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Conference 7.286::space

Title:Space Exploration
Notice:Shuttle launch schedules, see Note 6
Moderator:PRAGMA::GRIFFIN
Created:Mon Feb 17 1986
Last Modified:Thu Jun 05 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:974
Total number of notes:18843

8.0. "Space Shuttle DISCOVERY Mission" by SILVER::WEAVER () Mon Jul 16 1984 10:06

Path: decwrl!decvax!genrad!grkermit!masscomp!clyde!burl!ulysses!allegra!alice!alb
Subject: Star-48 Nozzle Compounds Scheduling Problem
Posted: Tue Jul 10 18:07:39 1984

Back in February, when two communications satellites, Westar-6
and Palapa-B, were placed into errant orbits, it was a Star-48
rocket nozzle that failed.  Back in May, engineers at MacDonald-
Douglas, which builds the solid fueled upper stage rocket, said
they had solved the problem.  But, just after the order had been
given to begin preparations to roll Discovery back to its hangar
so that two satellites from the mission after this could be loaded
aboard, in a decision to combine the aborted mission with its
successor, tests at MacDonald-Douglas revealed another faulty
nozzle.  Thus the order was rescinded, and NASA is again confused
about the shuttle schedule.  If MacDonald-Douglas and its customers
decide to wait until more tests can be conducted, the aborted
mission may launch by early August; however, the mission after that
could very well be postponed several months, thus putting the whole
shuttle schedule up in arms.  NASA is unsure over just what to do
next, and the agency has not released a date for a decision.


Path: decwrl!decvax!tektronix!uw-beaver!cornell!vax135!houxz!houxm!mhuxl!ulysses!allegra!alice!alb
Subject: Missions Combined -- Launch Date Set
Posted: Thu Jul 12 17:37:56 1984

NASA today announced that it will combine the aborted mission
and its successor into one flight of the Discovery.  That flight
is now scheduled to launch on 24 August.  On Saturday, the
shuttle is to be rolled back to the hangar so that two satellites
from the second mission can be loaded aboard.  The Star-48 nozzle
failure earlier this week was attributed to test conditions and
was ''probably not due to the nozzle itself,'' said a McDonnel-
Douglas statement.  Thus, the two satellites will fly; if it is
found that the nozzle was indeed at fault, they can always be
removed.  One Leasat satellite from mission 1, in addition to
the space solar panel and pharmaceutical experiments, will be
retained; a second Leasat satellite will be moved to the 1
October launch of the Challenger (beginning with the 1 October
launch, shuttle are scheduled to fly at least once a month.)
The crew for the combined mission will be the crew from mission
1, commanded by Henry Hartsfield; the crew from mission 2 will
be reassigned as soon as possible.


Path: decwrl!amd!dual!zehntel!ihnp4!ihlts!rjnoe
Subject: Re: Missions Combined -- Launch Date Set
Posted: Fri Jul 13 06:30:06 1984

I had heard that Leasat-2 would be added to mission 51A, currently set for
launch Nov. 2 and that SPARTAN-1 would be put with 41G, to launch Oct. 1.
What's the real scoop?  And have they made a decision whether or not 51A
will really be used to rescue Westar 6 and/or Palapa B-2 or will it just
deploy its Telesat of Canada comsat and run its experiments (including the
GAS stuff)?
--
	Roger Noe			ihnp4!ihlts!rjnoe


Path: decwrl!amd!dual!zehntel!ihnp4!mhuxl!ulysses!allegra!alice!alb
Subject: Re: Missions Combined -- Launch Date Set
Posted: Fri Jul 13 11:39:30 1984

Conflicting reports are not new.  I'll try to get more
information on Leasat-2.  51A will only rescue Westar-6
and Palapa-B if the owners pay for the rescue mission.
So far, I've not heard that they intend to do so.


Path: decwrl!decvax!ittvax!dcdwest!sdcsvax!sdcrdcf!hplabs!zehntel!zinfandel!ihnp4!mhuxl!ulysses!allegra!alice!alb
Subject: Discovery Back in VAB
Posted: Sat Jul 14 13:57:23 1984

The Discovery was moved back to the VAB today, the first
time a space shuttle has been removed from the launch pad
after being rolled out there, so that workers could separate
the ship from its external tank and SRB's.  After the
separation, the shuttle will be moved to the OFP, where
modifications will be made to the cargo bay to enable the
ship to take two extra comminucations satellites up in
August.  The new launch date is, again, 24 August.

