Space & Innovation

'Exhilarated' British Astronaut on First Spacewalk

Each step of the six-and-a-half hour historic spacewalk was meticulously planned.

Astronaut Tim Peake on Friday became the first Briton to walk in space, undertaking a tricky mission in the dark to replace an electrical unit.

Peake and US colleague Tim Kopra switched their spacesuits to battery power at 1248 GMT, marking the official start of the floating maneuver for Peake, who is also the first British astronaut to fly to the orbiting International Space Station.

As Peake climbed out of the space station, American astronaut Scott Kelly positioned a camera from inside so that the British flag on the arm of Peake's spacesuit was visible to viewers watching live on NASA television.

Space Station Welcomes its First British Astronaut

"Great to see the Union flag out there," said Kelly.

"It's great to be wearing it," answered Peake. "It's a privilege."

The 43-year-old Peake's first job was to haul a bulky component called a sequential shunt unit, contained in a white bag as big as a suitcase.

He carried the unit, which would weigh 200 pounds (90 kilograms) on Earth, to the far end of the space station's truss, about 200 feet (60 meters) from the exit.

UK to Send First Astronaut to Space Station

The replacement voltage regulator unit is nicknamed "Dusty," because it arrived on the space station back in 1999, said NASA commentator Rob Navias.

Kopra, 52, making his third career spacewalk, toted the tools needed to remove the old unit and replace it with the new one.

The team's work was precisely timed to coincide with a nighttime pass of the space station to avoid sparks from any residual electrical current in the solar-powered equipment.

Photos: An Astronaut's View of the 2015 Hurricane Season

The ISS circles the Earth every 90 minutes, spending 31 of those minutes on each pass in the dark.

The first portion of the nighttime job began at 1437 GMT and was finished about 20 minutes later.

"Everything is going swimmingly," Navias said.

Next, the astronauts will route cable and install a vent in a cramped space that spacewalk officer Paul Dum described this week as a "challenging work site."

Photos: How a NASA Astronaut is Paving the Way to Mars

- ‘No pressure' -

In a blog post on Thursday, Peake said he felt "exhilarated" but had "no time to dwell on these emotions."

Peake said he had spent months on Earth training for the mission, including virtual-reality sessions to prepare "for the worst-case scenario of becoming detached from the space station."

Each step of the six-and-a-half hour spacewalk was "meticulously planned," he added.

"But I guess nothing can prepare for the feeling of being outside of a spacecraft in the vacuum of space."

As the first British person to reach the ISS - following the first British citizen in space, Helen Sharman, who flew to the Russian Mir space station in 1991 - Peake has drawn plenty of attention from his compatriots.

Among them was the Beatles legend Paul McCartney, who offered a message of "good luck" on Twitter.

"We're all watching, no pressure! Wishing you a happy stroll outdoors in the universe," McCartney wrote.

Scott Kelly is a NASA astronaut working for a year in space on the International Space Station. Does he have the stuff of "The Martian,"

the highly anticipated Matt Damon movie to be released on Oct. 2

, chronicling the life of a stranded astronaut on the surface of Mars? While Kelly certainly isn't on his own in space, much of the work he is doing would be useful for a trip to Mars. Here are some of the things the astronaut is working on that Mark Watney (Damon's character in "The Martian") would appreciate.

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The sun goes through an 11-year cycle of activity, and we are just past the peak of one of those cycles. The solar peak is a time when the sun unleashes more flares and coronal mass ejections (charged particles). When these particles hit the Earth's magnetic field, they can produce spectacular auroras.

But they also can give astronauts a higher dose of radiation.

The space station monitors radiation levels for astronauts close to Earth; in fact, one of the reasons Kelly was selected for this mission was he did not exceed the lifetime radiation levels allowed for astronauts. Radiation is expected to jump for those travelling outside of Earth's magnetic influence. Mars doesn't have much magnetic field to speak of, and the Curiosity mission is monitoring radiation levels on the surface to get more information for future human missions.

MORE: Killer Radiation: How to Protect Martian Astronauts

Working in space is a harsh business. You're busy all the time, you're stuck in a small environment with several people, and your family and friends are far away. NASA keeps close tabs on its astronauts' psychological health through measures such as doctor calls with astronauts, and

having the astronauts keep journals

during their missions. This will especially be important for Mars, as astronauts will need to be even more self-sufficient due to the time delay in communications between planets. NASA has

an ongoing comm delays study

for astronauts doing simple tasks; these tasks and their effects on astronauts will be studied as the station work continues.

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Microgravity is hard on your body. NASA has its astronauts exercise for a couple of hours a day, which seems to help counteract bone loss for missions of six months. But what about a year, or longer? That's part of what Kelly's mission is supposed to answer. Bones aren't the only things to worry about, either. Muscles shrink, eye pressure increases, your sense of balance changes. Even your immune system may be affected, something that

NASA is also looking at

in detail. So while we think of astronauts as boldly doing spacewalks and experiments on station, understand that they are also part of the experiment. Their very health is being watched for the benefit of future space missions.

MORE: Space Missions Turn Astronauts' Hearts Spherical

While Watney develops a certain affection for potatoes, Kelly recently posted a picture of himself looking pretty pleased next to a floating pile of fruit. It turns out that little comforts do go a long way for astronaut morale, and any nutritionist would tell you that a varied diet of healthy foods is good for you -- not just the freeze-dried stuff the Apollo astronauts survived on during their missions. NASA has an experiment in place to see how well

astronauts are meeting nutritional requirements for their work on station

, and also for their long-term health.

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Astronauts are very tied to shipments from Earth right now in terms of eating ... but that is changing in a small way.

Thanks to an experiment called Veggie

, astronauts got to taste some food grown aboard the space station this summer. Lettuce, of course, does not an entire meal make. But as the movie Contact (1997) reminds us, it's through "small moves" that we learn about science. The hope is eventually this experiment will translate into a better way of harvesting crops beyond Earth. For Mars, we're even wondering how viable the soil could be to support plants.

MORE: 'Smart' LED Farming Could Make Space Veg Viable

"#ILookLikeAnEngineer on @space_station. Also a scientist, medical officer, farmer & at times a plumber," Kelly wrote with this image in August. What's more, he has to do all those things in a small space. Since every pound hoisted to space costs money, astronauts are accustomed to working in claustrophobic quarters. But NASA, concerned about its astronauts' efficiency and happiness, also has an

experiment that is supposed to look at how best to construct a living space for astronauts

. That way, the habitats designed for Mars will be suitable for long-term living.

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During a recent Twitter chat, Kelly was asked if he wanted to go to Mars. He said yes, as long as he could return. Getting to Mars and back will take hundreds of days of transportation, let alone the time on the surface. The gravity on Mars is less than 40% what we experience here on Earth. And unless spacecraft design changes substantially, the astronauts will be in microgravity on the way there and back. NASA has an experiment to see

how well (or badly) astronauts work on the surface shortly after landing

, an experiment that Kelly is participating in. This will be important not only for returning to Earth, but seeing how well a crew can get adapted to Mars after being in microgravity for the transit.

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