More Bad News for X-ray Telescope

Like a recurring nightmare, astronomers have learned that the launch of a long-awaited space observatory is on hold once again. Yesterday, NASA officials grounded indefinitely the troubled $2 billion Chandra X-ray Observatory due to a suspect rocket motor.

Scientists have been planning and building the 5-ton telescope--a sister to the Hubble Space Telescope--for 2 decades. Originally slated for launch last summer, Chandra is designed to capture detailed images of galaxies, quasars, and other celestial objects. But costly delays, caused by everything from bug-ridden software to faulty circuit boards, have plagued the craft. Those problems finally seemed settled earlier this year when NASA officials set a 9 July launch date.

A failed military satellite launch on 9 April, however, threw a new wrench into the plans. That's because the $250 million Air Force craft, used to monitor missile launches, uses the same upper-stage rocket motor that will boost Chandra out of the shuttle's cargo bay into orbit. Military officials suspect the motor misfired, leaving their spy bird tumbling in the wrong orbit. NASA officials say they won't launch Chandra, which is sitting at the Kennedy Space Center in Florida, until the Air Force figures out what went wrong. No one knows how long that might take.

Although frustrated by the delay, astronomers--knowing that even a minor orbit error could doom their prized instrument--have not criticized NASA's decision to play it safe. Unlike Hubble, Chandra will orbit beyond the shuttle's operating range, meaning astronauts will be unable to come to the rescue if anything goes wrong. Says Fred Wojtalik, Chandra program manager at NASA's Marshall Space Flight Center in Huntsville, Alabama: "We are going to take all the time that is necessary to ensure that when we do launch Chandra, it will successfully perform."