Conference 7.286::space

Fascinating.  and a good read at that.

Another point about the 'Twang' affect; the end to end bowing of the SRB's, at
the time of orbiter ignition is approx. 25".

I would be suprised if there were NOT another flight this year.  While there is
an enormous amount of data to pour through, there are several aspects to this
flight that will settle into the box marked 'As a result of the problem, but
not THE problem'.  While the detaching of the bottom of the SRB and its
resulting pivot action are a part of the investigation, it should become
apparent, shortly that this is not the problem, rather a result of the problem.

This, and a thousand other points of interest, are being studied in an effort
to discover if other 'unknowns' exist within the shuttle design or maintinance.
The shuttle investigation will, most likely, continue long after the ships are
flying again.  I don't feel that NASA will launch a shuttle that they think
is unsafe, nor do I feel that they will delay launching until 'ALL' is known
of all possible problems.

anyway, let's keep the information flowing!

jim

re .1:

>  nor do I feel that they [NASA] will delay launching until 'ALL' is known
>  of all possible problems.

Due to the extreme public scrutiny this is receiving, NASA may not be able
to make a decision to resume flights without at least the tacit approval
of Congress and the President.  It's not clear to me what their criteria
will be, but emotion may be one of them.


Speaking of SRB's, I think I read that the Vandenberg shuttle flights will
use a new, lower-weight SRB casing not made of steel.  Is this true?  Is
it a totally new design, or does it have major structural elements in common,
e.g., O-rings, etc.  Could they be used from Canaveral?


How does one subscribe to Aviation Week?  I used to read it all the time
15 years ago when I had an aero roommate, and I was always impressed with
their approach to reporting -- lots of facts, little hype.  And it was always
much more interesting than my professional (computer) magazines!

Bob Fleischer

re .2:

Yes, Vandenberg will use new composite srbs rather than steel.  I don't know
how much they have in common with the steel.  I believe that they COULD totally
replace the steel ones, but they are more expensive.  They are needed at
Vandenberg for polar-orbit flights because the shuttle can put less mass
in polar orbit than in equatorial orbit.  Thus they need every kg they can
get.

Burns

The new filiament wound casings are designed to save weight, as indicated,
allowing more payload or higher orbit from KSC, and helping make up for
the lack of equatorial rotational velocity when launching into polar orbit
from Vandenberg.  I don't know much about them other than they are lighter
and they have re-designed o-rings, according to a report I heard this morning.

Vandenberg launches may subject the SRB's to more stress since they are
bolted to a concrete launch pad instead of the more flexible crawler
vehicle used to transport the shuttle at KSC, according to that same
report (on NPR, I believe).  There are other potential unknowns about
Vandenberg, as well as a smaller work force, some of which has to be
imported from the Cape. All in all, I hope NASA takes the time to get
a thorough understanding of the Challenger accident before flying again,
especially from Vandenberg.

As for AW&ST, each issue contains a subscription form -- I got one from
an issue in my DEC library.

re .4, subscriptions:  Right.  As one who works in the computer field, you
qualify for the favored subscription rate, as opposed to the higher rate
for the general public.  (BTW, FWIW: I believe this is because AW&ST guarantees
its advertisers a certain demographic profile, for which they can get more
for ads.  Thus, if you don't fit the profile, you don't help raise their
ad rates, so you have to pay for it)

Burns

First, can someone supply the subscription information?  By the time I
get to the library, the subscription card is gone.  (Or can someone send
me one from his private copy - M/S OGO1-2/F13).

Second, one of the things that came up in the news reports was that the
SRB's are poured, etc., in Utah, the shipped to KSC in the segments.  One
of the stated reasons for doing it in segments is that larger assemblies
could not be easily (cheaply?, quickly?) shipped.  Vandenberg is a lot closer
to Utah, hence one-piece shipping may be more feasible, or the shipping
costs less concern to the DoD.

	                          
		AVIATION WEEK & SPACE TECHNOLOGY
		P.O. BOX1505
	        NEPTUNE, N.J.  07754-1505

		1 YR	$51
		2 YR	$83
		3 YR   $112

		"Rates apply to management, engineers and scientists in 
	aviation, aerospace and related technologies; military officers
	and government officials.  All others $65 for one year.  Please
	allow 4 to 6 weeks for receipt of your first issue.  Rates apply
	to US subscribers only."

