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mheslep
#6
Mar27-08, 02:30 PM
PF Gold
P: 3,081
Thanks for the replies all!

Quote Quote by Danger View Post
I can't give you specific details or numbers, but I can say for certain that the weight of the actuator mechanisms alone would be enough to make the thing nearly un-launchable.
This one I don't follow. The actuators on swept wing aircraft don't make them impractical. If there's some non-linear factor in scaling that up to the shuttle I don't see it. Also Im proposing to lose the heat shield weight by the time the wings deploy - so perhaps that counters the actuator weight a bit.

Quote Quote by Danger
There's also the matter of internal space to store the parts while they're not in service.
Yes that might be show stopper.
Quote Quote by Danger
Last, but not least, there would be serious fluid flow problems resultant of the various slots and ports needed for storage of the flight surfaces while retracted.
Why does there need to be any fluid flow during storage? I would think only during deploy and only then if you went hydraulic vs electric.

Quote Quote by Danger
An F-14 or any other swing-wing aeroplane doesn't face anything like max-Q.
Well that supports my point. I want to totally remove the aerial surfaces from ascent and max Q. That implies a much reduced drag coefficient on ascent and thus some substantial (?) savings in fuel. From Wiki:
Around a point called Max Q, where the aerodynamic forces are at their maximum, the main engines are temporarily throttled back to avoid overspeeding and hence overstressing the Shuttle, particularly in vulnerable areas such as the wings.
Quote Quote by russ_watters View Post
The shuttle needs its wings for re-entry. They are what slow it down.
Well of course in general a re-entry vehicle historically does not need wings to slow it down, it only needs blunt body drag to slow it down as has been done in the past with Apollo et al. The shuttle happens to use its wings for that purpose in a series of high G turns.

Quote Quote by FredGarvin View Post
The shuttle is already the most complex machine on the planet. I think that adding these features are going to add way too many places for possible failures. The return isn't worth the risk.
Yes, I'm suggesting wing storage does away some significant contributors to that complexity: that fragile, tile based heat shield which must be seen as an Achilles heal of the current design; I read now that management of the surface foam on ascent (which killed Columbia) is problematic - requiring telescopic inspection of the shuttle in orbit, etc, etc. A stored wing does away with all of that and use a traditional monolithic heat shield as has been done in the past.

Quote Quote by Astronuc View Post
Storing the wing and tail would be problematic (compare wing/tail dimensions with fuselage), and for that reason alone it is not practical.
Likely so, though thats not clear to me. I was thinking the wings we be scissored, overlapped for storage underneath the fuselage.
Quote Quote by Astronuc
Moreover movable/deployable wings/tail would require additional mechanical systems which would increase probability of failure,
Yes, but there's experience w/ swept wing mechanicals and I'm proposing elimnation of much more complexity in return, I believe.
Quote Quote by Astronuc
and that wing system must sustain heavy loading during the slowing down in the atmosphere.
Not if they don't deploy until late into re-entry. I suggest deployment a little higher than when the shoots popped on capsule re-entries.
Quote Quote by Astronuc
Thirdly, the thermal protection system must provide a tight, continuous seal otherwise hot gases may leak through and undermine the structural integrity of the wing/fuselage as was the case with the loss of Columbia.
Yes exactly, replace all of that a single monolithic shield. Eject the shield as done w/ capsules exposing deployable wings.