| Mission Description |
Mission Overview ================ Venus Express was ESAs first mission to Venus. It reused the design of the Mars Express spacecraft. Many of the instruments were upgraded versions of those developed for ESAs Mars Express and Rosetta missions. The scientific objectives of the mission were to study the atmosphere, the plasma environment, and the surface of Venus in great detail. Venus Express was launched by a Soyuz-Fregat launcher from the Baikonour Cosmodrome on 9 November 2005. After separation, Venus Express, with a mass 1244 kg, was placed into an interplanetary transfer orbit. After a 153 day cruise to Venus, the spacecraft entered Venusian orbit on 11 April 2006. The first capture orbit was an eccentric polar orbit and lasted 9 days. Several manoeuvres over the period 15 April to 6 May 2006 lowered the spacecraft into its operational orbit: a 24-hour elliptical, quasi-polar orbit. The pericentre altitude was 250 km and the apocentre altitude was 66000 km. Pericentre altitude 250 km Apocentre altitude 66000 km Period 24 h Inclination ~90 deg Pericentre latitude 80 deg The mission has been described in many papers ESA2005; HUNTER2004. Details about the mission launch sequence and timeline can be obtained from the Mission Calendar DAUVIN2005 and from the Consolidated Report on Mission Analysis (CREMA) SANCHEZ&RODRIGU2005. Mission Phases ============== The mission timeline defines the different spacecraft and payload operations required per phase to prepare the spacecraft for Venus operational orbit acquisition, science data acquisition and transmission. The pre-routine mission phases were: - the pre-launch phase - the launch and early orbit phase - the near earth commissioning phase - the interplanetary cruise phase - the venus orbit insertion phase - the venus orbit commissioning phase. PRELAUNCH --------- Pre-launch operations started approximately 6 months before the launch and covered the period from delivery of the spacecraft to the launch site until L-8 hrs in the launch countdown sequence. During this period the Venus Express Mission Operations Centre (VMOC) at ESOC performed its final simulation programme including the validation of the Flight Operations Plan (FOP) and the final mission control system. mission phase start time : ~June 2005 mission phase stop time : 2005-11-09 LAUNCH AND EARLY ORBIT PHASE (LEOP) ----------------------------------- The Venus Express spacecraft was launched on a Soyouz-Fregat rocket from the Baikonur Cosmodrome at 3:33:34 UT on 9 November 2005. The three-stage Soyuz launcher lifted the Fregat autonomous upper stage (fourth stage) with Venus Express mounted on it into a sub-orbital trajectory. After separation from the Soyuz third stage, a Fregat main engine burn (at an altitude of about 200 kilometres) for around 20 seconds placed the Fregat-Venus Express composite into an almost circular parking orbit. After a coast phase of about 70 minutes in low Earth orbit, a second Fregat engine burn, lasting 16 minutes, moved the combined craft from the parking orbit into an escape trajectory, after which the Fregat stage and Venus Express separated. After separation, Venus Express spent approximately 150 days in an interplanetary transfer orbit. During this phase, trajectory corrections were performed using the spacecrafts own thrusters. Duration : 3 days mission phase start time : 2005-11-09 mission phase stop time : 2005-11-11 NEAR EARTH COMMISSIONING PHASE (NECP) ------------------------------------- Near-Earth Commissioning included the following activities for the spacecraft: - spacecraft commissioning. - deployment of the MAG Boom. - Payloads commissioning. Duration : 3 weeks mission phase start time : 2005-11-12 mission phase stop time : 2005-12-16 INTERPLANETARY CRUISE PHASE --------------------------- The Interplanetary Cruise Phase finished about one month before Venus capture. During this 3 month phase, the spacecraft was on a Sun-centred ballistic orbit to Venus. Most of this phase was not dedicated to any specific activity, except the cruise orbit determination and correction. Duration : 107 days mission phase start time : 2005-12-17 mission phase stop time : 2006-04-04 VENUS ORBIT INSERTION PHASE (VOI) --------------------------- The Venus Orbit Insertion (VOI) phase was the period of transition between the Interplanetary Cruise phase and the final operational orbit around Venus. It started before the Venus capture manoeuvre and ended when the satellite reached the operational orbit. The duration of this phase was about 2 weeks. A final course adjustment was performed on 29 March to fine tune the arrival hyperbola for Venus Orbit Insertion. The VOI manoeuvre took place on 11 April 2006. To enable capture of the spacecraft, it was first slewed such that the main engine was aligned to the direction of travel. The main engine burn lasted around 50 minutes and decelerated the spacecraft by approximately 1251 m s-1 (~4500 km h-1). The spacecraft initially entered a highly elliptical polar orbit with a pericentre of 400 km, an apocentre of 350 000 km and a period of 9 days. To achieve the final operational orbit a series of correction manoeuvres were necessary: Date Activity Velocity Change (m/s) 15 April 2006 Pericentre Control Manoeuvre #1 5.8 20 April 2006 Apocentre Lowering Manoeuvre #1 199.9 23 April 2006 Apocentre Lowering Manoeuvre #2 105.3 26 April 2006 Apocentre Lowering Manoeuvre #3 9.2 29 April 2006 Apocentre Lowering Manoeuvre #4 8.0 2 May 2006 Apocentre Trim 2.0 6 May 2006 Pericentre Control Manoeuvre #2 3.1 Duration : 15 days mission phase start time : 2006-04-05 Venus capture manoeuvre : 2006-04-06 mission phase stop time : 2006-04-19 VENUS ORBIT COMMISSIONING PHASE --------------------------------- The Venus Payload Commissioning phase started when the spacecraft reached the operational orbit and ended when it was declared ready for science data acquisition and transmission to the Earth. It was dedicated to spacecraft commissioning activities, payload commissioning and demonstration activities prior to operational science operations. The duration of the Payload Commissioning phase around Venus was about 1 month. The operations to be performed during the phase were the following: - S/C in-orbit commissioning, - Payloads in-orbit commissioning, - Isolation of the Propulsion system. Duration : 44 days mission phase start time : 2006-04-20 mission phase stop time : 2006-06-03 ROUTINE OPERATIONS PHASE ------------------------ The selected operational orbit was inertially fixed, so that coverage of all planetocentric longitudes was accomplished in one Venus sidereal day (243 Earth days). The nominal mission orbital lifetime was two Venus sidereal days (486 Earth days). It consisted in science data acquisition from the payloads, data storage in the SSMM and data transmission to the Earth. There were two different phases of operations for Venus Express once it was in operational orbit: the Earth Pointing phase and the Observation phase. The Earth pointing phase was dedicated to communication with Earth and battery charging. It was used whenever the spacecraft was not in the observation phase. In the Earth pointing phase, one of the two High Gain Antennas was oriented towards Earth. The antenna was selected according to the season, so that the spacecrafts cold face remained always protected from illumination by the Sun. The rotation angle around the Earth direction was optimised in order to avoid any entrance of Sun light on the side walls radiators. High rate communication was performed 8 hours per day in X-band, in order to transmit to Earth all science data stored in the Solid State Mass Memory. An average of 2 Gbits of science data was downlinked every day to the new ESA ground station of Cebreros, Spain. The observation phase consisted of several different modes of observation, depending on the payload configuration and spacecraft orientation: Nadir pointing, Limb observation, Star occultation, Radio science. During observation, the Sun could illuminate under transient conditions any spacecraft face, except for the cold face. The duration of observation was therefore limited by thermal constraints and by battery discharge. The maximum duration of an observation period depended on the Sun direction with respect to the orbit plane, which varied along the mission. Observations and spacecraft activities were planned based on the following principles: 1. Complete and uniform the coverage of the science themes 2. Balance between distant and close-up view of Venus 3. Balance between observations of the Northern and Southern hemisphere 4. Synergy between experiments in covering science objectives 5. Use of two cases in each orbit: one in apocentre, one in pericentre 6. Even distribution of pericentric cases with priority given to the solar and Earth radio occultation experiments in specific seasons 7. Apocentric cases (2, 3) were grouped in campaigns of 10 orbits that was required by the atmospheric dynamics mission objectives 8. Maximum compliance with the current flight rules. Individual Objectives per Instrument ------------------------------------ ASPERA On during the entire mission and permanently collecting data. Survey observations in the beginning of the mission and more specific and detailed observations on selected part of the orbit later in the mission. Data was collected at different rates depending on the selected mode. MAG On during the entire mission and permanently collecting data. Data was collected at different rates depending on the selected mode. SPICAV The main goal of SPICAV was to sound the Venus atmosphere in solar and stellar occultation geometry with sufficient latitude and local time coverage. SPICAV did also nadir and corona observations (90 deg slew from nadir pointing and back to nadir). VeRA 4 types of observations 1. Earth occultation with as good as possible latitude and local time coverage of Venus. 2. Bi-static sounding of surface targets. The radio signal was sent to selected targets on the Venus surface. Reflected and scattered signal was received by ground station. As the signal was weak, the experiment depended on the Earth Venus distance, geometry and surface target properties. 3. Solar corona observations in vincinity of conjunctions. 4. Gravity anomaly campaign. It consisted of the precise tracking of the s/c while it passed over global geological formations on Venus solid body. Duration : 486 days mission phase start time : 2006-06-04 mission phase stop time : 2007-10-02 EXTENDED OPERATIONS PHASE ------------------------- The nominal mission ended on October 2, 2007 when the first extended mission started. The first extended mission phase was approved until 30 May 2009, end of MTP 040, orbit 1135. It was followed by the second mission extension from MTP 041 that started in 31 May 2009, orbit 1136. The second extension was followed by the third extension that started with MTP 057, 22 August 2010, orbit 1584. The third extension ended with MTP 085 in December 2012. The third extension was followed by the fourth extension that started with MTP 088, 6 January 2013, orbit 2452. Summary of extended mission phase starts ---------------------------------------- NOMINAL MISSION MTP 002 Day 4 June 2006 Orbit 44 EXTENSION 1 MTP 019 Day 3 October 2007 Orbit 530 EXTENSION 2 MTP 041 Day 31 May 2009 Orbit 1136 EXTENSION 3 MTP 057 Day 22 August 2010 Orbit 1584 EXTENSION 4 MTP 088 Day 6 January 2013 Orbit 2452 Note: To make the grouping and delivery of products to the archive easier, the start date of the EXTENSION 4 data sets was set to 1 January 2013. EXTENSION 1, 2, 3, 4: General Observation strategy ----------------------------------------------- The first extended mission had the following objectives: - Improve and complete spatial and temporal observational coverage - Study in detail the phenomena discovered in the nominal mission - Take advantage of the new operation modes (case #2 pendulum, spot pointing, ...) - Perform pericentre lowering down to the altitude that still allows usual operations without entering aerobraking mode (around 170 - 270 km) - Perform necessary studies and tests preparing the spacecraft for future aerobraking campaign These goals determined the following planning outline for the extended mission: - 3 October 2007 - 31 May 2008 (MTPs 19 - 27): like nominal mission - 1 June 2008 - 16 May 2014: operations with low pericentre. - 20 May 2014 - 12 July 2014: aerobraking campaign. - 13 July 2014 - end of mission: non-routine operations due to changed orbital period. Pericentre lowering campaign: The pericentre altitude was maintained between 250 km and 350 km during the first 8 months of the extended mission. After 31 May 2008 the pericentre was lowered to the range of 170-220 km. This pericentre lowering was aimed at observing plasma at this altitude range. The apocentre and the pericentre latitude did not change (66000 km, about 78 deg). Science sub-phase ---------------- For the purpose of fine-structuring the payload operations planning, the mission phases were further divided into science sub-phases. The majority of the sub-phases were the medium term planning (MTP) cycles, which consisted of 28 day periods. The 28 day periods, for the majority of the mission, were composed of four 7 day periods, known as Command Periods (CP). A Command Period was also a Short Term Planning (STP) period. From MTP 107 onward, when aerobraking was used to reduce the orbit period, each MTP still consisted of 28 days, but contained more than 28 orbits. Note: Science sub-phases defined after PHASE 38 include only one MTP. To ease the mapping between science sub-phases and MTPs, it was agreed to name these sub-phases following the convention: MTP nn. Phase name Date Orbit CRUISE 2005-11-09 -1 VOI 2006-04-11 0 VOC 2006-04-20 1 MTP 01 2006-05-07 16 MTP 02 2006-06-04 44 MTP 03 2006-07-02 72 MTP 04 2006-07-30 100 MTP 05 2006-08-27 128 MTP 06 2006-09-24 156 MTP 07 2006-10-22 184 MTP 08 2006-11-19 212 MTP 09 2006-12-17 240 MTP 10 2007-01-14 268 MTP 11 2007-02-11 296 MTP 12 2007-03-11 324 MTP 13 2007-04-08 352 MTP 14 2007-05-06 380 MTP 15 2007-06-03 408 MTP 16 2007-07-01 436 MTP 17 2007-07-29 464 MTP 18 2007-08-26 492 MTP 19 2007-09-23 520 MTP 20 2007-10-21 548 MTP 21 2007-11-18 576 MTP 22 2007-12-16 604 MTP 23 2008-01-13 632 MTP 24 2008-02-10 660 MTP 25 2008-03-09 688 MTP 26 2008-04-06 716 MTP 27 2008-05-04 744 MTP 28 2008-06-01 772 MTP 29 2008-06-29 800 MTP 30 2008-07-27 828 MTP 31 2008-08-24 856 MTP 32 2008-09-21 884 MTP 33 2008-10-19 912 MTP 34 2008-11-16 940 MTP 35 2008-12-14 968 MTP 36 2009-01-11 996 MTP 37 2009-02-08 1024 MTP 38 2009-03-08 1052 MTP 39 2009-04-05 1080 MTP 40 2009-05-03 1108 MTP 41 2009-05-31 1136 MTP 42 2009-06-28 1164 MTP 43 2009-07-26 1192 MTP 44 2009-08-23 1220 MTP 45 2009-09-20 1248 MTP 46 2009-10-18 1276 MTP 47 2009-11-15 1304 MTP 48 2009-12-13 1332 MTP 49 2010-01-10 1360 MTP 50 2010-02-07 1388 MTP 51 2010-03-07 1416 MTP 52 2010-04-04 1444 MTP 53 2010-05-02 1472 MTP 54 2010-05-30 1500 MTP 55 2010-06-27 1528 MTP 56 2010-07-25 1556 MTP 57 2010-08-22 1584 MTP 58 2010-09-19 1612 MTP 59 2010-10-17 1640 MTP 60 2010-11-14 1668 MTP 61 2010-12-12 1696 MTP 62 2011-01-09 1724 MTP 63 2011-02-06 1752 MTP 64 2011-03-06 1780 MTP 65 2011-04-03 1808 MTP 66 2011-05-01 1836 MTP 67 2011-05-29 1864 MTP 68 2011-06-26 1892 MTP 69 2011-07-24 1920 MTP 70 2011-08-21 1948 MTP 71 2011-09-18 1976 MTP 72 2011-10-16 2004 MTP 73 2011-11-13 2032 MTP 74 2011-12-11 2060 MTP 75 2012-01-08 2088 MTP 76 2012-02-05 2116 MTP 77 2012-03-04 2144 MTP 78 2012-04-01 2172 MTP 79 2012-04-29 2200 MTP 80 2012-05-27 2228 MTP 81 2012-06-24 2256 MTP 82 2012-07-22 2284 MTP 83 2012-08-19 2312 MTP 84 2012-09-16 2340 MTP 85 2012-10-14 2368 MTP 86 2012-11-11 2396 MTP 87 2012-12-09 2424 MTP 88 2013-01-06 2452 MTP 89 2013-02-03 2480 MTP 90 2013-03-03 2508 MTP 91 2013-03-31 2536 MTP 92 2013-04-28 2564 MTP 93 2013-05-26 2592 MTP 94 2013-06-23 2620 MTP 95 2013-07-21 2648 MTP 96 2013-08-18 2676 MTP 97 2013-09-15 2704 MTP 98 2013-10-13 2732 MTP 99 2013-11-10 2760 MTP 100 2013-12-08 2788 MTP 101 2014-01-05 2816 MTP 102 2014-02-02 2844 MTP 103 2014-03-02 2872 MTP 104 2014-03-30 2900 MTP 105 2014-04-27 2931 MTP 106 2014-05-25 2956 MTP 107 2014-06-21 2984 MTP 108 2014-07-18 3012 MTP 109 2014-08-16 3043 MTP 110 2014-09-13 3073 MTP 111 2014-10-11 3103 MTP 112 2014-11-08 3133 VOI and Phase 0 --------------- This initial phase was devoted to the spacecraft and payload checkout and in-orbit commissioning. The phase consisted of: Venus Orbit Insertion: - orbit insertion - multi-day insertion orbit - experiments commissioning (until 14 May 2006, orbit 23). - science case commissioning (14 - 27 May 2006, orbits 23 - 36). - extended case commissioning (28 May - 3 June, orbits 37 - 43). The ECC also occupied the first half of phase 1. This phase contained the first eclipse season which ended at orbit 40. VOI --- Initial, multi-day insertion orbit. Dates : 6 April - 19 April 2006 Orbits : VOI - 0 Phase duration : 14 days VOC --- Spacecraft checkout period. Dates : 20 April - 6 May 2006 Orbits : 1 - 15 Phase duration : 17 days Phase 0 ------- Start of science instrument commissioning and science case testing. Dates : 7 May - 3 June 2006 Orbits : 16 - 43 Phase duration : 28 days MTP : 1 Phase 1 ------- Phase 1 was favourable for observations of the evening terminator vicinity. In particular, the following observations were performed: - Cloud observations; - Lightning on the nightside; - Stellar occultation on the dark limb (North/South asymmetry of the aerosol vertical structure); - Solar occultation (horizontal structure of hazes above the main cloud deck); - Thermal mapping of Ishtar Terra and Maxwell Montes; - Limb observations (vertical structure of haze layers); - Observations of nightglows (O2, NO, ...), their latitudinal and vertical variability; - Bistatic sounding of Maxwell Montes (BSR #1); - Comet Mrkos by SPICAV and VMC on 5 June 2006. Surface targets included (note that coordinates given throughout this catalog are the center latitude and longitude, in a planetocentric coordinate system with +East in a range of 0 - 360 degrees): Maxwell Montes (65.2 degrees N, 3.3 degrees E) Ishtar Terra (70.4 degrees N, 27.5 degrees E) SPICAV observed nadir and stellar occultations. VeRA performed bi-static sounding (BSR #1) of Maxwell Montes. VIRTIS observed the evening sector of the planet, nightside mosaics, thermal mapping of Maxwell Montes and limbs. VMC observed the evening sector of Venus, limbs and performed thermal mapping of Maxwell Montes. Dates : 4 June - 10 July 2006 Orbits : 44-80 Phase duration : 37 days MTP : 2 - 3 Phase 2 ------- Phase 2 started at the beginning of the first Earth occultation season in orbit 81 and ended at the end of the second eclipse season in orbit 145. It provided favorable conditions for nadir observations of the nightside. The following observations had the priority: - Solar eclipse; - Earth radio-occultations; - nightside dynamics with high spatial resolution; - Twilight limb observations in forward scattering geometry; - Nightglow observations; - Thermal mapping of the surface. The nightside surface targets were: Theia Mons (22.7 degrees N, 281 degrees E) Lakshmi Planum (68.6 degrees N, 339.3 degrees E) Beta Regio (25.3 degrees N, 282.8 degrees E) Phoebe Regio (6 degrees S, 282.8 degrees E) Ishtar Terra (70.4 degrees N, 27.5 degrees E) ASPERA took measurements of the nightside plasma. SPICAV observed in nadir mode and the solar occultations. VeRA observed during the Earth occultation season #1 and participated in gravity campaign #1. VMC observed the nightside: atmospheric dynamics, nightside surface mapping of the targets listed above. They also observed nightglow and searched for lightning. Dates : 11 July - 13 September 2006 Orbits : 81 - 145 Phase duration : 65 days MTP : 3 - 5 Phase 3 ------- The Venus dark side could be observed in the beginning of Phase 3. Phase 3 also had conditions for systematic observations of the morning/evening terminator and for solar corona studies. The phase contained the first superior solar conjunction (orbits 179 - 201). The following observations were performed: - Clouds at terminator (study of cloud and haze structure); - Coordinated campaign of atmospheric dynamics observations in Northern and Southern polar regions; - Search for lightning on the nightside; - Double stellar occultation on the dark limb (North-South asymmetry of aerosol vertical structure); - Mapping of surface targets (Ishtar Terra); - Limbs (vertical structure of haze layers); - Nightglows (O2, NO, ...): latitude and vertical variability; - Solar corona studies. Surface targets included: Ishtar Terra (70.4 degrees N, 27.5 degrees E) ASPERA observed the morning sector. SPICAV observed nadir and stellar occultations. VeRA observed the solar corona. VIRTIS observed the North/South polar dynamics, the Ishtar Terra nightside target and the morning sector. VMC observed the North/South polar dynamics, the Ishtar Terra night side target, the high-resolution atmospheric dynamics, nightglow and searched for lightning. Dates : 14 September - 15 November 2006 Orbits : 146 - 208 Phase duration : 63 days MTP : 5 - 7 Phase 4 ------- Phase 4 started at the beginning of the 3rd eclipse season in orbit 209 and ended at the end of the 2nd Earth occultation season in orbit 285. Surface targets included: Theia Mons (22.7 degrees N, 281 degrees E) Lakshmi Planum (68.6 degrees N, 339.3 degrees E) ASPERA observed in detail the nightside plasma. SPICAV observed solar occultations and nadir. VeRA observed during Earth occultation season, and the solar corona. VIRTIS and VMC observed on the dayside but also nightside of Theia Mons and Lakshmi Planum. Dates : 16 November 2006 - 31 January 2007 Orbits : 209 - 285 Phase duration : 77 days MTP : 7 - 10 Phase 5 ------- Phase 5 started at the end of the Earth occultation season #2 and ended at the beginning of the eclipse season #4. It had favorable conditions for observations of the evening terminator. Focus was also placed on the nightside. The following observations were performed: - Cloud observations at terminator (study of cloud and haze structure); - North-South atmospheric dynamics; - Search for lightning on the nightside; - Double stellar occultation on the dark limb (North-South asymmetry of aerosol vertical structure); - Mapping of surface targets: Atla Regio, Ozza Mons; - Limbs (vertical structure of haze layers); - Nightglows (O2, NO, ...): latitude and vertical variability. Surface targets included: Ozza Mons (4.5 degrees N, 201 degrees E) Atla Regio (9.2 degrees N, 200.1 degrees E) ASPERA observed the evening sector in detail. SPICAV observed nadir and stellar occultations. VeRA did not observe anything. VIRTIS and VMC did mosaic and off-pericentre observations. They participated in the North/South Pole dynamics campaign. They also observed the nightside. Dates : 1 February - 16 March 2007 Orbits : 286 - 329 Phase duration : 44 days MTP : 10 - 12 Phase 6 ------- Phase 6 started at the beginning of the eclipse season #4 in orbit 330. It ended with the same season in orbit 369. The phase provided good conditions for observations of the nightside and atmospheric sounding in solar occultation geometry. Solar occultations were used to study the composition and structure of the atmosphere above the cloud top. Campaigns of off-pericentre observations and apocentre VIRTIS mosaics were used to study the composition and dynamics of the deep atmosphere on the nightside. Conditions were also favourable for observations of nightglow to study the composition and dynamics of the thermosphere and search for lightning. Limb observations in forward scattering geometry (spacecraft in eclipse) provided a good opportunity to study the vertical structure of hazes above the main clouds. Thermal mapping of the surface and a search for active volcanism was performed. One bi-static sounding experiment (BSR #4) was scheduled. The nightside surface targets were: Beta Regio (25.3 degrees N, 282.8 degrees E) Theia Mons (22.7 degrees N, 281 degrees E) Phoebe Regio (6 degrees S, 282.8 degrees E) Themis Regio (37.4 degrees S, 284.2 degrees E) SPICAV observed nadir and solar occultations. VeRA performed the bi-static sounding experiment #4. VIRTIS and VMC observed off-pericentre and in mosaic mode. They observed Themis and Phoebe Regio on the nightside. Dates : 17 March - 25 April 2007 Orbits : 330 - 369 Phase duration : 39 days MTP : 12 - 13 Phase 7 ------- Phase 7 started with Earth occultation season #3 in orbit 370 and ended in orbit 435. Proximity to the Earth created excellent conditions for bi-static sounding and radio-occultation observations that could reach maximum sounding depth. It was used to study the atmosphere with high spatial resolution. As earlier in phases 1, 3 and 5, the terminator sector of the planet was available for observations in this phase. Cloud structure and atmospheric dynamics studies were important goals. The nightside surface targets were: Gula Mons (21.9 degrees N, 359.1 degrees E) Ozza Mons (4.5 degrees N, 201 degrees E) Sif Mons (22 degrees N, 352.4 degrees E) Maxwell Montes (65.2 degrees N, 3.3 degrees E) Atalanta Planitia (45.6 degrees N, 165.8 degrees E) Guinevere Planitia (21.9 degrees N, 325 degrees E) Atla Regio (9.2 degrees N, 200.1 degrees E) Ishtar Terra (70.4 degrees N, 27.5 degrees E) SPICAV observed nadir and stellar occultations. VeRA was on during the radio occultation season 4 and performed the bi-static radar experiment #5 (Ozza Mons). VIRTIS and VMC did off-pericentre and mosaic observations. They observed Ishtar Terra and Maxwell Montes on the nightside. Dates : 26 April - 30 June 2007 Orbits : 370 - 435 Phase duration : 66 days MTP : 13 - 15 Phase 8 ------- Phase 8 started and ended with eclipse season #5. Thus a significant portion of the orbits were devoted to solar occultation observations. This phase was favourable for investigation of dayside dynamics. Proximity to the Earth provided good conditions for solar corona studies and bi-static sounding. Gravity campaign #2 targeted Atalanta Planitia, which was poorly covered by the Magellan observations, but had to be cancelled due to an anomaly with the S-Band antenna. The thermal mapping covered Beta and Phoebe Regio. Surface targets included: Theia Mons (22.7 degrees N, 281 degrees E) Atalanta Planitia (45.6 degrees N, 165.8 degrees E) Beta Regio (25.3 degrees N, 282.8 degrees E) Phoebe Regio (6 degrees S, 282.8 degrees E) SPICAV observed nadir and solar occultation. VeRA performed bi-static radar sounding #6 (Beta Regio and Theia Mons). VIRTIS and VMC did off-pericentre and mosaic observations of the dayside. Dates : 1 July - 21 August 2007 Orbits : 436 - 487 Phase duration : 52 days MTP : 16 - 17 Phase 9 ------- Phase 9 contained Earth occultation season #3a. It was favourable for observations of the region of the evening terminator. The main scientific goal of this phase was to provide observations of the evening terminator. The following observations were carried out: - Cloud observations at terminator (study of cloud and haze structure); - Search for lightning on the nightside; - Double stellar occultation on the dark limb (North/South asymmetry of the aerosol vertical structure); - Grazing solar occultation (horizontal structure of the hazes above the main cloud deck); - Mapping of the surface targets; - Limb (vertical structure of haze layers); - Nightglows (O2, NO) and their latitude and vertical variability. The nightside surface targets were: Atalanta Planitia (45.6 degrees N, 165.8 degrees E) Guinevere Planitia (21.9 degrees N, 325 degrees E) Ishtar Terra (70.4 degrees N, 27.5 degrees E) SPICAV observed nadir and stellar occultation. VeRA performed bi-static radar sounding #6a. VIRTIS and VMC observed the morning and evening sectors. Dates : 22 August - 3 October 2007 Orbits : 488 - 530 Phase duration : 43 days MTP : 17 - 19 Phase 10 -------- Phase 10 had no eclipse or occultation seasons. A routine sequence of off-pericentre observations followed by nadir, limb or stellar occultations was carried out. The nightside surface targets were: Zemina Corona (11.7 degrees S, 186 degrees E) Maat Mons (0.5 degrees N, 194.6 degrees E) Ozza Mons (4.5 degrees N, 201 degrees E) Sapas Mons (8.5 degrees N, 188.3 degrees E) Atla Regio (9.2 degrees N, 200.1 degrees E) SPICAV-SOIR did not make any observation during this phase (no occultations). Dates : 4 October - 26 October 2007 Orbits : 531 - 553 Phase duration : 23 days MTP : 19 - 20 Phase 11 -------- Phase 11 started with eclipse season #6 in orbit 554. However, solar occultations were only possible from orbit 576 to 596 because of the temperature conditions due to the position of the Sun. The surface targets included: Rhea Mons (32.4 degrees N, 282.2 degrees E) Theia Mons (22.7 degrees N, 281 degrees E) Atalanta Planitia (45.6 degrees N, 165.8 degrees E) Gunda Planitia (16 degrees S, 267 degrees E) Hinemoa Planitia (5 degrees N, 265 degrees E) Kawelu Planitia (32.8 degrees N, 246.5 degrees E) Asteria Regio (21.6 degrees N, 267.5 degrees E) Beta Regio (25.3 degrees N, 282.8 degrees E) Phoebe Regio (6 degrees S, 282.8 degrees E) VIRTIS performed some airglow campaigns in nadir and limb geometry. VMC observed the surface on the nightside. The observation targets were Asteria Regio, Hinemoa, Gunda and Kawelu Planitia, Beta Regio (Rhea and Theia Mons) and Phoebe Regio. SPICAV observed stars at large distances, later in the phase. Two spot pointings were performed in orbits 561 and 571 (study of cloud scattering phase function). Gravity campaign #3 was performed over Atalanta Planitia in orbits 615, 617, 619, and 621. Meteors occurred in orbit 555. SPICAV-SOIR did not make any observations nor calibrations until 25 November 2007, despite the solar occultation that began 27 October 2007, due to thermal reasons in the Quadrature period. Dates : 27 October 2007 - 3 January 2008 Orbits : 554 - 622 Phase duration : 69 days MTP : 20 - 22 Phase 12 -------- Phase 12 started with Earth occultation season #4 and ended with eclipse season #7. Earth occultation season began in orbit 624 and ended in orbit 692. Pendulum observations were also performed in this phase. From orbit 659 to orbit 680, three periods overlapped: Earth occultation, eclipse season, and solar opposition. The solar opposition was favorable for apocentre mosaics by VIRTIS. The surface targets for this phase were: Atahensik Corona (19 degrees S, 170 degrees E) Zemina Corona (11.7 degrees S, 186 degrees E) Ozza Mons (4.5 degrees N, 201 degrees E) Atalanta Planitia (45.6 degrees N, 165.8 degrees E) Atla Regio (9.2 degrees N, 200.1 degrees E) Pendulum: the observation points to Nadir, then out to space, then back to Nadir, then back to space, etc., mimicking a pendulums movement. VIRTIS near-IR did temperature sounding in the same region. Then cross-correlation on results were made possible. From orbit 612 to 631 there was the VIRTIS apocentre mosaic season. Solar occultations and pendulum observations were mainly performed at the end of the phase (from orbit 690 onwards). VeRA had priority for pericentre observations of the Southern Hemisphere. However, VeRA measurements were not possible from orbit 645 to 658 due to New Norcia (NNO) station maintenance. Dates : 3 January - 31 March 2008 Orbits : 623 - 710 Phase duration : 88 days MTP : 22 - 25 Phase 13 -------- There was no specific season during most of phase 13. During this phase, pericentre observations, stellar occultation observations, and limb observations at pericentre were performed. At the end of phase 13, in orbit 769, the mission entered a superior conjunction phase and telecommunication outage period (orbits 769 to 790) during which all science operations were suspended. Dates : 1 April - 4 June 2008 Orbits : 711 - 775 Phase duration : 65 days MTP : 25 - 28 Phase 14 -------- Phase 14 started with eclipse season #8 and Earth occultation season #5. At the beginning of the phase, the solar superior conjunction prevented any science observations. The eclipse and Earth occultation seasons overlapped (orbits 777 - 821). The Earth occultation period lasted until orbit 833. During this phase, there was a pericentre lowering campaign in orbits 814, 815, 821, 822, 829 and 830. The targets for the surface observations were: Parga Chasmata (20 degrees S, 255 degrees E) Zewana Chasma (9 degrees N, 212 degrees E) Ozza Mons (4.5 degrees N, 201 degrees E) Atla Regio (9.2 degrees N, 200.1 degrees E) with a focus on the East flank VMC performed surface imaging and wind tracking. SPICAV did solar occultations (ingress and egress solar occultations in orbits 811 - 819), night and plane limbs and UV observations of the exosphere on the dayside. Stellar occultations have been performed in coordination with VeRA. They observed dayglow when flying perpendicular to terminator. Sub-solar point tracking was performed by SOIR. VIRTIS observed night limbs together with SPICAV and surface imaging. VeRA Earth occultation experiments began in orbit 817. Dates : 5 June - 31 July 2008 Orbits : 776 - 832 Phase duration : 57 days MTP : 28 - 30 Phase 15 -------- There was no specific season during phase 15. The pericentre lowering campaign that began in the previous phase ended at orbit 836. This phase includes the 1st Atmospheric Drag Experiment (ADE) campaign, which focused on testing the spacecraft systems to ensure future ADE campaigns would not endanger the spacecrafts safety. SPICAV performed night limbs, plane limbs and stellar occultations. Later in the phase, SPICAV performed dayside limbs. VMC performed wind tracking on the dayside. VIRTIS did nightside and terminator monitoring and limb observations together with SPICAV at the beginning of the phase. Later in the phase, dayside and terminator monitoring was performed. Dates : 1 August - 22 September 2008 Orbits : 833 - 885 Phase duration : 53 days MTP : 30 - 32 Phase 16 -------- This phase started with eclipse season #9 (orbits 866 - 934). There was also a Mosaic season (orbits 903 - 969) and Earth occultation season #6 (orbits 921 - 985). Pendulum observations were frequently used. There was a joint VIRTIS-SPICAV campaign of nightside nadir airglow observations in the equatorial zone. There were good opportunities for SOIR nadir observations. Surface targets included: Aphrodite Terra (5.8 degrees S, 104.8 degrees E) SPICAV performed solar occultation and limb observations. VMC performed monitoring and wind tracking on the dayside, and surface imaging between solar occultations. Around orbit 967, they performed nightside imaging of Aphrodite Terra. VIRTIS performed dayside monitoring, limb observations together with SPICAV. Later in the phase, VIRTIS also performed Mosaic observations at apocentre. VeRA performed radio occultations. VIRTIS suffered a failure of the M cooler on 27 October 2008. As a consequence, from this date onward, there was no M-IR data. Dates : 23 September - 31 December 2008 Orbits : 886 - 985 Phase duration : 100 days MTP : 32 - 35 Phase 17 -------- This phase started with the end of the Earth occultation season. Orbit 1001 started eclipse season #10. The phase ended at the end of the eclipse season. Surface targets included: Ganis Chasma (18 degrees N, 189 degrees E) Sapas Mons (8.5 degrees N, 188.3 degrees E) Rusalka Planitia (3 degrees N, 170 degrees E) Atla Regio (9.2 degrees N, 200.1 degrees E) Ovda Regio (2.8 degrees S, 85.6 degrees E) Aphrodite Terra (5.8 degrees S, 104.8 degrees E) SPICAV observed day and night limbs and performed solar occultations. VMC performed nightside imaging of Aphrodite Terra and Rusalka Planitia. VeRA performed radio observations. VIRTIS had observations every second orbit. Dates : 1 January - 1 March 2009 Orbits : 986 - 1045 Phase duration : 60 days MTP : 35 - 37 Phase 18 -------- This phase included an inferior solar conjunction. There was no specific season. This phase focused on the Venus morning sector. Every second orbit, a coordinated campaign of ground-based observations were organised. Surface targets included: Aino Planitia (40.5 degrees S, 94.5 degrees E) Tahmina Planitia (23 degrees S, 80 degrees E) Ovda Regio (2.8 degrees S, 85.6 degrees E) Manatum Tessera (4 degrees S, 64 degrees E) Tellus Tessera (42.6 degrees N, 76.8 degrees E) Aphrodite Terra (5.8 degrees S, 