2

I encountered this reddit post, which is a video of a test of some sort of device hovering precisely in place & maneuvering using some slightly underexpanded reaction control system. I'm also assuming there's some reaction wheels aboard, as it yaws without me seeing any corresponding plumes.

A commented added:

This is actually fairly old technology developed during the Cold War. It is designed to be used to intercept incoming ICBM’s in space.

I find this very unlikely for multiple reasons:

  • Why would such a system require such a precise maneuvering control system? To be able to hover like this is no small feat of control systems design.

  • Why would it have such limited reaction mass? In the video it burns out quite rapidly. To reposition to intercept an ICBM would not only require about a zillion of these things in orbit over the US at all times, but likely a massive amount of dV on each to be able to rapidly reposition to where a collision would occur.

  • The video quality seems too good to be from the 50s-80s.

  • It doesn't look like a vacuum optimized system. Sure, maybe it's just missing some nozzle inserts, but the thought was still in my mind.

  • I can't find anything on this through some cursory google searches. So I turn to you guys.

What the heck is this thing?

Anton Hengst
  • 10,687
  • 40
  • 78
  • 6
    Does this answer your question? Does this kill vehicle contains momentum wheels? Watch how it moves! – Russell Borogove May 19 '20 at 21:48
  • 1
    No reaction wheels; some of the thrusters are offset from the center of mass, so depending on which combination it fires it can either rotate or translate. In use it'll mostly be translating -- it'll be put on a near intercept course by something else and just divert a bit in the terminal phase. – Russell Borogove May 19 '20 at 21:50
  • That's helpful information! However, my question is what is this thing, not how does it work. – Anton Hengst May 19 '20 at 22:02
  • It has such a limited reaction mass because if it lives more than some minutes, it missed the ICBM it was supposed to intercept. One way or the other, its job is done shortly after it's launched. These would never get anywhere near orbit, they'd be launched on suborbital trajectories when an ICBM is to be intercepted. You don't need zillions of them because you launch them at the ICBMs with missiles...they're interceptors, not orbital mines. – Christopher James Huff May 19 '20 at 22:33
  • It seems to be armed with deadly thermos bottles. – Organic Marble May 20 '20 at 01:38
  • 1
    If it's just a suborbital guided missile, why test it hovering in earth gravity at all? – ikrase May 20 '20 at 02:31
  • @ikrase Iteration time. You can recover the vehicle, refuel it, update the software, and try again several times a day inside that cage. If you tested it in a suborbital trajectory outside of atmosphere, you wouldn't have cameras ten feet away and you wouldn't get the hardware back in minutes, if ever. I assume the hover thruster would not be present on final hardware; it's just there to facilitate the test. – Russell Borogove May 20 '20 at 05:24
  • 1
    Thermos bottles are pretty dangerous at a closing speed on the order of 10km/s. – Russell Borogove May 20 '20 at 05:25
  • It looks like it's not so much a hover thruster as that the translation thrusters have >1g of acceleration. – ikrase May 20 '20 at 10:26
  • @RussellBorogove especially if they are filled with my coffee. – Organic Marble May 20 '20 at 13:19
  • @ikrase: because it demonstrates the degree of control needed while allowing the test to be performed in a small room in a lab? – Christopher James Huff May 24 '20 at 22:21

1 Answers1

4

That's the Multiple Kill Vehicle.

The filmed test took place in December 2008.

enter image description here

The MKV mission was to destroy medium-range through intercontinental-range ballistic missiles equipped with multiple warheads or countermeasures by using a single interceptor missile. During an actual hostile ballistic missile attack, the carrier vehicle with its cargo of small kill vehicles would have maneuvered into the path of an enemy missile. Using tracking data from the Ballistic Missile Defense System and its own seeker, the carrier vehicle would have dispensed and guided the kill vehicles to destroy any warheads or countermeasures.

Source: Wikipedia

Organic Marble
  • 181,413
  • 9
  • 626
  • 815