GREENBELT — |TC GREENBELT -- The space shuttle Atlantis streaked into orbit yesterday morning on a five-day mission to deploy the heaviest U.S. astronomy satellite ever and conduct the first spacewalk by astronauts since 1985.
Four months after the National Aeronautics and Space Administration's manned space program was stalled by cracks found in the shuttle fleet's fuel-door hinges, launch director Bob Sieck declared the nearly flawless countdown and liftoff "one of the best, if not the best," in the 39 launches since flights began in 1981.
The cracks identified on Atlantis -- deemed too small to postpone its departure on the first shuttle mission of 1991 -- posed no problem during the fiery ascent. The orbiter's fuel doors shut tightly after the huge external fuel tank was jettisoned.
"We were confident that was going to work," said Mr. Sieck. "There was no drama."
Larger cracks on Discovery and Columbia are considered safety hazards, and their hinges are being replaced. Discovery is tentatively scheduled for a Defense Department mission to begin April 25.
Atlantis roared away from Kennedy Space Center at Cape Canaveral, Fla., at 9:23 a.m. -- after a five-minute weather delay -- carrying Air Force Col. Steven R. Nagel, the commander; Marine Corps Lt. Col. Kenneth D. Cameron, the pilot; and Air Force Lt. Col. Jerry L. Ross, Linda M. Godwin and Jay Apt, mission specialists.
Stuffed in its cargo bay was the $617 million Gamma Ray Observatory, scheduled to be released from the shuttle's robot arm by Dr. Godwin tomorrow at 1:46 p.m. EDT. The long process of grappling the satellite and maneuvering it into position begins at 7:20 a.m. EDT.
The 17-ton GRO -- 31 feet long, with solar panels stretching 70 feet from tip to tip -- is the second of NASA's four "Great Observatories" scheduled to be launched this decade. The first was the $2 billion Hubble Space Telescope.
From its vantage point 279 miles high, the science satellite will point its four massive instruments for up to two weeks at a time at invisible-from-Earth sources of gamma rays, the hottest, most energetic radiation in the electromagnetic spectrum.
Scientists hope that the observatory's unprecedented ability to detect gamma rays -- emitted by violent denizens of the universe such as supernovas, quasars and black holes -- will reveal secrets about cosmic evolution and the formation of Earth's heavy-metal elements.
"The science is very exciting; it will open a new window for astronomy," said John Hrastar, GRO project manager at NASA's Goddard Space Flight Center, which will control the satellite round-the-clock for its two- to six-year lifetime.
Astronauts Ross and Apt will be standing by tomorrow for an emergency spacewalk if the deployment of the GRO runs into snags, but the first spacewalk since December 1985 is officially scheduled to begin Monday at 8:28 a.m. EDT.