Stardust Status Report

July 13, 2001

There was one Deep Space Network (DSN) tracking pass in the past week. All subsystems are performing normally.

The Cometary and Interstellar Dust Analyzer (CIDA) instrument continues to observe the interstellar dust stream with an optimal spacecraft attitude when not in communication with Earth.

The remaining Navigation Camera guide star images were downlinked. These images looked at the exact star field that will be behind Comet Wild 2, 2.5 years from now. Before launch, it was expected that the longest effective exposure would be about 1 second, limited by attitude rates being 1 pixel per second or larger. Based upon these rates, it was expected that a perfect, uncontaminated navigation camera could see as star as dim as about10.5 visual magnitude. We were pleased to see that the lowest attitude rate is 10 times less than predicted. Also, in one five-second exposure guide star image, at least 90 stars were identified the dimmest was as low as 11.7 visual magnitude. There are many more star-like images that were not identified. These could be stars dimmer than 11.7 magnitude, since the star catalog that was used only went down to 11.7 visual magnitude.

The power subsystem engineers have been conducting tests of the spare flight battery to simulate the expected performance when the spacecraft is at 2.4 AU from the Sun. These tests indicate that we can expect just over two hours of communications per DSN pass before the battery will need to be recharged. The pre-launch prediction was nearly three hours of communications. The test assumed the spacecraft is at a 0.95 state of charge (SOC) when the DSN pass starts and will be at a 0.60 SOC at the end. Fault protection is activated if the SOC reaches 0.50. The expected recharge time is approximately 25 hours, matching the pre-launch predict.

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