104.8 degrees E) SPICAV observed stellar occultations and dayside tangential limbs. VMC did wind tracking in the evening sector and nightside imaging of the western part of Aphrodite Terra. VIRTIS did terminator studies, limb observations with SPICAV and night side surface observations with VMC. VeRA performed gravity campaigns #4 - 7. Dates : 2 March - 4 May 2009 Orbits : 1046 - 1109 Phase duration : 63 days MTP : 37 - 40 Phase 19 -------- This phase started with eclipse season #11, at orbit 1110. It ended when the eclipse season ended, at orbit 1159. The dayside observations had good illumination conditions. The nightside surface observations were in eclipse. Surface targets included: Atahensik Corona (19 degrees S, 170 degrees E) Atalanta Planitia (45.6 degrees N, 165.8 degrees E) Rusalka Planitia (3 degrees N, 170 degrees E) SPICAV observed solar and stellar occultations as well as dayside tangential limbs. VeRA performed gravity campaign #8. VMC did dayside observations and nightside imaging of the Atalanta and Rusalka Planitia and of Atahensik Corona. VIRTIS observed on the dayside and performed limb observations with SPICAV. Dates : 5 May - 23 June 2009 Orbits : 1110 - 1159 Phase duration : 50 days MTP : 40 - 41 Phase 20 -------- This phase started at the end of eclipse season #11, at orbit 1160. It ended after the end of Earth occultation season #7 and during the following eclipse season, #12. Nightside surface targets were: Llorona Planitia (18 degrees N, 145 degrees E) Aphrodite Terra (5.8 degrees S, 104.8 degrees E) VeRA observed during the Earth occultation season and was given priority, and also performed gravity campaign #9. SPICAV did nadir observations around terminator (SO2), solar occultation before pericentre, and exospheric limb observation after pericentre. VMC observed night limb (O2 emission and surface) before pericentre and dayside nadir after pericentre. They observed in spot pointing mode (see VEX_POINTING_MODE_DESC.TXT) for phase function studies (study of the same place with different light conditions). They also performed VMC mosaic observations. VIRTIS-H observed meridional cross-sections. Dates : 24 June - 19 September 2009 Orbits : 1160 - 1247 Phase duration : 88 days MTP : 41 - 44 Phase 21 -------- This phase started during eclipse season #12, at orbit 1248. During the eclipse season, the nightside of the surface was observed. At the end of the phase (orbits 1271 - 1275) Drag campaign #2 was performed, meaning that the pericentre pass was devoted to spacecraft tracking by NNO and no observations within +/- 2 hours from the pericentre were foreseen. SPICAV-SOIR was given the priority in pericentre observations. SPICAV observed solar occultations. They did a campaign of nadir night side observations (NO emission). They also observed exospheric limbs. VMC observed dayside nadirs. They did mosaic and spot pointing for phase function studies (see phase 20). VIRTIS observed meridional cross sections of the nightside. Dates : 20 September - 17 October 2009 Orbits : 1248 - 1275 Phase duration : 28 days MTP : 45 Phase 22 -------- This phase did not contain any particular season. It ended just after the beginning of Earth occultation season #8. The observations focused on the morning sector of the planet. In orbit 1332, there was an Orbital Correction Manoeuvre (OCM). SPICAV followed their previous nadir nightside campaign of NO emissions. They also did nadir observations of SO2 around terminator. VMC did dayside observations with off-track (see explanation in phases 20 & 21). They also observed night limbs. VIRTIS observed meridional cross-sections. Dates : 18 October - 16 December 2009 Orbits : 1276 - 1335 Phase duration : 99 days MTP : 46 - 48 Phase 23 -------- This phase started at the beginning of eclipse season #13 (orbit 1336). It contained both Earth and solar occultations, but Earth occultations (season #8) could not be performed due to conjunction. For most of this phase, no science was performed due to the telecommunication outage caused by superior solar conjunction #3. SPICAV did solar occultations and exospheric limbs. VMC observed in pendulum mode and dayside with off-track. VIRTIS observed meridional cross sections. VeRA did not observe due to the proximity of the conjunction. Dates : 17 December 2009 - 1 February 2010 Orbits : 1336 - 1382 Phase duration : 47 days MTP : 48 - 49 Phase 24 -------- This phase had neither Earth nor solar occultations. It started at the end of eclipse season #13 (orbit 1382) and ended with the start of eclipse season #14 (orbit 1447). The evening sector of the planet was observed. Drag campaign #3 was scheduled for orbits 1401 - 1456, in two parts, and was mainly contained in this phase. A pericentre OCM was scheduled in orbit 1402 and another one in orbit 1430. SPICAV observed stellar occultations and limbs with short pendulum modes every 2 orbits. VMC did pendulum observations, dayside with off-track and night limb observations. VIRTIS observed meridional cross sections. Dates : 2 February - 6 April 2010 Orbits : 1383 - 1446 Phase duration : 64 days MTP : 49 - 52 Phase 25 -------- This phase started with eclipse season #14 at orbit 1447 and ended with it at orbit 1499. Drag campaign #3 ended during this phase. During this phase Earth occultation season #9 started at orbit 1470. The nightside surface of Venus was observed in eclipse. Gravity campaign #11 was scheduled for orbits 1461, 1463 and 1465. An apocentre OCM was scheduled in orbit 1458. SPICAV observed stellar occultations, solar occultations and exospheric limbs. VMC observed on the dayside for latitude tracking, VMC mosaic, and spot pointing for cloud phase function. VIRTIS did meridional cross-sections. VeRA performed radio occultations. Dates : 7 April - 29 May 2010 Orbits : 1447 - 1499 Phase duration : 53 days MTP : 52 - 54 Phase 26 -------- This phase started at the end of eclipse season #14 and ended at the end of Earth occultation season #9. A pericentre OCM was scheduled in orbit 1500. SPICAV observed stellar occultations, limbs, nadir around terminator (SO2) and Earth. VMC observed on the dayside for latitude tracking, VMC mosaic, and spot pointing for cloud phase function. VeRA did radio occultations. VIRTIS-H observed meridional cross-sections. Dates : 30 May - 11 July 2010 Orbits : 1500 - 1542 Phase duration : 43 days MTP : 54 - 55 Phase 27 -------- This phase focused on the morning sector of the planet. It started at the end of Earth occultation season #9 at orbit 1543 and ended at orbit 1560. Gravity campaign #12, initially scheduled for this phase, was cancelled. SPICAV observed stellar occultations and limbs. They also observed nadir around terminator (SO2). VMC observed the dayside with off track to the dayside for latitude tracking, VMC mosaic, and spot pointing for cloud phase function. VeRA did radio occultations during the Earth occultation season. VIRTIS-H observed meridional cross-sections. Dates : 12 July - 29 July 2010 Orbits : 1543 - 1560 Phase duration : 36 days MTP : 55 - 56 Phase 28 -------- This phase included eclipse season #15. Solar occultation occurred after pericentre. Night surface observations in eclipse covered Thetis Regio of Aphrodite Terra and Llorona and Niobe Planitia. At egress from eclipses the Artemis corona could be imaged. Surface targets were: Artemis Corona (35 degrees S, 135 degrees E) Llorona Planitia (18 degrees N, 145 degrees E) Niobe Planitia (21 degrees N, 112.3 degrees E) Thetis Regio (11.4 degrees S, 129.9 degrees E) Aphrodite Terra (5.8 degrees S, 104.8 degrees E) SPICAV did solar occultation observations after orbit 1571. There were some joint SPICAM-SPICAV observations of hydrogen distribution in the solar corona. VIRTIS did day latitude track (off-pericentre), dayside spectroscopy (H) and night limb tracking surface (H, pericentre). VMC did dayside monitoring (off-pericentre), latitude tracking, day limb tracking and night limb tracking (pericentre). Dates : 30 July - 13 September 2010 Orbits : 1561 - 1606 Phase duration : 45 days MTP : 56 - 57 Phase 29 -------- This phase focused on the evening sector of the planet. Drag campaign #4 occurred during this phase. After the Drag campaign, the pericentre was raised to 340 km. During this phase Venus approached inferior conjunction. Surface imaging was possible either from apocentre by VIRTIS or at close approach by VMC. SPICAV did solar occultation (pericentre) and stellar occultations (off-pericentre). SPICAV-SOIR did calibrations and observed aeronomic emissions at pericentre. SOIR calibrations consisted of 2 miniscans, 1 alignment and 1 thermal performed in any part of the orbit outside the eclipse. VIRTIS did day latitude track full mosaics (off-pericentre) and, at pericentre, day spectroscopy (H) and night limb tracking (H). VMC did dayside monitoring and observed terminator (off-pericentre) and, at pericentre, latitude day tracking, day limb tracking, and surface out of eclipse. Dates : 14 September - 18 November 2010 Orbits : 1607 - 1671 Phase duration : 64 days MTP : 57 - 60 Phase 30 -------- This phase included eclipse season #16. It also coincided with Akatsukis arrival. Akatsuki is a Japanese spacecraft (JAXA) sent on May 20, 2010 to study Venus Atmosphere dynamics. Unfortunately, Akatsuki experienced some problems during the orbit insertion manoeuvre and failed to get captured in Venus orbit. During this phase, solar occultation occurred before pericentre. Surface targets were: Artemis Corona (35 degrees S, 135 degrees E) Niobe Planitia (21 degrees N, 112.3 degrees E) Llorona Planitia (18 degrees N, 145 degrees E) Ovda Regio (2.8 degrees S, 85.6 degrees E) Thetis Regio (11.4 degrees S, 129.9 degrees E) Aphrodite Terra (5.8 degrees S, 104.8 degrees E) Tellus Tessera (42.6 degrees N, 76.8 degrees E) SPICAV-SOIR did calibrations and was given priority in pericentre observations. SPICAV did stellar occultations (off-pericentre) and observed exosperic limbs (pericentre). VIRTIS did day latitude track (off-pericentre) and, at pericentre, spectra and night limbs (M). VMC did dayside monitoring (off-pericentre) and observed surface and limbs in eclipse at pericentre. Dates : 19 November 2010 - 16 January 2011 Orbits : 1672 - 1731 Phase duration : 59 days MTP : 60 - 62 Phase 31 -------- This phase included Earth occultation #10 and the beginning of eclipse season #17. No solar occultation was possible during this phase. SPICAV-SOIR did calibrations (off-pericentre). SPICAV observed stellar occultations (off-pericentre) and at pericentre, NO emission mapping in nadir, and SO2 at terminator. There were also joint SPICAV SPICAM observations. VeRA did radio occultations. VIRTIS did day latitude track off-pericentre and at pericentre, limb scans and day spectra. VMC did dayside monitoring off-pericentre and observed morning sector and evening sector at pericentre. Dates : 17 January - 22 March 2011 Orbits : 1732 - 1796 Phase duration : 64 days MTP : 62 - 64 Phase 32 -------- This phase included eclipse season #17. Surface targets were: Niobe Planitia (21 degrees N, 112.3 degrees E) Tahmina Planitia (23 degrees S, 80 degrees E) Ovda Regio (2.8 degrees S, 85.6 degrees E) Thetis Regio (11.4 degrees S, 129.9 degrees E) Manatum Tessera (4 degrees S, 64 degrees E) Tellus Tessera (42.6 degrees N, 76.8 degrees E) SPICAV-SOIR did calibrations (off-pericentre) and solar occultations (pericentre). SPICAV did joint observation with SPICAM and stellar occultations (pericentre). VeRA did radio occultations. VIRTIS did day latitude track off-pericentre and spectra and limb scans at pericentre. VMC did dayside monitoring off-pericentre and, at pericentre, day latitude tracking and surface observations. Dates : 23 March - 25 April 2011 Orbits : 1797 - 1830 Phase duration : 33 days MTP : 64 - 66 Phase 33 -------- This phase included Drag campaign #5. The pericentre was as low as 165 km and was raised to 290 km after the campaign. SPICAV did joint observations with SPICAM off-pericentre. At pericentre SPICAV observed nadir for SO2 measurements, and did limb observations and stellar occultations. VIRTIS did a full mosaic