PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM LABEL_REVISION_NOTE = "H. TAYLOR, 2000-09-14; B. SEMENOV, 2003-02-19; B. SEMENOV, 2004-06-10; T. FARNHAM, 2006-07-10; Updated events through the end of the primary mission; B. CARCICH, 2011-07-31; Added appendix for Stardust-NExT; B. CARCICH, 2011-08-03; Typo fixed; " OBJECT = INSTRUMENT_HOST INSTRUMENT_HOST_ID = "SDU" OBJECT = INSTRUMENT_HOST_INFORMATION INSTRUMENT_HOST_NAME = "STARDUST" INSTRUMENT_HOST_TYPE = "SPACECRAFT" INSTRUMENT_HOST_DESC = " This description was copied from the ''Stardust Mission Plan'' document with permission from the Stardust project. It has been updated to reflect the completion of the primary mission. SDN: This description has been updated for the Stardust-NExT extended mission. The original description was left largely intact and a short section added at the end for SDN. The prefix 'SDN' occurs before that section. STARDUST was a 3-axis stabilized spacecraft designed to perform its prime mission (Wild 2 encounter) at 1.9 AU from the sun and 2.6 AU from the earth. During the cruise periods to and from this encounter, it was able to function adequately at a maximum distance of 2.7 AU from the sun and 3.6 AU from the earth. The spacecraft was equipped with a power subsystem, fixed solar panels and one rechargeable battery, capable of delivering a minimum of 170 watts (W) during standard cruise operations at aphelion and a minimum of 300 W at comet encounter. The solar panels had a maximum off-sun pointing constraint of 60 degrees to avoid problems caused by refraction of light. Communications were achieved via either a high-gain, medium-gain or one of three low gain antennas. During the mission, Deep Space Network (DSN) support was provided with primarily 34-m antennas with 70-m support being used during the close comet encounter, trajectory correction maneuvers, and other special activities. These antennas provided the capability for a minimum of 4000 bits per second (bps), 7900 bps expected, at encounter via the high-gain antenna and a 70-m DSN station. This data rate could be increased to 22120 bps with additional tight attitude control. At maximum Earth range, 40 bps could be achieved via the medium gain antenna and a 34-m DSN station. The low-gain antennae, in conjunction with a 34-m DSN antenna, were ideal for near-Earth phases (Launch, Earth flyby and Earth return) when Sun-Earth-spacecraft angles were near 90 degrees, especially since they could support communications within 0.05 AU (+3 dB margin) of the earth at a minimum data rate of 40 bps. Attitude control and propulsive maneuvers were performed using a redundant helium-fed mono-propellant (hydrazine) propulsion subsystem. The subsystem was comprised of one titanium propellant tank and a total of 16 thrusters (two strings of 8), all mounted on the lower deck of the spacecraft (opposite the high-gain antenna and solar panels - pointing toward the -z-axis of the spacecraft). Eight of these were 0.2 lb-f (0.89 N) thrusters and were used primarily for attitude control. The other eight are 1.0 lb-f (4.45 N) thrusters and were used for propulsive maneuvers. To avoid potential contamination of the aerogel collector, placement of thrusters on the upper deck (+z) was avoided. This configuration, however, generated uncoupled thrusts during attitude control burns and added complexity to trajectory simulations. The normal spacecraft attitude during the mission pointed the +z-axis of the spacecraft to the sun. Deviations from the normal attitude were performed during communication periods and delta-velocity burns. Off-sun pointing was also permitted during non-primary science experiments, comet and interstellar dust particle collection, as long as the power generated by the solar arrays was adequate at the desired off-sun angle. During the comet encounter period, the +x-axis was pointed to the dust stream. Whipple shields were placed on the spacecraft to protect it from high velocity dust impacts during the comet encounter. The barriers were designed to stop a 1 cm size particle traveling at 6 km/s (which was essentially equal to the comet encounter relative velocity). Science objectives were met using three science subsystems: Aerogel Dust Collector and Sample Return Capsule (SRC), Cometary and Interstellar Dust Analyzer (CIDA) and the Dust Flux Monitor Instrument (DFMI). The imaging camera was also used for science purposes but its main function was to perform optical navigation prior to encounter with comet Wild 2. The current best estimate of the mass breakdown of the flight system is summarized in this table: STARDUST Mass Element List (Rev. Z) Component Mass (kg) Component Mass (kg) S/C Power 33.378 Navigation Camera 12.686 S/C Harness 20.971 DFMI 1.530 S/C Telecom 19.222 CIDA 10.966 S/C ACS 9.951 SRC Avionics 1.992 S/C C&DH 10.394 SRC Harness 0.869 S/C Thermal 10.060 SRC Thermal 13.683 S/C Structures 104.412 SRC Structures 9.271 S/C Mechanisms 6.131 SRC Mechanisms 17.184 S/C Propulsion 19.538 SRC Parachute 4.194 Pressurant (He) 0.202 Total Dry 305.397 Propellant 85.000 Total Wet 390.599 SDN: Stardust-NExT update ========================== Extended mission ---------------- The Stardust spacecraft flew by Earth in January, 2006 to successfully return the SRC. The Stardust-NExT extended mission was developed soon after and used SDU, without the SRC and with an estimated 14kg+ of fuel, to fly the remaining instruments (CIDA, DFMI, and NAVCAM) as a scientific investigation past the comet 9P/Tempel 1 in February, 2011. The limited fuel made flying the extended mission quite challenging, but maneuvers and operations were optimized to minimize fuel usage, and the spacecraft successfully encountered Tempel 1 on 15 February, 2011 with all instruments in working order. Postscript ---------- In March, 2011 the project commanded SDU to perform a final propulsive maneuver designed to burn the remaining fuel to exhaustion to calibrate and/or validate the fuel estimation techniques which had been used. The final telemetry from the Stardust spacecraft activity indicated that the fuel consumed during this activity was no more than could be accounted for by the volume of the fuel system lines. So at the end of two scientific missions, the Stardust fuel tank was literally empty. " END_OBJECT = INSTRUMENT_HOST_INFORMATION OBJECT = INSTRUMENT_HOST_REFERENCE_INFO REFERENCE_KEY_ID = "BROWNLEEETAL2003" END_OBJECT = INSTRUMENT_HOST_REFERENCE_INFO OBJECT = INSTRUMENT_HOST_REFERENCE_INFO REFERENCE_KEY_ID = "TSOUETAL2003" END_OBJECT = INSTRUMENT_HOST_REFERENCE_INFO OBJECT = INSTRUMENT_HOST_REFERENCE_INFO REFERENCE_KEY_ID = "VEVERKAETAL2011" END_OBJECT = INSTRUMENT_HOST_REFERENCE_INFO END_OBJECT = INSTRUMENT_HOST END