An artist's concept of the Stardust spacecraft during interstellar dust collection. Photo: NASA

NASA's Stardust spacecraft has successfully deployed its aerogel collector, enabling it to begin collecting interstellar dust from a stream of particles that flows through our solar system.

Data from the spacecraft indicate that the deployment timeline was followed precisely, and all systems are operating normally. The heat shield on the spacecraft's sample return capsule opened, then a motor moved the aerogel collector out of the capsule. At that point, a second motor extended the collector fully to its collection position. This raised it high enough so that Stardust would be able to collect samples of comet dust when it flies by Comet Wild-2 in 2004. After deployment, however, engineers commanded the spacecraft to retract the collector by about 50 degrees to position it correctly for the current interstellar dust collection.

The aerogel collector has two sides, one designed to gather interstellar dust, while the other is for comet dust collection. Engineers can control which side of the collector is exposed to a dust stream by orienting the spacecraft. Right now, Stardust is oriented so that the interstellar dust particles are hitting the backside of the collector. The current interstellar dust collection will continue through at least May 25. After that, it will be returned to its stowed position until mid-2002, when another period of interstellar dust collection is scheduled.

As its name indicates, the interstellar particles to be collected now are from outside of our solar system. There is a very tenuous dust cloud within our galaxy, the Milky Way, which our solar system is moving through. The direction of the interstellar dust is opposite to the motion of the sun, which drags the planets with it, relative to the particle media. Thus the dust motion is small relative to the solar system motion that is controlling the direction of interstellar dust passing through our solar system.

Microscopic photo of aerogel with a dust particle. Photo: NASA

The interstellar dust stream was detected many years ago by earth orbiting spacecraft and information on this stream has been improved by early Pioneer and Voyager spacecraft. More recently the Ulysses and Galileo spacecraft have confirmed the stream direction as well as indicated that the density of particles in the stream is very low. With the size of the STARDUST collector being only about 0.1 meter square, we expect to collect on the order of 100 such particles during the 2 collection periods. We have just started the historic first collection period and will perform the second collection period in about two years, when again the spacecraft is traveling in the direction of the particle stream.

After Stardust collects comet dust samples from Wild-2 in 2004, all the samples captured in the aerogel collector will be retracted into the sample return capsule. They will then be returned to Earth via a soft landing at the U.S. Air Force's Utah Test and Training Range in 2006.

Stardust was launched on February 7, 1999. The principal investigator for the mission is Dr. Donald C. Brownlee of the University of Washington. The mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Space Science, Washington, DC. Lockheed Martin Astronautics, Denver, CO, built and operates the spacecraft. Science instruments were provided by the Jet Propulsion Laboratory, the University of Chicago and the Max Planck Institute, Garching, Germany. JPL is a division of the California Institute of Technology, Pasadena, Calif.