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.

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.

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.

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.


or,

After engine failure on ascent?


Abort to orbit
From the NASA.gov website, search term ATO

An ATO is an abort mode used to boost the orbiter to a safe orbital
altitude when performance has been lost and it is impossible to reach
the planned orbital altitude. If a space shuttle main engine fails in
a region that results in a main engine cutoff under speed, the
Mission Control Center will determine that an abort mode is necessary
and will inform the crew. The orbital maneuvering system engines
would be used to place the orbiter in a circular orbit.

--
Craig Fink
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--
Craig Fink
Courtesy E-Mail Welcome @