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
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: