spacecraft damage and loss

Skylab

As the atmosphere heats up and expands, it reaches higher altitudes. When this happens, satellites can be slowed down by the extra air resistance. That’s bad news because a slower-moving satellite can't stay in the same orbit and drops to a lower altitude. Lower down the atmosphere is thicker still, which slows the satellite even further... without help, the satellite could be in real trouble.

Aurorae are the warning lights that the Earth’s atmosphere is being disturbed and that satellite orbits might be affected. More than 1500 satellites slowed down in their orbits and lost several kilometres of altitude as a result of the great solar storms of March 1989.

Flipping the switch

Particles from solar storms can damage sensitive electronic components of a satellite by causing so-called 'phantom switches'. Data bits on board are switched from '1' to '0' or vice versa because of an electrical pulse caused by a particle strike. The most severe damage of this kind is caused by particles from solar flares.

Skylab was the first American manned space station and it flew during 1973-1977.

It ended up falling out of the sky and nobody was exactly sure where it would land.

It weighed 75 tonnes and could have caused a lot of damage, perhaps even killed people if it had landed in the wrong place. In the end, though, nobody was hurt, but there were a few large holes in Australia.

Sometimes satellites are deliberately destroyed.

This is done by making them fall out of orbit to be burnt up in the atmosphere. The most famous example of this in recent times is the Mir space station.

Killing satellites

On 11th January 1997, an American satellite, Telstar 401, died suddenly just hours after a CME struck the Earth's magnetosphere. It is rumoured to have been showing StarTrek at the time! This doesn't happen often, but when it does it is a very expensive and inconvenient loss.

These three images show the aurora that was created by the storm that killed the Telstar 401 satellite, an artist’s impression of the satellite and a YOHKOH image showing the start of the solar CME which was believed to have caused the solar storm.