[FPSPACE] UK's first orbital attempt

[Jonathan McDowell]

My understanding is a little different, Phil:
the 13 kg sphere + the 69 kg instrument package total 82 kg between
them. 'X-2' refers to the combined payload sometimes, and to just
the sphere other times. Geoff's note makes it sound like "the 82 kg X2"
is in *addition* to the 13 kg and the 69 kg, but I don't think
that's the case. 

 - Jonathan