"Jeff Findley" writes:

I'm just a lowly member of the peanut gallery, but everytime I see
someone talking about waiting just a little longer I think about
people using sleep() as a syncronization mechanism in a computer
program. Is there no other way to be certain the stages are far
enough apart before igniting the next stage?

You could solve this with some sort of fancy sensor. Perhaps a space
qualified laser range finder similar to the ones used for rendezvous and
docking to ISS. But obviously this drives up the cost and is a lot more
complex and prone to failure when compared to a simple timer.

Put a length of thin wire between the stages and don't fire the upper
stage engine as long as this wire hasn't snapped.

The russian method of avoiding instead of solving this problem by
connecting the stages with a lattice structure and igniting the second
stage before separation seems better, though...


Jochem

--
"A designer knows he has arrived at perfection not when there is no
longer anything to add, but when there is no longer anything to take away."
- Antoine de Saint-Exupery