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Comment by yasp | Hacker News Reader

What kinds of places were you told not to look? (I'm guessing you couldn't physically point it at targets on the ground, so I assume certain sections of the sky.) Who was it that was commanding you not to look?

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I work adjacent to some satellites that do visual-spectrum imaging of the earth, and even we fall under these regulations.

In addition to all the NOAA licensing for imaging the ground, you need extra licenses for taking pictures of space. (it's useful, for example, to image the moon as a way of calibrating cameras & telescopes without atmospheric interference, and tracking stars is one of the most reliable ways to determine spacecraft attitude)

One of the requirements is that if we take a picture of space and there's anything moving in the picture (presumably a near-earth satellite), we delete all copies of the picture and forget we ever took it, but only after offering it for sale to the Air Force at a commercially reasonable price.

I'm sure there are additional layers on top of it, that's just the facets of it that I've been exposed to in the mandatory company-wide regulatory training.

> but only after offering it for sale to the Air Force at a commercially reasonable price.

That sounds like a business model - what is a commercially reasonable price, and where do I sign up?

> That sounds like a business model

Does it? You have one potential customer, and you have to create product on spec, offer it to them at a price you don't control, and destroy the unsold material whether or not the one customer pays for a copy.

Building a viable business model around that without corrupt influence over the single buyer seems impractical.

Sure, the US has considerable leverage over the sorts of things people are allowed to launch into space, but I have a hard time believing it could maintain a similar degree of control over ground-based telescopes.

I won't elaborate. A neat book just came out though : Accessory to War: The Unspoken Alliance Between Astrophysics and the Military https://g.co/kgs/XdRZFu

Thanks for the link. I haven't seen the book, but I know when I took a computational physics class as an undergrad (~25 years ago), there was a definite overlap between the modeling necessary to understand stellar collapse, and the modeling necessary to build better nuclear weapons.

A late friend who worked on type II supernova simulations was once invited to talk about his team's software with some gentlemen at an NNSA lab, Los Alamos or Livermore or Sandia (I forget which one.)

At the conclusion of the talk, the DOE guys said appreciative things about the current work, but also pointed out that certain avenues of investigation into certain characteristics might lead to the gov't declaring this software classified, and restricting who might have access to it. My friend was at the time not a US citizen, so he would have been locked out of contributing to his own work.

"Nice piece of software you have there, would be a shame if something...happened to it..."

There's a story about a US astrophysicist grad student working on stellar evolution. A visiting Soviet scientist came to give a talk. At the end the student asked a question about one aspect of the talk, something like, how do you know the plasma is transparent to photons at that temperature? The visiting Russian just said "it is." Later, the grad student mentioned it, quizzically, to his advisor. His advisor pointed out that it was something that came out of nuclear bomb research.

I looked, but could not find that anecdote.

Did they attempt to open source the software?

IIRC, the code in question was written under an NSF grant, and probably not that hard to obtain.

Hopefully not

Since subcosmos won't answer, I'll take a guess: Spy satellites.

Anyone can look at those though, they can't really hide them

I worked on a project that happened to have some spy satellite data as noise...

You can hide them. A common practice is to do an orbital maneuver when the satellite is directly between the Sun-Earth line-of-sight, where attempts to use instruments are pretty well saturated/destroyed.

With that said, it is still possible to see where the satellites go after such a boost if you are able to look really close to the limb of the sun with the right kind of equipment :)

Not every hobbyist had access to 1m+ mirrors, though. I imagine you could take a reasonably revealing picture of eg an Orion: https://en.m.wikipedia.org/wiki/Orion_(satellite)

I don't understand this thread. Sure with enough effort and manpower you can prevennt your own civilians from discovering these. How would the US government stop civilian entities in say Russia or China from discovering these? I still see a marginal potential utility though: not showing adversaries that you have noticed their satellites (in order to prevent them from improving their stealth).

People have done a lot with less than 1m.

http://www.satobs.org/telescope.html

https://satelliteobservation.net/2017/04/20/observing-satell...

I gasped when I read their main antenna is 330’ wide.

Not as easily if they're equipped with this: http://www.bisbos.com/space_misty.html

Wouldn't that also obscure the camera? I don't actually know what spy sattelites would be used for besides visual imaging aimed at Earth.

Could easily be intended not for visual surveillance but for gathering electromagnetic signals, where an inflatable dome would not be a problem.

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