[X] My Assistant

[Guest_Bobby_*]

Just read at MSNBC that a large U.S. spy satellite will hit Earth by the end of February or early March.
Better keep our hard hats ready???

Here is the article:

http://www.msnbc.msn.com/id/22857051/

[Tman]

http://spaceweather.com/ (19. Feb) reports that rumor has it that the US Navy may make its first attempt to hit USA 193 this Wednesday evening as the satellite passes over the Pacific Ocean. Because of Ted Molczan has drawn attention to a NOTAM issued by the US Government that might point to a possible ASAT attempt on USA 193 on Feb 21, between 2:30 and 5:00 UTC.

If they hit exactly the tank with the hydrazine, at that great combined speed, I would think the missile (without a warhead) penetrates the tank and maybe other parts entirely without larger impact on the orbit of the rest of the satellite.

[ElkGroveDan]

If they hit exactly the tank with the hydrazine, at that great combined speed, I would think the missile (without a warhead) penetrates the tank and maybe other parts entirely without larger impact on the orbit of the rest of the satellite.

As we all know it's all about mass and velocity. If that impactor arcs up and strikes the satellite at a high velocity opposite to the direction of travel then it will indeed impact the orbit of the doomed satellite. I suspect that this is part of the plan, or if not it has been calculated for. Not knowing the impactor mass and it's expected impact velocity it would be difficult for us to even pencil it out here, but the orbital effect will be significant (with a small number on the mass side of the equation, but a very large multiplier on the velocity side.)

[Jim from NSF.com]

As we all know it's all about mass and velocity. If that impactor arcs up and strikes the satellite at a high velocity opposite to the direction of travel then it will indeed impact the orbit of the doomed satellite. I suspect that this is part of the plan, or if not it has been calculated for. Not knowing the impactor mass and it's expected impact velocity it would be difficult for us to even pencil it out here, but the orbital effect will be significant (with a small number on the mass side of the equation, but a very large multiplier on the velocity side.)

The impactor's velocity is not really part of the "equation", it could be zero. The bulk of the energy is from the satellite. The velocity differences are on the order of several km/sec.
The impactor just has to get in the path of the satellite at the right time. Sort of like throwing up a baseball glove to knock down a fly ball.

[ElkGroveDan]

I get your point, but come on now there is no such thing as a zero velocity except with respect to another body. If the velocity is zero with respect to the satellite then there will be no damage (and no impact for that matter). Even if the impactor is moving in the same direction of travel, albeit slower, its momentum must be factored in to the final momentum of the system after the impact. And in every instance I can imagine, the result will be greater decay in the orbit of the satellite and it's fragments.

[Jim from NSF.com]

I get your point, but come on now there is no such thing as a zero velocity except with respect to another body. If the velocity is zero with respect to the satellite then there will be no damage (and no impact for that matter).

Didn't say with respect to the satellite , I was referring with respect to the earth (basically hovering)