Spacewalking? Here’s spacefloating
Flipside 30 features an in-depth look at Columbus, Europe’s zero-g laboratory aboard the International Space Station, highlighting the spacewalks needed to bring it to life. But what would happen if a spacewalker cut their umbilical and drifted away?
  What would happen to an astronaut cast out into space? Hopefully we never find out for real, but an experiment called SuitSat provides a clue. In January 2006 a Russian Orlan spacesuit was loaded with sensors and a radio to transmit its condition to the ground, then cast adrift from the ISS. SuitSat was pushed off backwards to slow it relative to the station, so it sinks to a lower orbit. Visual contact was soon lost by its radio continued transmitting for two weeks, and SuitSat was sighted by a ground-based astronomer three months later. Radar shows a separate object has broken off from it, possibly a GloveSat. Tenuous air drag will eventually cause it to burn up in the atmosphere. Orlan spacesuits are designed to be disposed of rather than returned to Earth, so other Orlans have previously been dumped in a similar way.
Usually astronauts stay firmly attached to the International Space Station via a communications umbilical and a set of handholds. But that wasn’t always the case. Jetpacks – or Maneuvering Units as they are officially known –have a long spaceflight pedigree. Today they are not flown operationally, but are relied on as a safety aid of last resort. Here’s a timeline:
June 1965
Ed White steers himself using a nitrogen-propellant 'zip gun'.
June 1966
An Astronaut Maneuvering Unit (AMU) is ready for flight, but problems with Eugene Cernan's spacewalk mean it is never tested.
July 1973
The second mission to Skylab: activities include flying an AMU inside, not outside their station – the fear is that gas fumes might affect an exterior telescope.
February 1984
The Manned Maneuvering Unit (MMU) is tested by Shuttle astronaut Bruce Candless, first person to fly untethered in space.
April 1984
Two astronauts fly MMUs to capture the Solar Max satellite; that November the MMU is used again to intercept the Palapa and Westar VI satellites.
January 1986
The Challenger disaster: new safety regulations introduced in its wake mean the MMU never flies again.
February 1990
Cosmonauts first test their own SPK Maneuvering Units off Mir. They prefer to move about on the end of the station's crane.
September 1994
The Simplified Aid for EVA Rescue (SAFER) jetpack is first tested. All current US ISS spacewalkers are fitted wear a SAFER pack as a 'lifebelt'.
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