wolit@mhuxd.UUCP (Jan Wolitzky) (01/30/86)
The videotapes of the Challenger explosion showed the still-burning solid rocket boosters corkscrewing away from the fireball. I've seen reports that at least one of them descended by parachute, which is the way they're normally recovered. Yet today, NASA said that they were destroyed by the range safety officer because one of them was headed toward a populated area. This should be fairly easy to confirm from eyewitness accounts. Were both SRBs destroyed by command or just one? What explanation is there for accounts of a parachute descending? Was any telemetry received from the SRBs following the explosion? (I believe they normally transmit at least a homing signal that aids in their recovery.) Am I correct in my understanding that, under less catastrophic conditions, the SRBs are capable of independent guidance, at least to keep them clear of the orbiter after jettisoning following burnout or during an abort? -- Jan Wolitzky, AT&T Bell Labs, Murray Hill, NJ; 201 582-2998; mhuxd!wolit (Affiliation given for identification purposes only)
cja@umich.UUCP (Charles J. Antonelli) (01/30/86)
In article <4270@mhuxd.UUCP> wolit@mhuxd.UUCP (Jan Wolitzky) writes: >Am I correct in my understanding that, >under less catastrophic conditions, the SRBs are capable of >independent guidance, at least to keep them clear of the orbiter >after jettisoning following burnout or during an abort? I would be surprised if the SRBs were capable of independent guidance. They have no control surfaces, and I doubt the SRB nozzles are on gimbals like those of the main engines. At burnout explosive bolts separate the SRBs from the rest of the orbiter which continues to accelerate away on its main engines. I'll admit I don't know the cause for the smooth peeling away of the SRBs following burnout. Maybe the top bolts blow first, and the aerodynamics do the rest. During an abort I suspect the orbiter must be flown away from the tank/SRB assembly. Does anyone know if there is a small fuel reserve within the orbiter for such an occasion?
rck@ihuxx.UUCP (Kukuk) (01/30/86)
It's my belief that NASA Launch Operations will regret that they intentionally destroyed the SRBs. As I understand that situation, there was only a POSSIBILITY that the SRBs could have fallen on populated areas. They surely would have burned for only a few more seconds. Would the parachute recovery mechanism have worked even after the shuttle explosion? Recovering those SRBs, even after a fall of ten miles, might have provided some evidence concerning the tragedy. Ron Kukuk
henry@utzoo.UUCP (Henry Spencer) (01/31/86)
> ...reports that at least one of [the SRBs] descended by parachute... > ... Yet today, NASA said that > they were destroyed by the range safety officer because one of them > was headed toward a populated area... What probably happened is that a fragment of one stayed attached to one of the chutes, which managed to open. The destruct system doesn't reduce them to atoms. > ... Am I correct in my understanding that, > under less catastrophic conditions, the SRBs are capable of > independent guidance, at least to keep them clear of the orbiter > after jettisoning following burnout or during an abort? I believe this is not the case. They are moved clear of the orbiter after burnout by smaller solid-fuel rockets that are present specifically for the purpose, as I recall. Their control comes entirely from the orbiter, and in any case after burnout they have little or no independent maneuverability. My recollection (which may be wrong) is that there basically is *no* abort available until SRB burnout, because there is no way to shut them down (short of destruction) and the jettison system can't safely cut them loose while the attachment points are carrying millions of pounds of thrust. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry
mrgofor@mmm.UUCP (Michael Ross) (01/31/86)
