ON his last space flight Andy Thomas rode the flight deck as the shuttle hurtled through space at Mach 25 – 25 times the speed of sound. It was night and he had the best seat in the house as the craft began to superheat as it re-entered Earth’s atmosphere, first glowing purple, then orange and finally brilliant red. So intense was the shuttle’s force as it collided with atmospheric particles, it forced molecules to dissociate into atoms that created a dancing shroud of incandescent plasma that shimmered around the craft.

“You can see plasma jumping around and sparks of electricity around the windows,” says Thomas. “As you get deeper into the atmosphere you slow down, the vehicle cools down and it begins to fly more and more like a conventional aeroplane.”

After more than two decades as an astronaut, four space flights and a space walk, Adelaide’s spaceman this year retired from NASA. His wife, Shannon Walker, is still in the NASA program based at Houston and is hoping for another flight. She visits Thomas on weekends at their 16ha ranch in mid-Texas where he has been project managing the construction of a small house.

Thomas, 62, is also spending more time in Adelaide, where his mother, Mary, lives. He was here last month and will return in November for an extended Christmas stay.

He is envious, he admits, that his wife will be spending the summer months in the Antarctic on a National Science Foundation field trip retrieving meteorites. Something about the way ice moves forces meteorites to the surface, making them easy to find if you know where to look.

“They’re black on the white ice so it’s easy to find them,” he says. “So I’m a little jealous.”

Not that Thomas is complaining. Much of his career was so extraordinary he virtually had to kick himself to make sure he wasn’t dreaming. He did not start out believing he could be an astronaut; after leaving St Peter’s College, he did a PhD in mechanical engineering at the University of Adelaide.

It wasn’t until his late 20s that he began to think he had the credentials to make a career in space possible. He moved to the US and in 1992 was selected from thousands of applicants into the NASA program.

Thomas became not only an astronaut but a cosmonaut. After his first flight on the Endeavour in 1996, he was looking for another space journey when a place came up as a back-up on the Soviet cosmonaut program. It meant training in Russian as part of a collaborative program with the Russians to fly to the Mir space station in 1998. All the seats were taken but Thomas signed on as a back-up for the final seat on the final flight.

“I volunteered to go and do the training with no expectation of flying because I thought it would be an amazing thing to do,” he says. “I dreamed about being an astronaut but I never in my wildest dreams thought about being a cosmonaut.”

As it happened, a US colleague, Wendy Lawrence, was on the flight schedule until the Russians realised she was too petite to wear the large, one-size-fits-all Russian space suits. In the event of an emergency that required a space walk, she would be unable to leave the space station. “The Russians did not build their suits to accommodate a wide range of people, certainly not women,” Thomas says. “It’s a very big suit, they’re quite cumbersome. They weigh around 100 kilos, they’re quite a mass.”

Lawrence was out and Thomas was suddenly flying to Mir for five months with two other cosmonauts, one from Russia, one from Kazakhstan. He claims that learning Russian isn’t as formidable as it might sound once you’ve mastered the Cyrillic alphabet, and he spoke enough conversational Russian to make himself understood. Even so, it was demanding.

“The hardest part was when we were at the dinner table at night on the space station and they’d be watching a Russian movie and the language is very fast, they talk a mile a minute, so that was very hard to follow,” he says. “It was hard to be spontaneous and make light conversation. I’d often know what I wanted to say but not know how to say it.” Apart from the foreign language, he also had to adjust to living for an extended period in zero gravity, eating and drinking from sealed capsules so the contents didn’t escape and tethering himself at night so he stayed in bed. The biggest psychological adjustment was to embrace the idea that to get somewhere you had to float.

“To push yourself you have to push through the centre of gravity, otherwise you won’t translate, you’ll start tumbling,” he says. “You can’t steer, it’s not like being in water. There are handrails across all the surfaces and you go from handrail to handrail.” That has its perils. Without realising it, by moving forward hand over hand you can build up momentum until confronting an immovable object in an inelegant space crash.

“If you’re inexperienced, at the end you’re going quite fast and suddenly have to stop at short distance,” says Thomas. “You come to a careening halt and slam into the walls, which people do a lot. So you have to learn to pace yourself. Slow is better.”

Keeping track of your possessions can be hard because of their tendency to drift away, which can make fine work with tools unusually difficult. You can’t leave anything untethered. “If you have a pen and paper and you let go of the pen it will float away somewhere and you will never find it, it will go behind some panel,” Thomas says. “On Mir I had one nail file for four months so I hung on to it, I had a bit of Velcro on it and stuck it on to the wall. One day I bumped it and it just floated off and before I knew it, it was gone. I never found it again.”

Coming out of zero gravity after almost five months on Mir presented its own problems. There was a treadmill on board for the astronauts to try to maintain muscle mass but the effects of zero gravity are akin to getting up after being bedridden. Astronauts are usually stretchered out and it took some hours before Thomas could even raise his head without the room spinning.

“The thing that surprised me was how ponderous and massive my legs felt,” he says. “The effort required to lift one leg up and put it down in front of the other we take for granted but it’s a lot of work.”

