsequent analysis using the reconstructed attitude information revealed that the two spikes are actually due to the apparent motion of the multiple star Rho Oph as Rosetta was tracking the asteroid: the initial spike is caused by the star gazing the wide top part of the Alice slit, the second spike is caused by the star grazing the wide bottom part of the slit, and the gap between the spikes is caused by the star lying outside of field of view of the narrow center segment of the slit. MIRO: the instrument was on during approximately 10 hours around CA. The instrument was operated in three modes: a)spectroscopic- dual continuum mode, b) dual continuum mode, and c)asteroid mode. High signal-to-noise responses to Steins were seen in both continuum channels, however the responses were of short duration (minutes), because of the s/c pointing. Near closest approach, the submillimeter beam boresight was located approximately on the limb of Steins, rather than near the center of Steins. As a result of the mis-pointing, phase coverage was severely limited. No spectral features were visible in the individual spectrum data. A preliminary study to search for water by integrating multiple spectra was carried out, but no spectral line of water was detected. The immediate plans are to compare the (dual frequency) continuum data with thermal models of Steins. For this purpose, both the reconstructed pointing data, and a (projected area) shape model for Steins are needed. Using the IR surface temperature maps provided by VIRTIS, the goal is to derive a subsurface temperature gradient, and the loss tangent of the regolith material. It is planned to continue the effort to detect or set an upper limit on the water abundance around Steins. The full spectrum will also be examined to search for other molecules. LANDER/ROMAP: ROMAP worked perfectly and all HK values are in the expected range. Magnetic field measurements were disturbed by MUPUS supply current. All the measured signatures were spacecraft generated. The magnetic field measurement showed that Steins does not interact significantly (>nT) with the solar wind. The global magnetization of Steins has to be therefore less than 1mAm2/kg. For the first time both magnetometers (ROMAP-MAG and RPC-MAG) worked in parallel doing a true interference test. LANDER/SESAME: The flyby at asteroid (2867) Steins and its observation on 5 September 2008 required an attitude change that moved Philae out of the orbiter shadow for about half an hour. This circumstance was used to obtain calibration measurements for the new CASSE temperature measuring method. CASSE listenings were used to investigate the vibration background caused by the orbiter reacion wheels (RW). It was found that part of the backgound vibration is not caused by the RW but other orbiter units or experiment. In addition, new possible harmonics of the RW have been identified. LANDER/MUPUS: MUPUS was continuously operated for 17h around CA, starting 7h before CA. During the heating period, a current of about 100 mA was drawn from the +12V line which disturbed the ROMAP measurements during the flyby. There were differences in temperature measurements between ANC-T and TCU sensors. It seems that a loss of sensitivity by about 28% compared to the ground calibration occurred in the MUPUS TM sensors (TBC during descent to comet). ROSINA: COPS was switched on to the highest sensitivity with both gauges. The COPS pressure is normally transmitted in the housekeeping, one value every minute. One hour before to one houre after CA COPS transmitted science data with a pressure value every 2 s. There is clearly a peak at closest approach. DFMS was switch on in an outgassing mode. The sensor gave error during CA due to the cold temperatude of the LEDA. Nevertheless, DFMS produced excellent scientific data. The oxygen peak measured by DFMS was much more pronounced during the closest approach than during normal background measurements. However, the S/C flip also produced a high oxygen peak and it remains to be seen what amount of oxygen can be attributed to the S/C water and what to the Steins exosphere. This needs modelling with the Rosetta S/C model. An interesting feature has been seen during the S/C flip: the COPS pressure rises much more rapidly than the DFMS oxygen signal. This means that the first gas sublimating from the S/C is probably not water but a molecule which does not contain oxygen. This is also compatible with the fact that COPS measured a much higher pressure peak during the flip than during CA whereas for the oxygen of DFMS both peaks have similar amplitudes. The table below summarizes the ROSINA switch on/off: -----------------------------------------------------------------Date | Time | 2/09/08| 06:00 | On: Outgassing mode 4/09/08| 18:00 | Calib and asteroid mode 5/09/08| 06:00 | Stand by and OFF 5/09/08| 15:45 | On 6/09/08| 05:00 | Stand by 6/09/08| 18:00 | OFF -----------------------------------------------------------------The general conclusion is that COPS and DFMS delivered good scientific data despite the DFMS issue. Outgassing of the s/c is a problem and has to be taken into account for all operations near the comet. RPC/ICA: ICA was not turned on in the appropriate mode (human error) so no data was taken. RPC/IES: IES operation during the flyby was nominal although no indication of material from the asteroid was seen. RPC IES was able to estimate solar wind velocity. RPC/LAP: LAP operations were nominal in the entire period of operations. The photoemission level was as small as expected (15 nA) due to the large heliocentric distance (around 2 AU). The results (variations in the time series) are still under investigation. RPC/MAG: RPC MAG was switch on between 2008-09-01T00:10:00 and 2008-09-10T06:01:00. The spectra of the magnetic field data measured by the OB sensor show, as usual, an influence of ROSETTAs reaction wheels when in Burstmode. The data of the flyby are disturbed by pulsed MUPUS heater currents. The currents generate magnetic disturbances in the order of 2nT (100nT at the location of the ROMAP sensors). The comparision between IB and OB data showed that the measurements are very sensitive to specific temperature changes at the single sensors. All flyby data are very disturbed. Disturbances occur in various time scales. The origin of the disturbance cannot clearly be identified (MUPUS?). Rotation of the solar array and movement of the HGA cannot be seen in the magnetic field data. Any signature of Steins cannot be seen in the magnetic field data. RPC/MIP: Very low values of MIP sensor temperatures are observed, affecting the electronics and MIP response. Interferences are observed in the whole frequency range when the temperature is particularly low (around -150 degrees). The apparition of these interferences is clearly correlated with the satellite manoeuvres. Nominal temperatures and spectra are obtained in favorable attitude configuration. LDL mode in Normal rate is affected due to the lack of emission in this period (to be confirmed/investigated). No plasma signature has been observed during the STEINS flyby. VIRTIS: TBW RSI: The Earth was tracked by the High-gain antenna for most of the time around the Steins flyby. However, it was known beforehand that a mass