The utility of using liquid metals or ionic salts to automate casting of a telescope mirror could offer a cheap way to build a massive telescope on the moon or in space.

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The image above, along with details of the idea are from http://science1.nasa.gov/science-news/science-at-nasa/2008/09oct_liquidmirror/. There is also information on the International Liquid Mirror Telescope Project currently building one India ( http://www.aeos.ulg.ac.be/LMT/), but there is no mention of proposals or plans to build one in space or on the moon.

Are there plans or detailed conceptual studies to build and deploy a liquid space telescope in space or on the moon by NASA or any other organization?

  • $\begingroup$ No. NASA floats ideas. Sometimes they sink. This one might float when NASA once again regains the ability to send humans to the Moon. Then again, it might not. $\endgroup$ Commented May 21, 2014 at 12:52
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    $\begingroup$ The major selling point for such assemblies is their reduced costs, but do we even have any good quotes on their mass? If the required materials (liquid salts, the silver coating,...) can't be produced on the Moon and need to be delivered, and all the equipment needed to erect it also has to come from the Earth, then I doubt that there would still be any cost benefits. And, of course, we currently don't have any ISRU facilities on the Moon, even if required raw materials are available there. With all other drawbacks, I think it's for the time being more of a daydream than serious proposal. $\endgroup$
    – TildalWave
    Commented May 21, 2014 at 13:44
  • $\begingroup$ This Nature article pubmed.ncbi.nlm.nih.gov/17581579 deals with metallic film deposition on ionic fluid as a construction method for a Lunar large aperture liquid telescope. This is an operational mercury liquid telescope operated by UBC near Vancouver. astro.ubc.ca/lmt/home.html Scientific American Feb 1994 had an Amateur Scientist article on casting a DIY resin mirror using a 33 1/3 RPM turntable. $\endgroup$
    – Woody
    Commented Dec 29, 2021 at 18:52

1 Answer 1


There are no serious plans at this time to build a liquid space telescope. All references I can find involve construction, as the planned size is ~100m. The plan was to use Ares 5 to help build a telescope on the moon, or similar. I'm sure this idea will come when we can get to the Moon again, and form a base, but I don't think any serious studies can be done that don't involve a human base on the Moon.


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