"Craig Fink" wrote in message
news
On Fri, 28 Jul 2006 02:53:48 +0000, Greg D. Moore (Strider) wrote:


"Craig Fink" wrote in message
news
On Fri, 28 Jul 2006 01:33:33 +0000, Shamaal wrote:

Craig Fink wrote in
news
After entry interface?

Or, Abort To Orbit and redock with the Space Station if a heat shield
failure has been detected during entry. Like doing a RTLS to the Space
Station instead of KSC.


Redock? Umm. No. Once they've hit re-entry, the shuttle is cominghome.

Technically, the shuttle should be able to rerendezvous and redock with
the space station. I believe the OMS tanks are big enough to do three
apogee burns; ascent circ, deorbit, rerendezvous circ. Plus they would
have to make up for a little drag, but that could be minimized.

I don't think this is at all possible, especially if it's flown low enough
to detect a heat shield failure, presumably by rising temperatures inside
the wings or some such technique. The OMS engines wouldn't have the fuel
and/or performance to do this.

Even considering something like ATO to the Space Station can lead to
improvements. Like rolling the vehicle heads down, instead of heads up for
the initial portion of entry. This would reduce the delta-V required for
the deorbit burn (more payload), by increasing the deorbit burn's perigee.
Heads down, the vehicle is grabbing the atmosphere and pulling itself in,
instead of trying to lift itself out. They are trying to come down not go
up.

You're really clueless of the shuttle's attitude, and the resulting
aerodynamic forces, early on during reentry. Not to mention aerodynamic
heating.

They might even be able to do a small rerendezvous plane change. The
atmosphere would be like a multiplier on the deltaV of any plane change.
At maximum L/D, lift could be used to change planes and the drag would
have to be made up with OMS fuel. But OMS fuel usage for the plane change
is multiplied by the maximum L/D of the Orbiter, yielding a much large
plane change.

Now you also appear to be clueless when it comes to orbital mechanics.

If NASA were to change it's plot/plan to include Lunar return aerobrake to
the
Space Station, something like ATO to the space station could be used to
develop aerobrake rendezvous concepts and software. Things like Maximum
Drag attitude, Minimum Drag attitude, Max L/D attitude would all be
important for aerobrake rendezvous with the Space Station.

I would think the cost in payload might be NASA's problem with doing
something like ATO to the Space Station.

You seem to be clueless about the delta-V required to go from lunar return
into ISS orbit. If you plan on doing this by aerobraking, you might as well
reenter the atmosphere as the heating loads aren't that much different.
Plus, you need fuel to circularize your orbit after aerobraking. If you do
a direct return, you don't need that fuel at all.

Why don't you tell us the mass of fuel you'd need for an aerobraking return
to ISS? Do the math and quit your hand waving.

Jeff
--
"They that can give up essential liberty to obtain a
little temporary safety deserve neither liberty nor
safety"
- B. Franklin, Bartlett's Familiar Quotations (1919)