determination of the small asteroid Steins would not be possible. SREM: SREM was on during the Steins flyby in its usual accumulation mode, but did not perform any Steins specific operations. OSIRIS: Slot Name Start Time End Time Purpose ---------------------------------------------------------------------| Steins | 2008-08-07 | 2008-09-04 | Campaign for determining the | |Navigation | | | position of 2867 Steins | | | | | before the flyby | ---------------------------------------------------------------------|2867 Steins| 2008-08-20 | 2008-09-06 | Observations of 2867 Steins | | flyby | | | | ---------------------------------------------------------------------| Micro- | 2008-09-06 | 2008-10-06 | | | -lensing | | | Detection of microlensing | | | | | events in the galactic center| --------------------------------------------------------------------- GIADA: TBW (the report has not been provided by the team) COSIMA: After the instrument power on 20080901, the highlevel task to image one of the D8 substrates was started. The TMU started from its initial position to grasp the D8 target holder from its exposed location in the COSIMA dust funnel. The TMU generated an error event during the grasping action and stopped any further COSIMA command execution. After the operator reported of the error to the COSIMA team, all the remaining operations were cancelled and COSIMA was left switched on. On the following day, 20080902, the COSIMA instrument was shutdown. The Rosetta first asteroid flyby was a success. The navigation campaign produced highly accurate predictions of the Steins position, and during the flyby most instruments worked without serious problems. Asteroid flyby mode worked well, although with somewhat lower tracking accuracy than expected. The operation report is: RO-SGS-RP-0020.pdf Earth swing-by 3 ---------------- Operations are essentially the same as for the Earth swing-by 2. The actual Earth swing-by takes place in Nov-09. The perigee altitude is 300 km. The relative approach and departure velocity is 9.9 km/s. Phase starts 3 months before the swing-by and ends 1 month later. Two short payload checkouts of about 5 days each are scheduled during this phase. The phase contains the Active Payload Checkout 10 (PC10). This section will first describe PC 10 and then the Earth Flyby. PC10 ---- The Active PC10 ran for 18 consecutive days from 18th September 2009 to 4th October 2009. It represented a target independent opportunity to perform interactive operations and to request spacecraft pointing. All payloads took part in this scenario, as interactive or non-interactive operations. There were approximately 425 hours of non-interactive and 68 hours of interactive operations. Four instruments required active s/c pointing with 15 targets observed (111 hours of dedicated s/c pointing). These were mostly for calibration purposes. ALICE ----- - EEPROM refresh - Instrument Checkout - Optics decontamination - Standard stellar flux calibration (narrow center boresight and wide top and bottom boresight) - Analyze performance at 5 different voltages and 8 detector discriminator thresholds to find the optimal operation parameter values - Determine the location of the center of narrow center boresight, of wide bottom boresight and of wide top boresight in OSIRIS WAC pixel coordinates (this was not achived). - Scan alog slit (psuedo flat field, slit corners location, pinhole aperture location) - Stray light observations (anomalous spike at 30 deg real?) - Point and stare at a star (flight software and instrument safety test) - Interference test CONSERT ------ - Interference test representative of comet observation with no Lander/Orbiter comm. - Orbiter electronics and noise level measurement - Turn on test - Investigation of the 2 second delays between switch on of the lander and of the orbiter (Switch on by ATTC or by RF Link commanding). COSIMA ------ - Passive Checkout - Emitter A and C test - s/w update (partial success) GIADA ----- - Standard procedures and full functional verification - GIADA/VIRTIS interference test - New parameters upload (emergency procedure) LANDER ------ - Philae Lander interactive and non interactive operations (report TBW) MIDAS ----- - Checkout and mechanism activation - High resolution image of a dust collector facet - Calibration of a scanner head - Magnetic Mode Test - S/w upload and functional checkout MIRO ---- - Payload Checkout partially achieved OSIRIS ------ - Pasive Checkout (insturment mechanisms, CCD sanity, instrument focus) - Calibration at different CCD temperatures ROSINA ------ - test of GIADA effect because of higher pressure than normal detected by COPS - test of Lander effect because of pressure peaks registered by DFMS and COPS. - PTOLEMY and COPS measurement comparison - Optimisation of DFMS settings because of possible outgasing from the s/c - Main and Redundant DPU s/w upload (partially achieved) - COPS microtips test - DFMS and RTOF covers test RPC --- - Passive Checkout: status check and instrument calibration MAG, IES: undisturbed solar wind measurement - IES/ROMAP Cross Calibration - Test MIP levels during LDL - test of MAG/LAP possible interference - ICA perform test - IES flight s/w upgrade and checkout RSI --- - USO behaviour under use of Transporter 2 results are TBD SREM ---- - SREM standard accumulation: monitor the radiation environment in the solar system during the cruise to the target comet. results are TBD VIRTIS ------ - S/w upload - verfication of full scientific operative modes - GIADA interference test Earth flyby 3 (EAR3) -------------- The EAR3 is the last of the three gravity assists from the Earth. The swing-by spacecraft operations were of highest priority. Rosetta had the opportunity to perform specific scientific observation of the Earth-Moon system, instrument calibrations using Earth and/or Moon and public relation observations. ALICE ----- - Instrument Checkout - Optic decontamination - Stellar calibration for cross comparision to Earth and Moon cals - Spectra of illuminated Earth to obtain measurements of Earths airglow for relative calibration at wavelengths below 912A. Earth will overfill the slit to be able to get flat field information at the various airglow wavelengths. - Observation of Moon limb * to see if there is any change in instrument sensitivity since EAR2 * for absolute calibration below 912 A * to measure scattered solar light when observing an extended object - Spectra of illuminated moon limb to obtain a flat field - Observation of the Moon as a point source * for absolute calibration - Dark count rate monitoring - Ride along with MIRO raster scan of the moon for flux calibration and possible boresight co-alignment information - Ride along with OSIRIS to get Earth cal spectra - Ride along with OSIRIS and VIRTIS to get Earth Aurora data - Ride along with VIRTIS to observe the Moon - Measurement of high energy electrons (HEET) while passing through Earth magnetosphere - Obtain baseline spectra of star for comparison to occultation spectra - Lunar atmosphere absorption spectra MIRO ---- - Observation of Earth (H2O line for CTS calibration) around closest approach - Moon observation around closest approach (H2O detection) - slew scan of Moon with OSIRIS (boresight alignment campaign) RPC --- - Sensors calibration and magnetospheric physics studies - MAG LAP interferences: confirm whether LAP is or isnt the source of the interference SREM ---- - Spatial distribution of radiation belts along trajectory of Rosetta around the Earth OSIRIS ------ - Stellar calibration - Flat field images and instrument calibration by pointing at illuminated ocean surface on Earth crescent. - Aurorae search by Earth night side targeted pointing during approach phase - Test of comet observations, monitoring of Moon motion by post-encounter Moon tracking - Lunar stray light calibration - Characterization of ghosts of bright objects in WAC and NAC optics - Slew scan of Moon with MIRO - Pre-encounter monitoring of Earth rotation - Observation of the Earth-Moon system when both are in the field of view of the WAC. VIRTIS ------ - Earth night side pointing - Earth limb scan, day and night side (non-LTE emission and Oxygen airglow studies) - Earth day side full-disk simultaneous acquisition by H and M - Moon side observation by H and M for temperature calibration - 4 cycles of scan across Earth day side to check the compression algorithm and binning algorithm performance - Limb to limb scan of Earth by H for calibration - Moon staring for performance verification of M visible channel - M-visible and H scan of Moon with MIRO (boresignt alignment) According to the available reports, the EAR3 can be considered as fully successful. The different reports are: PC 10: RO-SGS-RP-0022.pdf EAR3 : RO-SGS-RP-0023.pdf Cruise phase 5 -------------- One Active checkout (12) was scheduled during this cruise phase. It can be noted that Passive Checkout 11 were cancelled since there was not enough time to include it between PC10 and PC12. PC 11 is passive meaning that it is mainly instrument healthcheck operations. PC 10 and 12 are active and more important to preserve. Lutetia Flyby (17/05/2010 - 03/09/2010) -------------- The second of the flybys took place on 10 July 2010 to the asteroid 21 Lutetia, discovered on 15 November 1852 by H. Goldschmidt. Its classification into a specific asteroid type had turned out to be ambiguous and included the possibilities of a C-type or an M-type asteroid. This contradiction made it an interesting object for close inspection. Closest Approach (CA) occurred at 15:45 UT at a distance of 3168.2km. The relative fly-by velocity was of 15 km/s. The fly-by strategy allowed continuous observations of Lutetia before, during and for 30 minutes after CA. Images obtained by OSIRIS revealed that Lutetia has a complex geology and one of the highest asteroid densities measured so far, 3.4+/-0.3g/cm3. Its geologically complex surface, ancient surface age and high density suggest that Lutetia is most likely a primordial planetesimal. This is the second of the two asteroids selected at the Science Working Team meeting on 11th March 2004 among all the available candidate asteroids, depending on the scientific interests and the propellant required for the correction manoeuvre. The following operations took place around the Lutetia fly-by: 21 May 2010 - 9 July 2010: Navigation campaign (astrometry) using the OSIRIS NAC and NAVCAM. 5 July 2010- 14 July 2010: scientific operations targeting the asteroid. The Lutetia fly-by was a success. The navigation campaign produced highly accurate predictions of the position of Lutetia and during the fly-by most instruments worked without serious problems (except Rosina, RPC IES and RPC ICA). Asteroid fly-by mode worked excellently. The objectives summarised below have been addressed by the instrument measurements: - Physical and thermal properties, mineralogy and geomorphology of Lutetia from spatially resolved multi-wavelengths remote-sensing observations between the extreme UV and the mm-range. - Determination of the mass of the asteroid from Doppler measurements of the spacecraft trajectory. - Global shape parameters from light curves taken days before CA. - Search for satellite/dust particles. - Search for an asteroid magnetic field. - Particle and field measurements. The following summarises the observations and results per instrument: ALICE - Surface reflectance, albedo, colour, light curve by spectrophotometry. - Surface composition by UV spectroscopy. - Asteroid exosphere search by UV spectroscopy: none detected - Alice optics decontamination before shutdown. - Standard stellar flux calibration using the Alice narrow center boresight - Standard stellar flux calibration using the Alice -X wide bottom boresight - Standard stellar flux calibration using the Alice +X wide top boresight - Dark exposures - Boresight cross-calibration with Osiris - Background COSIMA - D8 substrates exposure: operational test, no asteroid dust identified. - All images were technically as expected. PHILAE - ROMAP: no magnetic field detected at CA +/- 30 min - PTOLEMY: exosphere search (Sniff mode) ANDREWSETAL2011 - COSAC: Verify mass spectrometer performance, characterise (spacecraft) gas environment, exosphere search. MIDAS - Dust search: Target exposure was as expected and dust collector facet scan: as expected. MIRO - Exosphere search by microwave (water). - Thermal properties by IR and sub-mm observations. - Observation of Lutetia during approach - Run asteroid mode sequence at CA - Observation of Lutetia during recession, includes slew to measure southern regions that are in seasonal night - Run asteroid mode sequence on dark sky. ROSINA ALTWEGGETAL2012 DFMS and COPS were switched off before closest approach due to software issue. However, RTOF provided excellent mass spectra. The data gained during the Lutetia rehearsal are valuable in distinguishing between spacecraft outgassing and real exosphere data. - DFMS: Outgassing - DFMS: Spacecraft background measurement - RTOF: Outgassing measurement. Signal was detected at CA. The cause ( Asteroid exosphere or spacecraft outgassing) is under investigation. RPC - Sensor calibration and magnetospheric physics studies (IES and ICA software issues) - IES: solar wind proton measurements. - LAP: observe the solar wind and look for any signatures that may relate to asteroid-solar wind to interaction. Determine photoemission at large heliocentric distance. Results gave no immediately striking signature of asteroid interaction (could be revealed in a full analysis). - MAG: Reaction wheel influence and the disturbance of the LAP instrument can be seen. Comparison between IB and OB showed that the measurements are very sensitive to specific temperature changes at the single sensors. The flyby data are disturbed most of the time. The magnetic impact of Lutetia is less than 1 nT at the fly-by distance of 3120km (maximum magnetic dipole moment 1x10e12 Am2). - MIP: same features than for Steins. No plasma signature is observed for the Lutetia fly-by. MIP electronics and response are affected by low values of sensor temperatures. - ICA: Soon after the switch on before Lutetia encounter, the temperature of the sensor quickly rose and the instrument was automatically powered off. RSI - Mass of Lutetia was accurately determined. OSIRIS - Stellar calibration using Vega Stare and 16 Cyg - Lutetia lightcurve at CA-80 hours - Lutetia observations at CA: Shape, global properties, geomorphology, surface composition obtained THOMASETAL2011, MASSIRONIETAL2012, CREMONESEETAL2012, KUPPERSETAL2011, VINCENTETAL2011 - Support Alice boresight determination - Exosphere search by Filter imaging (OH, Na) VIRTIS - Lutetia spectral light curve determination successful - Lutetia mineralogic mapping successful during and after CA - Thermal properties by Spectrophotometry SREM - On during flyby in its usual accumulation mode but did not perform any Lutetia specific operations. The report of the Lutetia mission phase is RO-SGS-RP-0028_1.pdf Rendez-Vous Manouver 1 (04/09/2010 - 13/07/2011) ---------------------- The deep space manoeuvre is carried out when the spacecraft has reached a distance from the Sun around 4.5 AU on 23-Jan-11. One passive check-out (13) is scheduled during this phase. One solar conjunction of 50 days and one solar opposition of 37 days happen during this phase.(see Solar Conjunctions section above). --PC 13 (1st-9th Dec 2010 + 14th Dec) This is the final Cruise Phase Checkout. A number of additional payload operations were also executed, to close out pending and essential requirements, and/or to configure instruments for the upcoming Deep Space Hibernation Phase. Only OSIRIS did not participate in PC 13. PC13 ran for 9 consecutive days between 1st and 9th December 2010. A RSI passive checkout was also completed on 14th December. All of the operations planned and executed were successful. Minor issues were observed by 4 instruments (Consert, Philae, Rosina, RPC). Alice performed succesfully some instrument checkout. Cosima did periodical maintenance and check its status. Giada checked successfully its status. Midas performed a normal passive check-out and an additional modified one for Deep Space Hibernation Preparation. Miro performed a normal and sucessful passive check-out. Osiris did not participate in the PC13 timeframe. However, on 23-26th March 2011 - post RVM1 - specific OSIRIS operations were performed in order to prepare and configure the instrument for the Rosetta Deep Space Hibernation. The Lander performed some operations and Consert performed an unit functional test; both were partially successful. Rosina did not participate in the nominal PC13 scenario, but conducted several specific operations immediately following completion of the nominal PC13 timeline. A spacecraft slew was executed with RTOF monitoring, to further investigate data observed during Lutetia fly-by. RPC PIU, IES, LAP, ICA performed checkout with some errors/anomalies reported, which were considered as no problem for the instrument. Virtis performed the checkout successfully. RSI measurements during PC13 showed some disturbances. The cause is unknown at the time being. SREM performed a successful checkout. The PC 13 report is: RO-SGS-RP-0029_2.pdf Cruise phase 6 -------------- The whole period is spent in Deep-Space Hibernation Mode (DSHM). Maximum distances to Sun and Earth are encountered during this period, i.e. 5.3 AU (aphelion) and 6.3 AU, respectively. During this phase, 3 superior solar conjuctions and 2 solar oppositions occur (see table above). Rendez-Vous Manouver 2 ---------------------- Not yet occured. Near comet drift (NCD) phase ---------------------------- The spacecraft reaches the comet on 22-May-14 at a distance of 4.0 AU from the Sun. A sequence of four rendezvous manoeuvres within 30 days reduce the relative velocity with respect to the comet from 780 m/s to 50 m/s. The spacecraft is in active cruise mode. During this phase Rosetta approaches the comet without observing the comet with the navigation camera (NAVCAM). The comet orbit is determined by a dedicated ground-based astrometric observation campaign. The errors in the estimated position of the comet can still be several tens of thousand km. The final point of the NCD phase is the Comet acquisition point (CAP) at 100000 km distance from the comet. The selection of this position depends on two factors: avoiding cometary debris (assuming there is any), and achieving good comet illumination conditions. The phase has not yet occurred. The report will be provided later. Approach phase -------------- -> Far Approach Trajectory (FAT) Far-approach trajectory operations start at CAP. During this phase the first images of the comet are obtained with the optical measurement system (NAVCAM, OSIRIS). After detection, knowledge of the comet ephemeris is drastically improved by processing the on- board observations. Image processing on the ground derives a coarse estimation of comet size, shape and rotation. The first landmarks are identified. The approach manoeuvre sequence reduces the relative velocity in stages down to 3.1 m/s after 30 days. The manoeuvre strategy is designed to: * retain an apparent motion of the comet with respect to the star background, * retain the illumination angle (Sun-comet-spacecraft) below 70 degrees, * avoid the danger of impact with the cometary nucleus in case of manoeuvre failure. The FAT ends at the Approach Transition Point (ATP), which is located in the Sun direction at about 1000 comet nucleus radii from the nucleus. During this phase the spacecraft is in active cruise mode with the navigation camera and some orbiter payloads switched on. -> Close Approach Trajectory (CAT) Close approach trajectory operations start at ATP and take 17 days. The spacecraft distance to the comet is decreased to 40 nucleus radii and the relative velocity falls below 1 m/s. The final point of this phase is called the Orbit Insertion Point (OIP) and is the point where the spacecraft starts orbiting the comet. The injection is performed by means of a hyperbolic orbit. Lines of sight to landmarks are processed together with on-ground radiometric measurements in order to estimate the spacecrafts relative position and velocity, the comet absolute position, attitude, nucleus angular velocity, gravitational constant and location of landmarks. -> Transition to Global Mapping (TGM) The transition to global mapping starts at OIP. A hyperbolic arc is used down to a distance to the comet of about 10-25 comet radii where a capture manoeuvre closes the orbit. The plane of motion is defined by the comet spin axis and the Sun direction. This plane is rotated slightly in order to avoid solar eclipses and Earth occultations. -> Global Mapping Phase (GMP) Mission scenarios have the objective of completing a science goal and require a trajectory and attitude profile which is driven by experiments selected to have priority in achieving this goal. The first scenario is the mapping scenario, during which at least 80 % of the comet surface is observed from a circular orbit with a radius in the range of 10-25 comet radii and the comet model increases in accuracy by evaluating the scientific results. -> Close Observation Phase (COP) In this second scenario detailed observations are made of up to five potential landing sites for the Rosetta lander from a distance of less than 1 nucleus radius. The phase has not yet occurred. The report will be provided later. Lander delivery and relay phase ------------------------------- The priority of this phase is the successful delivery of the lander to the surface of the comet. After the landing, the Rosetta orbiter is brought into a trajectory which is optimised such that the orbiter can act as a relay for the lander-ground communications. Note