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Mission Status 2008
Kevin V. Gilliland Stardust Spacecraft Team
September 17, 2008
All subsystems are nominal. Stardust-NExT made contact Monday, Sept.15, and the next pass will be Oct. 7. Once-a-month contacts will be coming to an end with 12 days on contact periods scheduled for October. More frequent contacts are desired as the team prepares for maneuvers and camera calibrations prior to Earth Gravity Assist in
Jan. 2009. NExT is 1.49 AU from the Sun and 0.85 AU from Earth. The spacecraft's rapidly decreasing range to Earth serves to increase the strength of the radio signal. Downlink data rates are now 7900 bits per second.
July 23, 2008
All subsystems are nominal. Stardust-NExt made contact yesterday, and the next pass will be August 21. Frequent contact periods will not be necessary until camera calibration and Earth flyby activities near the end of 2008. The team remains busy during this period of infrequent contacts: Systems, the Spacecraft Test Lab, and Telecommunications engineers are updating the Loss of Signal and Safemode Recovery plans. The updates include NExT-specific requirements and lessons learned from the Stardust prime mission. The Navigation team is trending spacecraft behavior to design TCM-23, the final correction before the January, 2009, Earth Gravity Assist maneuver. Increased thruster activity, likely due to torque from solar pressure on the aft end of the bus, is working to reduce the size of the next required correction. So, there is no need to pursue improved effeciency at this time. The spacecraft will remain in its Earth-pointed orientation with the Sun nearly 40 deg off the solar array normal. Navigation Camera calibration planning continues. The calibration planned for November and December will include decontamination heating and images of several star pairs. NExT is 1.64 AU from the Sun and 1.46 AU from Earth. Background sequence SN013 is the active sequence; SN014 is on board and will become active on Sunday, August 3.
July 23, 2008
All subsystems are nominal. Stardust-NExT made contact yesterday, and the next pass will be August 21. Frequent contact periods will not be necessary until camera calibration and Earth flyby activities near the end of 2008.
The team remains busy during this period of infrequent contacts: Systems, the Spacecraft Test Lab, and Telecommunications engineers are updating the Loss of Signal and Safemode Recovery plans. The updates include NExT-specific requirements and lessons learned from the Stardust prime mission. The Navigation team is trending spacecraft behavior to design TCM-23, the final correction before the January, 2009, Earth Gravity Assist maneuver. Increased thruster activity, likely due to torque from solar pressure on the aft end of the bus, is working to reduce the size of the next required correction. So, there is no need to pursue improved effeciency at this time. The spacecraft will remain in its Earth-pointed orientation with the Sun nearly 40 deg off the solar array normal. Navigation Camera calibration planning continues. The calibration planned for November and December will include decontamination heating and images of several star pairs. NExT is 1.64 AU from the Sun and 1.46 AU from Earth. Background sequence SN013 is the active sequence; SN014 is on board and will become active on Sunday, August 3.
July 16, 2008
All subsystems are nominal. Stardust-NExt made contact on Sunday, and the next pass is scheduled for Tuesday, July 22nd. With the successful execution of TCM-22 last month, NExT will resume one contact per month. Frequent contact periods will not be necessary until camera calibration and Earth flyby activities near the end of 2008.
NExT is 1.65 AU from the Sun, just past aphelion for this orbit. The spacecraft is approximately 1.54 AU from Earth and rapidly coming closer. The Sun-spacecraft-Earth geometry is presenting a challenge to the control. The Sun is illuminating the back side of the spacecraft now, and the solar pressure contribution from that side of the spacecraft has resulted in slightly increased thruster firings. The Navigation and Spacecraft teams are working on a plan to provide more efficient control during periods when the Sun-to-spacecraft angle is large. Background sequence SN013 is the active sequence; SN014 is built and will be uplinked on Tuesday.
July 3, 2008
All subsystems are nominal. Stardust-NExt made contact earlier this morning, and the next pass is scheduled for Sunday. The Spacecraft Team completed TCM-22 analysis and presented results during the weekly meeting. The computed magnitude error was 8.5 mm/sec, with 5.7 mm/sec crosstrack velocity. The Navigation Team continues to develop post-burn analysis with tracking data. The next maneuver is planned approximately 30 days before January's Earth flyby. Background sequence SN012 is the active sequence; SN013 is on board and will become the active sequence Sunday, July 7th. By the end of July, NExT will use 1 contact per month.
