NASA craft survives solar flare hit

The Associated Press
Saturday November 25, 2000

PASADENA — A NASA spacecraft on a seven-year mission to collect comet dust survived a blinding zap from an enormous solar flare this month. 

For a while, the Stardust spacecraft had too many stars in its eyes after it was hit Nov. 9 by a storm of high-energy particles that was 100,000 times more intense than usual, according to Jet Propulsion Laboratory, which manages the mission. 

Protons from the solar wind electrified pixels in Stardust’s star cameras, which it uses to control its orientation, and produced dots that the spacecraft interpreted as stars. 

The spacecraft processor normally compares the 12 brightest images in its field of view with patterns in its star catalog, but with hundreds of false star-like images the spacecraft could not recognize its attitude in space. 

Stardust automatically put itself in standby mode with its solar panels pointed toward the sun to ensure plenty of power and waited for communication from Earth.  

In the meantime it tried switching to a second star camera but got the same result. 

Flight controllers, who had been concerned about the solar flare’s effect, were unable to communicate with Stardust the next morning and suspected it was in standby mode, which meant it would send a signal to Earth within 24 hours. 

Scientists left the spacecraft in standby mode to allow the proton stream to diminish, and on Nov. 11 sent commands to reset the first star camera and turn it back on. 

The last images taken before the spacecraft went into standby mode were retrieved, revealing hundreds of false images. 

The spacecraft was put back in normal operation several days later. Images taken after the flare subsided showed the camera fully recovered from the proton hits. 

Stardust was 130 million miles from the sun when it was hit by the fourth largest solar flare since 1976, NASA said. 

Built by Lockheed Martin Astronautics, was launched Feb. 7, 1999, on a mission to intercept the comet Wild 2 in 2004, collect dust flying off its nucleus and return to Earth in 2006 to drop off the samples in a parachute-equipped capsule. 

On the Net: 

Stardust mission: http://stardust.jpl.nasa.gov