The spaceship lifted off at 12:28 a.m. EDT with a shattering roar and brilliant flash of light that peeled away the darkness.

NASA had planned to launch Columbia on July 20, but aborted the flight seven seconds before liftoff because of potentially high levels of hydrogen in the engine compartment. The problem turned out to be a faulty sensor and managers quickly cleared Columbia for a second launch attempt.

The shuttle is carrying an X-ray telescope called Chandra, which is a sister craft to the Hubble Space Telescope and the Compton Gamma Ray Observatory. The telescope is to be carried into an orbit that will reach one-third of the way to the moon by an upper-stage rocket motor. NASA plans to fly the fourth and final member of its Great Observatory family - an infrared telescope -- in two years.

The two-woman, three-man shuttle crew is scheduled to release the Chandra X-ray Observatory from the cargo bay at 7:45 a.m. EDT Thursday. Eileen Collins, who is making her third spaceflight, is the commander . A former Air Force pilot, Collins, 42, is the first woman who will actually fly and land the shuttle. Assisting is pilot Jeff Ashby, the crew's only space rookie. Steve Hawley, making his fifth spaceflight, is the flight engineer. Mission specialists Cady Coleman, who is making her second flight, and French Space Agency astronaut Michel Tognini, who spent two weeks on the Russian Mir space station, round out the crew.

NASA plans to keep the shuttle in orbit just five days, with touchdown at the Kennedy Space Center targeted for 11:24 p.m. EDT Monday.