[ExI] Spacecraft (was MM)

[spike]

... On Behalf Of spike
Subject: Re: [ExI] Spacecraft (was MM)

... On Behalf Of Keith Henson...
>>Talk to Spike about the control problem...Keith

>There are ways to do stuff like this using fast steering secondary mirrors,
adaptable aperture, lostsa cool notions for laser propulsion that were
actually developed from a weapons program, Airborne Laser:
http://en.wikipedia.org/wiki/Boeing_YAL-1  ... most of the pointing control
and accuracy infrastructure was subcontracted to Lockheed Missiles ...  We
would need to get tricky with our optical feedback loops, but I think this
is doable with current control law.  spike


Ooops I realized the way I worded this earlier may be misleading.  The ABL
pointing accuracy and stability is not arc-second class, or even close to
that.  You really can't get all the way down to arcseconds at all on a
moving platform or when one is firing thru air.  Eewww, messy stuff is this
"air."  I like breathing as much as the next guy, but the atmosphere is
nothing but problems for the optical controls guys.  An unpredictable,
dirty, shifty, diffacty bastard is this "atmosphere."  If we could assume it
away, our task would be so much simpler and cleaner.

In any case, we could still do second stage ablative boost firing thru this
"atmosphere" methinks.

spike