Discovery crew probes spaceship for launch damage
HOUSTON, July 6 (Reuters) Astronauts aboard space shuttle Discovery conducted a painstaking inspection of their spacecraft, using a sensor-laden robotic arm to look for damage after launch from Florida on a mission critical to the shuttle program's future.
NASA executives said flecks of insulating foam flew off the orbiter's problem-plagued fuel tank during Tuesday's Fourth of July takeoff, but that Discovery looked to be in good shape.
The shuttle's seven crew members spent their first full day in orbit scanning vulnerable parts of the ship's heat shield for any sign of damage from possible debris impacts during Tuesday's liftoff. Foam shedding from the fuel tank triggered the 2003 Columbia disaster. The problem reoccurred during the first post-Columbia mission last year.
''Overall, the tank performance was really outstanding,'' flight director John Shannon told reporters in a briefing late yesterday.
Before Discovery's flight, NASA engineers removed two long foam wind deflectors from the tank, changed insulation around heater wires and extended coverings over metal brackets that previously had been shielded by the deflectors.
Overall, the US space agency spent 1.3 billion dollars over the last three years to fix the fuel tank and make safety upgrades to the shuttle, which included the sensor system to look for damage. It was first used on last year's flight. ''We're very happy with the modifications we made,'' Shannon said.
NASA needs a successful mission to resume construction work on the International Space Station, which has been on hold since the Columbia accident and will require 16 shuttle flights to complete. Another accident or serious problem could ground the shuttle fleet permanently.
Engineers were still reviewing video and photographs taken during liftoff that showed small pieces of insulation popping off the tank as Discovery rocketed into space. But the bits of foam flew off when the shuttle already was so high in the atmosphere that they posed little risk of damaging the spacecraft, NASA officials said.
SUPERHEATED GASES Columbia was hit by a 1.67-pound (756 gram) chunk of foam that damaged its wing during launch. As the shuttle attempted to return to Earth for landing, superheated atmospheric gases blasted inside the wing, ripping it apart. Seven astronauts died in the accident.
NASA redesigned the tank, but a 1-pound (453 gram) piece of foam fell off when Discovery was launched in July 2005 on a test flight. The debris did not strike the shuttle, but NASA grounded the fleet again for additional repairs. Tuesday's launch was only the second flight since the accident.
In addition to launch photography, the shuttle astronauts and the space station crew will be scrutinizing Discovery to make sure it is safe for the plunge back into Earth's atmosphere. The first part of the inspection was completed yesterday the crew using the sensor-laden robot arm, or boom, to scan the ship's wings and nose cap.
Shannon said engineers saw nothing of concern, but that analysis would continue for several days. Streaks on one of the wings, seen in NASA's televised broadcasts of the inspection, were determined to be bird droppings, and posed no threat to the shuttle.
The next survey will be performed by the space station crew as the shuttle approaches the space station for docking today. Stopping about 600 feet (182 meters) before the station, Discovery Commander Steve Lindsey will flip the shuttle backward so station commander Pavel Vinogradov and flight engineer Jeffrey Williams can take high-resolution images and video of black ceramic tiles on the ship's belly.
The shuttle is scheduled to dock at the station at 10:52 a.m. EDT for an eight- or nine-day stay. Discovery is carrying badly needed supplies and equipment to the space station.
Reuters DH VP0755