Nasa called it ”a gift to the nation”. On Tuesday the shuttle Discovery finally blasted off after several days of delays to lend a spectacular fiery flourish to the United States’s Independence Day celebrations.
The agency’s first July 4 launch in 45 years of manned spaceflight provided a welcome distraction from the controversy about the safety of the fuel tank’s foam insulation and the frustration of two aborted liftoffs owing to poor weather at the Kennedy Space Centre.
”I can’t think of a better place to be on the Fourth of July,” said Steve Lindsey, the shuttle commander, moments before Discovery roared into a clear Florida sky.
The crew of seven, including the British-born astronaut Piers Sellers (51) enjoyed an apparently flawless ascent to orbit after the launch at 2.38pm. Thunderstorms that had threatened to cause a third postponement remained at sea. ”Today was one of our better days. They don’t get much better than this,” said Dr Michael Griffin, the Nasa administrator.
Mission managers immediately began a painstaking study of images from 107 cameras on the ground and aboard the spacecraft to check for any damage sustained during the first minutes of its 13-day, 8-million kilometre mission to the International Space Station (ISS).
Pictures shown on Nasa TV showed three or four chunks of debris falling from the fuel tank two minutes and 47 seconds into the flight. Another two pieces fell around two minutes later, though it was unclear whether any struck Discovery.
”It will probably be a couple or three days to get the whole story,” said Wayne Hale, the shuttle programme manager, who warned before the flight that small pieces of foam coming off were a certainty.
A more pressing concern could be a report from the astronaut Michael Fossum that he filmed what appeared to be a five to eight-feet section of the thermal protection blanket flying off the orbiter.
”This is one of those times when pictures are worth thousands of thousands of words,” Colonel Lindsey said.
It was a briefcase-sized slab of foam peeling from the external fuel tank at lift-off that struck a hole in the wing of the shuttle Columbia in 2003, leading to the death of seven astronauts as deadly hot gases seeped into the spacecraft and blew it apart on re-entry.
Despite a redesign of the fuel tank, the problem happened again during last year’s first return-to-flight mission when a 0,45kg chunk of foam narrowly missed Discovery. And Tuesday’s blastoff was also in doubt when launchpad technicians found a 12,7cm crack and a 7,6cm piece of foam missing near a fuel-line bracket after the tank was drained after the abandoned launch on Sunday.
Engineers spent all Monday assessing the damage before concluding that it was not severe enough to stop a flight.
Sellers, who was born in Crowborough, East Sussex, but became a US citizen to join the astronaut corps in 1996, emerged from the crew room and boarded the ”astrobus” to the launchpad waving a small stars and stripes flag.
Walking beside him was the German Thomas Reiter (47) the only non-American among the crew. When Discovery returns to Earth on July 17, Reiter will remain aboard the ISS, raising its complement to three astronauts for the first time since May 2003.
The mission, Nasa’s second since the Columbia disaster, will deliver 12,5 tonnes of supplies and equipment to the ISS and continue testing $1,3-billion of safety and repair techniques introduced since the tragedy. Nasa is racing to finish the construction of the ISS before the shuttle fleet is retired in 2010.
Sellers will conduct the first of his scheduled spacewalks on Saturday, when he and Fossum (48) will test the load-bearing capabilities of the shuttle’s 30m robotic arm extension. If successful, it can be used in missions to transport astronauts to the underside of the orbiter to inspect the heat shield for damage. The second ”extra-vehicular activity”, as the spacewalks are known, will be two days later, when the pair will attempt to replace a broken power cable outside the space station. On a third walk, they will apply resin to deliberately broken thermal tiles to see if the ”repairs” could withstand the 1 650°C heat of re-entry.
Sellers, the third Briton in space after Helen Sharman and Michael Foale, is on his second shuttle trip. The other astronauts are pilot Mark Kelly (41) and mission specialists Lisa Nowak (42) and Stephanie Wilson (39). – Guardian Unlimited Â