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Journalism of Courage
Astronauts on the shuttle Discovery slowly scanned the wings and nose of their spacecraft with a laser-equipped robot arm on Wednesday in a critical safety inspection never before performed on a shuttle mission.
Manoeuvering the computer-aided arm from within the orbiter, the astronauts looked for cracks that could endanger the shuttle when it returns to the Earth’s atmosphere for its August 7 landing, hurtling down in temperatures up to 2,500 degrees F.
Television shots from space showed the procedure from the laser’s perspective as the robot arm crept along the wing’s edge.
Almost halfway through the inspection, which was expected to take seven hours, no signs of damage had been apparent. At one point, engineers on the ground asked for a second look at a suspect spot, but astronauts went back over the area with the camera at a different angle and it showed nothing.
‘‘Everything has gone exceptionally well,’’ NASA spokesman Rob Navias said.
The painstaking inspection is one of many safety measures put in place after the fatal 2003 Columbia disaster, when a loose chunk of insulating foam at launch damaged the wing and caused the shuttle to disintegrate on re-entry, killing its seven astronauts.
The piece of foam weighed no more than 1.67 pounds.
Discovery’s Tuesday launch was smooth but not flawless. Video from one of the array of cameras at takeoff showed a nick in heat-protective tiles near the nose landing gear and an unexplained piece of debris falling away from the exterior fuel tank.
The debris did not strike the shuttle, but the 2.5 cm gouge in the tile would require further study, said flight operations manager John Shannon.
Tile damage to the shuttle is not unusual. From the fist shuttle flight in 1981, orbiters have been hit by debris some 15,000 times, mostly on liftoff.
However, under new safety rules, NASA must ensure that any problem does not hold the potential for a Columbia-like disaster.
The shuttle is en route to the International Space Station where they will hook up 355 km above Earth for a week.
Before docking, commander Eileen Collins will park Discovery 182 metres away from the station and put the shuttle in a slow backflip while station crewmembers Sergei Krikalev and John Phillips take shots of its underside in search of signs of damage.
Since Columbia, NASA has spent more than $1 billion on safety upgrades and worked to change a culture that investigators charged had become too casual about risk.
If NASA engineers determine there is dangerous damage to Discovery, the astronauts could try to repair it with experimental fixes they plan to test later in the flight.
In the worst case, the crew could take refuge on the International Space Station and await a rescue flight from shuttle Atlantis. —Reuters