His six-and-a-half-hour space walk happened on his third flight, in 2001, on a shuttle flight to the International Space Station. Thomas and his shuttle brought up a replacement crew and were required to do some assembly tasks on the outside of the station, which meant leaving the spacecraft and walking into space.

Surprisingly, you don’t hear the secrets of the universe. Rather, you hear the welcome sound of a fan circulating air around the large and unwieldy space suit.

“It’s a bit like a vacuum cleaner but you want to hear that; that’s good, if you didn’t hear it, it would be bad,” he says.

Manipulating the suit is difficult and fine work is hard to do with puffy, gloved fingers. Just flexing the arm of the suit or the fingers was physically hard and after six and a half hours Thomas was exhausted. But it was a peak experience, particularly when he was up high on a solar ray tower engaging a latch as the station orbited the dark side of the Earth. “It was just black, total blackness, but a very three-dimensional blackness,” he says. “You could just tell you were looking to infinity. You feel it goes forever.”

The other magic moment came when the ground controllers told him Australia was just coming into view and he watched our nation pass between his feet from 400km away. That was nice, he says. The Earth’s topography is clearly visible and when during the 1996 flight the then premier Dean Brown told people in Adelaide to turn on their lights, he saw them from the Endeavour.

“Yes, they did leave the lights on. They probably didn’t need to because the street lights are pretty bright anyway,” he says.

He busts the myth that the Great Wall of China is the only human construction visible from space; if it is, he didn’t see it. What he could see was the Indian Pacific railway track from Sydney to Perth, which was identifiable because of its unnatural straightness. “It’s a very fine line, it’s like someone has drawn a very fine pencil line across the desert,” he says.

It’s also a fine line between survival and disaster in space.

In 2003 when the Columbia shuttle and its seven crew were lost, Thomas was deputy chief of the NASA office based at Houston, which had a contingency action centre ready in the event of an accident. The landing was due at 8am and he arrived at work unshaven, expecting to be home in an hour. Sixteen hours later he was still there.

The first inkling something was wrong came when Columbia’s communication failed; it can happen during the 10-minute re-entry but never for long.

“Then it reached the point where we knew that the entry was over and they should have had communications,” Thomas says. “And the ground controllers had lost telemetry (the wireless transmission and reception of data). There’s a continuous stream of telemetry which documents

the health of all the systems and that had gone away.”

Family waiting to greet the returning crew were rushed into a private area.

“We knew something was up because the shuttle hadn’t shown up and it’s always on time,” says Thomas. “They were told the vehicle had been lost and there was very little likelihood of survival because the altitude was so high.”

Later, air traffic control produced a radar plot showing a stream of debris over northern Texas and northern Louisiana. The debris was falling out of the sky and NASA was getting calls from sheriffs of small towns in Texas saying there was debris in the main street and what should they do?

“We had to quickly send people to those areas to make sure the public was safe because some of this stuff was dangerous, there were propellants and things like that,” Thomas says. “We farmed out search crews – NASA people, the forestry department – who systematically walked the debris line collecting items for forensic examination. And of course we had to recover human remains as well.”

Thomas is measured in his criticism but he does not absolve NASA from blame for the disastrous end to the Columbia flight. A piece of foam had come loose during the ascent and crashed into the leading edge of the wing. NASA’s engineers ran computer analyses of the debris in the air stream to estimate how much damage was done and decided everything was fine.

“They basically cranked out a computer code and they concluded from that there was no issue,” says Thomas.

Clearly there was. Thomas believes this over-reliance on an engineering solution came at the cost of a more balanced, common sense assessment that might have alerted NASA to the risk and allowed other strategies to be considered.

“We punish ourselves, and I’ve done this; I’m guilty of this too. We punish ourselves for not really thinking about what that meant in terms of the physics of it,” he says. “In hindsight if you’d done a very simple back-of-the-envelope calculation that thought about the physics, you would have reached a different conclusion. We did not have an engineering organisation that approached problems that way.”

But what could have been done? The damage was done during the ascent, which would seem to leave little margin for fixing anything. Thomas says for a start a decision could have been made to use reconnaissance satellites to photograph the leading edge of the wing and send images of the damage. Yet on the basis of the computer analysis, this was thought not to be needed.

“So that was the wrong decision,” he

says. “If they had understood the analyses better, they would say ‘we want the full

story so we had better photograph the vehicle’. That didn’t happen and that is a reflection of a cultural approach within the technical community within the agency

that is not healthy.”

Thomas signed up for the Return to Flight mission in 2005, which psychologically reclaimed the NASA program and continued the assembly of the International Space Station. The same problem happened – a piece of foam came loose during the ascent – but it happened high in the atmosphere and didn’t strike the shuttle.

“We thought the problem with foam coming loose had been fixed but it hadn’t, not completely,” he says. “That was a problem with the shuttle for the remaining flights. It’s a problem with the design; having it aerodynamically in the airstream of other objects that can shed debris is very dangerous. We were high enough and the air was very thin so the foam didn’t get a chance to accelerate very much and it missed the wing. But we were surprised.”