In article <4270@mhuxd.UUCP> wolit@mhuxd.UUCP (Jan Wolitzky) writes: >The videotapes of the Challenger explosion showed the still-burning >solid rocket boosters corkscrewing away from the fireball. I've >seen reports that at least one of them descended by parachute, which >is the way they're normally recovered. I understood that they fell into the ocean - I was not aware that they even had parachutes. >Yet today, NASA said that >they were destroyed by the range safety officer because one of them >was headed toward a populated area. This should be fairly easy to >confirm from eyewitness accounts. Were both SRBs destroyed by command >or just one? Yes - I saw the footage on TV. >What explanation is there for accounts of a parachute >descending? I saw footage of parachutes on TV - they were part of the rescue and search efforts - not part of the SRBs. Perhaps this caused the confusion. >Was any telemetry received from the SRBs following the >explosion? (I believe they normally transmit at least a homing signal >that aids in their recovery.) Am I correct in my understanding that, >under less catastrophic conditions, the SRBs are capable of >independent guidance, at least to keep them clear of the orbiter >after jettisoning following burnout or during an abort? I don't know, but I would doubt it. Why go to all the added expense of a guidance system when it would never be used except in emergency - which is already taken care of by the Air Force's self-destruct ordinance? >-- >Jan Wolitzky, AT&T Bell Labs, Murray Hill, NJ; 201 582-2998; mhuxd!wolit >(Affiliation given for identification purposes only) --MKR
danny@sftig.UUCP (L.Rosler) (01/31/86)
> During an abort I suspect the orbiter must be flown away from the > tank/SRB assembly. Does anyone know if there is a small fuel > reserve within the orbiter for such an occasion? There is a large fuel tank. The shuttle uses that fuel to gain higher orbits, adjustments in flight and reentry burn. Dan Rosler ihnp4!attunix!danny
rt@cpsc53.UUCP (Ron Thompson) (01/31/86)
> >Am I correct in my understanding that, > >under less catastrophic conditions, the SRBs are capable of > >independent guidance, at least to keep them clear of the orbiter > >after jettisoning following burnout or during an abort? > > I would be surprised if the SRBs were capable of independent guidance. > They have no control surfaces, and I doubt the SRB nozzles are on gimbals > like those of the main engines. At burnout explosive bolts separate the > SRBs from the rest of the orbiter which continues to accelerate away > on its main engines. I'll admit I don't know the cause for the smooth > peeling away of the SRBs following burnout. Maybe the top bolts blow > first, and the aerodynamics do the rest. The SRB nozzles swivel (or gimbal) up to 6 degrees to direct the thrust and steer the Shuttle. - THE SPACE SHUTTLE OPERATOR'S MANUAL,Joel/Kennedy This, of course does not fully answer your question of independent guidance - it would seem more likely though. > During an abort I suspect the orbiter must be flown away from the > tank/SRB assembly. Does anyone know if there is a small fuel > reserve within the orbiter for such an occasion? There are three abort procedures, RTLS(return to launch site), AOA (abort once around) and ATO(abort to orbit). "RTLS does not begin until after the SRB's have burned out and have been jetisoned." At that point, all remaining fuel is burned heading down-range by the main engines, both OMS engines and the 4 aft-firing maneuvering rockets till a halfway mark is reached. Direction is then reversed towards the launch site, remaining fuel expended, external tank jettisoned and a normal landing. Should the mains be out or turning out of the question, the Shuttle should land at Naval Air Station, Spain. AOA is used when the mains fail or the SRC's burn out before orbit can be acheived, and I suspect the mission is too far along for RTLS. The OMS and RCS engines are used till emergency landing at White Plains. ATO is used after trouble in late ascent, the OMS are used to acheive less than target orbit. Probably important to note that there are no abort procedures until the SRB's are finished. I've had the manual since last summer's visit to the Cape and have enjoyed the good level of detail. -- Ron Thompson AT&T Information Systems Customer Programming (404) 982-4217 Atlanta, Georgia Services Center ..{ihnp4,akgua}!cpsc53!rt (Opinions expressed are mine alone.)
