Commander Eileen Collins sat calmly in the cockpit of the space shuttle Discovery, the joystick gripped tightly in one hand. Around her, the craft shuddered and jolted, and Earth raced to meet her through the windows.
Discovery had just survived a catalogue of disasters, from failed computers to a navigation system gone haywire and a huge loss of power. Yet Collins had brought the crippled craft home with confidence, her voice barely rising an octave.
”Welcome home, Discovery,” rasped the voice from mission control.
Last week’s mission was a computer simulation for Collins (48) and her crew. She and everyone at Nasa is hoping next month’s real mission will be smoother when Discovery becomes the first shuttle to blast off into space since Columbia disintegrated in the sky above Texas in 2003.
More than two years since a shuttle last rolled down the runway in Florida’s Kennedy Spaceport, Discovery last week began the process of ”rolling out”, inching its way towards the landing site, already attached to its rocket boosters and bright orange fuel tank.
”It was a beautiful sight,” said Collins.
It was also one full of risk, however. Since seven astronauts died when Columbia exploded after a wing was damaged by a piece of insulating foam during take-off, Nasa has gone through turmoil. Engineers have been determined to erase the physical causes that might risk another disaster.
They have also changed an ”organisational culture” that failed to spot the risk to Columbia even as the doomed craft finished its mission and descended to Earth. The question of whether they have succeeded will be answered next month.
Collins stood deep in the bowels of a Nasa training building in Houston and demonstrated how Discovery plans to land. With a peppy enthusiasm that would not be out of place in a high school, she waved a plastic model of the shuttle through the air, showing how the craft begins re-entry to the Earth’s atmosphere flying backwards and upside down at 27 200kph.
Such an ungainly trajectory has given the craft the nickname the ”flying brick” — not that Collins is anything but excited about it.
”I put myself in the mental state that I am just flying another airplane,” said the former air-force pilot. It just happens to be an ”airplane” with two million working parts and more than 480km of wiring that travels at more than 25 times the speed of sound.
New York-born Collins became the first woman shuttle commander in 1999 when she took Columbia into space. She has been on two other shuttle flights. Now she faces the mission of her life in the full glare of the world’s press as the shuttle returns.
The craft she will pilot has been practically reborn. After two years, Discovery has had 286 safety modifications, many designed to prevent foam breaking off the fuel tank and hitting vital areas of the shuttle.
The foam is a problem because as the shuttle blasts off, even small pieces can have enough power to punch a hole in the protective layers needed to absorb the heat of re-entering the Earth’s atmosphere.
Columbia was hit by a suitcase-sized piece that weighed only just more than half a kilogram, and gashed the leading edge of a wing. As it descended to Earth, super-heated gas leaked into the wing, melting it from the inside out.
Nasa engineers believe that they have now minimised this risk. But they know it has not been eliminated.
”There is still going to be a possibility that something could hit us. We are still going to be flying with some risk,” said Wayne Hale, deputy manager of the shuttle programme.
That will lead to an intensive Nasa surveillance of Discovery to see if any damage is caused this time. As it takes off, more than 100 Earth-based cameras will look for debris strikes. Two fighter jets will circle, also taking pictures. The shuttle’s wings have been fitted with impact sensors, and the craft itself now carries a camera boom that can survey every inch of the ship.
Finally, as Discovery nears the international space station, it will flip itself over and present its underside to the station, whose crew will take detailed photographs.
If the craft is damaged, its crew now has equipment to repair it during space walks. This ranges from a ”goo” that can fill holes to titanium patches, a little like a bicycle puncture repair kit.
Worries remain
Yet worries remain. Despite the work, nothing in the repair kit can fix a hole bigger than 10cm in diameter. The hole that knocked out Columbia was 15cm wide.
Discovery‘s crew have openly doubted whether they could really fix the shuttle well enough for a return to Earth.
”I do not have the confidence to say to any crew, or my own crew, to get in the vehicle and come back,” said Charlie Camarda, one of its seven astronauts.
Such openness is seen as a breath of fresh air in Nasa. In the wake of the Columbia catastrophe, it was revealed that some officials had warned of the dangers of a foam strike. But a breakdown in communications meant no action was taken. The crew was oblivious to the risk and tried to return to Earth normally.
Now Nasa says dissent and speaking out are encouraged. It has even changed the shape of the tables where top managers sit to encourage debate.
”They are round, like with King Arthur,” said one official.
Despite the much-vaunted repair kit, Nasa’s likely first response to a problem with Discovery will be a rescue mission, not to patch up the shuttle. The crew would wait in the international space station for the shuttle Atlantis to collect them.
It would be touch and go. The crew could survive there for 45 days, not exercising to reduce their use of oxygen and eating only 1 000 calories a day. It would take at least 32 days to launch Atlantis. Any of the delays common on shuttle launches could be catastrophic. If Atlantis were damaged as well, two crews would be stranded in space.
But Hale backed this.
”It is better to have a plan than not to have one,” he said. ”We are not going to be in a position to say to the crew and the American public that there is nothing we can do.”
Long-term goals
The concerns and problems of the shuttle programme have led some people to question its worth, but not at Nasa or in the White House. President George Bush last year announced an ambitious long-term goal of returning to the moon and eventually sending humans to Mars.
The international space station is a vital launch pad for those goals and the shuttle is needed to build it. It does, however, mean that when the station is completed in about 2010, the shuttle will be put out of commission. Its resources of billions of dollars will then be diverted to the Moon, Mars and Beyond programme.
The loss of the Columbia crew still pains Nasa. Astronauts are a tightly knit community, and two years ago many mourned the loss of friends as well as colleagues.
”Columbia will cross our minds. I don’t think we would be human if that wasn’t the case,” said Leroy Cain, the flight director who will guide Discovery on its descent.
Yet standing on the floor of mission control in Houston, where the Columbia disaster unfolded, the usually phlegmatic Cain was emotional as he described the importance of the shuttle at Nasa.
”We need to fly. We need to fly the shuttle again,” he said determinedly.
Then, of course, whatever critics say, there is always that view from space. The great blue orb of Earth, the blackness of infinity and the changed perceptions it causes in the handful of men and women who explore it.
Last week, floating weightlessly aboard the international space station, astronaut Leroy Chiao told reporters on Earth how it had affected him.
”Every part of the Earth is beautiful,” he said, grinning. ”It has made me step back and look at what is important in life. I try not to worry about little things.”
Nasa scientists are not so lucky. They know even the tiniest glitch can be fatal. With Discovery already on the launch pad, not sweating about the small stuff is simply not an option. — Guardian Unlimited Â