	While not cheap I do think it is an excellent source for keeping
	up on the world of aviation and space.  Single issues are marked
	$5 and up but I have never seen single issues for sale anywhere.
	This is the one Christmas present that my wife lets me indulge in
	every year!

    ...sort of matching the title if not the content of this topic
    
    Can anyone who was this year's AvLeak calendar explain what we are
    looking at this month?

Article: 5599
From: [email protected] (Henry Spencer)
Newsgroups: sci.space.news
Subject: space news from Feb 7 AW&ST
Date: 16 Apr 1994 14:34:56 -0700
Organization: U of Toronto Zoology
Sender: [email protected]
 
Several letters commenting on Jerry Grey's lukewarm view of SSTO.
 
Loral to build a GPS-based attitude-sensing system for [LEO] satellites,
using technology licensed from Trimble, based on the system designed for
Gravity Probe B.
 
First H-2 launched successfully 4 Feb, after a two-day delay due to bad
weather and a one-day delay for a mechanical problem.
 
Clinton FY95 budget hits NASA hard, jeopardizing shuttle developments
like the new AlLi tank, and pushing NASA to consider drastic measures
such as mothballing an orbiter.  [That last has been officially denied.]
 
Discovery launched 3 Feb for the Wake Shield Facility mission.
 
The investigation of the TOS separation mess during ACTS deployment last
year has reported...  When separation from the shuttle was commanded,
both the primary *and* backup explosive cords in the separation mechanism
fired, rupturing the confinement tube and showering the cargo bay with
debris, including 22 reinforcing plates from the separation joint.  One
of the plates punched a 1/8x1/2in hole in the aft bulkhead; others did
various bits of minor damage to insulation blankets etc.
 
The problem was a design error.  The "Fire 1" command went to the port-side
detonators for both cords, instead of to the port and starboard detonators
for the primary cord.  ("Fire 2" was supposed to go to the backup cord.
[They don't say, but I would guess, that "Fire 2" went to both starboard
detonators.])  The wiring harness was designed incorrectly in 1984, and
none of the later reviews found the flaw.  Test equipment verified the
design instead of checking for the desired end results.  Documentation
was incomplete, terminology inconsistent, and labelling "incomplete and
confusing".  There was no single schematic showing both electrical and
mechanical subsystems of the separation system.  "The technical reviews...
had little chance of detecting the embedded error.  Even after [we knew
what to look for], detecting the design error through drawing reviews
was difficult for experienced personnel..."  A 1992 design review had
some "to be determined" items for the separation system, and it is not
clear why this didn't raise an alarm.  The report recommends that payload
safety verification procedures should test for end results, not conformance
to the design; that the tests should be run on the flight hardware; and
that in areas where full testing is impossible, such as pyro hardware, the
people devising the verification procedures should not be the ones who
designed the hardware.
 
US and Russia to informally share data from tracking of the Oderacs
radar-calibration spheres being deployed from Discovery.  The sharing
will be informal partly because the last such effort, on tracking of the
two Pion spheres released by Resurs F in 1992, was a bit of a fiasco:
the Russians supplied poor data very late.
 
The main purposes of the Oderacs spheres is calibration of US debris-
tracking radars, especially the Haystack radar.  Precision tracking will
also give useful data on the extreme upper atmosphere, since the spheres
are in a fairly low orbit that's expected to last only a few months.
 
Telesat Canada initiates a $3M effort to rescue Anik E2, by developing
software to use its maneuvering thrusters for attitude control.  This
will be somewhat of a first.  The tricky part is that yaw sensing will
have to be done from the ground, and equipment must be added for this.
The ground-control equipment will also be made more redundant.  The
extra fuel consumption will cut 1-2 years off the satellite's life.
(E2 is already a bit short on fuel because of the maneuvers done to
free its stuck antenna shortly after launch.)  The new control system
will also be available as a backup in case Anik E1 loses its remaining
momentum wheel.  Most of E2's full-time traffic has been temporarily
moved to E1 or Galaxy 6, but Telesat Canada will be unable to serve
many occasional-use customers until E2 is restored.  The six-month
outage will cost Telesat tens of millions of dollars in lost revenue
[plus the rent on those Galaxy 6 channels, I expect].
 
