Is TMT a military installation?

This lie is the favorite of the conspiracy theory crowd. It plays upon the fundamental distrust and enmity towards the US military that many segments of our island community hold. How can you have a giant structure on the mountain without the military being in charge? With lasers!

The Thirty Meter Telescope
An artist concept of TMT at night, with the laser guide star system illuminated.

Why does TMT think #MaunaKea is worth all this trouble vs. the Canary Islands?

Is it the subtle cloud cover difference, or the FACT that Hawaii is heavily militarized with all 4 branches nearby?

Spoiler: major weapon contractors reside in current telescopes.

Kaniela Ing‏ @KanielaIng on Twitter, 16July2019

There is even a military base positioned to protect it! Never mind that base is a training base that has no troops more than half the time.

As someone on the inside I know this to be false. How to prove that? A bit more difficult as none of my answers are going to be heard by the true believers.

There are some practical considerations that should make this clear. The largest telescopes are not capable of tracking something as fast as a low earth orbit satellite, where the spy satellites operate. These big telescopes simply can not move fast enough to follow these objects across the sky. I work on the drive systems, I know.

Aside from military satellites there is simply nothing else in the sky of any interest to the military. Why should they be interested in a large telescope? Answer… They are not.

The instruments and cameras on the telescope are designed for very specific purposes, and those designs are quite public. If there were nefarious military purposes behind the observatory the design specifications would not be quite so open.

There is a seed of truth here… The observatories do occasionally buy military technology from the usual defense contractors. Things like infrared detectors can be used for both tracking enemy vehicles or observing distant galaxies, what is called dual use technology. Such tech is not classified, but still is monitored by the US government to insure that it is not misused. This is really a case of turning military tech to peaceful purposes, swords into plowshares if you will.

There are several telescopes in the islands with military involvement. US Air Force Space command runs several small telescopes on Haleakala and a defense contractor has a part share in UKIRT on Mauna Kea. telescopes that are much smaller and more nimble, with drive systems purpose built to track satellites. These telescopes are used for a fairly mundane purpose, to track satellites and space debris, and to establish accurate orbits for all the stuff up there.

Aside from the expected military functions, like keeping track of the other side’s spy satellites, this has very practical civilian benefits. Knowing the orbits of everything in orbit, and there is a surprising amount, is necessary when launching the satellites we all depend on for weather, communications, and satellite television. Who does this? The US Air Force Space Command. They even publish this data for everyone to use.

The lasers? At one point we heard them described as “laser cannon” during the contested case hearing. Yes, they look impressive, but are really not that dangerous. The maximum power from the AO lasers is about 20-30 watts. To be a weapon you really need to be talking about kilowatts or more, several orders of magnitude more. I have stood in the full power beam from one of our lasers, with appropriate eye protection, it barely felt warm, sunlight is more powerful.

Another version of this claim that pops up on occasion is that the telescope could be used to spy on folks? Yes, that bad. The telescopes cannot aim below the horizontal and performance would be truly terrible if they could due to atmospheric distortion. If you suspect someone is spying on you I would suggest you look for a nondescript van at the end of your street rather than a telescope on top of the mountain.

Of course you really do not need to trust me on this one. The major telescopes atop Mauna Kea are pretty open about who is using them. You can go to the websites and see the telescope schedules yourself, or even wander through all of the data taken with the telescopes, the archives are public.

Result: Mostly False

Author: Andrew

An electrical engineer, amateur astronomer, and diver, living and working on Mauna Kea, Hawai'i.

5 thoughts on “Is TMT a military installation?”

  1. Andrew – just a point of clarification regarding UKIRT. Although a smaller and more nimble telescope than the larger telescopes on Maunakea and yes, it was used to track orbital debris but the telescope wasn’t used to observe anything in LEO – even UKIRT wasn’t designed to track that fast. The telescope was used to track and attempt to identify and understand the composition of debris threatening satellites in geosynchronous orbit, e.g., communication satellites. This was part of the Planetary Defense contract we had with NASA and included determining the structure, density and composition of potential Earth-threatening asteroids.

    Thank you for allowing me to make this clarification.


      1. No problem! We did actually try to track something at around 800 miles altitude if I remember correctly, but it was an utter failure. In theory we can slew that quickly but certainly can’t track at that rate!


  2. For TMT, I also like to point out that it is a collaboration of US universities, China, India, Japan, and Canada. These countries and entities usually work *against each other* on military issues. The TMT is really a place where countries that often have conflicts are coming together in peace.

Leave a Reply