Stardust Mission Status
15 Mar 1999
(Source: Jet Propulsion Laboratory)
MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
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NASA's Stardust spacecraft is in excellent health as it ventures away from Earth. Last week, the spacecraft switched over to its medium gain antenna and a higher data rate than is possible with the low-gain antenna used in previous weeks when Stardust was much closer to Earth.
Stardust sent back new data from two instruments - one that measures "hits" by dust particles and another that will analyze comet and interstellar dust samples. With the higher data rate, the spacecraft also successfully sent back an engineering test image - Stardust's first - taken by the star camera navigation aid. The instrument data and star camera image had been "backlogged" on board while the low-gain antenna and its lower data rate was in use.
The star camera's first image shows Mars shining brightly against the star background as seen from the Stardust's view. The image will be posted on the Stardust web site at http://stardust.jpl.nasa.gov this week. The dust particle counter, called the dust flux monitor, continues to operate normally, and high voltage was switched on for the comet and interstellar dust analyzer for the first time last week.
Testing of the star camera was started late Monday, March 8, to prepare for its use in tracking so that the spacecraft will not have to rely on its gyro system, called an inertial measurement unit, to control its orientation in space. Moving to "all stellar" control will preserve operating life on the inertial measurement unit for Stardust's encounter with Comet Wild-2, in addition to other operations where the gyro will be needed.
After an hour of successful testing, an error occurred in the star camera's data readout, causing the spacecraft to automatically move to its "safe" mode, switching back to the low- gain antenna and minimizing operations until it received new commands from controllers on Earth. Such fault-protection software is used on all of NASA's robotic spacecraft to ensure a controlled response to unplanned events or anomalies. This protects the spacecraft and allows engineers to find any problems, develop solutions and resume routine operations.
The flight operations team moved back to communications with the spacecraft over the low-gain antenna and verified that the spacecraft was in its expected state and in excellent health. Late Tuesday, March 8, the spacecraft's data history on the testing was radioed to mission controllers so that a detailed tracing could be performed to identify the cause of the data error and subsequent triggering of the spacecraft's fault protection system. Detailed analysis is underway to understand the suspect operation and correct it.
Stardust's objectives are to gather particles flying off the nucleus of Comet Wild-2 and return them to Earth for scientific analysis, and to collect and return samples of interstellar dust flowing through our solar system. Stardust is the first spacecraft ever launched on a mission to bring back material from beyond the Moon. It is also the first U.S. mission to a comet. Stardust's sample return capsule is due to parachute into Earth's atmosphere and land on the U.S. military's Utah Test and Training Range near Salt Lake City on January 15, 2006.
Stardust, launched February 7, 1999, is now 15 million kilometers (9.3 million miles) from Earth. The spacecraft was built and is operated by Lockheed Martin Astronautics, Denver, and is managed for NASA by the Jet Propulsion Laboratory, Pasadena, California. JPL is a division of the California Institute of Technology, Pasadena, California.