that the other experiments are also operating during this phase, regular science planning is performed. However, the operations of other experiments cannot interfere with the lander operations. The phase has not yet occurred. The report will be provided later. Escort phase ------------ -> Comet activity: low activity (LOW) Starting from 3.5 to 3.3 AU the comet develops a measurable coma. At this point spacecraft resources limit the on-board orbiter experiments to be fully operational and time-sharing by choosing priorities determines the operations. Over the interval of 3.3 to 2.6 AU the activity is low and more or less constant, but occurrences of outburst are possible. The nominal start of the scientific mission is 3.25 AU and spacecraft resources are capable of supporting full experiments operations. It is a mission preference that the lander is separated preferably before 3 AU while the comet is still relatively in-active. Therefore the lander separation and relay has to be executed as soon as a landing site has been selected. (Note that the lander team baselines a delivery at 3 AU and not before.) -> Comet activity: moderate increase (MINC) The overall activity is expected to show a steady and moderate increase. The completion of the science objectives drive the selection of the mission scenarios for this phase. -> Comet activity: sharp increase (SINC) A sudden and steep increase in activity together with a change in outgassing conditions are expected for this phase from previous observations. Special orbit requirements, like dust/gas jet crossings, are possible for mission scenario selection. -> Comet activity: high activity (HIGH) The production rate of gas and dust is expected to have a steep increase indicating a distinct change in outgassing conditions. The thermal conditions of the spacecraft for distances smaller then 1.4 AU may influence the science operations capabilities and time-sharing of the payload operations may be necessary. The phase has not yet occurred. The report will be provided later. Near perihelion phase --------------------- This phase is likely to show a steady increase of overall activity. The phase has not yet occurred. The report will be provided later. Extended mission ---------------- Nominally, unless a mission extension is agreed and if the spacecraft survives in the cometary environment, the mission ends at the perihelion pass after 11.5 years. If possible, however, the mission is continued. More risky or more time consuming scenarios may be executed. The phase has not yet occurred. The report will be provided later. Orbiter Experiments ===================================================================== ALICE ----- ALICE, an Ultraviolet Imaging Spectrometer, will characterize the composition of the nucleus and coma, and the nucleus/coma coupling of comet 67 P/Churyumov-Gerasimenko. This will be accomplished through the observation of spectral features in the extreme and far ultraviolet (EUV/FUV) spectral regions from 70 to 205 nm. ALICE will make measurements of noble gas abundances in the coma, the atomic budget in the coma, and major ion abundances in the tail and in the region where solar wind particles interact with the ionosphere of the comet. ALICE will determine the production rates, variability, and structure of H2O and CO, and CO2 gas surrounding the nucleus and the far-UV properties of solid grains in the coma. ALICE will also map the cometary nucleus in the FUV, and study Mars and the Rosetta asteroid flyby targets while en route to Churyumov- Gerasimenko. Instrument References: STERNETAL2007 CONSERT ------- CONSERT (Comet Nucleus Sounding Experiment by Radio wave Transmission) is an experiment that will perform tomography of the comet nucleus revealing its internal structure. CONSERT operates as a time domain transponder between the Lander which will be on the comet surface and the Orbiter will orbit the comet. A radio signal passes from the orbiting component of the instrument to the component on the comet surface and is then immediately transmitted back to its source, the idea being to establish a radio link that passes through the comet nucleus. The varying propagation delay as the radio waves pass through different parts of the cometary nucleus will be used to determine the dielectric properties of the nuclear material. Many properties of the comet nucleus will be examined as its overall structural homogeneity, the average size of the sub-structures (Cometesimals) and the number and thickness of the various layers beneath the surface. Instrument References: KOFMANETAL2007 COSIMA ------ The Cometary Secondary Ion Mass Analyser is a secondary ion mass spectrometer equipped with a dust collector, a primary ion gun, and an optical microscope for target characterization. Dust from the near comet environment is collected on a target. The target is then moved under a microscope where the positions of any dust particles are determined. The cometary dust particles are then bombarded with pulses of indium ions from the primary ion gun. The resulting secondary ions are extracted into the time-of-flight mass spectrometer. Instrument References: KISSELETAL2007 GIADA ----- The Grain Impact Analyser and Dust Accumulator will measure the scalar velocity, size and momentum of dust particles in the coma of the comet using an optical grain detection system and a mechanical grain impact sensor. Five microbalances will measure the amount of dust collected as the spacecraft orbits the comet. Instrument References: COLANGELIETAL2007 MIDAS ----- The Micro-Imaging Dust Analysis System is intended for the microtextural and statistical analysis of cometary dust particles. The instrument is based on the technique of atomic force microscopy. This technique, under the conditions prevailing at the Rosetta Orbiter permits textural and other analysis of dust particles to be performed down to a spatial resolution of 4nm. Instrument References: RIEDLERETAL2007 MIRO ---- MIRO (Microwave Instrument for the Rosetta Orbiter) is composed of a millimetre wave mixer receiver and a submillimetre heterodyne receiver. The submillimetre wave receiver provides both broad band continuum and high resolution spectroscopic data, whereas the millimetre wave receiver provides continuum data only. MIRO will measure the near surface temperature of the comet, allowing estimation of the thermal and electrical properties of the surface. In addition, the spectrometer portion of MIRO will allow measurements of water, carbon monoxide, ammonia, and methanol in the comet coma. Instrument References: GULKISETAL2007 OSIRIS ------ OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) is a dual camera imaging system operating in the visible, near infrared and near ultraviolet wavelength ranges. OSIRIS consists of two independent camera systems sharing common electronics. The narrow angle camera is designed to produce high spatial resolution images of the nucleus of the target comet. The wide angle camera has a wide field of view and high straylight rejection to image the dust and gas directly above the surface of the nucleus of the target comet. Each camera is equipped with filter wheels to allow selection of imaging wavelengths for various purposes. The spectroscopic and wider