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8.1SILVER::WEAVERFri Aug 03 1984 10:2210
Path: decwrl!amd!dual!zehntel!ihnp4!mgnetp!burl!ulysses!allegra!alice!alb
Subject: Jilted Crew Reassigned
Posted: Wed Aug  1 05:15:46 1984

The five crewmembers who were bumped from their flight due
to the combined mission have been reassigned to a shuttle
mission scheduled to blast off on 12 February, 1985.  With
the crew, commanded by astronaut Karol Bobko, will be a
sixth crew member, a French mission specialist.

8.2SILVER::WEAVERMon Aug 13 1984 11:1029
Path: decwrl!decvax!linus!utzoo!watmath!clyde!burl!ulysses!allegra!alice!alb
Subject: Shuttle Liftoff Scheduled
Posted: Wed Aug  8 20:14:23 1984

NASA today scheduled the liftoff of the combined shuttle flight,
setting launch for 0835 EDT on 29 August, and landing at EAFB
on 4 September.


Path: decwrl!amd!dual!zehntel!ihnp4!mgnetp!burl!ulysses!allegra!alice!alb
Subject: Discovery on Pad
Posted: Fri Aug 10 06:35:42 1984

The Discovery was rolled back to the launch pad yesterday
and bolted in place for its 29 August launch.


Path: decwrl!decvax!tektronix!uw-beaver!cornell!vax135!houxz!houxm!mhuxl!ulysses!allegra!alice!alb
Subject: Discovery Misaligned on Pad
Posted: Sun Aug 12 21:05:47 1984

NASA today discovered that the mobile launch platform on
which the Discovery sits was placed about three inces
off center on the launch pad yesterday.  The misalignment
left the mobile platform well within its tolerance limits,
but the huge tractor tansporter was rolled back to the pad
today, and the mobile platform and shuttle along with it
were realigned.

8.3SILVER::WEAVERThu Sep 13 1984 10:48115
Path: decwrl!decvax!genrad!grkermit!masscomp!bonnie!clyde!burl!mgnetp!ihnp4!ihlts!rjnoe
Subject: Discovery flight postponed again
Posted: Wed Aug 29 22:58:27 1984

NASA announced late Tuesday evening that the first flight of the space
shuttle Discovery had been postponed for the third time in two months.
Launch has been rescheduled for 8:36 a.m. EDT Thursday, August 30.

Tuesday afternoon, technicians discovered problems with an onboard electronic
device called the master events controller (MEC).  The MEC commands the
separation of boosters and fuel tanks and begins the firing of the boosters
and the detonation of the explosive bolts that hold the shuttle to the
launch pad.

Twice before, the crew of six had entered the shuttle, only to have the
launch scrubbed.  A computer failure stopped the countdown at T-9 minutes
June 25 and the next day a faulty valve in one of the main engines caused an
abort just seconds before the solid rockets were to have been ignited.
This time, the crew was asleep when NASA officials made the decision less
than 12 hours before the scheduled liftoff.  Loading the shuttle's huge
external tank with supercold liquid hydrogen and liquid oxygen had not
yet begun.

The weather for Thursday morning looked good for a launch, forecasters said.
--
Roger Noe			uucp: ihnp4!ihlts!rjnoe


Path: decwrl!decvax!genrad!grkermit!masscomp!bonnie!clyde!burl!mgnetp!ihnp4!ihlts!rjnoe
Subject: Discovery lifts off
Posted: Thu Aug 30 07:20:26 1984

Space shuttle Discovery lifted off from Kennedy Space Center today at
08:41:50 EDT.  The planned 10-minute hold at T-9 minutes was extended
by almost 7 minutes to allow two aircraft to exit the intended solid
rocket booster impact area.  Discovery, although the lightest of the
three orbiter vehicles, will be carrying a more massive payload into
orbit than any shuttle mission to date.  The first satellite deployment
for Discovery is scheduled for later this afternoon.
--
Roger Noe				ihnp4!ihlts!rjnoe


Path: decwrl!amd!fortune!hpda!hplabs!hao!seismo!ut-sally!ut-ngp!pyle
Subject: Discovery's 1st stage performance low?
Posted: Thu Aug 30 20:16:56 1984

Just after SRB separation on Discovery's launch, Capcom informed the
shuttle crew: "First stage - nominal."  Shortly thereafter, Capcom came
back with a revised evaluation that first stage performance was "low."
Interestingly, the CNN people didn't pick up on this and nothing else
was exchanged between the crew and ground (at least nothing that CNN
aired) on the subject.