rcj@burl.UUCP (Curtis Jackson) (01/31/86)
In article <958@ihuxx.UUCP> rck@ihuxx.UUCP (Kukuk) writes: >It's my belief that NASA Launch Operations will regret that they >intentionally destroyed the SRBs. As I understand that situation, >there was only a POSSIBILITY that the SRBs could have fallen on >populated areas. They surely would have burned for only a few >more seconds. Would the parachute recovery mechanism have worked even >after the shuttle explosion? Recovering those SRBs, even after >a fall of ten miles, might have provided some evidence concerning >the tragedy. > >Ron Kukuk > And also may have provided a scapegoat. I didn't want to post this before, but I'm *very* pissed off at NASA at the moment. They kept us waiting for over an hour on the afternoon of the explosion only to tell us that they wouldn't tell us anything. My father was intimately involved in the shuttle program on the safety end of the business for about 8 or 9 years. He called the director of flight safety for the SRBs in Florida shortly after the explosion and was told that the pilot knew there was a problem and had made the decision to jettison both the SRBs and the ET and abort back to ground, but that the thing exploded before he could accomplish any of this. This means that there had to be air-to-ground audio traffic on this matter, but we never heard any. I did notice in the press conference that the deputy director (or whoever he was) said that the shuttle blew approximately 1.5 minutes after launch (close enough), but he said *twice* that there was no evidence of any problems at all *UP TO ONE MINUTE AFTER LAUNCH*. Of course, no one in the press corps had the intelligence to do a little subtraction and ask a pointed question. Also, from a (possibly) less reliable source: The thing that came down on a parachute that took forever (almost 20 mins.) to fall was supposedly the "black box"; just like the flight recorders used on airliners. I don't know if it was successfully recovered. Please don't write me for extra "inside" information because I don't have any that I consider even remotely outside the realm of speculation. I do have it from several people in the program that they do NOT suspect the SRBs of burning through at this time -- I just hope they don't try to blame it on them anyway and get anyone else killed. Anything I hear will be posted post-haste, -- The MAD Programmer -- 919-228-3313 (Cornet 291) alias: Curtis Jackson ...![ ihnp4 ulysses cbosgd mgnetp ]!burl!rcj ...![ ihnp4 cbosgd akgua masscomp ]!clyde!rcj
john@frog.UUCP (John Woods, Software) (01/31/86)
> The videotapes of the Challenger explosion showed the still-burning > solid rocket boosters corkscrewing away...at least one of them descended > by parachute. Yet today, NASA said that they were destroyed by the range > safety officer because one of them was headed toward a populated area. > I heard conflicting reports of "they were destroyed" and "one was destroyed". Typical of the quality of our "news" media, I suppose. The TV picture of the parachute didn't look like an entire SRB, so it could have been the nose cone of a destroyed SRB whose parachute managed to work. > [are] the SRBs...capable of independent guidance? > I doubt it. They would need independant stabilizers which would only add weight that is unnecessary normally. Also, I believe that the boosters can't be detached while they are firing; I suspect that NASA just hoped that nothing serious would go wrong with them [[[ There are extremely knowledgable people on the net here, I hope that one of them will correct my no-doubt confused notions ]]]. I never did trust the SRBs all that much... -- John Woods, Charles River Data Systems, Framingham MA, (617) 626-1101 ...!decvax!frog!john, ...!mit-eddie!jfw, jfw%mit-ccc@MIT-XX.ARPA This space dedicated to Challenger and her crew, Francis R. Scobee, Michael J. Smith, Ellison S. Onizuka, Judith Resnik, Ronand E. McNair, Gregory B. Jarvis, and Crista McAuliffe. "...and slipped the surly bonds of Earth to touch the face of God."
kenny@uiucdcsb.CS.UIUC.EDU (01/31/86)
It is fairly obvious that a parachute which can be observed descending
amidst the debris following the explosion is not a paramedic (contrary to
the statement of the announcer on the NASA-Select feed), nor in fact a
personnel 'chute at all. Personnel 'chutes have ``modifications'' --
openings cut into them to permit the user to steer and control his descent
by adjusting tension on the shrouds. The parachute that was visible had no
modifications and was descending in an uncontrolled fashion.
The recovery crew reports that among the debris was a ``fifteen foot conical
object'' with a parachute attached to it. While the recovery officer was
unwilling to commit to its identity, it seems fairly obvious that the object
was an SRB nosecone, or at least a piece of one. I suspect that the
consistent explanation of all these observations is that the SRB's were
indeed destroyed by the range safety officer, but that the nosecone of one
survived the self-destruct and had its recovery apparatus deploy normally.
All of this is just uneducated speculation. Can someone ``in the know''
confirm any of it?
Kevin Kenny
UUCP: {ihnp4, pur-ee, convex}!uiucdcs!kenny
ARPA: kenny@B.CS.UIUC.EDU ( kenny@UIUC.ARPA for old-fashioned
nameservers)
CSNET: kenny@UIUC.CSNET
O Spirit, Whom the Father sent
To spread abroad the firmament,
O Wind of Heaven, by Thy might,
Spare those who dare the eagle's flight,
And keep them in Thy watchful care
From every peril of the air.
``A Service Hymn-Book,'' 1937
Almighty Ruler of the all,
Whose power extends to great and small,
Who guides the stars with steadfast law,
Whose least creation fills with awe,
Oh, grant Thy mercy and Thy grace
To those that venture into space.
Robert Anson Heinlein, 1948bjb@nvzg2.UUCP (Bernie Brown) (01/31/86)
> During an abort I suspect the orbiter must be flown away from the > tank/SRB assembly. Does anyone know if there is a small fuel > reserve within the orbiter for such an occasion? From what I've read over the years, and it the current coverage, the shuttle only has the possible use of the small manuvering rockets for attitude control. This is to get the craft oriented for a landing at any of the emergency airstrips (There are three, Kennedy Space Center, one in Europe, and one in Africa.). After getting oriented correctly, it's all up to the pilot, with some help from the on-board navigation system, to make a dead-stick landing. Just like a normal landing, it's the world's biggest glider. -- Bernie Brown (AT&T-IS, Altamonte Springs, FL) UUCP ...!ihnp4!codas!nvzg2!bjb This is my commentary not theirs. I don't know, or care, if they care anyway.
devils1@hou2g.UUCP (D.DARBY) (02/01/86)
>It's my belief that NASA Launch Operations will regret that they >intentionally destroyed the SRBs. As I understand that situation, >there was only a POSSIBILITY that the SRBs could have fallen on >populated areas. They surely would have burned for only a few >more seconds. Would the parachute recovery mechanism have worked even >after the shuttle explosion? Recovering those SRBs, even after >a fall of ten miles, might have provided some evidence concerning >the tragedy. > >Ron Kukuk --- You have to remember that it only takes multiple seconds for the SRBs to reach the ground, and that even with the parachute deployed, they may have drifted out of contol. As I understand it, (please correct me if I'm wrong) they destruct the SRB by re-directing the thrust, forcing the rocket to blow itself up. Without any fuel left in the rocket, there would be no way to destruct it. The decision must be made before there is even the slightest chance that some debris will fall on some populated area. They had already lost the seven crew members, shuttle and payload: they surely didn't want a lawsuit on their hands. --- Dave Darby AT&T Bell Labs Holmdel, NJ we won't forget them!!!
ccs025@ucdavis.UUCP (Johan) (02/01/86)
> In article <4270@mhuxd.UUCP> wolit@mhuxd.UUCP (Jan Wolitzky) writes: > > >Am I correct in my understanding that, > >under less catastrophic conditions, the SRBs are capable of > >independent guidance, at least to keep them clear of the orbiter > >after jettisoning following burnout or during an abort? > > I would be surprised if the SRBs were capable of independent guidance. > They have no control surfaces, and I doubt the SRB nozzles are on gimbals > like those of the main engines. I agree. It would seem the three main engines would exert enough control. > At burnout explosive bolts separate the > SRBs from the rest of the orbiter which continues to accelerate away > on its main engines. I'll admit I don't know the cause for the smooth > peeling away of the SRBs following burnout. Maybe the top bolts blow > first, and the aerodynamics do the rest. And most importantly, the SRBs are usually not thrusting after they are released. Burnout occurs first, then they are released. This leaves only drag to slow them down. Durring the accident the SRBs had thrust without a guidance system, hence the spiral. > > During an abort I suspect the orbiter must be flown away from the > tank/SRB assembly. Does anyone know if there is a small fuel > reserve within the orbiter for such an occasion? I do not know if there is a reserve tank for the main engines, but there is always the OMS (orbital manuevering) engines or the mant RCS (reaction control) engines. BUT, at a point where escape velocity will not be reached and orbit insertion is not possible, NO engines would be used in an abort. The vehicle is on it's back and would disengage from the External Tank. It would then fall away as the tank continued by using the control surfaces (elevons, rudder) if there was sufficient air density, or they would fall until there was. Even with the poor glide ratio the shuttle has, when you are 10 miles up you have a decent chance of making it back to Kennedy. If not, then an ocean ditch would be made. Preperation for this possibility is the reason so many ships and planes were ready to search for wreckage so fast. The commander would be very busy trying to land safely, without having to worry what firing the engines would do. The experts can correct me if I am in error, but I do not even think the crew can manually control the gimbal of the main engines without a series of lengthy computer entries. The sticks in the cockpit only control the smaller engines for fine-tuning once in orbit. But what do I know, I'm still a student of all this. I have a few books with some specifics, and I will try to clarify the above speculations, unless someone has completely slashed my logic by then ;-). -- Martin Van Ryswyk {dual,lll-crg,ucbvax}!ucdavis!deneb!ccs025 uucp ucdavis!deneb!ccs025@ucbvax.berkley.edu arpa
yee@ucbarpa.berkeley.edu.BERKELEY.EDU (Peter E. Yee) (02/01/86)
In article <437@umich.UUCP> cja@umich.UUCP (Charles J. Antonelli) writes: >I would be surprised if the SRBs were capable of independent guidance. >They have no control surfaces, and I doubt the SRB nozzles are on gimbals >like those of the main engines. According to the Space Shuttle Operator's Manual (a source whose veracity I can't vouch for), the SRB nozzle's can gimbal six degrees. Not an overwhelming amount of control, but they are adjustable. -Peter Yee ..ucbvax!yee yee@ucbarpa.BERKELEY.EDU
greg@ncr-sd.UUCP (Greg Noel) (02/01/86)
In article <437@umich.UUCP> cja@umich.UUCP (Charles J. Antonelli) writes: >I would be surprised if the SRBs were capable of independent guidance. You are correct, they aren't. >Maybe the top bolts blow first, and the aerodynamics do the rest. At the height where the separation usually takes place, there isn't much aerodynamics. They are pushed away by very small rockets at the tip and tail of the SRB. >During an abort I suspect the orbiter must be flown away from the >tank/SRB assembly. Does anyone know if there is a small fuel >reserve within the orbiter for such an occasion? There is a fair amount of manuevering available -- don't forget that the orbiter needs to apply the final push into orbit as well as the burn to bring it back down. -- -- Greg Noel, NCR Rancho Bernardo Greg@ncr-sd.UUCP or Greg@nosc.ARPA
rodean@hpfcla.UUCP (02/01/86)
The self-destruct mechanism on the SRB blows off the top of the rocket
and ignites the fuel at that end (i.e. burning a candle at both ends).
This cancels the thrust and the rocket burns its fuel twice as fast with
no acceleration. The SRBs are not 'destroyed' in the usual sense, and
provided that they can be found, ought to be in fairly good condition
since they were able to continue flight after the explosion.
Bruce Rodean
{ihnp4|hplabs}!hpfcla!rodeanmas3619@wucec2.UUCP (Marc Andrew Sarrel) (02/01/86)
In article <958@ihuxx.UUCP> rck@ihuxx.UUCP (Kukuk) writes: >It's my belief that NASA Launch Operations will regret that they >intentionally destroyed the SRBs. As I understand that situation, >there was only a POSSIBILITY that the SRBs could have fallen on >populated areas. > >Ron Kukuk I think that NASA made the correct descision when they destroyed the SRBs, Regardless of any help that they might have been in the invvestigation. They did not want to take the chance of more injuries or casualties, especially if those people are 'innocent bystanders.' Can you imagine the criticism NASA would have had to endure if the SRB's had killed some citizens? They have enough headaches as it is. -- -Marc ..!{seismo,cbosgd,ihnp4}!wucs!wucec2!mas3619 Marc Sarrel 6515 Wydown Blvd Box 4481 St. Louis, MO 63105 The views expressed here are mine and not necessarily anyone else's.
