Collision risk

Rob Matson (Rob_Matson@cpqm.saic.com)
27 Feb 1996 12:23:46 U

                      Subject:                              Time:  12:02
  OFFICE MEMO         Collision risk                        Date:  96/02/27

On a slightly different subject vis-a-vis TSS and its tether, Philip Chien
writes:

> ... yeah there's a one in kazillion chance that the satellite and tether
> would run in to another spacecraft, or even tangle up into Mir's
> structure, but not enough to be a concern.  There's been plenty of
> other debris which has been put up their accidentally and hasn't
> been a concern (e.g. HST solar array, SFU solar arrays, etc.)

There's a world of difference between the tether and a solar array.  This
isn't an area issue -- it's a cross-section intersection issue, and linear
dimension becomes more important.  The probability of a 10-meter by 3-meter
solar array intersecting a particular 1 square-meter cube (say) is hundreds of
times smaller than a 20-km tether intersecting that same volume, even if it IS
only 1/10" thick.