PDS_VERSION_ID = PDS3 LABEL_REVISION_NOTE = " 2000-09-14 SDU:Taylor Initial version; 2003-02-25 NAIF:Semenov Pre 2003 peer-review update; 2004-06-10 NAIF:Semenov Post 2003 peer-review update; 2005-03-01 NAIF:Semenov Post 2004 peer-review update; 2005-08-19 NAIF:Semenov Post 2005 peer-review update " RECORD_TYPE = STREAM OBJECT = MISSION MISSION_NAME = "STARDUST" OBJECT = MISSION_INFORMATION MISSION_START_DATE = 1999-02-07 MISSION_STOP_DATE = UNK MISSION_ALIAS_NAME = "N/A" MISSION_DESC = " This description was copied from ``Stardust Mission Plan'' document and its addendum with permission from the Stardust project and later revised by Edward Hirst, Stardust Mission System Manager, to address liens from 2004 peer-review. Mission Overview ================ The primary science goal of the STARDUST mission is to collect Wild 2 coma samples, plus bonus interstellar dust samples, in aerogel, and return them to Earth. Additional science return was accomplished in the form of images of the comet coma and nucleus, Comet and Interstellar Dust Analyzer (CIDA) based dust particle analysis and Dust Flux Monitor (DFMI) via an instrumented comet dust shield. Trajectory ---------- The STARDUST mission was designed for a low velocity (6.1 km/s) flyby of the comet Wild 2 during its active period (at a solar distance of 1.9 AU) and to have a low energy Earth returning trajectory. The first orbital loop was a two year loop with a 170 m/s deterministic delta-V near aphelion. Deep Space Maneuver #1 (DSM1) set up the orbit for an Earth swing-by that pumped the orbit up to a 2.5 year loop. The spacecraft stayed on this loop twice and encountered the comet Wild 2 approximately 163 days after the second perihelion of the mission, 98.5 days after the comet's perihelion. A small, 3 m/s, deterministic maneuver (DSM2) was required near the second aphelion to maintain the desired trajectory. At approximately 199 days before encountering Wild 2, the third deterministic delta-V (DSM3, 71 m/s) was performed to properly target to Wild 2. The last deterministic maneuver, DSM4, was also small, 5 m/s, was performed after the Wild 2 encounter, and was used to target back to Earth. Comet Encounter --------------- The spacecraft was aimed to flyby the comet on the sun-ward side at a closest flyby distance of 250 km with a delivery uncertainty of 16 km (1-sigma). The relative velocity between the comet and the spacecraft was such that it was the comet that was actually catching up with the spacecraft from behind in their travel around the Sun. The spacecraft approached Wild 2 on the sun-lit side with a phase angle of 73 degrees, reached a minimum approaching 0 degrees near closest approach and departed at a phase angle of 107 degrees. Interstellar Dust Collection ---------------------------- The interstellar dust collection periods were planned to be near the first and second near-aphelion portions of the trajectory when the spacecraft velocity direction was such that the spacecraft-dust relative velocity was at a minimum. Though possible, no collection was performed on the third loop as it was undesirable to re-open the SRC after comet encounter. In addition to the favorable velocity alignment, these collection periods were further defined by the need to avoid large off-Sun pointing of the solar panels, collection of solar beta meteoroids, and execution of deep space maneuvers. Particle Analysis ----------------- CIDA and DFMI experiment periods were planned at every available opportunity during the mission. The main constraint on their operation was the availability of spacecraft power and conflicts with other mission activities. Prime experiment periods were defined, however, as those where the interstellar particle was made to fall within the CIDA field-of-view. In general, these periods coincided with the outbound (post-perihelion) segments of loops 1 and 2. After launch, DFMI operation was eliminated these experiment periods due to a flight anomaly that allowed the DFMI to operate correctly for periods lasting only approximately 35 minutes. This operation time was sufficient to support comet encounter, but not extended cruise experiments. Earth Return ------------ Upon Earth return, the Sample Return Capsule (SRC) will directly enter the atmosphere and land with the aid of a parachute. The planned landing site is the Utah Test and Training Range (UTTR). Following touchdown, the SRC