off-pericentre and at pericentre observed day spectroscopy and night limb. VMC observed the terminator off-pericentre and, at pericentre, the surface and the limb. Dates : 26 April - 13 June 2011 Orbits : 1831 - 1879 Phase duration : 48 days MTP : 66 - 67 Phase 34 -------- This phase included both Earth occultation season #11 and eclipse season #18. From orbit 1895 to 1907, Venus, Earth and Sun were on one line. Radio and solar occultations sounded approximately the same regions on Venus. This created a rare opportunity for co-located soundings by VeRA and SOIR. The end of this phase included superior solar conjunction #4. Surface targets were: Ovda Regio (2.8 degrees S, 85.6 degrees E) Manatum Tessera (4 degrees S, 64 degrees E) Tellus Tessera (42.6 degrees N, 76.8 degrees E) SPICAV-SOIR performed calibrations off-pericentre and solar occultations (pericentre). SPICAV did joint observations with SPICAM and stellar occultations off-pericentre and, at pericentre, observed zodacial light and exospheric limbs. VIRTIS did off-pericentre day latitude tracking. They observed limbs and did M spectral measurements at pericentre. They suffered a failure in the H cooler on 13th June 2011. From this date onward, there was no H data. VMC did dayside monitoring off-pericentre and, at pericentre, they observed the limb and the surface. Dates : 14 June - 26 August 2011 Orbits : 1880 - 1953 Phase duration : 73 days MTP : 67 - 70 Phase 35 -------- This phase included Drag campaign #6. SPICAV-SOIR performed off-pericentre calibrations. SPICAV did off-pericentre joint observation with SPICAM. They also did stellar occultations off-pericentre. At pericentre they did SO2 measurements in nadir modes and at terminator. VIRTIS did day latitude track (off-pericentre). At pericentre they did limb scans and spectral measurements. VMC did dayside monitoring at terminator (off-pericentre) and day latitude tracking at pericentre. Dates : 27 August - 24 October 2011 Orbits : 1954 - 2012 Phase duration : 58 days MTP : 70 - 72 Phase 36 -------- This phase included eclipse season #19 and the first half of Earth occultation #12. Surface targets were: Niobe Planitia (21 degrees N, 112.3 degrees E) Tahmina Platinia (23 degrees S, 80 degrees E) Ovda Regio (2.8 degrees S, 85.6 degrees E) Manatum Tessera (4 degrees S, 64 degrees E) Tellus Tessera (42.6 degrees N, 76.8 degrees E) SPICAV-SOIR performed off-pericentre calibrations and solar occultations at pericentre. SPICAV did joint observations with SPICAM and stellar occultations off-pericentre. At pericentre, they observed zodacial light. VIRTIS did off-pericentre day latitude track. At pericentre, they did limb scans, and measured day spectra. VMC did off-pericentre dayside monitoring. At pericentre, they did day latitude tracking and observed the surface. Dates : 25 October - 10 December 2011 Orbits : 2013 - 2059 Phase duration : 47 days MTP : 72 - 73 Phase 37 -------- This phase included the second half of Earth occultation season #12 and the start of Drag campaign #7. SPICAV did tangential limb and stellar occultations at pericentre. VeRA did radio occultations. VIRTIS did off-pericentre day latitude track and full mosaic. At pericentre, they did day spectroscopy and night limb tracking. VMC did dayside monitoring off-pericentre. At pericentre they did day latitude tracking and observed the surface. Dates : 11 December 2011 - 7 January 2012 Orbits : 2060 - 2087 Phase duration : 28 days MTP : 74 Phase 38 -------- This phase included Drag campaign #7. The pericentre was as low as 176 km. SPICAV-SOIR performed calibrations off-pericentre. SPICAV did off-pericentre stellar occultations. At pericentre, they observed nadir mode at terminator and measured aeronomic emissions. VIRTIS did dayside tracking off-pericentre, and 2 full mosaics. At pericentre, they did limb tracking. VMC observed the surface, the limb and did day latitude tracking at pericentre. Dates : 8 January 2012 - 4 February 2012 Orbits : 2088 - 2115 Phase duration : 28 days MTP : 75 >From this phase on, there were two new observation types defined for SPICAV and SPICAV-SOIR. The first one were observations in eclipse of the NO airglow using inertial mode. The spacecraft is held in inertial mode such that the observed point sweeps a wide range of latitudes while the spacecraft is in eclipse. The second one defined for SOIR intended to observe light reflected from the dayside cloud top. MTP 76 ------ This MTP included the start of eclipse season #20 in orbit 2119. The solar occultation occured before pericentre. Before pericentre (nightside), every other orbit was allocated to VIRTIS-MVIS night limb search for airglow. After pericentre (dayside), this MTP could be used for SPICAV dayside limb observations of airglow. Surface targets were: Bereghinya Planitia (28.6 degrees N, 23.6 degrees E) Eistla Regio (10.5 degrees N, 21.5 degrees E) with a focus on the central portion Ishtar Terra (70.4 degrees N, 27.5 degrees E) Lada Terra (62.5 degrees S, 20 degrees E) VIRTIS did mosaic from apocentre, and limb track airglow observations. SPICAV did sub-solar point observations, for Cross Polarization calibration, and Zodiacal Light Observation during eclipse. SPICAV-SOIR performed nadir observations. SPICAV and VIRTIS did nadir observations at pericentre (optimised for nadir absorption spectroscopy). VMC did phase function observations, mosaics of dayside at pericentre. Dates : 5 February - 3 March 2012 Orbits : 2116 - 2143 Phase duration : 28 days MTP : 76 MTP 77 ------ The entire phase was in eclipse season #20. The long Earth occultation season #13 started at the end of this phase (in orbit 2167). Surface targets were: Tepev Mons (29 degrees N, 44.3 degrees E) Bell Regio (32.8 degrees N, 51.4 degrees E) Eistla Regio (10.5 degrees N, 21.5 degrees E) with a focus on the Eastern portion Ishtar Terra (70.4 degrees N, 27.5 degrees E) VIRTIS did M-VIS limb-track observations (nightside in eclipse). SPICAV did stellar occultations, and VEX-SOHO joint observations. SPICAV-SOIR dir solar occultations. VeRA did radio occultations. Dates : 4 March - 31 March 2012 Orbits : 2144 - 2171 Phase duration : 28 days MTP : 77 MTP 78 ------ Eclipse season #20 ended in orbit 2178. The long Earth occultation season #13 continued throughout the phase. Atmospheric Drag Experiment (ADE) campaign #8 started during this phase. Surface targets were: Ovda Regio (2.8 degrees S, 85.6 degrees E) Tellus Tessera (42.6 degrees N, 76.8 degrees E) VeRA did ingress passes probing low latitudes, radio occultation passes in pure Earth-pointing combined with the drag passes (torque only). VIRTIS-M-VIS searched for airglow, global spectro-imaging from apocentre. SPICAV did stellar occultation. There were no SPICAV-SOIR observations. Dates : 1 April - 28 April 2012 Orbits : 2172 - 2199 Phase duration : 28 days MTP : 78 MTP 79 ------ The long Earth occultation season #13 continued throughout the phase. The beginning of the phase (orbits 2200 - 2206) saw the continuation of Atmospheric Drag Experiment #8. Almost every pericentre pass was reserved for radio science. The surface target was: Lada Terra (62.5 degrees S, 20 degrees E) VeRA did occultations during drag passes in pure Earth-pointing mode, from orbits 2204 - 2224 a campaign of consecutive VeRA ingress occultations on every orbit repeatedly probed the same latitude (~30 - 35 degrees S). VMC saw that meteor showers occurred. VIRTIS-M-VIS did cloud morphology imaging in spot-tracking mode. Dates : 29 April - 26 May 2012 Orbits : 2200 - 2227 Phase duration : 28 days MTP : 79 MTP 80 ------ This MTP included an inferior solar conjunction, during which a transit of Venus occurred (6 June 2012, 01:29:35 UT, orbit 2238). The long Earth occultation season #13 continued throughout the whole of this phase. Eclipse season #21 started on 6 June, orbit 2238. Special observations performed due to Venus Transit: - VIRTIS off-pericentre observations. - SPICAV-SOIR grazing occultation. - SPICAV limb imaging. - VMC suffered an anomaly that shut down the instrument on 4 June 2012, orbit 2236 at 01:42. - SPICAV UV imaging of the Sun immediately prior to the transit day, in orbit 2237 (05 June 2012, DOY157), for cross calibration with ISS/SOLSPEC Surface targets were: Bereghinya Planitia (28.6 degrees N, 23.6 degrees E) Eistla Regio (10.5 degrees N, 21.5 degrees E) with a focus on the central portion Ishtar Terra (70.4 degrees N, 27.5 degrees E) Lada Terra (62.5 degrees S, 20 degrees E) VIRTIS did high resolution morphology observation close to pericentre, atomic oxygen airglow monitoring before and after each eclipse season. VeRA had activity after orbit 2238, start of eclipse season. SPICAV did joint observations with SPICAM near apocentre at orbits 2248 - 2250. Dates : 27 May - 23 June 2012 Orbits : 2228 - 2255 Phase duration : 28 days MTP : 80 MTP 81 ------ The long Earth occultation season #13 continued throughout this phase. Eclipse season #21 ended on 15 July 2012 (orbit 2277). Surface targets were: Tepev Mons (29 degrees N, 44.3 degrees E) Bell Regio (32.8 degrees N, 51.4 degrees E) Eistla Regio (10.5 degrees N, 21.5 degrees E) with a focus on the Eastern portion Ishtar Terra (70.4 degrees N, 27.5 degrees E) SPICAV-SOIR did consecutive observations in orbits 2256 - 2261 to search for day-to-day variability at high latitudes and to probe latitudes > 70 degrees S. VeRA ran a campaign for orbits 2254 - 2266 of consecutive VeRA ingress occultations on every orbit to repeatedly probe the same latitude (~20 degrees N). VIRTIS did hi-resolution cloud morphology imaging by VIRTIS-M-VIS, atomic oxygen airglow monitoring before and after each eclipse season, and 2 apocentre mosaic campaigns. Dates : 24 June - 21 July 2012 Orbits : 2256 - 2283 Phase duration : 28 days MTP : 81 MTP 82 ------ The long Earth occultation season #13 continued throughout this phase. Atmospheric Drag Experiment campaign #9 started on 22 July 2012 (orbits 2284 - 2325). There were no particular surface targets. VEX-SOHO joint observations carried out in orbits 2308 - 2310. Dates : 22 July - 18 August 2012 Orbits : 2284 - 2311 Phase duration : 28 days MTP : 82 MTP 83 ------ The long Earth occultation season #13 continued throughout this phase. Atmospheric Drag Experiment campaign #9 continued in this MTP, until 1 September (orbit 2325). There were no particular surface targets. VIRTIS did atomic oxygen airglow monitoring before and after each eclipse season. Dates : 19 August 2012 - 15 September 2012 Orbits : 2312 - 2339 Phase duration : 28 days MTP : 83 MTP 84 ------ The long Earth occultation season #13 finished by the end of this MTP (orbit 2360, 6 Oct 2012). Eclipse season #22 started in orbit 2343. Surface targets were: Gula Mons (21.9 degrees N, 359.1 degrees E) Innini Mons (34.6 degrees S, 328.5 degrees E) Sif Mons (22 degrees N, 352.4 degrees E) Maxwell Montes (65.2 degrees N, 3.3 degrees E) Dione Regio (31.5 degrees S, 328 degrees E) Eistla Regio (10.5 degrees N, 21.5 degrees E) with a focus on the Western portion VMC did near-zero phase angle campaign (after pericentre). SPICAV performed NO observation campaign. Dates : 16 September - 13 October 2012 Orbits : 2340 - 2367 Phase duration : 28 days MTP : 84 MTP 85 ------ Eclipse season #22 continued throughout this MTP. Surface targets were: Bell Regio (32.8 degrees N, 51.4 degrees E) Eistla Regio (10.5 degrees N, 21.5 degrees E) with a focus on the central portion VMC did near-zero phase angle campaign (after pericentre). SPICAV did NO observation campaign to map NO airglow across nightside, using an inertial pointing. Dates : 14 October - 10 November 2012 Orbits : 2368 - 2395 Phase duration : 28 days MTP : 85 MTP 86 ------ Eclipse season #22 finished in orbit 2404 (19 Nov 2012). This MTP includes the beginning of ADE campaign #10 on 15 November 2012 (orbit 2400). There were no particular surface targets. VIRTIS did atomic oxygen airglow monitoring before and after each eclipse in orbits 2419 - 2430. Dates : 11 November - 8 December 2012 Orbits : 2396 - 2423 Phase duration : 28 days MTP : 86 MTP 87 ------ Local time at ascending node changed from 05:40 to 