band infrared imaging capabilities originally proposed and incorporated in the instrument name were descoped during development. Instrument References: KELLERETAL2006 ROSINA ------ ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) consists of two mass spectrometers, since no one technique is able to achieve the resolution and accuracy required to fulfil the ROSETTA mission goals over the range of molecular masses under analysis. In addition, two pressure gauges provide density and velocity data for the cometary gas. The two mass analysers are: * A double focusing magnetic mass spectrometer with a mass range of 1 - 100 amu and a mass resolution of 3000 at 1 % peak height, optimised for very high mass resolution and large dynamic range * A reflectron type time-of-flight mass spectrometer with a mass range of 1 -300 amu and a mass resolution better than 500 at 1 % peak height, optimised for high sensitivity over a very broad mass range Instrument References: BALSIGERETAL2007 RPC --- RPC (Rosetta Plasma Consortium) is a set of five sensors sharing a common electrical and data interface with the Rosetta orbiter. The RPC sensors are designed to make complementary measurements of the plasma environment around the comet 67P/Churyumov-Gerasimenko. The RPC sensors are: * ICA: an Ion Composition Analyser, which measures the three- dimensional velocity distribution and mass distribution of positive ions; * IES: an Ion and Electron Sensor, which will simultaneously measure the flux of electrons and ions in the plasma surrounding the comet; * LAP: a Langmuir Probe, which will measure the density, temperature and flow velocity of the cometary plasma; * MAG: a Fluxgate Magnetometer, which will measure the magnetic field in the region where the solar wind plasma interacts with the comet; Instrument References: GLASSMEIERETAL2007B * MIP: a Mutual Impedance Probe, which will derive the electron gas density, temperature, and drift velocity in the inner coma of the comet. Instrument References: CARRETAL2007 RSI --- RSI (Radio Science Investigation) makes use of the communication system that the Rosetta spacecraft uses to communicate with the ground stations on Earth. Either one-way or two-way radio links can be used for the investigations. In the one-way case, a signal generated by an ultra-stable oscillator on the spacecraft is received on earth for analysis. In the two way case, a signal transmitted from the ground station is transmitted back to Earth by the spacecraft. In either case, the downlink may be performed in either X-band or both X -band and S-band. RSI will investigate the nondispersive frequency shifts (classical Doppler) and dispersive frequency shifts (due to the ionised propagation medium), the signal power and the polarization of the radio carrier waves. Variations in these parameters will yield information on the motion of the spacecraft, the perturbing forces acting on the spacecraft and the propagation medium. Instrument References: PAETZOLDETAL2007 VIRTIS ------ VIRTIS (Visible and Infrared Thermal Imaging Spectrometer) is an imaging spectrometer that combines three data channels in one instrument. Two of the data channels are committed to spectral mapping and are housed in the Mapper optical subsystem. The third channel is devoted solely to spectroscopy and is housed in the High resolution optical subsystem. The mapping channel optical system is a Shafer telescope consisting of five aluminium mirrors mounted on an aluminium optical bench. The mapping channel uses a silicon charge coupled device (CCD) to detect wavelengths from 0.25 micron to 1 micron and a mercury cadmium telluride (HgCdTe) infrared focal plane array (IRFPA) to detect from 0.95 micron to 5 microns. The high resolution channel is an echelle spectrometer. The incident light is collected by an off-axis parabolic mirror and then collimated by another off-axis parabola before entering a cross- dispersion prism. After exiting the prism, the light is diffracted by a flat reflection grating, which disperses the light in a direction perpendicular to the prism dispersion. The high-resolution channel employs a HgCdTe IRFPA to perform detection from 2 to 5 microns. Instrument References: CORADINIETAL2007 SREM ---- The Standard Radiation Environment Monitor (SREM) is a monitor-class instrument intended for space radiation environment characterisation and radiation housekeeping purposes. SREM will provide continuous directional, temporal, and spectral data of high-energy electron, proton, and cosmic ray fluxes encountered along the orbit of the spacecraft, as well as measurements of the total accumulated radiation dose absorbed by SREM itself. This instrument is a facility monitor flown on several ESA spacecrafts. It is not considered as a PI (Principal Investigator) instrument. Instrument References: MOHAMMADZADEETAL2003 LANDER (PHILAE) ===================================================================== The 100 kg Rosetta Lander, named Philae, will be the first spacecraft ever to make a soft landing on the surface of a comet nucleus. The Lander is provided by a European consortium under the leadership of the German Aerospace Research Institute (DLR) and the French Space Research Center (CNES). Other members of the consortium are ESA and institutes from Austria, Finland, France, Hungary, Ireland, Italy and the UK. A descripion of the Lander can be found in RO-EST-RS-3020. The box-shaped Lander is carried in piggyback fashion on the side of the Orbiter until it arrives at Comet 67P/Churyumov-Gerasimenko. Once the Orbiter is aligned correctly, the ground station commands the Lander to self-eject from the main spacecraft and unfold its three legs, ready for a gentle touch down at the end of the ballistic descent. On landing, the legs damp out most of the kinetic energy to reduce the chance of bouncing, and they can rotate, lift or tilt to return the Lander to an upright position. Immediately after touchdown, a harpoon is fired to anchor the Lander to the ground and prevent it escaping from the comets extremely weak gravity. The minimum mission target for scientific observations is one week, but surface operations may continue for many months. Science Objectives ------------------ It is the general aim of the scientific experiments carried and operated by the Rosetta Lander to obtain a first in situ composition analysis of primitive material from the early solar system, to study the composition and structure of a cometary nucleus, reflecting growth processes in the early solar system, to provide ground truth data for the Rosetta Orbiter experiments and to investigate dynamic processes leading to changes in cometary activity. The primary objective of the Rosetta Lander mission is the in situ investigation of the elemental, isotopic, molecular and mineralogic composition and the morphology of early solar system material as it is preserved in the cometary nucleus. Measurement of the absorption and phase shift of electromagnetic waves penetrating the comet nucleus will help to determine its internal structure. Seismometry and magnetometry will also be used to investigate the interior of the comet. The scientific objectives of the Rosetta Lander can be listed according to their priority as follows: 1. Determination of the composition of cometary surface and subsurface matter: bulk elemental abundances, isotopic ratios, minerals, ices, carbonaceous compounds, organics, volatiles - also in dependence on time and insolation. 