Question: do satellites need to be maintained in space? if so how do you do it?

Alexander Finch answered on 17 Dec 2015:

In general – no, because they can’t be. Getting them up there into orbit is hard enough; getting a repair crew up is basically impossible, especially wit the Shuttle no longer flying.

So, when we build satellites, we make sure they work perfectly! And they have to keep working for years without big problems. We design them so that if something breaks (because something will always break eventually), there’s a spare thing we can swap to. Almost all the components in a satellite are duplicated like this.

There was a couple of maintenance and repair missions though – the most famous being the three Shuttle missions to repair and update the Hubble Telescope. It was thought to be so valuable that it was worth visiting and working on!

In the near future, we may see some possibility of basic maintenance on satellites done by robotic spacecraft. One of the most useful things that could be done is to refuel old satellites – the fuel they use to keep themselves in the right orbit gets gradually used up over the years, and eventually runs out! This is often the reason that old satellites are shut down, so being able to refuel would be very useful!