Mission Status 2010
Tim Larson Stardust Spacecraft Team
June 23, 2010
The spacecraft team successfully commanded the spacecraft to its back-up side this week. All side B components are healthy and operating as expected. The spacecraft has now exited safe mode and is back in its nominal cruise configuration, ready to complete the mission on the new side. This will now enable the mission to be completed on IMU B, with more than enough life to support the remaining mission. Full time use of IMU B will significantly reduce risk to the comet imaging, optical navigation, and data playback, and will also yield fuel saving benefits due to its effect on day to day attitude control thruster firings. The spacecraft is now operating on the background sequence, and the next planned activity on board is a Navcam calibration in early August.
June 16, 2010
The spacecraft is healthy, and operating as expected. The team is preparing for the side swap scheduled next week for June 21. The last attempt in early May exposed a flaw in the safe mode sequences that prevented a successful cold boot of the spacecraft. This root cause has been identified, and the Fault Protection parameters have been updated to enable the spacecraft to successfully complete a cold boot. This side swap will enable the project to fully characterize the B side of the spacecraft, and, more importantly, complete the mission with a healthy IMU, needed for fine pointing control.
May 26, 2010
The spacecraft is in cruise mode again after successful completion of TCM-29 on May 24. The planned maneuver was a 1.1 m/s adjustment, and initial navigation feedback shows that the execution was within 1.5% of the desired performance. The spacecraft is healthy and operating as expected. On June 1 the spacecraft will be rotated around the sun line to place the star camera in a more favorable star field. This will avoid excessive fuel consumption due to noisy attitude solutions.
May 19, 2010
The spacecraft is in cruise mode and operating on Side A. The investigation into the cold boot anomaly has identified the order and timing of ACS and propulsion commanding in the safe mode configuration files as the cause of the problem. The most direct fix for this problem is a modification of two fault protection parameters to enable the system to get through the start up process and get to nominal operation. These results have been reviewed with LMSS and JPL senior management and the project received approval to implement this change. The project is now negotiating with the DSN for coverage to re-attempt the side swap at the earliest opportunity in order to get to the IMU on side B for the rest of the mission.
May 12, 2010
The spacecraft is in normal cruise mode and operating on Side A. The investigation into the root cause of the cold boot anomaly that prevented the swap to Side B last week is progressing well. The analysis of the software code and the spacecraft error logs is confirming the suspected cause of this behavior. The testbed team expects to begin tests to confirm the findings early next week.