What is considered in this evaluation?  Was the SSME and/or SRB thrust
too low?  For that matter, how much is "low?"

Keith Pyle

UUCP: . . .{ihnp4,seismo,ctvax,kpno,gatech}!ut-sally!ut-ngp!pyle
ARPA: pyle@ut-ngp


Path: decwrl!amd!fortune!hpda!hplabs!hao!seismo!brl-tgr!jcp
Subject: Re: Discovery's 1st stage performance low?
Posted: Fri Aug 31 23:23:59 1984

The 'SRB Performance Low' call you heard has occurred on almost every
shuttle mission, and represents the Solids not achieving nominal
thrust parameters.  Due to the way solid rocket engines work, their
performance is much more variable than equivalent liquids.  The Discovery
automatically compensates for low SRB performance by boosting thrust
on the Space Shuttle Main Engines, or moving the throttle-back point
slightly, (the region of maximum dynamic pressure).  Typical 'low' values
are 3 to 7 percent below nominal, I believe.  Sufficient reserve fuel
is always carried to compensate for low solid performance, as the
shuttle must reach a fairly precise 'window in space' at the time
of Main Engine shutdown in order to the OMS system, (which is much smaller
than the SSMEs) to execute the orbit circularization burn successfully.
None of the shuttle flights have had their orbital parameters significantly
affected by low 1st stage performance.

Most of this I learned from articles on the subject in Aviation Week

							-JCP-


Path: decwrl!decvax!tektronix!uw-beaver!cornell!vax135!houxm!ihnp4!ihlts!rjnoe
Subject: Discovery lands
Posted: Wed Sep  5 10:02:57 1984


Space shuttle mission 41-D ended successfully as the orbiter Discovery touched
down on dry lake runway 17 at Edwards Air Force Base, California at 6:38 a.m.
PDT after a mission elapsed time of 6 days, 56 minutes.  All three
communications satellites deployed on this mission (SBS-D, Syncom IV-1, and
Telstar 3-C) have reached geosynchronous orbital altitude without any
problems at all.  Also, the OAST-1 folding structure worked at least as
well as expected and the continuous flow electrophoresis (CFES) experiment
monitored by McDonnell Douglas Astronautics engineer Charles Walker produced
valuable pharmaceutical samples despite some problems with the equipment.
Apparently the crew experienced no space adaptation syndrome problems and
the waste collection system functioned properly until another system clogged
its discharge port with ice.

The next mission, 41-G, is scheduled to begin October 1 with the launch of
the orbiter Challenger.  This ten-day mission will be commanded by Robert
Crippen and piloted by Jon McBride.  Mission specialists David Leetsma,
Sally Ride, and Kathryn Sullivan and payload specialists Marc Garneau and
Paul Scully-Power will round out the crew to seven, the largest yet for a
space shuttle mission.  Cargo will include the large format camera Earth
resources mapping system and the Earth Radiation Budget Satellite (ERBS).
Crew members will conduct a fluid transfer experiment.
--
	Roger Noe			ihnp4!ihlts!rjnoe
8.4DAEMON::GENTRYThu Sep 13 1984 17:4911
I was part of a 4-man crew which covered (for an obscure service) the
landing of 41-D at edwards.  I would just like to echo a previous note
in saying that a landing is NOT boring.

Besides the impressive nose-down angle after clearing the heading
alignment cylinder, it was interesting to note that the shuttle
apparently has control over the contrail it leaves.  In fact, this
time, several people noted that the contrail was actually morse code.

Has anyone else noted this at previous landings?

8.5MOTHER::SILVERSat Sep 15 1984 21:013
Any idea what the code said?

- Craig
8.6HELOS::ROSENBLUMFri Sep 21 1984 08:246
the announcer on CNN said that the contrails are actually the
manuvering jets firing.  It seems that they don't actualy fly
the shuttle untill it goes below mach 1 they use the manuvering
jets to stear above the speed of sound...

					Mike
8.7SUMMIT::GRIFFINMon Oct 01 1984 22:5911
Use of manuvering jets has very little to do with the speed of
the shuttle.  The avionics software combines the use of thrusters
versus control surfaces based on the density of the air.

By the time we see it in a landing, I'd be willing to guess that
they are using only control surfaces to manuver the ship.  Control
jets would have little use in the atmosphere...

I'd say a better explanation would be venting of fuel...

- dave