Stardust Status Report

December 14, 2001

There were two Deep Space Network (DSN) tracking passes during this past week, and all subsystems are normal. Stardust is currently 2.57 AU from the Sun.

In preparation for the upcoming solar conjunction, the command loss timer was increased to twenty days from its present seventeen-day value. Solar conjunction, occurring from December 21 through 30, is when the angle between the Sun, Earth, and Stardust is less than three degrees. When the spacecraft looks so close to the Sun from Earth, the DSN antenna is looking directly into the Sun, making communication to and from the spacecraft unreliable. The smallest angle will occur late Christmas Eve.

Though three DSN passes are scheduled during the solar conjunction, we assume that a command will not successfully reach the spacecraft. Therefore, the timer was increased to twenty days to ensure the spacecraft does not prematurely assume there is an antenna problem, invoke safe mode and swap antennas.

Based on the existing DSN schedule, the pass on December 17th is the last time we expect to reliably send a command to the spacecraft. January 4th is the first opportunity after the solar conjunction to successfully send a command to Stardust. Radio scientists will use the DSN passes scheduled during the conjunction period to measure the effects of the Sun as the signal passes close by it.

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