Question: How long does it take to build a satellite?

Alexander Finch answered on 6 Dec 2015:

It varies! Some satellites can be built pretty “quickly” – in like two or three years. But most take more – four to seven years from first proposal to it actually working in space is more normal. Some particularly large or unusual satellites, like the Hubble Space Telescope, would take more than ten years to make.

Only a bit of that – maybe a year or two – is actually spent physically making the thing. Most of the time is designing, planning and testing before the launch.