Conference 7.286::space

re.; .0

I heard that debris recovery is being hampered somewhat by the presence of 
older wreckage (didn't hear from what or where) in the search area.  It seems 
that several large pieces of the fuselage have been located, including 
instrument gauges from the cockpit.  Also, a large square section of what 
might be the orbiter wing has been recovered.  As far as crew remains: This 
morning the news reported that a foot (in a sock) washed ashore.  
Also, it may be that the two cones (which have telemetry equipment inside) 
from the SRB's were located and recovery efforts were underway as of last 
night.

This morning's paper said that a fragment of bone and tissue measuring 6
inches, by 4 inches, by 1 inch was found washed up on a beach approximately
35 miles south of the Cape. A piece of navy blue sock was attached to the
fragment. NASA stated that crew members are NOT issued navy blue socks (I
can't remember what color IS issued) but that crew members do not always
wear "official" socks on flights. The fragment has being analyized (sp?).

"Tons" of wreckage is being found and returned to NASA for evaluation, a
Coast Guard cuter has located a large object on the ocean floor which may,
or may not, be a portion of the fuselage. The doubt is due to the fact that
this portion of the ocean is referred to as the rocket graveyard (or something
similar) because of all the spent boosters and wreckage on the ocen floor
from many launches over the years.

This evenings news showed the unloading of a recovered section of the
orbiter. It was from the right front, starting at the nose. (A little
around the side) and extending back past the wing joint (a small part of
the leading edge is attached). Included was one of the hatches marked
clearly with a rescue pointer. Christa McAuliffes seat had been immediately
adjacent to that hatch.

NASA officials also said that they were investigating a larger piece of
wreckage which MIGHT well be the crew compartment. There was some possibility
that the compartment is intact. NASA statedt that they would not comment on
remains today regardless of findings, out of respect for the families.

One of the SRB nose cones has allegedly been retrieved.

						-Brian

NASA has released more information which included video at a slightly different
angle which showed an "unusual flume" on the lower portion of the right SRB.

They also reported that the jettison rockets of the SRB's had not been used
which indicates that the crew were not aware of any problems or at least
had not gone into an abort sequence.

NASA is still being VERY coy about the submerged objects which many people
believe will reveal the crew compartment.  One would think that it shouldn't
be too long before these objects can be examined.

Don

The bottom currents in the search area keep blowing the robots around. 

Progress is slow in identifying the object and I'm sure they want to be sure.

						-Brian

In Monday's USA Today, I read something which is of interest.  They reported
that the range saftey mechanism to terminate the SRB's is to separate the
nose cone from the booster case.  This effectively reduces the SRB to a
137 foot tube full of buring rocket fuel with no thrust vector.  They went
on to say that the SRB was expected to fragment when it impacted with the
Atlantic at ~2000 MPH.  I was under the impression that when the booster
was destroyed by the range saftey officer, it was blown to little pieces.
This offers hope that some large pieces of SRB can be recovered intact.

-Glenn

NASA issued a report concerning the large objects that have been found approx.
200 feet under water.  Sorry to say, the First item was a helecopter and the
second was a small airplane.

regards,
jim

	You are right there is still hope of finding the boosters still 
quite intact, especially if they destruct the way the Polaris and Minuteman
missiles use to in the old days. The art of destructing solid fuel rockets
left much to be desired. In the days of the Polaris they tried to destruct 
one in the same way they do the SRB's it kept flying like a ram-jet and 
just missed a trailer in a park by 9 feet in the town of Cape Canaveral.
	It would certainly be good if they find the SRB. I was astonished
to learn that they do not do x-ray inspection of these before refurbishing,how 
about anyone else ?

Re: .8

I probably should not respond because I'm extrapolating information, but
what the hay...

I'm not sure what good x-raying would do.  My understanding of
the SRB construction is that it is primarily wound fibers - sort
of like a very tall tire on its side.  Unlike solid metal, stress
points are probably difficult to isolate amongst the maze of
fibers, although cracks might be detectable - if you can have
cracks in such a material. 


