Sounds interesting, one clarification question I have is:During your hypothetical de-spin of the Zenit 2 stage, are you suggesting to keep the StarLink bus flying in formation with the Zenit 2, and using the exhaust of the ion drive to perform the de-spin maneuver without physically contacting the spinning Zenit 2 stage? Then once the Zenit 2 is despun, moving in for the attach and de-orbit?I think that's what you mean and it sounds like a very cool approach!
Might it not be easier to harpoon it near the center of rotation and put a slip bearing on the harpoon line so the rotation isn't transmitted to the tug?
But wouldn't the Starlink move away from the spinning piece of debris? Even worse, the debris would take up the momentum and move away from the Starlink as well. The lower the distance between Starlink and the debris, the lower the momentum that can be transferred. This seems like a very self-limitinig process.
This is approximately 200mN, or 100mN if it has to stationkeep on the debris.
Quote from: Bynaus on 06/06/2019 12:37 pmBut wouldn't the Starlink move away from the spinning piece of debris? Even worse, the debris would take up the momentum and move away from the Starlink as well. The lower the distance between Starlink and the debris, the lower the momentum that can be transferred. This seems like a very self-limitinig process.Mostly accounted for above:Quote from: SpeedEvilThis is approximately 200mN, or 100mN if it has to stationkeep on the debris.I am implicitly assuming that the Starlink derived tug is a small fraction of the mass of the thing to be moved, so there is not an additional correction needed for the target moving away.Yes, you probably want to connect in some manner once the target is safely despun, but the amount of thrust needed to despin even a very large fast rotating satellite is not significant, and it would significantly simplify things if instead of having to harpoon a fast rotating craft precisely on the axis, it is basically stationary.For debris much lighter than the starlink craft, there is little reason to tether, as the majority of the thrust goes into keeping up with the target as you push it away.
Why waste time and propellant despinning it if you could simply slow it down and deorbit it directly with the ion exhaust while it spins? And how coherent is the ion exhaust? Is most of the stream going to hit the target from, say, 50 m away? 10 m?
Is there a Starlink bus derived approach for small debris too?
Quote from: Ludus on 06/06/2019 08:07 pmIs there a Starlink bus derived approach for small debris too? Sounds like stationkeep with them, just ahead in their orbit, and bathe the debris in thruster exhaust while also firing in the opposite direction to stay put. The debris gradually decelerates, so you fire slightly more than exactly equal, or something like that. As it decelerates it is also going to change altitude so it's probably more complex than I make it. But the basic idea is bathe it in exhaust, which will have an effect due to impingement. That's my guessThis actually has a lot of legs, I think. you just have to know where it is.
On the subject of knowing where it is ... Could be as simple as a camera and a LED strobe so you can image the target somewhat independent of lighting conditions. If you know the divergence angle of the ion exhaust, simply position the debris tug so that the target mostly covers that solid angle. You don't actually need to know the size of the target nor the absolute distance, just that you are close enough to push it, and that it is in the right position relative to the tug (based on orbital velocity vector).
Sounds like stationkeep with them, just ahead in their orbit, and bathe the debris in thruster exhaust while also firing in the opposite direction to stay put. The debris gradually decelerates, so you fire slightly more than exactly equal, or something like that. As it decelerates it is also going to change altitude so it's probably more complex than I make it. But the basic idea is bathe it in exhaust, which will have an effect due to impingement. That's my guessThis actually has a lot of legs, I think. you just have to know where it is.
Completely honest question here and trying not to be hyperbolic, but what would the world/headlines have to say about "Elon Musk intends to operate a fleet of hundreds-thousands of space lasers". Regulatorilly speaking, is there anything to prevent them from adding such a feature to their Starlink units already planned? It seems like the FCC would have quite a lot to say about additional emissions, but is that just a paperwork hurdle, or would they have some legitimate ground to prevent the lasers?
Agreed. But I think this was for after.
The big stuff is easy, unless it's spinning a lot, then it's medium difficulty. Just nudge it by pressing up against it.