DC-X, on the brink of program termination, is saved... by NASA!?!  By
direct order from Goldin, NASA gives the program $1M from its Advanced
Concepts And Technology funding, to preserve the hardware and team until
the politics of continuation can be resolved.  The vehicle has been cared
for properly, and work will now begin on getting it ready for flight again,
although flights cannot actually resume until the $5M that Congress allocated
for it is actually delivered by DoD.
-- 
"...the Russians are coming, and the    | Henry Spencer @ U of Toronto Zoology
launch cartel is worried." - P.Fuhrman  |  [email protected]  utzoo!henry

Article: 5600
From: [email protected] (Henry Spencer)
Newsgroups: sci.space.news
Subject: space news from Feb 14 AW&ST
Date: 16 Apr 1994 14:35:10 -0700
Organization: U of Toronto Zoology
Sender: [email protected]
 
More letters on DC-X/SSTO.  [I'm not going into details because most of
the points raised should be familiar by now...]
 
Delta launch of a comsat aborted 9 Feb at the Cape, during main engine
ignition.  No details yet, and no firm date for another attempt.
 
First Long March 3A, capable of about 5klbs to GTO, launched successfully
8 Feb, carrying a research satellite and a dummy second payload.
 
Loral buys an Atlas 2AS launch for a direct-broadcast satellite for Tempo.
 
White House says that a policy on loosening controls on high-resolution
remote sensing will be out Real Soon Now, in response to sharp criticism
from House panels for lack of progress.
 
As predicted, the FY95 budget kills FEWS, although it starts funding for
a lower-cost missile-warning system.
 
The NASA FY95 budget situation is not a happy one:  an actual reduction
in overall spending (made worse, of course, by inflation), and threats
of more to come for the next five years.  Dire predictions that the shuttle
and Fredovitch would eat the entire science budget have not come true,
however.  Cassini and AXAF both survived, and there is a little bit of
money to start Mars Surveyor, an MO replacement:  two small orbiters,
one for 1996 launch and one for 1998.  The long-duration orbiter program
will be closed down [mistake] as will procurement of orbiter structural
spares [big mistake].  Manned spaceflight will generally be squeezed;
overall expenditures on it through the 1990s will be 30% lower than last
year's budget envisioned.
 
The Wake Shield Facility is working... sort of.  Communications problems
and an attitude-control-sensor failure scuttled repeated attempts to
deploy it as a free-flyer, so it will do the best it can on the end of
the arm.  It looks like the bottom line will be proving the concept, but
with a vacuum not much better than can be achieved on Earth.  The next
flight, about a year from now, should do better.
 
The Oderacs radar-calibration spheres have been deployed, as has U of
Bremen's Bremsat.  There have been minor temperature-control problems
due to holding a gravity-gradient attitude for WSF.
 
New Hubble images of Shoemaker-Levy 9.  The 11 largest pieces are now
estimated at 2-4km diameter.
 
Titan IV returned to flight status 7 Feb, launching the first Milstar.
 
NASDA declares the first H-2 launch a "100% success".  Orbits were as
planned.
 
NASDA says that it does not consider the H-2's main engine to be reliable
enough for man-rating the H-2.  They would want to redesign it with
computerized engine controls, at the very least.
 
Intelsat confirms orders for two Ariane launches for Intelsat 8s (a
vote of confidence in Ariane, currently grounded for investigation of
the latest failure).
 
NASA Lewis orders two Atlas launches (the second subject to need) and
puts options on seven more.  The firm payload is launch of the first EOS
bird from Vandenberg; a strong candidate for the second launch is the
next GOES (after the one that's now on the pad).
 
The UK's Institute of Satellite Navigation says that a switch to redundant
systems on GPS satellite PRN19 appears to have cleared up the anomalies
in its signals.
-- 
"...the Russians are coming, and the    | Henry Spencer @ U of Toronto Zoology
launch cartel is worried." - P.Fuhrman  |  [email protected]  utzoo!henry