polish@garfield.columbia.edu (Nathaniel Polish) (02/02/86)
Newsgroups: net.columbia Subject: Re: Challenger disaster Summary: Expires: References: <787@decwrl.DEC.COM> <496@eneevax.UUCP> <1771@bbnccv.UUCP> Sender: Reply-To: polish@garfield.UUCP (Nathaniel Polish) Followup-To: Distribution: Organization: Columbia University Keywords: There seems to be some confusion about the tank. It is not reused. Also, the range safty system (self-distruct) is included on almost every rocket every built. This is necessary for obvious reasons. The external tank uses a linear shaped charge with a battery and encoded receiver made by Motorola. The kind of ordinace used is very hard to set off accidently. As for the rapid mixing and explosion: at 2000 miles per hour things mix very fast with no help from explosives. There was at least one near burn through of an SRB last year so this is a possable source of the explosion. The flare that we all saw appears quite a bit behind the umbilical area of the orbiter. But, who knows, the pictures are not very clear and the events occured so rapidly that it is hard to figure which is cause and effect.
desj@brahms.BERKELEY.EDU (David desJardins) (02/02/86)
In article <977@burl.UUCP> rcj@burl.UUCP (Curtis Jackson) writes: > ... My father was intimately involved >in the shuttle program on the safety end of the business for about 8 or 9 >years. He called the director of flight safety for the SRBs in Florida >shortly after the explosion and was told that the pilot knew there was >a problem and had made the decision to jettison both the SRBs and the ET >and abort back to ground, but that the thing exploded before he could >accomplish any of this. > >This means that there had to be air-to-ground audio traffic on this matter, >but we never heard any. That is exactly what it means. Not only did we not hear any, but my understanding is that NASA has specifically denied that there was such traffic. NASA has admitted that they have information which is not being released (e.g. pictures from other angles), but I find it *very* hard to believe that they would lie about something like this. They would certainly be found out; obviously they can't keep the air-to-ground traffic (or anything else about the accident) secret forever. If we find out in a few days or weeks that this is in fact true NASA is certainly going to feel some heat! Also, does anyone know for sure if there is in fact a capability for abort before the SRBs have burned out? I seem to recall that there was something in the early flights but that they weren't too confident about its chances for success. >Also, from a (possibly) less reliable source: The thing that came down on >a parachute that took forever (almost 20 mins.) to fall was supposedly >the "black box"; just like the flight recorders used on airliners. I don't >know if it was successfully recovered. This I am virtually certain is false; there is no such object on the shuttle. -- David desJardins
kenny@uiucdcsb.CS.UIUC.EDU (02/02/86)
As a follow-up to this discussion, NASA confirmed yesterday that the conical
object recovered from the sea was an SRB nosecone. The recovery parachute
had, in fact, deployed normally. The separation motors were still intact,
implying that Scobee and Smith had not attempted to blow the SRB's and ditch
the External Tank, which would have been the procedure they would have
followed if they had had warning of the impending explosion.
In the same press release, NASA acknowledged the sighting of abnormal flames
forward of the nozzle of one SRB (visible as early as 0:58 after launch from
some camera angles) and confirmed a drop in combustion-chamber pressure in
that SRB consistent with a flame leak. NASA spokesman Hugh Harris refused
to speculate as to the significance of this finding and stated that these
observations were ``an area of interest; not the only area of interest''.
Does anybody recall discussion in this newsgroup several months ago about a
near-disastrous fault in an SRB on an earlier flight which nearly caused a
burnthrough shortly before SRB sep? Does anyone still have a transcript of
that discussion, or at least remember the salient points?
