Cornell's space team cheers a tense but successful launch

By David Brand

A view of the STIRF launch from Cocoa Beach, Fla., Monday, Aug. 25, 2003, 1:35 a.m. Nicola Kountoupes/Cornell University PhotographyCopyright © Cornell University

After Cornell-based research going back to 1976 and many launch delays, the space capsule containing the observatory soared into the Florida sky accompanied by cheers and yells of approval from researchers on the beach two miles from launch pad 17B at Cape Canaveral Air Force Station. The rocket seemingly hung like a shimmering orange ball before arcing across the sea and disappearing over the eastern horizon.

The Cornell team that developed one of SIRTF's three instruments, led by astronomy professor James Houck, shouted with elation as first six then three of the solid boosters separated from the rocket. As the second stage burned over the Indian Ocean, the observatory was carried into a solar orbit. It is now trailing the Earth in orbit around the sun, where, hopefully for at least five years, it should return some of the most impressive images of distant space ever seen and reveal the makeup of distant stars and interstellar gas clouds.

"Getting through launch operation into primitive operation of the satellite is an enormous milestone," said a greatly relieved and smiling Houck. "The reason is that there were a thousand things that could have gone wrong."

Nearly 27 years ago, Houck and his colleagues first proposed an infrared space telescope. Since 1984 he has headed a NASA team at Cornell developing an instrument called the Infrared Spectrograph. And since 1997 that work has been funded under a $39 million contract with the Jet Propulsion Laboratory in Pasadena, Calif., which is managing the SIRTF mission. The IRS and the observatory could provide new information about the early universe, studying nascent stars that previously have been hidden from view by clouds of insterstellar dust. The observatory consists of a telescope with a 33.5-inch-diameter (85 centimeter) mirror, the Cornell spectrograph and two other instruments designed to detect infrared radiation, much of which cannot be observed from the ground because it is blocked by the Earth's atmosphere.

On the beach during take off! Jim Houck, center, and others see the event approx. 1:35 a.m. Aug. 25, 2003 Nicola Kountoupes/Cornell University PhotographyCopyright © Cornell University

But the launch almost didn't happen. After delays going back to last April, the launch was finally set for Aug. 23. But last week the launch was postponed until Aug. 25. Then, on Friday, engineers reported a potential failure of two power and control boxes on the rocket, similar to ones that had developed problems during testing.

"On Saturday things looked pretty bleak," said Houck, who is the Kenneth A. Wallace Professor of Astronomy. "I think that if you had polled the SIRTF group you would have gotten an answer that there was not more than a 30 percent chance of a launch on Monday." But engineers inspected a huge amount of data and finally, at 5 p.m. on Saturday, presented their case that there was no risk. And at 5:45 p.m. on Saturday it was agreed to go ahead with the Monday launch.

In the final moments of the launch countdown, though, thunderstorms moved into the area. Then an engineer reported concerns about a door in the telescope that seemed to be taking too long to open. "It's intimidating to go into a one-second launch window. If anything goes wrong there is esentially no time to get it fixed," said Houck. If the rocket didn't get off the pad in that one second, it couldn't get into the right orbit, and the launch would have been scrubbed until Wednesday.

On Monday morning, Aug. 25, 2003, hours after the launch, a happy Jim Houck discusses the details with Cornell News Service Science Writer David Brand Nicola Kountoupes/Cornell University PhotographyCopyright © Cornell University

After the launch, more problems developed. Houck went to the hangar where the satellite had been assembled and learned that vital telemetry had not been received from the tracking and instrumentation ship in the Indian Ocean. For several tense minutes it wasn't known if the rocket burned smoothly, was pointing in the right direction or was traveling at the correct speed. Then, another failure was reported in the satellite's positioning camera. But by 7:30 a.m. the reports were that all was well.

Not all the problems are fixed, though. Before the launch there was an indication that the IRS had a damaged filter in one of its wavelength modules, and NASA decided not to replace it. The question now is, did it survive the launch? "We won't know how it is doing for another month," said Houck. "It could be a significant issue, there is no doubt about that."

The IRS team will spend the next three months checking the observatory. The first of the three instruments will be turned on within a week, and the telescope will be calibrated by pointing at a particular star. After two months the observatory will carry out its first scientific observations. On Dec. 18 the first significant release of information is expected.

Houck is philosophical about SIRTF's problems in getting off the ground. "This was a piece of cake. After all, it was only lost for 10 minutes," he said with a grin.

- 30 -