08:40, thus it started at the morning terminator. Illumination conditions were similar to those in MTP 79. Earth occultation season #14 started in orbit 2445 (30 Dec 2012). The beginning of this MTP saw the continuation of VEX ADE campaign #10 until 15 Dec (orbit 2430). Observation geometry allowed VIRTIS to again target two volcanoes identified as possibly recently active: Innini Mons (34.6 degrees S, 328.5 degrees E) Mielikki Mons (27.8 degrees S, 280.5 degrees E) Dates : 9 December 2012 - 5 January 2013 Orbits : 2424 - 2451 Phase duration : 28 days MTP : 87 MTP 88 ------ Earth occultation season #14 continued throughout the whole MTP. This MTP includes the start of eclipse season #23 in orbit 2464 (18 Jan 2013). Eclipse and Earth occultations both occurred after pericentre, so VeRA and SOIR observations were in conflict. Illumination conditions were similar to those in MTPs 72 and 80. A focus on surface observation was proposed in this eclipse season once the eclipse duration was greater than 25 minutes (starting in orbit 2468): Gula Mons (21.9 degrees N, 359.1 degrees E) Sif Mons (22 degrees N, 352.4 degrees E) Maxwell Montes (65.2 degrees N, 3.3 degrees E) Where possible, the surface observations were combined with a SOIR and/or VeRA occultation observation. Dates : 6 January - 2 February 2013 Orbits : 2452 - 2479 Phase duration : 28 days MTP : 88 MTP 89 ------ Earth occultation season #14 ended in orbit 2493, and eclipse season #23 ended in orbit 2500. Illumination conditions were similar to those in MTP 81. The focus on surface mapping started in the last MTP continued, with targets: Oshun Farra (4.2 degrees N, 19.3 degrees E) Dzalarhons Mons (0.5 degrees N, 34 degrees E) Tepev Mons (29 degrees N, 44.3 degrees E) Bereghinya Planitia (28.6 degrees N, 23.6 degrees E) Bell Regio (32.8 degrees N, 51.4 degrees E) Eistla Regio (10.5 degrees N, 21.5 degrees E) with a focus on the Eastern portion Ishtar Terra (70.4 degrees N, 27.5 degrees E) Unnamed Tessera (4 degrees S - 4 degrees N, 36 - 46 degrees E) Dates : 3 February - 2 March 2013 Orbits : 2480 - 2507 Phase duration : 28 days MTP : 89 MTP 90 ------ There were no eclipse, occultation, or drag activities in this MTP. This MTP therefore offered an opportunity to catch up on observation types including stellar occultations and limb tracks, as well as VMC wind tracking in the morning and evening sectors of the planet. VEX approached superior conjunction on 28 March 2013. There was a communications outage for 28 days starting in orbit 2523 (18 March 2013). Dates : 3 March - 30 March 2013 Orbits : 2508 - 2535 Phase duration : 28 days MTP : 90 MTP 91 ------ MTP 91 saw VEX emerge from the communication outage at superior conjunction in orbit 2544. There were no further eclipse or occultation observations during the MTP. The MTP started with near-terminator orbits, but due to the superior conjunction Atmospheric Drag campaign #11 could not be conducted. This provided an opportunity for SPICAV stellar occultations to probe the variation of the nightside mesospheric density as a function of distance from the terminator. This involved, starting in orbit 2550, a series of stellar occultations using the same star in consecutive orbits. Following this stellar occultation campaign, nightside observations were devoted to the NO observation campaign proposed for MTPs 91-94. Priority on the dayside was given to VMC cloud-tracking observations. Dates : 31 March - 27 April 2013 Orbits : 2536 - 2563 Phase duration : 28 days MTP : 91 MTP 92 ------ This MTP saw the start of eclipse season #24 in orbit 2567, and the start of Earth occultation season #15 in orbit 2575. Local time at ascending node changed from 20:45 to 23:45, thus illumination conditions are similar to those in MTP 84. Accessible surface targets in this MTP are similar to those imaged in MTP 88: Comnena crater (1.2 degrees N, 343.7 degrees E) Innini Mons (34.6 degrees S, 328.5 degrees E) Hathor Mons (38.7 degrees S 324.7 degrees E) Dione Regio (31.5 degrees S, 328 degrees E) However, due to the focus on surface observations in the last eclipse season, it was proposed instead in this eclipse season to focus on nightside NO observations. NO observations in inertial or nadir mode occurred on alternate orbits throughout the eclipse season until orbit 2629 in MTP 94. Note that these fit around the radio occultation schedule, which occurred on alternate orbits from orbit 2575 until orbit 2656 in MTP 95. Solar occultations were combined with other observations where possible. Dates : 28 April - 25 May 2013 Orbits : 2564 - 2591 Phase duration : 28 days MTP : 92 MTP 93 ------ Earth occultation season #15 and eclipse season #24 continued throughout the whole of this MTP. Local time at ascending node changed from 23:45 to 02:45, thus illumination conditions are similar to those in MTP 85. Accessible surface targets included many of those imaged in MTP 89: Carmenta Farra (12.4 degrees N, 8 degrees E) Oshun Farra (4.2 degrees N, 19.3 degrees E) Gula Mons (21.9 degrees N, 359.1 degrees E) Sif Mons (22 degrees N, 352.4 degrees E) Maxwell Montes (65.2 degrees N, 3.3 degrees E) Bereghinya Planitia (28.6 degrees N, 23.6 degrees E) Eistla Regio (10.5 degrees N, 21.5 degrees E) with a focus on the Eastern portion There was a continued focus on the SPICAV NO observations started in the last MTP. VeRA and SOIR observations also continued throughout the MTP. Dates : 26 May - 22 June 2013 Orbits : 2592 - 2619 Phase duration : 28 days MTP : 93 MTP 94 ------ Earth occultation season #15 continued throughout the whole of this MTP, and eclipse season #24 ended on orbit 2629. High priority was given to Drag campaign period #12: the drag passes occurred in orbits 2623 - 2654, with pre-ADE passes beforehand. The drag campaign reached pericentre altitudes of 170 km, and included radio tracking from New Norcia ground station as well as torque measurements onboard VEX. The main priority for this MTP continued to be the SPICAV NO mapping campaign. There was some limited scope at the beginning of this MTP to observe two surface targets: Dzalarhons Mons (0.5 degrees N, 34 degrees E) Unnamed Tessera (4 degrees S - 4 degrees N, 36 - 46 degrees E) After the end of the eclipse season, priority was given to VMC cloud-tracking observations to ensure good coverage with respect to local solar time. Dates : 23 June - 20 July 2013 Orbits : 2620 - 2647 Phase duration : 28 days MTP : 94 MTP 95 ------ VEX Atmospheric Drag Experiment (ADE) campaign #12 was continued with orbits 2648 - 2654. VeRA occultations were performed in the two orbits left before the end of Earth occultation season #15 (orbits 2655 - 2656). Local time at ascending node changed from 05:45 to 08:45, thus starting at the morning terminator. After the drag passes were finished, the science priority was SO2 measurements. A dayside SO2 nadir observation was performed at least on every other orbit. These were sometimes preceded by VMC cloud-tracking observations. SPICAV UV day glow observations were carried out on the orbits in which SO2 measurements were not performed. Dates : 21 July - 17 August 2013 Orbits : 2648 - 2675 Phase duration : 28 days MTP : 95 MTP 96 ------ Priority in this MTP was given to the SO2 measurement campaign. In the first two weeks of the MTP there were SPICAV dayside nadir observations. After the beginning of eclipse season #25 in orbit 2689, there were dayside nadir and SOIR observations. SOIR observations in orbits 2688 - 2706 were given high priority, because the terminator sounded by SOIR was visible from Earth. Due to the long duration of the eclipses, surface observations in eclipse were combined with SOIR observations. Surface targets included: Hathor Mons (38.7 degrees S, 324.7 degrees E) Innini Mons (34.6 degrees S, 328.5 degrees E) Dione Regio (31.5 degrees S, 328 degrees E) Dates : 18 August - 14 September 2013 Orbits : 2676 - 2703 Phase duration : 28 days MTP : 96 MTP 97 ------ Eclipse season #25 ended in orbit 2724. Quadrature illumination started in orbit 2721. Local time at ascending node changed from 11:40 to 14:40. The main science priority in this MTP was SO2 observations, as in the previous MTP. Until the beginning of quadrature, there were dayside nadir observations on every orbit, as well as SOIR observations in at least 3 out of every four orbits. The terminator sounded by SOIR in orbits 2706 - 2725 was not the one visible from Earth, so they were not r^ant for co-ordinated ground-based observations and thus had a lower priority than SOIR observations in the previous MTP. Due to the long duration of the eclipses, surface observations in eclipse were combined with SOIR observations. >From orbit 2721, the spacecraft was in quadrature illumination. Due to thermal constraints, this meant that no hot observations were allowed during this period unless a communications pass was skipped. Dayside nadir observations and SOIR observations were both categorized as hot observations. In this quadrature period, 2 to 3 communications passes per week could be skipped in order to allow the continuation, on a 2 - 4 day interval, of the SO2 measurement campaign. The continuation of SO2 measurements in this MTP was particularly important for co-ordination with ground-based measurements, because the nadir dayside observations probed the afternoon quadrant of Venus which was visible from Earth. Surface targets included: Comnena crater (1.2 degrees N, 343.7 degrees E) Gula Mons (21.9 degrees N, 359.1 degrees E) Sif Mons (22 degrees N, 352.4 degrees E) Dates : 15 September - 12 October 2013 Orbits : 2704 - 2731 Phase duration : 28 days MTP : 97 MTP 98 ------ In this MTP, science priority was given to the SO2 campaign started in August 2013. In this quadrature period, 2 to 3 communications passes per week were skipped to allow the continuation, on a 2 - 4 day interval, of the SO2 measurement campaign UP until the beginning of the drag season on 30 Oct 2013. These nadir measurements of SO2 by SPICAV-UV were important for co-ordination with ground-based observers, because the afternoon sector sounded by the nadir observations was the one visible from Earth, and a co-ordinated ground-based campaign was planned. Earth occultation season #16 started on 26 Oct 2013. At the end of this MTP (orbits 2751 - 2759), ADE campaign #13 was conducted. This only included torque measurements (i.e. no radio tracking from ground), with a pericentre altitude of 190 km. Quadrature illumination applied throughout the entire MTP. Dates : 13 October - 9 November 2013 Orbits : 2732 - 2759 Phase duration : 28 days MTP : 98 MTP 99 ------ The MTP started with a terminator orbit and thereafter the season was cold. The long Earth occultation season #16 continued throughout this MTP. There was no particular science priority early in this MTP, and activities included VMC cloud-tracking observations, SPICAV stellar occultations and limb observations. Starting in orbit 2775 (25 Nov 2013), VEX started a South polar dynamics campaign, which combined radio occultation with imaging for context and wind velocity determination. A VeRA occultation was scheduled on every orbit, and priority was also given to VMC and VIRTIS cloud-tracking observations of the polar region. VIRTIS observations took place near apocentre, in the ascending branch. VMC cloud tracking observations of the South Polar region occurred in the ascending branch and could also be scheduled after a VeRA pass. In addition to VeRA egress observations, VeRA ingress occultations were scheduled with a cadence of one ingress per four orbits. Dates : 10 November - 7 December 2013 Orbits : 2760 - 2787 Phase duration : 28 days MTP : 99 MTP 100 ------- The South polar dynamics campaign, started in the last MTP, continued through this MTP, ending on 31 Dec 2013. A VeRA radio science egress campaign was scheduled, and priority was also given to VMC and VIRTIS cloud-tracking observations of the South polar region. VMC cloud tracking observations took place after the VeRA observations. VIRTIS observations took place near apocentre, or after VPER-07h00 in the ascending branch. Eclipse season #26 (MTPs 