Stardust Responds On First Command From Earth
7 Feb 2007
Allan Cheuvront, Stardust Flight Director February 5, 2007
It has been nearly a year since Stardust successfully released the capsule that returned the Wild 2 dust particles to earth and sent its last signal before being placed in a hibernation state. That situation changed when the Spacecraft Team (SCT) recently radiated commands to have STARDUST resume communications in order to determine the spacecraft's health for a follow-on mission to the comet Tempel 1. As usual, the reliable spacecraft responded to our commands and the signal was received at the expected time. There was concern that a large solar flare last December could have placed the spacecraft in an unknown state. The first telemetry indicated a processor reboot had occurred but the spacecraft's subsystems were in excellent condition. After restoring communication, the remainder of the Deep Space Network (DSN) pass was used to obtain the history data for the last year.
After saying "bon voyage" on January 29, 2006, the spacecraft passed through its perihelion (0.92 AU), the closest approach to the sun for the spacecraft, and made it safely through. On July 10, 2006, a spontaneous reboot of the processor occurred. The cause of the reboot is unknown but was probably due to solar/space interference. The spacecraft returned itself to its safe mode state and continued
The spacecraft returned itself to its safe mode state and continued cruising. On December 7, 2006, another large solar flare created problems for the Star Camera. After struggling for several hours to obtain good star images, an attitude control error caused the spacecraft to re-enter safe mode. Once again the spacecraft returned to its nominal safe mode state where it remained until contacted last Monday.
Our second DSN pass was used to clear the reboot counters, exit safe mode and ready the spacecraft for the instrument checkout scheduled. We will check out the health of the instrument suite including, Dust Flux Monitor (DFM), Cometary Interstellar Dust Analyzer (CIDA) and Navigation Camera (NAVCAM). The playback of the science instruments will take the remaining DSN passes through early February. After all the recorded data has been received on the ground we will again command the spacecraft into its safe mode or hibernation state. The spacecraft will remain in hibernation until the final decision is made concerning the Stardust-NExT follow-on mission.
The Stardust-NExT (New Exploration of Tempel) mission would encounter the comet Tempel 1 in 2011 and image the crater made by the Deep Impact mission. The program is currently developing a Concept Study Report that provides additional information about the proposed follow-on mission. The final decision is expected in the May/June timeframe.