🚀 go-pugleaf

Jon Kirwan schrieb:

> Of all those single points of failure, the ones that worried
> me the most were the pyros. You can test a lot of things --
> like the 65,000 pounds of force the parachute had to bear.
> But you can't test the ACTUAL pyros you will use. No matter
> what you do, the ones you place in there can't have been
> tested. We know how to make explosives of great uniformity,
> of course. But all of that has to go into a system and it
> must fire exactly correctly, under buffeting circumstances,
> without a single point of failure in a single pyro. Just one
> and that is it. Not that the rest wasn't also difficult. But
> some of the things, since as the novel use of an imbalance in
> weight distribution in order to permit direction control
> during entry, can have errors in one part of the software be
> compensated by the outer control loop in another part. So
> even there, there is a backup hope. But the pyros either
> work, or don't. That's what I was watching mostly for, though
> the rest was also sincerely knuckle-whitening as well.

Hello,

pyros have been used for more than five decades in space missions and 
they were critical for each mission. They were used for stage 
separation, four or more for each stage and all should work perfect.
But it is possible to test the cabling and the fuse of the pyro by 
measuring the resistance without blowing them. I guess there were more 
than twenty pyros necessary for this mission.
If hundred pyros were built within one lot, you may test fifty or more 
and use only the rest if all tests were perfect. You may even test some 
just before the start, if one fails all pyros of this type and lot have 
to be replaced. Not cheap, but a failing pyro is much more expensive.

Bye

Bye