Continuing on from Where-to-put-your-giant-telescope: now that you have found a place to put it, how do you pay for a giant telescope? Do astronomers buy telescope time, and who would be selling it? The short answers: governments and private donations, not directly, and observatories that need the money. This issue has come up in the debate over TMT in that the University of Hawai’i leases the observatories’ land on Maunakea for a dollar a year; people figure that someone must be getting rich.
Building telescopes is expensive. They are usually paid for by some combinations of governments, private donors, or universities (for which the money ultimately comes from, you guessed it, governments or private donors). In Canada, the relevant government agency is the National Research Council, in the US it’s the National Science Foundation, in the UK it’s the Science and Technology Facilities Council, and that is about where my knowledge stops. The European Southern Observatory is a somewhat different sort of animal; it’s a treaty organization (like CERN) that countries pay into.
Once you have your telescope built, you need to operate it: keep the electricity and the Internet connection on, pay for water and other utilities, and maintain the road. And of course pay the staff who maintain the facility and build new instruments and feed the astronomers and process the data and manage the proposals and all kinds of other things. So the logical way to get those operating funds would be to charge the astronomers who use the observatory, right? That is certainly how things work in some fields of science. However, astronomers who travel to an observatory usually pay for room and board while they are there, but not for use of the telescope itself.
With a few exceptions, the participating members (countries, universities, etc) in an observatory all get observing time in proportion to the share of the funds they commit, and they allocate it with a competitive proposal system. Selling observing time to the highest bidder might make sense if astronomers were rich, but usually we’re not. The money to pay for it would probably be coming out of the same governments that funded the telescope in the first place, so it’s been considered more reasonable to just run them as national facilities. With a number of US space telescopes, you even get funding if you have a successful proposal, the idea being that this supports the people who will analyze the resulting data. We don’t have this system in Canada. This has some people worried about Canadian astronomers being able to effectively use the upcoming James Webb Space Telescope towards which Canada has made a large contribution.
OK, but I said above that some observatories do sell time. This can happen because they don’t have enough money to run their operations: budgets get cut, or utility prices go up, or something else. In that case it’s not uncommon for observatories to seek additional partners for their operation, which can effectively mean that blocks of time are sold off: both Gemini and CFHT have done this in recent years. As far as I know, those blocks of time are still awarded by their new owners in a competitive procedure. Telescope time isn’t cheap: it is hard to get exact numbers, but we’re talking multiple thousands of dollars per night. (Don’t be late coming back from your midnight lunch!)
So we don’t pay for our telescope time (and we do pay to publish our results). This makes people who work in the real world think that astronomy is a funny kind of business. And it is: but I would argue that the rules under which much of the business world operates are just as arbitrary and human-generated. Maybe it’s good to have an area of human endeavour that runs under a different system, just for comparison.