to the International Space Station. Running four days late because of bad weather and trouble with a hydrogen valve in the shuttle’s engine compartment, Discovery’s two solid-fuel boosters ignited with a crackling roar at 11:59 p.m., instantly pushing the spacecraft away from launch pad 39A atop twin torrents of 5,000-degree flame.
Wheeling about to line up on a northeasterly trajectory, Discovery arced away on a course paralleling the East Coast, putting on a spectacular late night sky show for area residents and tourists.
Two minutes after liftoff, the shuttle’s boosters fell away, their 1.1 million-pound loads of solid propellant exhausted, and Discovery continued toward orbit under the power of its three main engines, looking like a brilliant star as it dropped toward the horizon.
Six and a half minutes later, with the shuttle traveling faster than 17,000 m.p.h. — more than 84 football fields a second — the powerful engines shut down and Discovery separated from its nearly empty external tank, safely slipping into its planned preliminary orbit.
Over the next two days, the shuttle commander, Col. Frederick W. Sturckow of the Marines, and the pilot, Kevin A. Ford, a retired Air Force colonel, plan to carry out a series of rocket firings to catch up with the space station, setting the stage for docking around 9 p.m. Sunday.
Colonel Sturckow, Colonel Ford and their crewmates — José M. Hernandez, John D. Olivas, retired Army Col. Patrick G. Forrester, Christer Fuglesang of the European Space Agency and Nicole P. Stott, who will join the space station crew as a flight engineer — plan to deliver 7.5 tons of supplies, science gear and life support equipment to the laboratory complex.
Along with installing a new 1,800-pound ammonia coolant system tank, the astronauts will deliver two research racks, a freezer for experiment samples, a new carbon dioxide removal system, a crew sleep station and a new treadmill named after the comedian Stephen Colbert.
Ms. Stott, a shuttle engineer who joined the astronaut corps in 2000, will replace Col. Timothy L. Kopra of the Army, who traveled to the station last month aboard the shuttle Endeavour. Colonel Kopra will return to Earth aboard the shuttle.
Discovery was cleared for takeoff last week after NASA managers concluded that the foam insulation on the ship’s external tank was solidly attached and up to the rigors of launching.
During the previous shuttle flight, in July, an unusual amount of insulation fell away from the central section of Endeavour’s external tank. While the orbiter’s fragile heat shield suffered no major impact damage, NASA managers ordered extensive testing to make sure Discovery’s tank was safe to launch.
In live television views from a camera mounted on the side of the huge tank, the foam appeared to perform as expected during Discovery’s climb toward space.
But it will take several days for engineers to fully assess the health of the shuttle’s heat shield based on ground-based imagery, data from inspections in orbit and photos shot during final approach to the space station. The 8-inch-wide liquid hydrogen valve that delayed Discovery twice earlier this week worked normally during fueling earlier Friday.
Three spacewalks are planned during Discovery’s visit before it undocks on Sept. 8 and lands back at the Kennedy Space Center two days later.
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