Astronomers are not just freely given nights at a telescope or time on orbiting satellites. There is a well-defined process to getting this time. It starts by the astronomer developing a project to do on the telescope. Then she/he writes the project down in a few-page summary we call a proposal.
The proposals from all astronomers interested in using a telescope in a given time period (usually 6 months or a year are dealt with at a time) are collected and given to a committee, the Time Allocation Committee, or TAC. This committee is made of astronomers who are familiar with either the science and/or the telescope in the proposal. The committee reads all of the proposals, talks about how important the science is, whether the science can be done on a given telescope, and whether a project represents the best use of a given telescope.
For example, one proposal may have the best science, but is not technologically feasible. Another proposal may be good science but requires 95% of the telescope for the next year. Another proposal may be okay science but could be done with a smaller telescope. And another proposal may be poorly written. So time goes to the remaining dozen proposals that do reasonable science in a reasonable amount of time.
I've been asked to be a member on a TAC that meets later this month. I have a few dozen proposals I need to read through, and a handful that I need to read in detail so I can lead the discussion about those particular proposals. The assignments (which proposals I have to read and which ones I have to lead discussion on) were made by other people, so I have a wide mix of things to read, some of which I know a lot about, some of which I don't know much about. And I will get to spend two full days talking about all of these proposals with the rest of the committee, which doesn't sound like a lot of fun. But it is an vital bit of community service, so I'm willing to do my share.
This is the first time I've been on a TAC, so it is a bit nerve-wracking. I want to make sure to do all the preparations I need to and make sure I give each proposal the consideration it deserves. At least it will keep me out of trouble for the next few weeks!