100 - 102, Dec 2013 - Feb 2014) included a dedicated SOIR campaign, with SOIR occultations scheduled on every orbit. As SOIR observations occurred before pericentre, they were still compatible with the continuation of the South polar dynamics campaign with a VeRA egress on each orbit and imaging of the South polar region. Once the eclipse duration was longer than 25 minutes, SOIR could conduct both ingress and egress observations on the same orbit. There was one surface target in this MTP: Unnamed steep-sided volcanic dome (11 degrees N, 301 degrees E) Dates : 8 December 2013 - 4 January 2014 Orbits : 2788 - 2815 Phase duration : 28 days MTP : 100 MTP 101 ------- This MTP included an inferior conjunction of Venus. The Sun-Earth-Venus angle never reached less than 5 degrees, so normal communications with the spacecraft were not interrupted. Eclipse season #26 and Earth occultation season #16 continued throughout this MTP. VEX went into eclipse on the ascending branch, before pericentre, and then went into occultation (hidden from the Earth) after pericentre, when it was on the dayside of the planet in the descending branch of the orbit. This MTP continued two observation campaigns which had already been started in the previous MTP. Before pericentre, high scientific priority was given to a SOIR (solar occultation) campaign, whereby the SPICAV-SOIR instrument observed on every orbit. Nadir observations in eclipse were included to permit surface imaging where this was compatible with SOIR observations. After pericentre, relatively high scientific priority was given to the South polar dynamics campaign. Although VeRA Egress radio occultations were no longer occurring on every orbit, continued VMC observations were made for dayside cloud tracking: (1) VMC imaging spot tracking of nearest VeRA sounded location; (2) VIRTIS-M-VIS cloud tracking from near apocentre; (3) further VMC imaging (spot tracking of the VeRA sounded location) in ascending branch at times up to VPER-1h. Surface targets included: Comnena crater (1.2 degrees N, 343.7 degrees E, orbit 2828) Gula Mons (21.9 degrees N, 359.1 degrees E, orbit 2834) Hathor Mons (38.7 degrees S, 324.7 degrees E) Innini Mons (34.6 degrees S, 328.5 degrees E) Sif Mons (22 degrees N, 352.4 degrees E, orbit 2839) Maxwell Montes (65.2 degrees N, 3.3 degrees E, orbit 2843) Dates : 5 January - 1 February 2014 Orbits : 2816 - 2843 Phase duration : 28 days MTP : 101 MTP 102 ------- At the beginning of this MTP, the SOIR observation campaign continued, with SOIR conducting solar ingress and egress observations on every orbit until the end of the eclipse season. Radio occultations continued in occultation season #16. Towards the end of the MTP, Atmospheric Drag Experiment (ADE) campaign #14 was started, covering orbits 2867 - 2878 (25 Feb 2014 - 8 March 2014). This campaign had a minimum pericentre altitude of 189 km. Torque data was acquired on all orbits within the campaign; tracking from Earth ground stations was performed on every second orbit. This was the final ADE campaign, since the aerobraking campaign that followed was better suited for accelerometer readings than the torque measurements of the ADE campaigns. VIRTIS nightside limb observations were to search for the oxygen green line in co-ordination with Earth-based observers. Dates : 2 February - 1 March 2014 Orbits : 2844 - 2871 Phase duration : 28 days MTP : 102 MTP 103 ------- Atmospheric Drag Experiment (ADE) campaign #14 continued in this MTP through orbit 2878. This campaign had a minimum pericentre altitude of 189 km. Torque data were acquired on all orbits within the campaign; tracking from Earth ground stations was performed on every second orbit. After this time, radio occultations continued at a rate of ~1 out of every 4 orbits until the end of Earth occultation season #16 in orbit 2893. VIRTIS nightside limb observations were performed to search for the oxygen green line in co-ordination with Earth-based observers. Dates : 2 March - 29 March 2014 Orbits : 2872 - 2899 Phase duration : 28 days MTP : 103 MTP 104 ------- For most of this MTP, VEX was in quadrature illumination condition. The focus in this MTP was on cold observations including nightside limb observations (to search for nightglow) and stellar occultations. >From orbit 2921 (20 Apr 2014) on VEX started a science campaign focusing on surface targets with nadir observations in eclipse on every orbit. This was combined with SOIR ingress/egress observations where possible. However, SOIR observations were hot and required skipping the following Earth communications pass. Eclipse season #27 started in orbit 2914. Surface targets were: Rhea Mons (32.4 degrees N, 282.2 degrees E) Theia Mons (22.7 degrees N, 281 degrees E) Beta Regio (25.3 degrees N, 282.8 degrees E) VMCs surface targets: Devana Chasma (22 degrees N, 283.5 degrees E) Unnamed depression (11 degrees N, 301 degrees E) VIRTIS surface targets: Hathor Mons (38.7 degrees S 324.7 degrees E) Innini Mons (34.6 degrees S, 328.5 degrees E) Mielikki Mons (27.8 degrees S, 280.5 degrees E) Dates : 30 March - 26 April 2014 Orbits : 2900 - 2927 Phase duration : 28 days MTP : 104 MTP 105 ------- The surface observation campaign started in MTP 104 continued throughout this MTP. Priority was given to surface observations in eclipse. Eclipse season #27 ended on 18 May 2014. The aerobraking walk-in period started at the end of this MTP on 20 May 2014, and is described in more detail in MTP 106 below. VMCs surface targets: Comnena crater (1.2 degrees N, 343.7 degrees E) Unnamed depression (11 degrees N, 301 degrees E) VIRTIS surface targets: Hathor Mons (38.7 degrees S 324.7 degrees E) Innini Mons (34.6 degrees S, 328.5 degrees E) Mielikki Mons (27.8 degrees S, 280.5 degrees E) Dates : 27 April - 24 May 2014 Orbits : 2928 - 2955 Phase duration : 28 days MTP : 105 MTP 106 ------- This MTP included the aerobraking walk-in period. No science pointings were performed. Only the Aspera and Mag instruments were operated. No Science Activity Plan (SAP) was created for this planning period. Earth occultation season #17 started on 17 Jun 2014 but no radio observations were made. As the aerobraking operations were not routine, the normal instrument constraints were not followed. This means that no instrument thermal constraints applied. No attempt was made to shield the VMC field-of-view from the Sun. Aspera was operated during the braking mode, which used thrusters to maintain spacecraft attitude during the pericentre period of the aerobraking passes. However, Aspera constraints about operating after wheel off-loadings (WOL) and orbital correction manoeuvres (OCM) were still applied; conflicting observations were removed by the flight control team. Mag was operated continuously. Dates : 25 May - 20 June 2014 Orbits : 2956 - 2983 Phase duration : 28 days MTP : 106 MTP 107 ------- This MTP was performed during the aerobraking period. No science pointings were performed. Earth occultation season #17 continued through the entire MTP, but only the Aspera and Mag instruments were operated. No Science Activity Plan (SAP) was created for this planning period. The aerobraking period lasted through 12 July 2014, followed by 7 days of of pericentre raising manoeuvres and platform reconfiguration during which no science observations were possible. As the aerobraking operations were not routine, the normal instrument constraints were not followed. This means that no instrument thermal constraints applied. No attempt was made to shield the VMC field-of-view from the Sun. Aspera was operated during the braking mode, which used thrusters to maintain spacecraft attitude during the pericentre period of the aerobraking passes. However, Aspera constraints about operating after wheel off-loadings (WOL) and orbital correction manoeuvres (OCM) were still applied; conflicting observations were removed by the flight control team. Mag was operated continuously. Dates : 21 June - 17 July 2014 Orbits : 2984 - 3011 Phase duration : 27 days MTP : 107 MTP 108 ------- This was the first MTP after aerobraking activities, which finished in orbit 3005 (12 July 2014). There were specific constraints on science planning during this MTP: 20 - 25 July Orbits had apocentre OCMs. One cold science pointing per orbit only. 20 July - 2 August One cold science pointing per orbit only. Baseline pointing is nadir starting on nightside, continuing on dayside briefly. 3 Aug onwards From Orbit 3029 (3 Aug 2014, DOY215), science opportunities expanded by including all pointings, under all previously approved thermal conditions. Observations were pre-planned using the projected orbit file #540 of 4 April. Prior to the start of the MTP, pointings were verified to be safe using a post-aerobraking orbit file. Any unsafe pointings were removed (but not replaced). Dates : 18 July - 15 August 2014 Orbits : 3012 - 3042 Phase duration : 29 days MTP : 108 MTP 109 ------- No Science Activity Plan (SAP) was created for this planning period, but the science goals were set by the Science adviser and Project Scientist in consultation with the Science Working Team. Earth occultations season #17 ended on 12 Sep 2014. One of the priorities in this post-aerobraking period was the search for volcanic activity based upon surface observations (VMC nadir nightside in eclipse). The whole of MTP 109 took place during eclipse season #28. The eclipse duration was sufficiently long to permit surface observations during eclipse. Where possible, the VMC surface observations were combined with a SOIR egress or ingress observation. Dayside observations with the SPICAV-UV channel were taken to measure mesospheric SO2 concentrations. Another observation goal encouraged by the SWT was continued dayside cloud tracking, to allow further investigation of the temporal evolution of wind fields, as well as the short-term correlation with SO2 mapping. Because the MTP was planned without a predicted orbit file, the temporal location of the Cebreros ground station (CEB) passes in the Venus Express orbit could not be known. The CEB passes were therefore shortened to 5 hours; this was meant to minimize the number of planned science observations which would subsequently have to be removed prior to the actual commanding. At the time just prior to commanding, but after planning, the temporal location of CEB passes were known, and some planned observations could have required removal due to overlap with a CEB pass. It also reduced the data volume a great deal. Specific surface targets were: Phoebe Regio (6 degrees S, 282.8 degrees E) Dolya Tessera (8 degrees S, 296 degrees E) Dates : 16 August - 12 September 2014 Orbits : 3043 - 3072 Phase duration : 28 days MTP : 109 MTP 110 ------- The aerobraking season was finished, and normal science pointings were allowed. Communications occurred in 5-hour windows whose timing changed throughout the MTP. This was due to the fact that the aerobraking campaign successfully reduced the orbital period by ~1.5 hours. When these communication windows conflicted with science pointings, the science observations were cancelled and the communications passes retained. Eclipse season #28 ended on 24 Sep 2014. The science focus during the first week of this MTP was, as in MTP 109, on surface observations. Therefore, the highest priority was given to VMC surface observations in eclipse, and to VIRTIS surface observations of the nightside in the ascending branch. On the dayside, SO2 observations were given the highest priority; VMC dayside observations for cloud tracking and cloud morphology were also favoured. Dates : 13 September - 10 October 2014 Orbits : 3073 - 3102 Phase duration : 28 days MTP : 110 MTP 111 ------- There were only observations in the first three orbits of this MTP. There were no operations in the remaining orbits due to superior solar conjunction #6. The Venus-Sun-Earth angle was too small to allow communications. For the first three orbits, the observations were the same as those of MTP 110. Dates : 11 October - 7 November 2014 Orbits : 3103 - 3132 Phase duration : 28 days MTP : 111 MTP 112 ------- Eclipse season 29 started on 24 Nov 2014. This was a hot season; the pericentre was on the dayside and eclipses occurred after pericentre. This meant that VEX was at a relatively high altitude when it was in eclipse, ideal for surface monitoring using VMC. The eclipse duration was relatively long, so SOIR observations were combined with the VMC observations. This MTP allowed observation of the same surface targets as in MTP 108, which enabled a search for changes on a 4-month timescale. Dayside observations included SO2 monitoring and cloud tracking. Cloud tracking was carried out at altitudes of 10000 - 30000 km, for observation periods of 1 hour. This was the first MTP after aerobraking in which a predicted orbit file was available for planning. On 28 November 2014 (DOY 332) following the sixth OCM (in a planned series of nine), the scheduled Cebreros ground pass failed to acquire telemetry from the spacecraft, though a weak X-band carrier was detected. Based on some very limited telemetry downlinked from the spacecraft after the anomaly, there was conclusive evidence for depletion of fuel (MMH - Monomethylhydrazine) as being the root cause for the original anomaly during the sixth OCM on 27 November 2014 (DOY 331): 1. During OCM 4 (DOY 329) depletion of the MMH tank occurred and the helium gas used to pressurize the fuel tank started to enter the MMH piping between the tank and the thrusters. 