Even as close as 15 meters the odds of them actually colliding are astronomically against. 15 meters is bigger than either satellite and we are talking about 3 dimensions rather than 2.
Even as close as 15 meters the odds of them actually colliding are astronomically against. 15 meters is bigger than either satellite and we are talking about 3 dimensions rather than 2.
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That was my first thought.
I definitely wouldn’t put good money on a bet for a collision, although if you gave me good enough odds (30:1 or better) I might drop a few bucks on it.
It’s a two-dimensional problem. The collision cross section is determined by the projection of the respective satellites silhouettes onto the plane perpendicular to direction of their relative velocity at the moment of closest approach.
The third dimension, the dimension in the direction of the velocity doesn’t count because at some point the separation in that dimension *will* go to zero by definition, at exactly the moment of nearest approach. It does not influence whether or not there is a collision, only when. (You can assume that the satellites are not rotating during the duration of the collision event. If the velocity of rotation about its own body center were comparable to the orbital velocity, the centrifugal force would exceed 10,000 g’s and would already have torn the satellite apart.)
“Even as close as 15 meters the odds of them actually colliding are astronomically against. 15 meters is bigger than either satellite and we are talking about 3 dimensions rather than 2.”
Pointing out that this is the problem that NMD had to solve with hit-to-kill warheads. Executing that last course adjustment to make impact — that’s the trick.
“... and we are talking about 3 dimensions rather than 2.”
We are talking about two dimensions.
The Navy satellite has several 20-meter booms sticking out of it. That’s enough for at least a glancing strike.
webheart wrote:
Even as close as 15 meters the odds of them actually colliding are astronomically against. 15 meters is bigger than either satellite and we are talking about 3 dimensions rather than 2.
Except...
“The 187-pound satellite has 59-foot-long gravity gradient booms that reach out into space—an obvious concern”
Thats 17.9 meters....