PDS_VERSION_ID = PDS3 LABEL_REVISION_NOTE = "H. TAYLOR, 2000-09-14; B. SEMENOV, 2003-02-25; B. SEMENOV, 2004-06-10" 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. 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 is anticipated 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 is 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 is a two year loop with a 168 m/s deterministic delta-V near aphelion. Deep Space Maneuver #1 (DSM1) sets up the orbit for an Earth swing-by that will pump the orbit up to a 2.5 year loop. The spacecraft stays on this loop twice and encounters the comet Wild 2 approximately 163 days after the second perihelion of the mission, 98.5 days after the comet's perihelion. A small, <1 m/s, deterministic maneuver (DSM2) is required near the second aphelion to maintain the desired trajectory. At approximately 207 days before encountering Wild 2, the third deterministic delta-V (DSM3, 69 m/s) is performed to properly target to Wild 2. The last deterministic maneuver, DSM4, is also small <1 m/s, is scheduled after the Wild 2 encounter, and is used to target back to Earth. Comet Encounter --------------- The spacecraft is aimed to flyby the comet on the sun-ward side at a closest flyby distance of 150 km with a delivery uncertainty of 10 km (1-sigma). The relative velocity between the comet and the spacecraft is such that it is the comet that is actually catching up with the spacecraft from behind in their travel around the Sun. The spacecraft approaches Wild 2 on the sun-lit side with a phase angle of 73 degrees, reaching a minimum approaching 0 degrees near closest approach and departing at a phase angle of 107 degrees. Interstellar Dust Collection ---------------------------- The interstellar dust collection periods are planned to be near the first and second near-aphelion portions of the trajectory when the spacecraft velocity direction is such that the spacecraft-dust relative velocity is at a minimum. Though possible, no collection is performed on the third loop as it is undesirable to re-open the SRC after comet encounter. In addition to the favorable velocity alignment, these collection periods are further defined by the need to avoid large off-Sun pointing of the solar panels, collection of beta meteoroids, and deep space maneuvers. Particle Analysis ----------------- CIDA and DFMI experiment periods are planned at every available opportunity during the mission. The main constraint on their operation will be the availability of spacecraft power and conflicts with other mission activities. Prime experiment periods are defined, however, as those where the interstellar particle (ISP) is made to fall within the CIDA field-of-view. 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 : 1999-03-08 The launch phase begins at the launch vehicle lift-off and ends with the completion of the activation and checkout of most of the spacecraft subsystems. Included in this phase are 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. The duration of this phase is 30 days. CRUISE 1 -------- Mission Phase Start Time : 1999-03-08 Mission Phase Stop Time : 2000-11-14 The Cruise 1 phase of the first part of the STARDUST mission, nearly six years long, was a period of relatively low activity. This part spans from launch through the Earth flyby. Within this phase are embedded the first ISP collection period and the CIDA and DFMI experiments. The ISP collection period during this phase of the mission nominally starts 380 days after launch and continues for 69 days. EARTH GRAVITY ASSIST -------------------- Mission Phase Start Time : 2000-11-14 Mission Phase Stop Time : 2001-02-14 The Earth flyby is performed primarily to provide a gravity assist to the STARDUST spacecraft thus reducing the delta-V requirements of the mission. The flyby changes the orbital period from 2 years to about 2.5 years. The spacecraft approaches 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 will nominally be ~6030 km. During the flyby the Sun-Earth-Probe angle cycles 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 is 15 January 2001 11:16 ET. One special activity is planned during the Earth Gravity Assist (EGA) phase, and it is the opportunity to take Earth-Moon images. CRUISE 2 -------- Mission Phase Start Time : 2001-02-14 Mission Phase Stop Time : 2003-09-24 The Cruise 2 phase is the second part of cruise, spanning from the Earth flyby through the Wild 2 encounter. Within this phase are embedded the second ISP collection period and the CIDA and DFMI experiments. The ISP collection period during this phase of the mission nominally starts 1275 days after launch and continues for 126 days. ANNEFRANK ENCOUNTER ------------------- Mission Phase Start Time : 2002-10-31 Mission Phase Stop Time : 2002-11-05 This phase is the part of the mission, during which STARDUST flies by an S-type, main belt asteroid Annefrank. The Annefrank flyby occurs with just over one month (out of four) remaining in the second ISP collection period and is 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 is to implement the entire Wild 2 encounter sequence in flight at Annefrank. The science potential as a result of the Annefrank flyby is limited but significant. Given the test nature of the activities, no special accommodations have been made for science. However, the images obtained during the flyby will help address questions of asteroid diversity by providing the first information on a few kilometer diameter, S-type, main belt asteroid. Annefrank is expected to be about 20 pixels across in the closest approach images. Even at this size, the images will help address questions of size, shape, albedo, albedo variation, phase function (150 deg to 2 deg) 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 nominally starts 100 days prior to and ends 50 days after comet encounter (Launch+1790.9 days). Independent of launch date, encounter with comet Wild 2 nominally occurs at a reference time of 02 January 2004 19:20:00 ET. The primary goal of obtaining comet coma samples during the encounter flyby is accomplished by a navigation plan that delivers the spacecraft with the required accuracy. Near the closest encounter, the spacecraft +x-axis is pointed in the S/C to Wild 2 relative velocity direction such that the dust shield protects the S/C. In this flyby configuration, the Earth is located in the direction of the spacecraft +z-axis (also HGA direction). The spacecraft approaches Wild 2 from above and recedes under the comet's orbit plane. Although the collection of cometary dust samples is the primary goal of the mission, it is totally passive. Occurring mostly during the closest encounter, it is enabled by deployment of the aerogel collector and the setting of the spacecraft / collector attitude perpendicular to the dust stream. Collector deployment is currently planned to occur approximately 9 days prior to encounter, and the encounter spacecraft attitude will be established after the last pre-encounter TCM performed at E-18 hours. The collector is planned to stay deployed until E+5 hours, which is approximately when the spacecraft exits the comet coma. A number of images will be taken during the encounter. Coma images will be acquired primarily during the far encounter part of this phase of the mission. Near-continuous imaging of the nucleus and real-time transmission of imaging data are planned from E-5 hours to E-5 min. Approximately 64 images will be taken between E+/-5 minutes, during the closest encounter. These images will be stored on board the spacecraft and transmitted to Earth after the encounter. At E-5 hours, communications will be continuous and CIDA and DFMI data will be included in the telemetry to Earth. It is after this time, that most, if not all, dust related activity is expected to occur. This configuration will continue through to approximately E-3 minutes at which time the telemetry link is interrupted by the roll maneuver. Data from CIDA events will be compressed and stored on board. Any free memory left from the encounter period will be allocated to the post-encounter imaging, until onboard memory is fully used for imaging after the primary encounter period. CRUISE 3 -------- Mission Phase Start Time : 2004-02-21 Mission Phase Stop Time : 2005-10-17 The Cruise 3 phase is the third part of cruise, spanning from the Wild 2 encounter to the return to Earth. During this period, no dust collection takes place. The dust collectors are stowed to protect the comet particles and to prevent any potential problems that might endanger their return to the Earth. 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 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. 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." 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 is anticipated in the form of images of the comet coma and nucleus, Comet and Interstellar Dust Analyzer 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) Provide 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 is possible using an aerogel collector. 2) Facilitate the intercept of significant numbers of interstellar dust particles using the same collection medium, also at as low a velocity as possible. 3) Return 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 END_OBJECT = MISSION END