Hacker News Reader

Comment by parvenu74 | Hacker News Reader

Lots of theories about what that vehicle does... the one I like the best is that it intercepts "enemy" satellites and reprograms them. Of course, what comes around goes around and it would only be a matter of time before the Chinese do that to us if that's actually one of this vehicle's missions. A more likely scenario is that it is doing maintenance on and/or bringing home some of our own stuff -- as well as being an observation platform in its own right.

View on HN

I don't know about reprogramming satellites but its possible it just grabs them and forces them to fall out of orbit. That's easier and quite effective.

Or it's just a moveable spy satellite that can hover over whatever it needs to.

Funny you mention the Chinese doing that to us. I just finished Snowden's book and he mentioned how he only learned what the NSA was doing after having to research what the Chinese were doing. Turns out, same thing!

The only place a satellite can 'hover' is directly above the equator in a geostationary orbit. Anywhere else and the best you can do is a highly eccentric orbit with a high inclination so you get lots of "hang time" over the target area, but that also means being very high up. From what I understand the X-37b was tracked by amateur astronomers to have a reasonably high inclination this time around, but an almost circular orbit.

Traditional spy satellites have very high inclinations because this lets gives them coverage of more of the planet (as the planet rotates beneath them.) The X-37 has thusfar to my knowledge not flown at a severely high inclination, from what I understand the most recent launch was somewhere around 54 degrees, and previous flights were lower. For reference the ISS is around 52 degrees.

The figures are all imprecise and the X-37b supposedly has the delta-v budget for relatively dramatic inclination changes, but even so 54 degrees is very far away from where earth-observing spy satellites traditionally are.

> its possible it just grabs them and forces them to fall out of orbit. That's easier and quite effective.

Honestly that seems neither easy, effective, nor subtle. To grab and deorbit something like that you'd need to grab it in such a way that let you thrust through it's center of mass which doesn't seem easy to do for a few reasons (not least because the distribution of mass inside the target satellite may not be known.) And since spy satellites can be massive, you'd need to burn a lot of fuel to do it. It's conceivable they're doing something a bit trickier, like slapping a time delayed ion thruster onto the side of victim satellites which would then slowly deorbit the target after the X-37 is long gone, but I'd still wager on the victim figuring out what was going on. Such anomalous thrust is something that would be noticed.

De-orbiting satellites I could see, but hijacking them seems more unlikely. Either they’re doing something physical to the satellite to hijack it (keep in mind every satellite is different, and this is an unmanned vehicle) or its over radio waves so why not do it from the ground?

Installing a modchip on a foreign satellite via robotic manipulation seems near impossible on the surface. Watching the Hubble service missions for example gives you an idea of just how much of a pain in the butt it is to service something in orbit, even when you have fully capable human beings doing the work. Building a robot to handle all of the unexpected hurdles of attempting such a task seems outside of our current capabilities. Even a waldo unit is a big ask.

>Even a waldo unit is a big ask.

why? the x37b has a shuttle bay at-least big enough for a solar array, i've seen pretty small waldos before.

Mostly because they aren't good enough yet. The manipulators struggle to balance small size, light weight, good grip, adequate cooling, and high strength. Getting the force feedback on the control solution correct is also difficult. And then you have to deal with communication delay as your bird is whipping around the world in LEO, constantly handing off between different ground stations, or worse, jumping through a sequence of Geo birds.

On the other hand, sometimes the government is willing to go to extreme lengths for intel purposes. The Glomar Explorer was outrageously ambitious, although ultimately only partially successful.

Even then you'd need intricate knowledge of the target satellite to hijack it - somehow opening and making electrical connections to a satellite you've never seen before seems rather infeasible - not even getting to the software side.

Nah I think it's far more likely it really was just a research vessel for more classified experiments they didn't want on the ISS.

Even just getting up close to another country's spy satellites would have value. The US keeps even the look of their current series of spy satellites classified; they're believed to be a lot like Hubble.

Apparently there was a quantity discount if nasa ordered one like Hubble.

> "Working with the LST science groups and contractors, the team reduced the telescope’s primary mirror from a 3-meter aperture to 2.4 meters. This major change mainly resulted from new NASA estimates of the Space Shuttle’s payload delivery capability; the Shuttle could not lift a 3-meter telescope to the required orbit. In addition, changing to a 2.4-meter mirror would lessen fabrication costs by using manufacturing tech- nologies developed for military spy satellites."

https://web.archive.org/web/20161130130303/http://history.ms...

Hubble's mirror is probably the same [size] as a KH-11: https://en.wikipedia.org/wiki/KH-11_Kennen#Size_and_mass

Myself, I think it shot down the Cara Delevigne selfie satellite

Reply on news.ycombinator.com