NASA Logo, National Aeronautics and Space Administration
NASA Space Science Data Coordinated Archive Header

Stardust Sample Return Capsule

NSSDCA/COSPAR ID: 1999-003D

Description

The Stardust Sample Return Capsule (SRC) was designed to store the cometary coma and interstellar particle samples collected by the Stardust mission and return them to Earth in a sealed compartment. The SRC was mounted on the main Stardust spacecraft bus during sample collection and released during Earth flyby in January 2006. The primary objective of the Stardust mission was to fly by the comet P/Wild 2 and collect samples (at least 1000 analyzable particles of diameter >15 microns) of dust and volatiles from the coma of the comet. It then returned these samples to Earth for detailed study. The secondary objectives were to collect and return to Earth at least 100 interstellar particles of diameter >0.1 micron.

Spacecraft and Subsystems

The SRC is a short truncated cone, 0.8 m diameter and 0.5 m high with a total mass of 46 kg. It is attached at its narrow end to the rear face of the bus. A paddle shaped sample collection disc can be extended from the capsule during periods of sampling, and stored inside the capsule enclosed by a cover when not in use. The sample reentry capsule also contains an aeroshield/basecover, navigation recovery aids (GPS translator and emergency S-band beacon), an event sequencer, batteries, and a parachute system.

Sample collection was achieved with the use of aerogel, a low-density (0.02 gm/cc) inert microporous silica-based substance which will allow capture of high-relative-speed particles with minimal physical and chemical alteration. The aerogel is in the form of a single disc-shaped sheet held by modular aluminum cells and deployed on a paddle. The aerogel is simply exposed to space during sample collection periods and stowed in the sample vault at other times. One side of the aerogel (the A side, 3 cm thick) was used for collection of cometary samples and the other (B, 1 cm thick) side for interstellar dust. The appropriate side was oriented toward the expected particle flux and particles striking the aerogel were slowed down and trapped within. The number of particles is small, the impacts left tracks in the aerogel enabling the particles to be located.

Mission Profile

After a one day delay Stardust was launched on 7 February at 21:04:15.238 (4:04 p.m. EST). The launch took place from Pad A, Launch Complex 17 at Cape Canaveral Air Station aboard a Delta 7426 (a Delta II Lite launch vehicle with four strap-on solid-rocket boosters and a Star 37FM third stage). The four boosters fell away one minute and 6 seconds after liftoff (1:06 MET, mission elapsed time), the first stage shut down and was ejected at 4:30 MET. The second stage ignited a few seconds later, burned until 9:55 MET, followed by an ~11 minute coast and a reignition of the 2nd stage for 2 minutes. The 2nd stage separated at 24:27 MET and at 25:04 MET the 3rd stage ignited and burned for about 2 minutes. Stardust separated from the 3rd stage at 27:19 MET and opened its solar arrays 4 minutes later. The spacecraft is now coasting in an elliptical heliocentric orbit.

The first interstellar dust collection took place from 22 February to 1 May 2000. After one solar orbit, an Earth flyby on 15 January 2001 at 6008 km altitude was used to boost the spacecraft aphelion to 2.7 AU and the inclination to 3.6 degrees. Another period of interstellar dust collection opened July to December 2002. On 2 November 2002 at 04:50 UT (1 Nov at 11:50 p.m. EST) Stardust flew within 3300 km of asteroid 5535 Annefrank. The relative velocity was 7 km/s. The dust collectors remained open throughout the flyby and images of the asteroid were taken. A second orbit of the sun was completed in mid-2003. The spacecraft entered the coma of comet P/Wild 2 on 31 December 2003. Close encounter took place on 2 January 2004. The fly-by had a closest approach within 250 km at roughly 19:45 UT (2:45 p.m. EST) at a relative velocity of about 6.1 km/s and took place 1.85 AU from the Sun and 2.6 AU from Earth. The sample collector was deployed on 24 December 2003 and was retracted, stowed, and sealed in the sample vault of the sample reentry capsule 6 hours after the fly-by. 72 images of the comet nucleus were also obtained, with predicted coverage of the entire sunlit side at a resolution of 30 m or better. The first (bumper) layer of the Whipple shield was breached by particle impacts at least ten times during the flyby.

On 15 January 2006 the capsule separated from the main craft (with a stabilizing spin of 1.5 rpm) at 5:57 UT (12:57 a.m. EST) and entered the atmosphere four hours later at 9:57 UT (4:57 a.m. EST). An aeroshell slowed the capsule down initially for about ten minutes, the drogue parachute was deployed at 10:00 UT and the main parachute 5 minutes later at an altitude of roughly 3 km. The capsule landed at 10:10 UT (5:10 a.m. EST, 3:10 a.m. local Mountain Standard Time) within a 30 x 84 km landing ellipse at the U.S. Air Force Test and Training Range in the Utah desert. High winds caused the capsule to drift about 5 miles north of its entry ground track, but with the aid of a locator beacon the capsule was found at 10:54 UT and was later transported by helicopter to a clean room, arriving at about 13:00 UT.

Comet P/Wild 2

Comet P/Wild 2 is a newcomer to the inner solar system and therefore represents a relatively 'fresh' comet which has not been overly heated and degassed by the Sun. Originally in an orbit in the region between Jupiter and Uranus (4.9 to 25 AU), its orbit was altered by a close pass by Jupiter on 10 September 1974. It now orbits between Mars and Jupiter (1.58 to 5.2 AU). The comet is approximately 5.4 km across. Comets were formed at the same time as the solar system and are made up of primitive condensates and grains incorporated into them at this time. The samples from the coma are expected to provide insights into the composition and dynamics of the early solar system.The interstellar dust grains represent a flux of fresh material entering the solar system from the direction of the constellation Scorpio. These particles are smaller and will impact at a higher velocity than the cometary particles. The size distribution, velocity profile, and compositional make-up of these particles are important to the study of processes taking place outside our solar system.

The total mission cost of Stardust was approximately $199.6 million, of which roughly $128.4 million was the cost of development and construction of the spacecraft and $40 million was for mission operations.

Facts in Brief

Launch Date: 1999-02-07
Launch Vehicle: Delta II 7426
Launch Site: Cape Canaveral, United States
Mass: 46.0 kg

Funding Agency

  • National Aeronautics and Space Administration (United States)

Discipline

  • Planetary Science

Additional Information

Questions or comments about this spacecraft can be directed to: Dr. David R. Williams.

 

Personnel

NameRoleOriginal AffiliationE-mail
Mr. Henry C. BrintonProgram ScientistNASA Headquarters 
Mr. Thomas C. DuxburyProject ManagerNASA Jet Propulsion Laboratorytduxbury@gmu.edu
Dr. Mark A. SaundersProgram ManagerNASA Headquarters 
Dr. Donald E. BrownleeMission Principal InvestigatorUniversity of Washingtonbrownlee@astro.washington.edu
[USA.gov] NASA Logo - nasa.gov