Unleash your inner nerd with the top-twelve most epic spacewalks of all time.
From the moment Japanese astronaut Soichi Noglichi bid a cheery wave wave to his US colleague Steve Robinson as they floated outside the International Space Station (ISS) 230-miles above the Earth, to Mike Massimino cheekily peeking through the flight deck window of his space shuttle, these pictures from orbit truly are out-of-this-world.
Called Extra-vehicular activity (EVA), spacewalks are performed by astronauts who face temperatures as cold as minus 150 degrees-Celsius and well over the boiling point of water, 120 degrees-Celsius.
Costing US$150-billion (£93-billion) the ISS has been flying around the Earth at 4.9 miles-per-second since it was constructed in 1998.
Other pictures show Nasa astronaut Steven L Smith standing on the end of the remote manipulator system of the space shuttle during a Hubble Space Telescope servicing mission in 1999, astronaut Joseph R Tanner on shuttle mission STS-82 (11-21 February 1997), when astronauts from the shuttle Discovery performed five EVAs to service the Hubble.
The daring feat of leaving the safety of a spacecraft to float in the airless void of space is performed only by elite astronauts with incredible coordination and nerves of steel. They perform external repairs or modifications to space shuttles or the ISS.
The first EVA was on March 18, 1965 when cosmonaut Alexei Leonov first departed the spacecraft in Earth orbit to test the concept, during the Soviet Union's Voskhod 2 orbital mission.
The longest EVA by Susan J Helms and James S Voss was eight hours and 56 minutes, during STS-102 on March 11, 2001.
Russian, Anatoly Solovyev currently holds the record for the most spacewalks, 16 in total and has clocked up an incredible 82-hours 22minutes in space.
A spacesuit weighs about 280 pounds on Earth but weighs nothing in the microgravity environment of space. Just as well really.