Since the completion of the International Space Station the shuttle program has been wound up. It is 45 years since man walked on the moon and the political appetite for ambitious, expensive, single-purpose space missions has waned. Thomas believes the future of space travel will be commercial, with NASA forming partnerships with aerospace companies or individuals with deep pockets, like Elon Musk, the PayPal founder and chief executive of Space X, who wants to die on Mars.

The Space Station is still operating –Thomas says there are six people up there right now – and will continue until the mid-2020s. But NASA has already announced it will rent space on private shuttles to service the Space Station, with Boeing and Space X to provide the service.

Commercial providers will sell seats to NASA, to other agencies and to members of the public if they want. Thomas welcomes the development because it will free NASA from the massive cost of providing regular low-orbit flights at the expense of looking farther afield to a return to the moon or a visit to Mars. Even so, private investment will need to be involved.

“Congress has shown a remarkable lack of enthusiasm for sponsoring the human space program,” he says. “They see it as low-hanging fruit at times of tough budgets; you can cut that without consequence because the return on space investment is way beyond the election cycle.”

Before leaving NASA, Thomas had a brush with Hollywood when he worked as an adviser on the much-admired space film Gravity. It starred George Clooney and Sandra Bullock and won seven Oscars, including best female actor for Bullock. The contact came when director Alfonso Cuaron rang the Jet Propulsion Laboratory at Pasadena asking to speak to someone who knew about space flight.

“Alfonso called me up and said he had this idea and I said ‘well you can’t do that because that defies physics’,” says Thomas. “They wanted to get the physics right, they wanted it to be credible.”

They were crushed when Thomas told them that what they were suggesting was impossible but he went on to tell them what they could do. “They got very excited they could align their storyline with something that wasn’t in violation of the laws of physics. It might have been in violation of the laws of reality … but at least it didn’t violate physics!” he says.

Thomas hasn’t seen the film, in which two astronauts are stranded in space after they are hit by debris and use the International Space Station to get back to Earth. He flew to London for a day and explained in detail what the interior of the spacecraft would look like, then spent about six months answering questions about how things worked and what would be likely to happen. The space walk scenes where Bullock’s character crashes into the side of the spacecraft, for instance, were technically correct – and definitely not something you would want to happen.

“The worst thing would be for you to slam into something and smash your visor, in which case you’re almost instantly dead,” he says. “It defied credibility a bit. It’s also breathtakingly dangerous to be in a situation like that.”

Apart from a credit as a consultant on the film, Thomas is also acknowledged in a scene in which Bullock’s character navigates along a passage past a “Kangaroos Ahead” sign stuck to the Space Station wall. It’s a nod to Thomas, who had the same sign on the wall of the Mir space station.

“I’ve still got that sign in Houston,” he laughs. “I got on quite well with the assistant producer and they did that to acknowledge my contribution, which was nice.”

He saw Bullock from a distance but didn’t get to meet Clooney. He also points out there is no way you could get from the Hubble space telescope to the International Space Station because they aren’t in the same orbit and wanted that explained in the film although it never was, which probably explains why he hasn’t seen it.

His Texan ranch is a nature retreat with deer, raccoons, armadillos, jack rabbits and hawks. He and Walker may decide to turn the ranch into an orchard but for now he is concentrating on getting a small house and workshop built, and maybe later a larger home. He gives talks on his space experience and has maintained a strong connection with Adelaide, supporting the successful bid by the Space Industry Association of Australia (SIAA) to host the 68th International Astronautical Congress (IAC) in Adelaide in 2017. It is the largest annual gathering of the international space community and attracts the head of NASA among others. Thomas calls it “the grand final of aerospace meetings” and says it is a stunning victory for Adelaide. He personally promoted the city as part of the bid and will retain a role in the lead-up to it.

“I know from my astronaut background what this conference needs and I was happy to write an endorsement. It will be a big deal,” he says.

Thomas is also passionate about sustainability and climate change and he speaks about this during his space talks. Looking at the Earth from above left him with no doubt about how densely populated our planet is. The amount of light in areas like Europe and the eastern seaboard of the US was staggering.

“It’s quite frightening because the coastline is delineated perfectly by lights,” he says. “It makes you realise just how many people there are on the planet.”

He harvests rainwater at his ranch and says he is glad to see people demonstrating about climate change because something has to change. He fears the unending pursuit of economic growth at all costs will ruin the planet.

“I hear people say ‘we can’t do anything about climate change because it will hurt our economy’ and I am just stunned,” he says. “That is a morally bankrupt policy; these people have no concept of what they are doing to the world 30 years from now. Talk about economic upheaval!”

He finds it morally irresponsible to argue that our immediate economic wellbeing justifies the ravaging of the planet – the use of groundwater for mining in SA worries him – and Australia through its export of raw materials is one of the worst polluters. Politicians who put the wellbeing of the country behind the short-term desire to create jobs are feeding a system that is starting to break, he says.

He is particularly passionate about what is at stake. “I am very disillusioned by the circumstances. It concerns me, it really does,” says the man who has seen the bigger picture. “The long-term wellbeing of the planet is in question.”