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Finally an image of X-37B/OTV-5, US Air Force's secretive space plane, in orbit (spaceweathergallery.com)
225 points by green-eclipse 17 days ago | hide | past | web | favorite | 50 comments

Since their photo site doesn't seem to link back to the main site, let me put in a good word for SpaceWeather.com:


Yes, it looks old fashioned and it has a lot of ads. But it's full of interesting stuff, like the photo of last Tuesday's total solar eclipse taken from Moon orbit by Longjiang-2.

The site is run by Dr. Tony Phillips, a high school science teacher in Bishop, California, and occasional writer for NASA. His students launch balloons to the edge of space and run science experiments on them:


The balloon rises until it pops, the payload parachutes down and the students scramble across the desert to pick it up.

To finance the missions, they fly jewelry, golf balls, stuffed toys and trinkets on the balloons and sell them in their online shop. Or you can sponsor one of their research flights for $500, send up whatever you want and get a video of your item in flight.

Maybe I can get a few ham radio operators together to send up some kind of radio experiment. Sounds like great fun for us, as well as sponsoring the student research.

I think Dr. Tony's students will do some great things in their careers!

Could do a home built VHF repeater, kinda like a cubesat, and see what the furthest distance is between contacts. Would need to coordinate frequencies and you'd probably want to run it like a contesting thing with very short QSO to maximize the number of contacts. I'd donate a hundred bucks. It would be nice to have a telemetry radio onboard too.

73 WT1J

Very cool idea. I will also kick it around with my friends in Parachute Mobile, they may have some ideas:


Of course it would also depend on things like weight limits on the balloon and what won't interfere with the student research packages (or maybe even collaborate with them?), but let's keep in touch!

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.

> 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.

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.

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.

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.

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


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.

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.

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

I doubt it will save them from detection in infrared

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.

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.

That doesn't really counter what they said.

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



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


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.

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.

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

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

On the one hand it’s amazing what private companies, especially SpaceX have been doing in the vacuum created after the end of the Space Shuttle. On the other hand, it kinda bums me out that I grew up knowing we had this very public space minivan and now we don’t. Or at least what we now have is a secret military craft.

But yes, the ISS is awesome, there’s still great stuff happening in space exploration. But I do miss the space minivan.

I really don't feel sorry that the shuttle is gone, over the lifetime of the program including all costs, it cost $1 billion per launch. The 1970s dream of an affordable, reliable, speedily re-usable spacecraft was not achieved. It's good that it's gone.

Also it was the most deadly launch system ever created, killing on average one astronaut for every ten launches.

The combination of needing human crew for every single mission and not having an launch escape system (something basically every other rocket had) wasn't a great compromise.

Of course I knew about both Challenger and Columbia, but I wasn't sure on the total number of flights... Two quick google searches say 135 flights and 14 fatalities, which statistically is quite bad. All of the fatalities related to Soyuz flights were, if I recall correctly, with very early versions that were rushed to launch by arbitrary soviet political deadlines.

The shuttle was only "public" in the sense that the public was paying for it and got to watch the fun on TV - it was not, however, available to the public in any meaningful sense. The fact that NASA occasionally took a schoolteacher or scientist or Saudi prince along for the ride does not change the fact that space travel remained a fantasy for most of us throughout the entire lifetime of the shuttle program. I grew up in the 80s and 90s (in the US) and I was never under the illusion that the shuttle was open to me, personally.

The only way the "public" will ever get to visit space is if the cost of launches is reduced, which is something that governments have been almost universally terrible at.

I'm pretty sure it's oriented the other way around in the image (belly up).

Look at this image: https://proxy.duckduckgo.com/iu/?u=https%3A%2F%2Fwww.hjkc.de...

I think the black tiles are not visible on the photo, this makes the cargo bay "protrude". The stairs on the tail than also begin to make sense.

This is the perfect tool to physically temper with telecom satellites.

No it’s not. Most comm sats are in geosynchronous orbit. This thing is in low earth orbit. Only the Iridium constellation is within its range.

Most likely it is for messing with other countries’ spy satellites.

You are right, yet the `constellation` / `mesh` / `starlink` type telecom service could be the new norm if it works out. Amazon made an FCC request recently to launch its own thing.

Also, if sent to space with a more powerful launcher, technically it could probably reach a Lagrangian point, even (slowly but efficiently) leave it. It would then probably burn out on re-entry with to much velocity, that would be the issue I'd say.

The actual things people are already launching into GSO to potentially fuck with telecom satellites aren't "this".

"This", so far, has stuck to low earth orbit.

So previously I believe the space shuttle style vehicle was thought to be inefficient, this seems similar. Is the usage different here?

It's not really comparable to the space shuttle. It's about 30 feet long (compared to the shuttle's 180 feet) and launches as a payload of a regular rocket.

It has some similarities in its heat shield, the wings and the runway landing, but as a tiny robotic vehicle that doesn't need fast turnaround because it's in space for many months at a time many of the problems of the space shuttle don't apply.

Ah, longer term flights seems like a big change in the equation.

The space shuttle design is decently efficient if you actually use the huge payload bay to bring back something bulky or fragile. Nothing else even has that capability.

If you won't use that capability, then providing it is a huge waste.

My understanding of this vehicle is that it can physically navigate in space. With stop and go functionality.

Any satellite can physically navigate in space, the question is how much for how long. Everything is in orbit, navigation is a question of adjusting orbits, which is a question of fuel.

I don't know about 'stop and go' though, that's usually called 'takeoff and landing'.

>> Any satellite can physically navigate in space,

Not cubesats. You need some sort of an engine and an orientation mechanism. You can forgo the engine if you only want to play around with drag via orientation, but the average cube/nano sat moves, falls, along the same path as any other bit of metal up there.

So cubesats are designed to only be in orbit for a short time? Even at LEO, without correction burns, things eventually re-enter the atmosphere. I guess it’s a feature, not a bug?

Many cubesats have engines, and even those that don't can use their reaction wheels to do small maneuvers by changing their orientation which causes drag to change the orbit.

There are other methods to deorbit like tethers, but due to reliability they're not used often

It is a feature. It ensures they don't litter orbits forever.

any idea why it seems the thruster is offside? [0]

Doesn't that complicate mobility/control?


Probably to fit something else there.

The thruster can gimbal/pivot, and the software already has to measure the current center of mass of the vehicle because payloads etc affect it enough to make you go in circles. So accounting for an offset thruster might not even be a software change since it's a parameter the software already has to find automatically.

Also note how the main engines of the space shuttles are really far offset at launch and fire at a weird angle to compensate.

Don't know why it's offset (probably just "form over function", it doesn't need to look pretty), but it's likely no big deal. Those thrusters are gimbaled anyway, it can point wherever you want, and is typically adjusted in realtime.


I don’t think anyone here has the knowledge to say. You’d normally want the thrust vector to pass through the center of mass. Maybe on orbit it hangs stuff off the starboard side.

It means that its centre of mass is significantly shifted, and that is likely mandated that it was built specifically to carry that payload.

I think your understanding might be incomplete. To "stop" in space, relative to a viewer on the ground, means going into geostationary orbit. Or, I suppose, to a Lagrange point.

To borrow an XKCD-ism, space isn't high so much as it's fast. You have to go very very fast to stay in orbit, and if you were to attempt to slow down and stop whilst orbiting, you'd essentially be executing a de-orbit burn and would find yourself re-entering the atmosphere.

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