BBC Future

Space Station

Taking a walk in space

About the author

Richard is a science journalist and presenter of the Space Boffins podcast. He edits Space:UK magazine for the UK Space Agency, commentates on launches for the European Space Agency and is a science presenter for BBC radio. You can also follow him on Twitter or Facebook.

  • Stepping out
    Space walks – known as extravehicular activities (EVA) – have become critical and parts of many space missions. (Copyright: Nasa)
  • First step
    On June 3, 1965, Ed White became the first American to conduct a spacewalk. It came two months after Russian Alexey Arkhipovich Leonov’s first stepped into space. (Copyright: Nasa)
  • Shell suit
    During all EVAs the astronaut relies solely on their spacesuit to protect them from the harsh space environment and keep them alive. (Copyright: Nasa)
  • Floating free
    Most space walks are tethered, but on 12 February 1984, Bruce McCandless used a nitrogen jet propelled backpack to fly around 100m (320ft) from the space shuttle. (Copyright: Nasa)
  • Construction job
    EVAs were crucial for constructing the International Space Station, with astronauts clocking up nearly 1,000 hours outside the ship. (Copyright: Nasa)
  • Hubble trouble
    The ability to move around outside a craft also allowed Nasa to carry out several repair missions to the Hubble space telescope. (Copyright: Nasa)
  • Helping hand
    Moving in space is difficult, so astronauts often have to have their feet attached to a plate or robot arm to allow them to carry out useful work. (Copyright: Nasa)
  • Quick dip
    Astronauts practice for space walks in an enormous water tank at the Johnson Space Center In Houston. (Copyright: Nasa)
  • Virtual space
    Nasa also uses virtual reality to allow astronauts to practice movements and get accustomed to moving around the ISS. (Copyright: Boffin Media)
  • Get a grip
    The author tries his hand in virtual space and gets a new for the skill and effort of astronauts on space walks. (Copyright: Boffin Media)
What’s it like to walk in space? In the first part of an examination of the challenges of living in space, our space correspondent steps outside the International Space Station.

“Ready?”

I nod.

“Here we go…”

“Whoah!” is all I can manage as I find myself transported from a cluttered office in Houston to Earth orbit. Below, 350km (220 miles) away, the blue and white crescent of the Earth. Above me is the glistening white hull of the International Space Station (ISS), its vast solar arrays glinting in the sunshine.

Nasa hasn’t invented teleport. This is the agency’s Virtual Reality (VR) Laboratory at the Johnson Space Centre where dreams of space travel really can come true.

The lab complements underwater training and prepares astronauts for EVAs [Extra Vehicular Activity] – space walks – and work with robotic arms. Most of the room looks like a regular office with desks, computers and monitors but the rear section resembles an eccentric gym. Ropes hang from the ceiling, metal boxes are suspended on bungee cords and the room is criss-crossed by lines and pulleys.

“That’s where most of the virtual reality takes place,” says James Tinch, chief engineer for the Robotics Astronaut Office and manager of the lab. “The crewmembers put on the helmets and they get the sensation that they’re at the space station. The metal boxes with the ropes and pulleys tied to them are a mass handling device, so the crews can get a feel for what it takes to handle a large mass in space and how much trouble they might have just to move it around.”

I sit on the chair at the centre of the test area and Tinch gently lowers a harness over my shoulders. This holds the electronics for the virtual reality helmet, which he tightens around my head, allowing me to see an image of the VR environment. Next come the gloves. They look like cycling gloves and are fitted with sensors for grip and movement. I pull them onto my fingers. A box mounted to the ceiling above me will track their position as I move my hands around.

Then Tinch clicks the start button and I’m in orbit reaching out to the handrail just outside the airlock. I truly feel that I’m in space and yet to look at me, I’m still sitting on a chair at the centre of a room.

“Right now you’re next to the ISS airlock, where the crew members come out,” says Tinch, calmly. But I’m feeling anything but calm as I struggle to comprehend my new surroundings.

Try before you buy

If I look down I can see the rest of my spacesuit; straight ahead and there are my hands, now encased in astronaut gloves, tightly clasping the handrail. After giving me a few minutes to get acquainted with the view, Tinch instructs me to try to pull myself across one of the space station modules by releasing my left hand from the rail and gripping again further along. The idea is to pull myself around, hand over hand. But I let go too quickly and end up pushing myself away. I try to ‘swim’ back towards the structure, waving my hands wildly back and forth, but realise there’s nothing to push against. One of the major challenges of space walking – and a fuller understanding of Newton’s laws of motion – starts to become apparent.

“In space your hands pretty well do all your work for you,” says Tinch. “So your legs can kick and do anything but they’re not helping you.”

“One of the things you’ll find in space is that your wrist is one of the primary sources of how you move your body around, so astronauts do a lot of exercises with their hands and wrists to make sure they’re strong enough,” Tinch explains. “It’s a long day in those suits as you’re working against the suit and working against yourself, trying to get the work done.”

Quite how difficult space walking could prove to be was first brought home to Nasa in 1966, when astronaut Gene Cernan left the confines of the Gemini 9 spacecraft for the world’s third EVA. Later described by Cernan as “the spacewalk from hell,” he fought to control his tether and tumbled in a “slow motion ballet.” By the end, his heart rate had tripled, his visor had fogged up and he struggled to get back into the capsule.

Although I wasn’t in any danger (except perhaps from falling off my chair), forty-six years later, I experienced similar problems. If I moved my arm one way, my virtual body spun the other. The normal rules of movement that we are accustomed to on Earth do not apply in space. Imagine the simple act of tightening a bolt – without something to push against, as you turn the bolt you end up spinning in the opposite direction, achieving nothing. To overcome this problem, the ISS is fitted with handrails, footholds and often the crew will also use a robotic arm to assist them.

And they cannot just pop outside when the mood takes them. Lessons learnt over the years mean that every EVA is meticulously planned and choreographed. In fact, “space dance” might be a better way of describing what’s involved. Tinch explains that the VR lab enables astronauts to solve problems before they try it for real.

“If I have these four bolts I have to undo, what’s the best way for my body position to be? So you’re trying to do the choreography of the EVA and trying to figure out what works best for that workspace.” For those already on the ISS, the lab is developing VR helmets that can hook up to the station’s own laptops so astronauts can refresh their training on the job.

After 20 minutes in orbit, I’m exhausted. My back aches, my face is dripping with sweat and my wrists are sore. As he lifts off the helmet, Tinch assures me that astronauts trying this for the first time have similar problems.

If this were real, I would be wearing a bulky spacesuit, looking through a visor and would not have the luxury of stopping when I got a bit tired. The experience has given me a new appreciation of the training, skill and effort it takes to operate in the uncompromising space environment. A reality check for those of us who advocate manned missions to the Moon and Mars that we should never take this stuff for granted. Space walking may look like fun but, once you get over the amazing view, it is hard. Really hard.

In future columns Richard will be reporting from inside the space station control room and the full-sized mock-up of the ISS at Houston to discover what it takes to keep the astronauts alive.

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