will be recovered by helicopter or ground vehicles and transported to the staging area at UTTR for the retrieval of the sample canister. The canister will then be transported to the planetary materials curatorial facility at Johnson Space Center. A divert maneuver will be performed on the spacecraft after the release of the SRC. The maneuver will re-target the spacecraft to prevent re-entry into Earth's atmosphere and will place the spacecraft in a heliocentric orbit. Mission Phases ============== Six mission phases were originally defined for significant spacecraft activity periods. These were the Launch, Cruise 1, Earth Gravity Assist, Cruise 2, Wild 2 Encounter, Cruise 3, and Earth Return. One more mission phase -- Annefrank Encounter, -- completely nested inside the Cruise 2 was added in 2002 when the asteroid flyby was approved as a full scale Wild 2 encounter test. LAUNCH ------ Mission Phase Start Time : 1999-02-07 Mission Phase Stop Time : 1999-03-09 The launch phase began at the launch vehicle lift-off and ended with the completion of the activation and checkout of most of the spacecraft subsystems. Included in this phase were spacecraft separation from the launch vehicle, establishment of attitude and communications, tracking of the spacecraft and the execution of the first trajectory correction maneuver (TCM-1) to correct the injection error. TCM-1 was canceled shortly after launch due to very small launch injection errors. The duration of this phase was 30 days. CRUISE 1 -------- Mission Phase Start Time : 1999-03-09 Mission Phase Stop Time : 2000-11-16 The Cruise 1 phase was the first of three periods of relatively low activity. This period spanned from launch through the Earth flyby. Within this phase was embedded the first ISP collection period and the CIDA experiment. The ISP collection period during this phase of the mission started 380 days after launch and continued for 69 days. EARTH GRAVITY ASSIST -------------------- Mission Phase Start Time : 2000-11-16 Mission Phase Stop Time : 2001-02-14 The Earth flyby was performed primarily to provide a gravity assist to the STARDUST spacecraft thus reducing the delta-V requirements of the mission. The flyby changed the orbital period from 2 years to about 2.5 years. The spacecraft approached Earth with a velocity of 6.5 km/s from the dark side and recedes back into the dark side having flown by the sunward side. At closest approach, the altitude was ~6010 km, at -40.5 degrees latitude and 38.1 degrees longitude (east of South Africa). During the flyby the Sun-Earth-Probe angle cycled from ~130 degrees to ~28 degrees at closest approach to a minimum of ~19 degrees (8 minutes after closest approach) and back up to ~90 degrees toward the end of the EGA phase. The Earth flyby time was 15 January 2001 11:14:28 UTC. One special activity was planned during the Earth Gravity Assist (EGA) phase, and it was use of the navigation camera to take 21 images of the Moon. CRUISE 2 -------- Mission Phase Start Time : 2001-02-14 Mission Phase Stop Time : 2003-09-24 The Cruise 2 phase was the second part of cruise, spanning from the Earth flyby through the Wild 2 encounter. Within this phase were embedded the second ISP collection period and the CIDA experiment. The ISP collection period during this phase of the mission started 1275 days after launch and continued for 126 days, with a brief interruption to conduct the Annefrank encounter. ANNEFRANK ENCOUNTER ------------------- Mission Phase Start Time : 2002-10-31 Mission Phase Stop Time : 2002-11-05 This phase was the part of the mission, during which STARDUST flew by an S-type, main belt asteroid called Annefrank. The Annefrank flyby occurred with just over one month (out of four) remaining in the second interstellar particle collection period and was fully embedded with Cruise 2 phase of the mission. This encounter was not present in original mission plan and was added in 2002 as a full scale Wild 2 encounter test. The main objective and supporting rationale for this test was to implement the entire Wild 2 encounter sequence in flight at Annefrank. The science potential as a result of the Annefrank flyby was limited but significant. Given the test nature of the activities, no special accommodations were made to enhance science. However, the images obtained during the flyby helped address questions of asteroid diversity by providing the first