[throw20102010]

What I find most amazing about this isn't the image (although it's pretty cool), it's the fact that a bunch of amateur astronomers[1] can locate a satellite in space with no help- even after the satellite makes an unannounced move. The US government literally spends billions of dollars to track things in outer space, and a bunch of amateurs can do basically the same thing. Granted, Space Fence tracks more and smaller objects, but the amateurs are winning on the price/performance ratio.

To clear things up- ephemeris (orbit parameters) are published for many satellites, but not for the X-37B. It had to be found by some educated guesses and a lot of staring at the sky.

[1] To be fair, some "amateur" astronomers use very high end equipment.

[jhayward]

> The US government literally spends billions of dollars to track things in outer space, and a bunch of amateurs can do basically the same thing

There is a whole lot of difference between an amateur being able, once in a blue moon, to track something and a military duty desk being able to track everything, all the time, and get it imaged/located/whatever in seconds to minutes, every time.

[dsl]

The X-37B also favors mobility over stealth.

Many US spy satellites are virtually untrackable because of the Vantablack S-VIS paint they use, which reflects only .2% of the light that hits it. You have to literally look for the missing stars that should be behind it.

Other sats make this even harder by hiding behind giant mirrors that reflect empty space from a 45 degree angle down to earth.

[adminu]

I'd be interested in a source. I wonder how a giant mirror could persist in space without being shattered by debris and other elements hitting it from time to time.

[daveslash]

This is a patent for stealth satellite technology. It's not a mirror, per-se, but it does demonstrate that there's interest in concealing satellites. Additionally, I'd expect that anything that could "shatter" a mirror would also be capable of shattering the entire satellite beyond operation; if we assume that statement is true, then the fact that so many satellites remain in service suggests that a mirror would also survive.

[daveslash]

I posted my above comment late last night after a long trip... I neglected to include the patent URL. My apologies.

https://patents.google.com/patent/US5345238A/en

[andbberger]

I think you have to leave your preconceptions about what a mirror is at the door when it comes to spaceflight. Much more likely to be something like aluminized mylar than a silvered glass mirror that could shatter.

[dsl]

I'll have to dig in to my bookshelf once I get home. I believe it was in The Wizards Of Langley, but Google book search is failing me at the moment.

[yencabulator]

How often have the ISS solar panels been shattered, so far?

[baybal2]

I doubt it will save them from detection in infrared

[Retric]

You are vastly underestimating how important size is. It’s a huge difference to track a pickup truck vs the nail that falls off of it. The military was tracking baseball sized objects in 1961, amateurs are over 50 years behind the curve on this stuff.

[greglindahl]

Wasn't the military using a huge radar to do that in 1961? Amateurs aren't even allowed to think about doing that, then or now.

[Semiapies]

That doesn't really counter what they said.

[sandworm101]

There are many techniques for finding and imaging secret stuff in orbit using 'amateur' equipment.

https://www.space.com/8458-wow-shuttle-space-station-photogr...

https://en.wikipedia.org/wiki/File:USA202_Mentor4.jpg

Hubble-class spy sat imaged, i think by same person: (2010)

https://www.universetoday.com/65458/spying-on-a-hubble-teles...

[throw20102010]

The way you say it kind of understates the difficulty. It is straightforward to image a large enough satellite if you know where it is going to be. I have even snapped a picture of the ISS with a hobby telescope and a cell phone mount. It's gigantic. Catching a shot of MENTOR 4 is cool, but it's up in GEO and doesn't move much, plus it's just a dot.

The picture of an old CRYSTAL bird is probably the closest thing to the OP in terms of difficulty. The satellite is big and in LEO. The difference between what Ralf did then is that CRYSTAL satellites move less often, so once someone finds them you have more time to wait on good weather. With the X-37, Ralf missed his first shot and by the time he was ready for another try it had already moved, and they had to find it again. That is super tough.

If you have no idea where something went, then the sky is very big and your telescope has a very small field of view, especially if you need to discriminate between different satellites that you see. The fact is, there aren't many techniques for finding secret stuff in orbit. You have two methods (but choose a wavelength)- passive and active- and maybe hacking into a space agency and just stealing the information from a computer. Passive means staring at a lattitude long enough until your satellite passes by and hope you spot it (if it doesn't you either missed it or it has a lower inclination than here you were looking). A smart person might get a computer to help them with the watching, but the task is the same. The problem is that the X-37 is real easy to miss. Even if you see something, it might not be the particular satellite you're hoping for, so you have to filter out all the unwanted things you don't want (usually you can match unwanted things up to known orbits). And even when you see the X-37, you've got to jump on it and track it so you can figure out the new orbit. Active methods are pretty much just radar, and that's out of reach for every amateur astronomer. They might be able to scrounge up some giant apertures but they'll never have the tx power. It's pretty incredible that people are able to do this.

[fit2rule]

Ralf might have missed it, but like it says in the article, there are volunteers around the world watching out for this thing, and they only needed to track it periodically - and communicate among themselves as a group about their findings - in order to keep tabs on it.

Things get exponentially easier when you've got more hands and eyes on the problem - not to say its not a difficult task, but lets remember - a group of people put it up there (that was pretty hard) - and now a group of people are tracking it.

[deepnotderp]

I agree it's amazing, but the main differences are reliability and size.

[Rebelgecko]

And also distance! It's a lot harder to see something that is 20,000 miles away than something that is only 200