2. OCM 5 (DOY 330) completed successfully as the required amount of MMH was present in the MMH piping downstream of the MMH tank. 3. The subsequent OCM (OCM 6) was interrupted by a lack of MMH at thruster level. No further telemetry was received after 11 December 2014 (DOY 345) nor was there any indication of an on-board lock. On 16 December (DOY 350) the final commands were sent to the spacecraft to switch TM modulation off in order to improve the carrier margin. From then until the end of January 2015, daily monitoring for the X-band carrier was performed. On 18 December (DOY 352) the end of the mission was officially declared. The last indication of a carrier signal from Venus Express was between 13:54z and 13:57z on 19 January 2015 (DOY 19). Dates : 8 November - 6 December 2014 Orbits : 3133 - 3163 Phase duration : 29 days MTP : 112 The tables of campaigns and seasons below represent windows of opportunity for certain types of observations, or types of events. This does not imply that the related observations were performed on each orbit without those time periods. Please refer to the instrument- or dataset-specific catalogs for further information on what measurements were performed. Eclipse Seasons =============== Eclipses, or solar occultations, occurred when Venus partially blocked out the Sun from the perspective of the Venus Express spacecraft. These periods of time were particularly favourable for SPICAV-SOIR measurements. Eclipse Dates Season # ------------------------------------- 1 | 16 Apr 2006 - 31 May 2006 2 | 06 Aug 2006 - 13 Sep 2006 3 | 16 Nov 2006 - 10 Jan 2007 4 | 17 Mar 2007 - 26 Apr 2007 5 | 29 Jun 2007 - 21 Aug 2007 6 | 27 Oct 2007 - 09 Dec 2007 7 | 09 Feb 2008 - 01 Apr 2008 8 | 06 Jun 2008 - 20 Jul 2008 9 | 23 Sep 2008 - 10 Nov 2008 10 | 16 Jan 2009 - 28 Feb 2009 11 | 05 May 2009 - 23 Jun 2009 12 | 27 Aug 2009 - 17 Oct 2009 13 | 17 Dec 2009 - 01 Feb 2010 14 | 07 Apr 2010 - 29 May 2010 15 | 30 Jul 2010 - 13 Sep 2010 16 | 18 Nov 2010 - 10 Jan 2011 17 | 13 Mar 2011 - 25 Apr 2011 18 | 29 Jun 2011 - 25 Aug 2011 19 | 25 Oct 2011 - 04 Dec 2011 20 | 08 Feb 2012 - 07 Apr 2012 21 | 06 Jun 2012 - 15 Jul 2012 22 | 19 Sep 2012 - 19 Nov 2012 23 | 18 Jan 2013 - 23 Feb 2013 24 | 01 May 2013 - 02 Jul 2013 25 | 31 Aug 2013 - 05 Oct 2013 26 | 11 Dec 2013 - 12 Feb 2014 27 | 13 Apr 2014 - 18 May 2014 28 | 22 Jul 2014 - 24 Sep 2014 29 * | 24 Nov 2014 - 27 Dec 2014 ------------------------------------- * This season was cut short by the end of mission, as described in the MTP 112 section above. Earth Occultation Seasons ========================= During Earth occultation seasons, from the spacecrafts point of view the Earth is blocked out (occluded) by Venus. This allowed the radio signal from Venus Express to pass through Venus atmosphere before being received on Earth, and thus provided opportunities to study atmospheric temperatures. Given the required geometry for this type of measurement, only the region near the North pole, near the spacecrafts pericentre, could be studied. Occultation Dates Season # ------------------------------------- 1 | 11 Jul 2006 - 30 Aug 2006 2 | 22 Nov 2006 - 31 Jan 2007 3 | 26 Apr 2007 - 01 Jul 2007 3a * | 04 Sep 2007 - 18 Sep 2007 4 | 04 Jan 2008 - 13 Mar 2008 5 | 05 Jun 2008 - 01 Aug 2008 6 | 28 Oct 2008 - 31 Dec 2008 7 | 16 Jul 2009 - 19 Sep 2009 8 | 10 Dec 2009 - 08 Feb 2010 9 | 30 Apr 2010 - 11 Jul 2010 10 | 17 Jan 2011 - 22 Mar 2011 11 | 14 Jun 2011 - 25 Aug 2011 12 | 15 Nov 2011 - 06 Jan 2012 13 | 27 Mar 2012 - 06 Oct 2012 14 | 30 Dec 2012 - 16 Feb 2013 15 | 09 May 2013 - 29 Jul 2013 16 | 26 Oct 2013 - 23 Mar 2014 ------------------------------------- * Note that season 3a is so named because it was unusually short, and conditions were not favourable for actual occultation observations. Superior Solar Conjunctions =========================== Superior solar conjunctions occur when Venus is on the opposite side of the Sun, from the point of view of an observer on Earth. During such times, communications with the spacecraft were difficult and science observations could not usually be conducted. There are also inferior solar conjunctions, when Venus and Earth are on the same side of the Sun and roughly form a line with the Sun. These inferior conjunction periods did not usually cause prolonged communication outages and thus are not listed here. Solar Dates Conjunction # ------------------------------------- 1 | 17 Oct 2006 - 08 Nov 2006 2 | 29 May 2008 - 19 Jun 2008 3 | 29 Dec 2009 - 23 Jan 2010 4 | 06 Aug 2011 - 26 Aug 2011 5 | 18 Mar 2013 - 08 Apr 2013 6 | 14 Oct 2014 - 06 Nov 2014 ------------------------------------- Atmospheric Drag Experiment Campaigns ===================================== During these campaigns, Venus Express solar panels were rotated to be offset from one another, so that the passage through the upper atmosphere would induce a torque on the spacecraft. Since the spacecraft was commanded to maintain 3-axis stabilisation using the reaction wheels during this period, the signal from the reaction wheels could be used to measure the atmospheric density. The dates listed in the table below also include the walk-in dates when the pericentre altitude was gradually lowered at the start of each campaign. Torque data was recorded at an 8 Hz frequency on those days as well, though the higher altitudes often make the density measurement technique more difficult. ADE Dates Campaign # ------------------------------------- 1 * | 01 Aug 2008 - 22 Aug 2008 2 * | 12 Oct 2009 - 17 Oct 2009 3a | 20 Feb 2010 - 28 Feb 2010 3b | 11 Apr 2010 - 16 Apr 2010 4 | 14 Sep 2010 - 25 Oct 2010 5 | 27 Apr 2011 - 03 Jun 2011 6 | 23 Aug 2011 - 24 Sep 2011 7 | 12 Dec 2011 - 19 Jan 2012 8 | 02 Apr 2012 - 05 May 2012 9 | 22 Jul 2012 - 01 Sep 2012 10 | 15 Nov 2012 - 15 Dec 2012 11 | Not possible due to | superior solar | conjunction #5 12 | 26 Jun 2013 - 27 Jul 2013 13 | 01 Nov 2013 - 09 Nov 2013 14 | 25 Feb 2014 - 08 Mar 2014 ------------------------------------- * Note that ADE campaigns 1 and 2 were test campaigns to ensure that the spacecraft settings worked and did not present too great a risk. No usable torque readings were generated during those two campaigns. Gravity Campaigns ================= The VeRA gravity observation campaigns were set up to measure anomalies in the planets gravitational field by analyzing the spacecrafts radio carrier signals received on ground, simultaneously in two radio bands. The detected anomalies provided insight into the properties of the crust and lithosphere of Venus. Gravity Dates Campaign # ------------------------------------- 1 | 01 Sep 2006 - 10 Sep 2006 2 | Cancelled due to S-Band | antenna anomaly 3 | 27 Dec 2007 - 02 Jan 2008 4 | 09 Mar 2009 - 15 Mar 2009 5 | 21 Mar 2009 - 27 Mar 2009 6 | 15 Apr 2009 - 19 Apr 2009 7 | 27 Apr 2009 - 01 May 2009 8 | 25 May 2009 - 31 May 2009 9 | 25 Jun 2009 - 01 Jul 2009 10 | 13 Oct 2009 - 17 Oct 2009 11 | 21 Apr 2010 - 25 Apr 2010 12 | 14 Jul 2010 - 20 Jul 2010 ------------------------------------- Other Campaigns or Events ========================= Name Dates -------------------------------------------------------------- Possible meteor showers | 13 Mar 2007 - 25 Mar 2007 MESSENGERs second Venus flyby | 06 Jun 2007 Mosaic Campaign | 10 Oct 2008 - 15 Dec 2008 Surface Imaging Campaign | 22 Jan 2013 - 20 Feb 2013 Spicav NO Campaign | 23 Apr 2013 - 14 Jul 2013 SO2 Campaign | 08 Aug 2013 - 28 Oct 2013 South Polar Dynamics Campaign | 25 Nov 2013 - 31 Dec 2013 SOIR Campaign | 11 Dec 2013 - 12 Feb 2014 Aerobraking | 20 May 2014 - 12 Jul 2014 -------------------------------------------------------------- Spacecraft Events ================= Event Dates -------------------------------------------------------------- Launch | 09 Nov 2005 Earth Moon observations | 22 Nov 2005 - 23 Nov 2005 Pointing Test 1 | 27 Nov 2005 - 04 Dec 2005 Interference Test | 14 Dec 2005 - 15 Dec 2005 Pointing Test 2 | 16 Jan 2006 - 21 Jan 2006 Venus Orbit Insertion (VOI) | 11 Apr 2006 Capture Orbit Observation 0 | 12 Apr 2006 Capture Orbit Observation 1 | 13 Apr 2006 Capture Orbit Observation 2 | 14 Apr 2006 Capture Orbit Observation 3 | 16 Apr 2006 Capture Orbit Observation 4 | 17 Apr 2006 Capture Orbit Observation 5 | 19 Apr 2006 First operational orbit | 07 May 2006 (17th apocentre) | Case Commissioning Start | 14 May 2006 Extended Case Commissioning Start | 28 May 2006 Nominal Science Start MTP 2 | 04 Jun 2006 Safe Mode 1 | 12 Jun 2006 02:00 UTC - | 14 Jun 2006 14:00 UTC Mission Commissioning Results | 04 Jul 2006 Review | Safe Mode 2 | 25 Aug 2006 18:15 UTC - | 26 Aug 2006 11:48 UTC Safe Mode 3 | 22 Sep 2006 19:24 UTC - | 23 Sep 2006 11:00 UTC Safe Mode 4 | 27 Sep 2006 04:37 UTC - | 27 Sep 2006 12:00 UTC Safe Mode 5 | 09 Oct 2006 04:20 UTC - | 09 Oct 2006 12:00 UTC VIRTIS-H and VIRTIS-M shutdown | 13 Aug 2007 due to cooling motors | VIRTIS-M restarted | 31 Aug 2007 Payload off due to SADE-A | 25 Aug 2007 - 27 Aug 2007 misalignment | VIRTIS-H restarted | 04 Nov 2007 Safe Mode 6 | 27 Jan 2008 05:35 UTC - | 28 Jan 2008 12:30 UTC VIRTIS-M cooler failure | 27 Oct 2008 23:58 UTC VIRTIS-M unit resumed non-cooler | 28 Jan 2009 operations in visible channel | VMC SSMM overflow | 11 Mar 2009 Safe Mode 7 | 30 Jul 2010 02:54 UTC - | 31 Jul 2010 16:03 UTC VIRTIS-H cooler failure | 13 Jun 2011 22:33 UTC Operations shutdown due to Star | 07 Mar 2012 12:00 UTC - Tracker blindness (solar flare) | 12 Mar 2012 13:26 UTC End of nominal science mission | 15 May 2014, orbit 2946 Start of Aerobraking Walk-in | 20 May 2014, orbit 2951 End of Aerobraking Campaign | 12 Jul 2014, orbit 3005 Post-Aerobraking science | 20 Jul 2014, orbit 3014 operations resume | Shutdown of operations for | 14 Oct 2014, orbit 3106 Superior Conjunction | Post-Conjunction operations resume | 08 Nov 2014, orbit 3133 Last day of returned science data | 27 Nov 2014, orbit 3153 Loss of nominal contact with VEX | 28 Nov 2014, orbit 3154 Venus Express End of Mission (EOM) | 18 Dec 2014 declared | Venus Express Post-Operations | 01 Jan 2015 process begun | Last signal seen from spacecraft | 19 Jan 2015 (unmodulated carrier signal) | -------------------------------------------------------------- SSMM SCET problem: About every 6 months the spacecraft experienced what was known as the SSMM SCET problem. Whenever the Data Management System (DMS) sent a packet with a spacecraft event time (SCET) value of 0xxxA205yy, the write operation of this packet into the SSMM would fail. Around these time periods, all payload operations (except for the magnetometer) were halted for about 15 minutes. The beginning and end of these SSMM SCET problem periods were noted in the ground station schedule file (the FECS file) using the flags SSSS and SSSR. |