information on a few kilometer diameter, S-type, main belt asteroid. The spacecraft flew past Annefrank on 2 November 2002 at 4:51:20 UTC and a closest approach distance of 3079 km. Annefrank was found to be 25 pixels by 35 pixels at its largest in the closest approach images, and the imaging sequence encompassed a solar phase angle range from 130 deg to 47 deg. Even at this size and low spatial image resolution, the images helped address questions of size, shape, albedo variation, phase function and the photometric phase function. WILD 2 ENCOUNTER ---------------- Mission Phase Start Time : 2003-09-24 Mission Phase Stop Time : 2004-02-21 The most important mission phase of STARDUST started 100 days prior to and ended 50 days after comet encounter (Launch+1790.9 days). Independent of launch date, encounter with comet Wild 2 occurred at 2 January 2004 19:21:32 UTC. The primary goal of obtaining comet coma samples during the encounter flyby was accomplished by a navigation plan that delivered the spacecraft with the required accuracy to a fly by distance of 236 km, as a balance between spacecraft survival and dust collection as per best known dust production models. Near the closest encounter, the spacecraft +x-axis was pointed in the S/C to Wild 2 relative velocity direction such that the dust shield protected the S/C. By design, in this flyby configuration, the Earth was located in the direction of the spacecraft +z-axis (also high gain antenna direction). The spacecraft approached Wild 2 from above and receded under the comet's orbit plane. Although the collection of cometary dust samples was the primary goal of the mission, it was totally passive. Occurring mostly during the closest encounter, it was enabled by deployment of the aerogel collector and the setting of the spacecraft / collector attitude perpendicular to the dust stream. Collector deployment occurred 9 days prior to encounter, and the encounter spacecraft attitude was established after the last executed pre-encounter TCM performed at E-2 days. The collector stayed deployed until approximately E+5 hours, which was approximately when the spacecraft exited the comet coma. A number of images were taken during the encounter. Coma images were acquired primarily during the far encounter part of this phase of the mission. Two images of the nucleus were taken and transmitted to Earth from E-5 hours to E-30 min. Approximately 120 images were taken between E-30 min to E-8 min, the bulk of them concentrated during the period between E+/- 5 minutes, during the closest approach. Of those, 72 images were were stored on board the spacecraft and transmitted to Earth after the encounter, including pairs that were used for stereo imaging. The solar phase angle for these images ranged from 72 deg at the start, dropped to a minimum of 3 deg and increased to 103 deg by the end. At E-5 hours, communications was continuous and CIDA data was be included in the telemetry to Earth. The DFMI was turned on at approximately E-15 min and its data were added to the telemetry stream. Science data transmissions to Earth ceased at E-8 min, and all subsequent data was stored on board the spacecraft and transmitted to Earth after the encounter. It was after this time that most, if not all, dust related activity occurred. This engineering data only configuration was held from E-8 min to E+12 min to protect against data loss as a result of a roll maneuver that was performed at E-6 min to keep the comet trajectory in the navigation camera's mirror panning plane. A roll back was performed at E+6 min. The magnitude of the roll angle required during the flyby was 4 degrees. EARTH RETURN ------------ Mission Phase Start Time : 2005-10-17 Mission Phase Stop Time : 2006-01-16 This phase of the mission begins 90 days before Earth Return (ER) and ends when the Sample Return Capsule (SRC) is transferred to the ground handling team. Earth approach contains three TCM's and a final divert maneuver, performed after SRC separation, to prevent the spacecraft from following the SRC into the Earth's atmosphere. Prior to separation, the spacecraft will be placed at the separation attitude and the SRC will be spun up using a spin release mechanism. This will provide the spin stabilization that the SRC requires for successful atmospheric entry. Immediately following release, the SRC will be imaged using the imaging camera. Although these images