Status Report

Stardust Status Report 17 November 2000

By SpaceRef Editor
November 17, 2000
Filed under ,

STARDUST exited safe mode early this week after entering this condition
late last week because of proton hits to the star cameras, coming from one
of the largest solar flares since 1976. All subsystems are performing
normally, including star camera A that is being used in the attitude
control loop. The spacecraft used the Inertial Measurement Units (IMU’s)
to control the spacecraft’s attitude initially after leaving safe mode, to
assess the star camera’s performance. After verifying that the camera was
performing normally, the spacecraft was then placed in all-stellar attitude
mode, and the IMU’s were turned off.

The star camera is currently viewing the Pleiades and Hyades star
clusters, and Jupiter and Saturn are also in the field. The planets are
not used to determine attitude since their positions change with time
relative to the fixed star fields.

Trajectory Correction Maneuver #4 (TCM 4) has been postponed from this week
to 28 November to allow time to reconstruct the trajectory after safe mode
and to accommodate Thanksgiving vacations. The magnitude of the trajectory
correction has increased from 1.8 meters/second to 2.4 meters/second due to the
thrusting during safe mode entry and to moving the maneuver closer to Earth gravity
assist (EGA). This will not affect the EGA or the comet encounter. The
probability of STARDUST entering the Earth’s atmosphere on its present
course before EGA is essentially zero to 27 decimal places and less than
this after the upcoming maneuver.

The project is supporting Deep Space Network loading from the late 2003 to
early 2004. Occurring within a month during this time: the Comet Wild 2
encounter by STARDUST, two US Mars Exploration Rovers landing, the ESA Mars Express
Orbiter goes into orbit and its lander, Beagle 2, touches down, the US Mars
’01 Odyssey and ISAS Nozomi will operate in Mars orbit, Deep Impact
launches and Cassini and Galileo have major science campaigns involving
international partners. It appears that current DSN resources are not
sufficient to support all of these activities, placing STARDUST and these
other missions at various levels of risk. This current study will continue
to develop plans for additional DSN resources and individual projects,
including STARDUST, assessing the feasibility and risks for reducing
tracking, changing encounter dates, etc. to mitigate these risks.

For more information on the STARDUST mission – the first ever comet
sample return mission – please visit the STARDUST home page:

http://stardust.jpl.nasa.gov

SpaceRef staff editor.