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Mission Status 2009
Kevin V. Gilliland Stardust Spacecraft Team
April 29, 2009
All subsystems are nominal. Stardust had five contacts this week. The next pass is Tuesday, May 5. By the end of May, we will reduce our contacts to one or two per month. Thruster string 2 continues to provide control. All aspects of string 2 behavior, including control, propulsion, and Navigation, indicate smooth operation. Propulsion engineering reports fuel consumption is 3.6 grams per day. During yesterday's pass, the on-board memory was consolidated. This memory defragmentation is performed periodically to improve memory access performance. Flight software engineering has also analyzed memory dumps and confirmed the file system configuration on board the spacecraft. Background sequence SN023 is executing now and sequence SN024 is in development.
April 22, 2009
All subsystems are nominal. Stardust had five contacts this week. The next pass is Friday, April 24. Monday, April 20, the spacecraft successfully commanded a swap to the backup control thrusters. The first thruster pulses following the swap were at 09-110/13:10:37 SCET UTC. String 2 control thrusters (RCS 5-8) are now in control of the spacecraft, giving the string 1 (RCS thrusters 1-4) a well-deserved break after more than 10 years in flight. The string 2 thrusters are performing well, providing smooth, low-rate control in all three axes. No significant change in fuel consumption has been observed since the swap on Monday morning. Monday's commanding concludes months of testing, failure analysis, program reviews, and more testing. Background sequence SN023 is executing now.
April 8, 2009
All subsystems are nominal. Stardust had two contacts this week. The next pass is Wednesday, April 15. Last Thursday, commands were sent to update the deadband thruster controller. The controller continues to maintain the required antenna-to-Earth pointing. As of this morning's pass, the first since the update, some reduction in firings is evident. The team will collect more trending data before attempting to quantify the savings. All testing for the proposed use of backup control thrusters has been completed. Before any commanding to the spacecraft, one more approval process will be completed. If approval is given, the switch to the backup control thrusters will be commanded April 20. Background sequence SN022 is executing now. Sequence SN023 is in development.
April 1, 2009
Stardust had one contact this week. The next pass is tomorrow, Thursday, April 2. While the end of March was devoted to configuring the spacecraft for its quiet post-Earth flyby cruise, April will be spent on improvements to efficiency. An updated deadband controller will be used beginning tomorrow. The update will improve the controller's response when commanding thruster pulses with noise in the star camera measurements. The team has also prepared commands to use 4 backup control thrusters. The commands have been built and a thorough test program is underway. The team is in the process of presenting the plan for review and approval. If approval is given, the switch to the backup control thrusters will be commanded April 20. Background sequence SN022 is executing now. Sequence SN023 is in development.