will have minimal OPNAV value, they are considered of high Public Information value. Earth Return will occur on 15 January 2006 09:58 ET The SRC aeroshell will protect the sample canister against the extreme aerodynamic heating experienced during atmospheric entry. The aeroshell also removes over 99 percent of the initial kinetic energy thus allowing the parachute system to place the SRC within the allowable touchdown requirements. The landing site is the Utah Test and Training Range (UTTR). Following touchdown, the SRC will be recovered by helicopter or ground vehicles and will be transported to a staging area at UTTR for the retrieval of the sample canister. The canister will then be transported to the Planetary Materials Curatorial Facility at Johnson Space Center. References ========== Additional information about the STARDUST mission is available in the set of Stardust-related articles published in the Journal of Geophysical Research in 2003: Brownlee, D. E., P. Tsou, J. D. Anderson, M. S. Hanner, R. L. Newburn, Z. Sekanina, B. C. Clark, M. E. Zolensky, J. Kissel, J. A. M. McDonnell, S. A. Sandford, and A. J. Tuzzolino, Stardust: Comet and interstellar dust sample return mission, J. Geophys. Res., 108, (E10), 8111, 2003. Tsou, P., D. E. Brownlee, S. A. Sandford, F. Horz, and M. E. Zolensky, Wild 2 and interstellar sample collection and Earth return, J. Geophys. Res., 108, (E10), 8113, 2003. Kissel, J., A. Glasmachers, E. Grun, H. Henkel, H. Hofner, G. Haerendel, H. von Hoener, K. Hornung, E. K. Jessberger, F. R. Krueger, D. Mohlmann, J. M. Greenberg, Y. Langevin, J. Silen, D. Brownlee, B. C. Clark, M. S. Hanner, F. Hoerz, S. Sandford, Z. Sekanina, P. Tsou, N. G. Utterback, M. E. Zolensky, and C. Heiss, Cometary and Interstellar Dust Analyzer for comet Wild 2, J. Geophys. Res., 108, (E10), 8114, 2003. Tuzzolino, A. J., T. E. Economou, R. B. McKibben, J. A. Simpson, J. A. M. McDonnell, M. J. Burchell, B. A. M. Vaughan, P. Tsou, M. S. Hanner, B. C. Clark, and D. E. Brownlee, Dust Flux Monitor Instrument for the Stardust mission to comet Wild 2, J. Geophys. Res., 108, (E10), 8115, 2003. Newburn Jr., R. L., S. Bhaskaran, T. C. Duxbury, G. Fraschetti, T. Radey, and M. Schwochert, Stardust Imaging Camera, J. Geophys. Res., 108, (E10), 8116, 2003. Anderson, J. D., E. L. Lau, M. K. Bird, B. C. Clark, G. Giampieri, and M. Patzold, Dynamic science on the Stardust mission, J. Geophys. Res., 108, (E10), 8117, 2003. Sekanina, Z., A model for comet 81P/Wild 2, J. Geophys. Res., 108, (E10), 8112, 2003" MISSION_OBJECTIVES_SUMMARY = " The primary science goal of the STARDUST mission is to collect Wild 2 coma samples, plus bonus interstellar dust samples, in aerogel, and return them to Earth. Additional science return was accomplished in the form of images of the comet coma and nucleus, Comet and Interstellar Dust Analyzer (CIDA) based dust particle analysis and Dust Flux Monitor via an instrumented comet dust shield. These science goals lead to the following objectives in the design of the STARDUST mission: 1) Provided a flyby of a comet of interest (Wild 2) at a sufficiently low velocity (less than 6.5 km/s) such that non-destructive capture of comet dust was possible using an aerogel collector. 2) Facilitated the intercept of significant numbers of interstellar dust particles using the same collection medium, also at as low a velocity as possible. 3) Returned as many high resolution images of the comet coma and nucleus as possible, subject to the cost constraints of the mission." END_OBJECT = MISSION_INFORMATION OBJECT = MISSION_HOST INSTRUMENT_HOST_ID = "SDU" OBJECT = MISSION_TARGET TARGET_NAME = "81P/WILD 2 (1978 A2)" END_OBJECT = MISSION_TARGET OBJECT = MISSION_TARGET TARGET_NAME = "5535 ANNEFRANK" END_OBJECT = MISSION_TARGET END_OBJECT = MISSION_HOST OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "BROWNLEEETAL2003" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "TSOUETAL2003" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "KISSELETAL2003" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "TUZZOLINOETAL2003" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "NEWBURNETAL2003" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "ANDERSONETAL2003" END_OBJECT = MISSION_REFERENCE_INFORMATION OBJECT = MISSION_REFERENCE_INFORMATION REFERENCE_KEY_ID = "SEKANINAETAL2003" END_OBJECT = MISSION_REFERENCE_INFORMATION END_OBJECT = MISSION END