[sci.space.shuttle] Launch Retry Turnaround

rcpilz@ablnc.ATT.COM (Robert C. Pilz) (12/02/88)

As everyone knows, the Dec 1 launch was scrubbed. What is the quickest
turnaround to launch again? What has to be done? I believe the amount
of turnaround time increases if they get closer to zero in a launch
sequence and then have to scrub the launch. 
I promise you better weather for the next few days. This morning,
a cold front swept through. It did not get through in enough time.
But the days should be clear for the next several days. The nights
may get into the low 40's (F), but the heaters on the new O-rings
should compensate for that. 
Here's hoping that NASA can give us an early Christmas present, a
beautiful safe launch and successful mission!

R. C. Pilz
AT&T IMS
Orlando, FL

gtww2z9z%gables.span@umigw.miami.edu (Jason Gross) (12/02/88)

In article <629@ablnc.ATT.COM>, rcpilz@ablnc.ATT.COM (Robert C. Pilz) writes:
> Here's hoping that NASA can give us an early Christmas present, a
> beautiful safe launch and successful mission!

Maybe it'll be a Hanukkah present instead of an "early Christmas present"!
:-) :-)


-- 
Jason Gross     Comp Sci Ugrad     University of Miami     Class of '91 (?)
===========================================================================
Four out of five doctors | Mail your invigorating replies to:      | Post 
think that life is the   |  GTWW2Z9Z%Gables.Span@Umigw.Miami.Edu   |  No
leading cause of death.  |  (What a lovely address, isn't it now?) | Bills
======================================================== IBM Sucks Silicon!

phil@titan.rice.edu (William LeFebvre) (12/15/88)

In article <629@ablnc.ATT.COM> rcpilz@ablnc.ATT.COM (Robert C. Pilz) writes:
>As everyone knows, the Dec 1 launch was scrubbed. What is the quickest
>turnaround to launch again? What has to be done? I believe the amount
>of turnaround time increases if they get closer to zero in a launch
>sequence and then have to scrub the launch. 

This is my understanding of what I have been told.  After two days, the
fuel tanks have to be "retanked".  I assume that means they have to be
purged and refilled.  That takes about two days.  So, if the second
attempt at launching Atlantis had not been successful, they would not have
been able to try the following day (I have heard contradictory information
from the media along the lines of "they may have to try again tomorrow",
but I trust my sources more than the media).

During prelaunch, once the APUs (Auxiliary Power Units) are started, there
is a limited amount of time which they can stay on before a launch.  By
limited I mean on the order of a few minutes.  The last chance hold is at
T-31 seconds.  The autosequencer forces a hold at that point if it
percieves that something is no go.  Since the APUs are already going at
that point (I believe they are started at T-5 minutes....by hand), the
hold at T-31 secs can only last for a few minutes.  If they hold too long,
they have to scrub the launch and repower the APUs (apparently a
non-trivial task).

Of course, once the SRBs start, there's no stopping! :-)

There are likely other restrictions.

The dream *IS* alive,		| William LeFebvre
ESPECIALLY at NASA.		| Department of Computer Science
				| Rice University
				| <phil@Rice.edu>

P.S.:  if Steve Ryan ever posts anything intelligent, please let me know.
I won't see it on account of my kill file :-)  And to think that he shares
the same last name with one of the greatest baseball pitchers that ever
lived.  Sigh.