Re: Why
Routine maintenance, mostly. Kinda hard to service a ship when it's out at sea, for example. Similarly, a spacecraft is difficult to maintain while it's out in space. A lot of the stuff you need to do a good job is stuck on Earth.
Routine maintenance, mostly. Kinda hard to service a ship when it's out at sea, for example. Similarly, a spacecraft is difficult to maintain while it's out in space. A lot of the stuff you need to do a good job is stuck on Earth.