Physics KS3 / GCSE: How did Felix Baumgartner's pressure suit and space capsule keep him alive?

Narrator:Felix Baumgartner is making a journey to the edge of space. His survival will rely on two crucial pieces of equipment, his pressure suit, and space capsule. Each poses significant technical challenges.

Narrator:The pressure suit is Felix's life-support system as he ventures to the very edge of the atmosphere. To do its job, the suit needs to be rigid and strong. Unfortunately, that makes it very difficult to skydive in. So Felix has to undergo special training.

Dr Jonathan Clarke:There're very few people that have jumped in pressure suits. Of those four people who did that, two died. And two lived.

Narrator:Retired Colonel Joe Kittinger was the first man to ever jump in a pressure suit. And Felix's suit is being made in the same factory where Joe's was, over 50 years ago.

Felix Baumgartner:You appreciate the suit a lot more if you see how it has been built. Next time when I step into my suit I gotta take my time, you know?

Narrator:Felix's pressure suit has been specially designed to give more flexibility whilst still giving as much protection as a full spacesuit. It will keep him warm, safely pressurised, and supplied with oxygen.

Mike Todd:There's actually four layers to this suit. The outer coverall that you see here is made out of Nomex, which is a fire-retardant material. The inner portion of the suit… One of the things that we have is something we call link-netting, and what link-netting does is it retains the torso shape of the body.

Mike Todd:Inside the link-netting we actually have the bladder material, which is made out of Gore-Tex, which actually vents the moisture out of the inside of the suit to the atmosphere, but it maintains pressure.

Narrator:The clever design and materials make Felix's suit a little easier to skydive in than a traditional pressure suit, but it's still highly restrictive.

Narrator:Felix is used to skydiving in clothes that offer virtually no restrictions on his movement, so he needs to get used to freefalling in the pressure suit. He begins training by jumping from 15,000ft.

Narrator:On one jump, things go terribly wrong. Felix has accidentally pulled the wrong cord, cutting away his main parachute.

Joe Kittinger:That's his parachute.

Narrator:And now he can't find his reserve. Just moments before it's too late, he finds it.

Art Thompson:We gotta go get him, we gotta go get him.

The restrictions of the suit caused him to confuse his parachute handles. The team are forced to redesign Felix's parachute rig to make it easier for him to use with the suit.

Felix Baumgartner:I'm still alive.

Narrator:Because the spacesuit is so restrictive, the team don't want to inflate it until they have to. So Felix will travel to his jump height in a pressurised capsule, only inflating the suit when he's about to jump. 'Because the capsule will be traveling to the edge of space, 'it has to be built to withstand low pressure and extreme cold.'

Art Thompson:The pressure capsule, the space capsule, what it does is the atmosphere is held at 16,000ft. So now his entire flight, throughout the three hour process, is just as if he's flying at 16,000ft. It's very low exposure, and his suit now is not inflated, so he has high mobility.

Narrator:The team have chosen materials that expand and contract at similar rates, so that the capsule remains pressure-tight all the way up.

Art Thompson:The pressure sphere itself is a composite epoxy-fibreglass. The acrylic door, it's a four foot diameter acrylic door, it's a half an inch thick. Most materials will reduce in size because of cold temperatures. The fibreglass contracts at about the same rate as the acrylic, so it's important to use fibreglass and epoxy on the pressure sphere.

Narrator:Thanks to his pressurised capsule, Felix only had to rely on his suit from the moment when the acrylic door swung open and his body was exposed to the near-vacuum of space.