2. Investigation of the structure and physical properties of the cometary surface: topography, texture, roughness, regolith scales, mechanical, electrical, optical, and thermal properties, temperatures. Characterization of the near surface plasma environment. 3. Investigation of the global internal structure. 4. Investigation of the comet/plasma interaction. The in situ measurements performed by the Rosetta Lander instruments will also provide local ground truth to calibrate Orbiter instruments. Lander Experiments ------------------ The Rosetta-Lander is equipped with a Sample Drill & Distribution (SD2) subsystem which is in charge to collect cometary surface samples at given depth and distribute them to the following instruments: CIVA-M (microscope (MS) & Infrared Spectrometer (IS)), the ovens, serving COSAC and PTOLEMY. Comet sample from pre-determinated and/or known (measured) depth are collected and transported by SD2 to well defined locations: * MS & IS viewing place * ovens for high temperature (800 deg C) heating * ovens for medium temperature (130 deg C) heating. * ovens with a window, where samples can be investigated by CIVA-M Here a description of all the instruments of the Lander: APXS: Alpha-p-X-ray spectrometer - - - - - - - - - - - - - - - - The goal of the Rosetta APXS experiment is the determination of the chemical composition of the landing site and its potential alteration during the comets approach to the Sun. The data obtained will be used to characterize the surface of the comet, to determine the chemical composition of the dust component, and to compare the dust with known meteorite types. Instrument References: KLINGELHOFERETAL2007 CIVA: Panoramic and microscopic imaging system - - - - - - - - - - - - - - - - - - - - - - - - The Cometary Infrared and Visible Analiser (CIVA) is an integrated set of imaging instruments, designed to characterize the landing and sampling site, the 360 deg panorama as seen from the Rosetta Lander, all samples collected and delivered by the Drill Sample and Distribution System, and the stratigraphy within the boreholes. It is constituted by a panoramic stereo camera (CIVA-P), and a microscope coupled to an IR spectrometer (CIVA-M). CIVA is sharing a common Imaging Main Electronics (CIVA/ROLIS/IME) with ROLIS. CIVA-P will characterize the landing site, from the landing legs to the local horizon. The camera is composed of 6 identical micro-cameras, mounted of the Lander sides, with their optical axes separated by 60 deg. In addition, stereoscopic capability is provided by one additional microcamera, identical to and co-aligned with one of the panoramic micro- camera, with its optical axis 10 cm apart. CIVA-M combines in separated boxes, two ultra-compact and miniaturized channels, one visible microscope CIVA-M/V and one IR spectrometer CIVA-M/I, to characterize, by non-destructive analyses, the texture, albedo, mineralogical and molecular composition of each of the samples collected and distributed by the Drill Sample and Distribution System. Instrument References: BIBRINGETAL2007A CONSERT: Radio sounding, nucleus tomography - - - - - - - - - - - - - - - - - - - - - - The Comet Nucleus Sounding Experiment by Radio wave Transmission (CONSERT) is a complex experiment that will perform tomography of the comet nucleus revealing its internal structure. CONSERT operates as a time domain transponder between the Lander which will be on the comet surface and the Orbiter will orbit the comet. A radio signal passes from the orbiting component of the instrument to the component on the comet surface and is then immediately transmitted back to its source, the idea being to establish a radio link that passes through the comet nucleus. The varying propagation delay as the radio waves pass through different parts of the cometary nucleus will be used to determine the dielectric properties of the nuclear material. Many properties of the comet nucleus will be examined as its overall structural homogeneity, the average size of the sub-structures (Cometesimals) and the number and thickness of the various layers beneath the surface. Instrument References: KOFMANETAL2007 COSAC: Evolved gas analyser - elemental and molecular composition - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - The COmetary SAmpling and Composition experiment COSAC is one of the two evolved gas analysers (EGAs) on board the Rosetta-Lander. Whereas the other EGA, Ptolemy, aims mainly at accurately measuring isotopic ratios of light elements, the COSAC is specialised on detection and identification of complex organic molecules. The instrument can be described as an effort to analyse in situ, mainly with respect to the composition of the volatile fraction, cometary matter nearly as well and accurately as could be done in a laboratory on Earth. Due to the Rosetta Lander rotatability, the instrument can conduct analyses and investigations at different spots of the landing site and, aided by the drill, take samples for analysis from a depth up to at least 0.2 m. Instrument References: GOESMANNETAL2007 PTOLEMY: Evolved gas analyser - isotopic composition - - - - - - - - - - - - - - - - - - - - - - - - - - - The size of a small shoe box and weighing less than 5 kg, Ptolemy will use gas chromatography / mass spectrometry (GCMS) techniques to investigate the comet surface & subsurface. The instrument concept is termed MODULUS which is taken to mean Methods Of Determining and Understanding Light elements from Unequivocal Stable isotope compositions. The scientific goal of the PTOLEMY is to understand the geochemistry of light elements, such as hydrogen, carbon, nitrogen and oxygen, by determining their nature, distribution and stable isotopic compositions. Instrument References: WRIGHTETAL2007 MUPUS: Measurements of surface and subsurface properties - - - - - - - - - - - - - - - - - - - - - - - - - - - - - The Multi-Purpose Sensor Experiment actually consists of four parts: 1. A penetrator, approximately 40 cm long, will be hammered into the ground about 1m apart from the Lander for measuring during the penetration process the mechanical strength of the material by means of a depth sensor and a densitometer. The penetrator is equipped with a series of temperature sensors and heaters for determining the temperature as a function of depth and insolation. 