Thomas Moore, Science correspondentAs detailed previously, commander of the Polaris Dawn expedition, Jared Isaacman -and one of his crewmates - will leave the relative safety of the SpaceX Dragon capsule more than 400 miles above the Earth and spend several minutes in the vacuum of space.A spacewalk is considered one of the most dangerous activities an astronaut can do in orbit.
The double-doored chamber - used on the International Space Station and the US Space Shuttle - allows crew to exit to space while still sealing the rest of the spacecraft from the vacuum.But Dragon is too small and not designed to host spacewalks.So the entire capsule has been modified - from fittings to computers - to allow it to be depressurised for the two-hour event. Even the two crew members staying on board will have to wear full spacesuits to survive.