[sci.space] Magellan & SRB exhaust

andy@syma.sussex.ac.uk (Andy Clews) (05/15/89)

If the Shuttle crew were able to watch Magellan as it fired off on its
trip to Venus, would they have been able to see the exhaust plume from
its solid motor?

The reason I ask this fascinating :-) question is that, years ago when
I watched the later-Apollo LEMs leave the moon (by the miracle of TV), I
noted that no exhaust was visible - only the debris blasted from the top
of the descent stage.  If liquid fueled motors burn "invisibly" in the
vacuum of space, what about the solid rocket motors? 

Also, (rather naive question), would the shuttle have been "showered"
with any of the impurities from the Magellan solid motor exhaust at burn
time, even though it was obviously a long distance from it?

-- 
Andy Clews, Computing Service, Univ. of Sussex, Brighton BN1 9QN, ENGLAND
JANET: andy@syma.sussex.ac.uk   BITNET: andy%syma.sussex.ac.uk@uk.ac
Voice: +44 273 606755 ext.2129

sw@cbnewsl.ATT.COM (Stuart Warmink) (05/17/89)

In article <982@syma.sussex.ac.uk>, andy@syma.sussex.ac.uk (Andy Clews) writes:
> [...deleted...] If liquid fueled motors burn "invisibly" in the
> vacuum of space, what about the solid rocket motors? 

   There are some rather pretty pictures of an OMS burn and a "yaw" thruster
   firing as seen from the Shuttle's rear windows in the book _Entering Space_
   by Joseph Allen (mission specialist). They clearly show whitish plumes, but
   it dissipates within a meter or so for the thruster firing. Both OMS and
   attitude thrusters are liquid (hydrazine) fueled engines.

   Solid rocket motor should have a far more visible plume, because of the
   many solid exhaust products which will glow brightly. Just look at the
   Shuttle's boosters!

> Also, (rather naive question), would the shuttle have been "showered"
> with any of the impurities from the Magellan solid motor exhaust at burn
> time, even though it was obviously a long distance from it?

   Not so naive, because that it exactly why the Shuttle turns its undersurface
   towards where the probe/satellite starts its burn. The worry is that
   exhaust particles could damage or dirty the orbiter's windows.

   P.S. "Let's go Seagulls!" :-)
-- 
------------------------------------------------------------------------------
"Captain, I see no reason to stand here  |  Stuart Warmink, Whippany, NJ, USA
 and be insulted" - Spock                | sw@cbnewsl.ATT.COM (att!cbnewsl!sw)
-------------------------> My opinions are just that <------------------------

andy@syma.sussex.ac.uk (Andy Clews) (05/18/89)

From article <606@cbnewsl.ATT.COM>, by sw@cbnewsl.ATT.COM (Stuart Warmink):
>    ..... The worry is that
>    exhaust particles could damage or dirty the orbiter's windows.

Hmmm. Perhaps the orbiter should be fitted with windscreen wipers :-) :-)

Thanks for the answers to my queries. I'm impressed with the speed - I get
answers from the US within a couple of days of posting in the UK.

Cheers!
-- 
Andy Clews, Computing Service, Univ. of Sussex, Brighton BN1 9QN, ENGLAND
JANET: andy@syma.sussex.ac.uk   BITNET: andy%syma.sussex.ac.uk@uk.ac
Voice: +44 273 606755 ext.2129

marcus@illusion.UUCP (Marcus Hall) (05/18/89)

In article <606@cbnewsl.ATT.COM> sw@cbnewsl.ATT.COM (Stuart Warmink) writes:
>   ... that it exactly why the Shuttle turns its undersurface
>   towards where the probe/satellite starts its burn. The worry is that
>   exhaust particles could damage or dirty the orbiter's windows.

Are the windows considered more critical than the bottom tiles?  I guess they
are possibly more fragile, but the bottom tiles experience much higher
temperatures than the top surfaces.  I guess that we know that even with some
of the bottom tiles missing, the orbiter doesn't suffer too much damage, so
I guess that turning the bottom to the burn makes sense, but it doesn't seem
to be clearly the obvious thing to do.

marcus hall

brent%terra@Sun.COM (Brent Callaghan) (05/19/89)

In article <982@syma.sussex.ac.uk>, andy@syma.sussex.ac.uk (Andy Clews) writes:
> Also, (rather naive question), would the shuttle have been "showered"
> with any of the impurities from the Magellan solid motor exhaust at burn
> time, even though it was obviously a long distance from it?

It seems that damage to Shuttle windows from high speed particles
of sold exhaust is a real concern.  According to the Space Shuttle
Operator's Manual, the orbiter turns its windows away and the
crew watch the burn with the TV camera on the elbow of the
manipulator arm.

Made in New Zealand -->  Brent Callaghan  @ Sun Microsystems
			 uucp: sun!bcallaghan
			 phone: (415) 336 1051

holroyd@dinl.uucp (kevin w. holroyd) (05/19/89)

In article <394@illusion.UUCP> marcus@illusion.UUCP (Marcus Hall) writes:
>		stuff deleted 
>Are the windows considered more critical than the bottom tiles?  I guess they
		stuff deleted

Only when it comes time to land and you can't see outside.

-- 
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Denver CO.				* 
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