adolph@ssc-vax.UUCP (Mark Adolph) (02/22/86)
*** YOUR MESSAGE ***
According to "The Shuttle Operators Manual," any shuttle abort involves
a firing of the OMS engines, both to maintain altitude and airspeed and
to dsipose of dangerous tetrazine fuel. It seems to me that with the
aeordynamic control due to an airspeed over mach 1 plus the extra push
from the OMS engines, an abort should be possible during the boost phase
of flight. The only reason I can think of that it wouldn't be possible
is that the g-forces during the maneuver are outside the limitations of
the orbiter's structural strength, much like one shouldn't do outside
loops in a DC-10.
More reliable information about this would be much appreciated.
--
-- Mark A.
...{uw-beaver|fluke}!ssc-vax!adolph
"1 + 1 = 1, for sufficiently small values of 1..."paul@axiom.UUCP (Paul O`Shaughnessy) (02/26/86)
NASA and its contractors have consistently maintained that a ditching of the shuttle during the SRB boost phase of the flight is impossible to perform survivably. The most believable reasons which I have heard on the net and in the media go something like this: Very early in the launch, detatching and landing the shuttle is impossible simply because there is insufficient altitiude. By the time there is sufficient altitude for anything other that a nosedive, the spacecraft is travelling at several times the speed of sound through atmosphere which is still quite dense. If the shuttle were to detach from the fuel tank at this point, it would not veer away gracefully as we might imagine, but would flip over backwards and its wings (at least) would be torn up by the excessive aerodynamic force. I don't think that such a detatchment is possible until the spacecraft is quite high, which is after the SRB's are jettisoned. I've also read that jettisoning the SRB's while they're still burning full force is near impossible because their exhaust would explode the fuel tank or frazzle the shuttle as they raced ahead of the spacecraft. Is this true? I certainly don't trust everything I read or hear, and I post this not as truth but as a concentrate of recent publications. Confirmations or corrections are appreciated. Also, could any of these ditching modes be made safe? ------------ Paul O'Shaughnessy Axiom Technology Corp. Newton, Massachusetts 'Home of the AT100'
allen@mmm.UUCP (Kurt Allen) (02/28/86)
In article <172@axiom.UUCP> paul@axiom.UUCP (Paul O`Shaughnessy) writes: >NASA and its contractors have consistently maintained that a ditching >of the shuttle during the SRB boost phase of the flight is impossible >to perform survivably. There are a few more scenarios that I have been made aware of recently, that would preclude shuttle survival in case of a SRB failure. These are 1) If one of the SRB's fails to ignite at launch. As it is impossible to stop the other SRB the shuttle would pinwheel uncontrollably, with no possibility of survival. 2) The shuttle lands at 190 knots. It is not expected to maintain structural integrity ditching in the ocean at this speed. -- Kurt W. Allen 3M Center ihnp4!mmm!allen