2. An accelerometer and a temperature sensor accommodated in the harpoon(s) 3. A four-channel infrared radiometer measures surface temperatures in the vicinity of the Lander. Density of the nearsurface (down to 20cm) material will be determined by measuring the absorption of gamma-rays emitted from a radioactive isotope mounted at the tip of the penetrator. Instrument References: SPOHNETAL2007 ROLIS: Descent & Down-Looking Imaging - - - - - - - - - - - - - - - - - - - The ROLIS Camera (Rosetta Lander Imaging System) will deliver first close-ups of the environment of the landing place of comet 67P/Churyumov-Gerasimenko during the descent. After landing ROLIS will make high-resolved investigations to study the structure (morphology) and mineralogy of the surface. Instrument References: MOTTOLAETAL2007 ROMAP: Magnetometer and plasma monitor - - - - - - - - - - - - - - - - - - - - The Rosetta Lander Magnetometer and Plasma Monitor ROMAP is a multi- sensor experiment. The magnetic field is measured with a fluxgate magnetometer. An electrostatic analyzer with integrated Faraday cup measures ions and electrons. The local pressure is measured with Pirani and Penning sensors. The sensors are situated on a short boom. The deployment on the surface of a cometary nucleus demanded the development of a special digital magnetometer of little weight and small power requirements. For the first time a magnetic sensor will be operated from within a plasma sensor. A prototype of the magnetometer, named SPRUTMAG, was flown on space station MIR. Instrument References: AUSTERETAL2007 SD2: Sampling, Drilling and Distribution Subsystem - - - - - - - - - - - - - - - - - - - - - - - - - - The sampling, drilling and distribution (SD2) subsystem will provide microscopes and advanced gas analysers with samples collected at different depths below the surface of the comet. Specifically SD2 can bore up to 250 mm into the surface of the comet and collect samples of material at predetermined and/or known depths. It then transports each sample to a carousel which feeds samples to different instrument stations: a spectrometer, a volume check plug, ovens for high and medium temperatures and a cleaning station. SD2 will be accommodated on the flat ground-plate of the Rosetta, where it will be exposed to the cometary environment. Instrument References: ERCOLIFINZIETAL2007 SESAME: Surface electrical, acoustic and dust impact monitoring - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - The SESAME (Surface Electrical, Seismic and Acoustic Monitoring Experiments) electronics board and the integration of the components are managed by the German Aerospace Center (DLR), Institute of Space Simulation, Cologne. The results of SESAME will help in understanding how comets, have formed and thus, how the solar system, including the Earth, was born. Instrument References: SEIDENSTICKERETA2007 GROUND SEGMENT ===================================================================== This section summarizes the roles and responsabilities for the Rosetta Ground Segment, which are defined in the Rosetta Science Management Plan RO-EST-PL-0001 and the Lander Project Plan RL-PL-DLR-97002. The primary responsibility for developing the payload operations strategy for the Rosetta Scientific Mission is the Rosetta Science Working Team. The Rosetta Science Working Team (SWT) monitors and advises on all aspects of Rosetta which affect its scientific performance. Rosetta Ground Segment ----------------------- The Rosetta ground segment will consist of two major elements: the Rosetta Mission Operations Centre (RMOC) and the Rosetta Science Operations Centre (RSOC). Rosetta Science Operations Center - - - - - - - - - - - - - - - - - - The Rosetta Science Operations Center (RSOC) is located at the European Space Research and Technology Center (ESTEC) in The Netherlands. The main task is to support the Rosetta Project Scientist in the planning of the science operations schedule and in the generation of coordinated operational sequences, the payload command sequences for all Rosetta instruments and their onward transmission to the Rosetta Mission Operations Centre (RMOC). In addition, the RSOC will prepare comet nucleus and comet coma models in collaboration with the Interdisciplinary Scientists, specialists from the Principal Investigator teams and the Lander teams. Rosetta Mission Operations Center - - - - - - - - - - - - - - - - - - The Rosetta Mission Operations Center (RMOC) is located at the European Space Operations Center (ESOC) in Darmstadt, Germany. The RMOC is responsible for the Spacecraft operations and all real time contacts with the spacecraft and payload, the overall mission planing, flight dynamics and spacecraft and payload data distribution. Rosetta Lander Ground Segment ------------------------------ The Rosetta Lander Ground Segment (RLGS) is made up of two operational teams. Due to the discussions when CNES joined the DLR consortium for developing the Lander, it was decided to divide the RLGS into 2 centers (see Lander Project Plan RL-PL-DLR-97002). These teams are responsible for the success of the Lander operations, to ensure that the Lander performs the science with regards to its status, and to give the data to the PIs and suppliers. Lander Control Center - - - - - - - - - - - - The Lander Control Center (LCC), located at DLR/MUSC in Koeln (Germany), in charge of Rosetta Lander operations during the flight segment definition, design, realization, assembly and tests. Science Operations and Navigation Center - - - - - - - - - - - - - - - - - - - - - The Science Operations and Navigation Center is under CNES responsibility, located in Toulouse (France). It is responsible for the navigation and mission analysis aspects, including separation, landing and descent strategies and generation of the scientific sequences. Rosetta Scientific Data Archive -------------------------------- All scientific data obtained during the full mission duration will remain proprietary of the PI teams and the Lander teams for a maximum period of one year after they have been received from ESOC. After this period, the scientific data products from the mission have to be submitted to RSOC in a reduced and calibrated form such that they can be used by the scientific community. RSOC will prepare the Rosetta Scientific Data Archive within one year of the receipt of the complete data sets from the individual Rosetta science investigations. Acronyms -------- For more acronyms refer to Rosetta Project Glossary RO-EST-LI-5012 ATTC Absolute Time Telecommand AU Astronomical Unit CA Closest Approach CAP Comet Acquisition Point CAT Close Approach Trajectory CNES Centre National dEtudes Spatiales COP Close Observation Phase DLR German Aerospace Center DSM Deep Space Manouver ESA European Space Agency ESOC European Space Operations Center ESTEC European Space Research and Technology Center EUV Extreme UltraViolet FAT Far approach trajectory FUV Far UltraViolet GCMS Gas Chromatography / Mass Spectrometry GMP Global Mapping Phase HGA High Gain Antenna HgCdTe Mercury Cadmium Telluride HIGH High Activity Phase (Escort Phase) HK HouseKeeping IRAS InfraRed Astronomical Satellite IRFPA Infrared Focal Plane Array IS Infrared Spectrometer LCC Lander Control Center LDL Long Debye Length LEOP Launch and Early Orbit Phase LOW Low Activity Phase (Escort Phase) LTE Local Thermodynamic Equilibrium MINC Moderate Increase Phase (Escort Phase) MGA Medium Gain Antenna MLI Multi Layer Insulation MS Microscope NNO New Norcia ground station OIP Orbit Insertion Point PI Principal Investigator P/L PayLoad PC Payload Chackout RF Radio Frequency RMOC Rosetta Mission Operations Center RLGS Rosetta Lander Ground Segment RL Rosetta Lander RO Rosetta Orbiter RSOC Rosetta Science Operations Center RVM Rendez-vous Manouver S/C SpaceCraft SINC Sharp Increase Phase (Escort Phase) SONC Science Operations and Navigation Center SSP Surface Science Package STR Star TRacker SWT Science Working Team TGM Transition to global mapping |