In terms of failure, it's improbable that pressure or structural
problem would cause an SRB to fail (except at the joints), but
rather improper fuel loading.  Solid rockets burn from the center
outwards along the length of the rocket.  If there is a void in
the (solid) fuel RADIALLY, then then the fire can reach the wall
prematurely.  [Insert NBC color graphic animation here] 


All things considered, it would take a LOT of x-raying to do the
job.  Remember, these suckers are 12 feet across and 15 stories
high (forgot the exact height) and you want to use at least 2 of
them per month.  It may be desirable, but it probably isn't
practical. 

You would also have to xray them before they are loaded with
fuel, which is prior to final assembly.

Nevertheless, if the SRB's are determined to be the cause
of the problem, then perhaps closer inspections/QC is required.

- dave

Re: destruction of SRB's

I heard a report which described the method of destroying the SRB's.  The range
master sends a signal to a shaped charge on board the SRB when it is determined
that they might impact near a populated area.  The charge is "a cord running the
length of the SRB with a V cut on the side of the cord towards the SRB."  When
this explosive is detonated, it has the effect of "unzipping" the skin of the
SRB.  Thus the SRB is NOT blown into a million tiny pieces and there is a chance
of recovering some large pieces.  According to the report that I heard, the
charge is on the opposite side as the rupture seen in the NASA films.  This
means that it is possible that the area around the rupture MAY be found intact.

---Phil
                                               

RE: .9 and X-raying the srb's

Aircraft (especially carrier based) are subjected to magna-fluxing, 
which as I understand it is essentially an x-raying technique, to 
determine if cracks have developed due to overstresses like hard 
landings. I would think if you can do this to a F-14 you could do it to 
the SRB's.

dave

I don't what they do to the casings in the way of x-ray or magnaflux but
they do examine the propellant after it has been cast in each segment for
structural problems (bubbles, fissures, areas of unusual density).

gary

re: Destruction of SRBs. .-a couple is correct. There is an external tube on
    the outboard side of the SRBs (the Systems Tunnel) which carries electronics
    (sensors on some flights, and the cables from fore to aft) and the destruct
    charges. Detonating them splits the casing down the side and allows the fuel
    to burn quickly and without a nozzle.

    From 2/10/86 Aviation Week and Space Technology:

	"A Thiokol booster recovery ship Feb. 4 obtained a solid sonar fix on
	what is believed to be a booster, lying in more than 1,000 ft. of water.
	Owing to the complexities of tracking debris after the explosion, board
	members are only about 80% sure that the motor believed located is the
	vehicle's right side booster and not the left motor, which would be less
	valuable from a data standpoint."

						-Brian

    Re: .8,.9,...
    
    
    According to AW&ST, after each flight the SRB casings are magnetized
    and then scanned.  Cracks, stress points, etc. are detected this
    way.
    
    I regret my misinformation about the composite SRB casings.  The
    "current" ones are solid steel, 0.5 inches thick (give or take a
    few hundreths).  The composite boosters haven't been used yet
    (see later notes on this subject).
    
    - dave

Article: 2143
From: [email protected] (Thomas J. Frieling)
Newsgroups: sci.space.tech
Subject: Searching for Challenger's Crew Cabin--Update
Date: Tue, 7 Jun 1994 13:48:37
Organization: Bainbridge College
 
The recent discussion regarding the Air & Space article by the diver
who found the Challenger Crew Cabin leads me to direct your attention
to the letters section of the June/July issue of same (p.7-8). 
 
Major Eric S. Buck, USAF (ret.) tells in his letter of how in the '60s
the Air Force at the Cape used a classified software package called
In-Line Integration Control (ILIC) that ran the radars and the
tracking cameras. This software was able to give real time coordinates
of outbound rockets as well as TV imagery. He uses the example of the
smoothly tracked long-range TV pictures of Apollo launches to
illustrate what this software could do. 
 
One day a missile test was blown up and seven pieces were tracked into
the Atlantic. Divers recovered the pieces the same day. 
 
When Challenger blew up and the weeks went by in the search for the
Crew Cabin, Major Buck called the Cape to inquire why ILIC haden't
tracked the debris. He was told that when NASA changed contratactors
on the range, the new contractor "improved" the tracking software and
that it didn't have the bandwidth it used to. 
 
After asking around if anyone had a copy of the original ILIC he was
told that all copies were destroyed:  "Anything in the safes over five
years goes." 
 
Can anyone out there confirm this story? If it's true it sure doesn't
sound like any way to run a range to me.