k**2
Kevin Kenny
University of Illinois at Urbana-Champaign
UUCP: {ihnp4,pur-ee,convex}!uiucdcs!kenny
CSNET: kenny@UIUC.CSNET
ARPA: kenny@B.CS.UIUC.EDU (kenny@UIUC.ARPA)
"Yes, understanding today's complex world is a bit like having bees live in
your head, but there they are."jer@peora.UUCP (J. Eric Roskos) (02/03/86)
> It's my belief that NASA Launch Operations will regret that they > intentionally destroyed the SRBs. As I understand that situation, > there was only a POSSIBILITY that the SRBs could have fallen on > populated areas. They surely would have burned for only a few > more seconds. Would the parachute recovery mechanism have worked even > after the shuttle explosion? It appeared from here that one of the SRBs was heading almost straight downward, under power, shortly before it was destroyed. -- UUCP: Ofc: jer@peora.UUCP Home: jer@jerpc.CCUR.UUCP CCUR DNS: peora, pesnta US Mail: MS 795; CONCURRENT Computer Corp. SDC; (A Perkin-Elmer Company) 2486 Sand Lake Road, Orlando, FL 32809-7642 xxxxx4xxx "There are other places that are also the world's end ... But this is the nearest ... here and in England." -TSE
john@frog.UUCP (John Woods, Software) (02/03/86)
> In article <958@ihuxx.UUCP> rck@ihuxx.UUCP (Kukuk) writes: > >It's my belief that NASA Launch Operations will regret that they > >intentionally destroyed the SRBs. Had SRB pieces (or entire SRBs) rained down upon a crowded shopping mall, the Shuttle disaster would have been forgotten by the Congressmen who finally had a concrete excuse to shut down NASA and turn that money over to decent businessmen in their home states... :-( > ...I'm *very* pissed off at NASA at the moment. They kept us > waiting for over an hour on the afternoon of the explosion only to tell > us that they wouldn't tell us anything. I'm willing to believe that NASA _knew_ nothing to tell. Perhaps the news media would have been deliriously happy had NASA elected to release a stream of "Well, it might have been X.... No, it might have been Y.... ", but the problems with this include (1) the vacillation would make NASA look stupid, because each guess (released only out of curtesy) would be treated as an Official Explanation, only to have that Official Explanation Officially Contradicted later, and (2) somewhere the engineers will examine the possibility that some human (or organization) seriously screwed up, and any further guesses released which didn't include that human error (like metal fatigue, etc.) would look like a cover-up, EVEN if the facts later gathered made the human error explanation unlikely (indeed, the better the evidence against, "the more thorough the cover-up", right?). I would dearly love to know, right now, what happened. So would a lot of people. Some of them work at NASA. > Also, from a (possibly) less reliable source: The thing that came down on > a parachute that took forever (almost 20 mins.) to fall was supposedly > the "black box"; just like the flight recorders used on airliners. I don't > know if it was successfully recovered. The Shuttle does not contain a flight recorder. The telemetry continually transmitted is considered sufficient (after all, it is hard to destroy radio waves after you let them go); this piece of misinformation makes me question the other paranoid statements (not included) of the author. -- John Woods, Charles River Data Systems, Framingham MA, (617) 626-1101 ...!decvax!frog!john, ...!mit-eddie!jfw, jfw%mit-ccc@MIT-XX.ARPA This space dedicated to Challenger and her crew, Francis R. Scobee, Michael J. Smith, Ellison S. Onizuka, Judith Resnik, Ronald E. McNair, Gregory B. Jarvis, and Christa McAuliffe. "...and slipped the surly bonds of Earth to touch the face of God."
john@frog.UUCP (John Woods, Software) (02/03/86)
Henry (>) says to someone (>>) in 6339@utzoo.UUCP > > ... Yet today, NASA said that > > they were destroyed by the range safety officer because one of them > > was headed toward a populated area... > > What probably happened is that a fragment of one stayed attached to one > of the chutes, which managed to open. The destruct system doesn't reduce > them to atoms. In fact, according to the Monday Boston Globe, "James Mizell, a retired NASA engineer working as a consultant to the space agency, said yesterday that in a ''thrust termination'' procedure, explosive charges were used to ''cut the top and bottom off, disableing the rockets.'' [PARAGRAPH] Under the procedure burning fuel then fires from both ends, Mizell said, stopping the rocket's forward motion." And thus, they expect to recover fairly sizable pieces of the SRBs (if they survived hitting the water faster than normal). > > ... Am I correct in my understanding that, under less catastrophic > > conditions, the SRBs are capable of independent guidance, at least to keep > > them clear of the orbiter after jettisoning following burnout or during > > an abort? > > > My recollection (which may be wrong) is that there basically is *no* abort > available until SRB burnout, because there is no way to shut them down > (short of destruction) and the jettison system can't safely cut them loose > while the attachment points are carrying millions of pounds of thrust. I would think to agree with this, but it was reported by NASA that because the SRB nosecones (the second was just recovered Sunday, BTW) both had their separation rockets intact and unfired, the pilot did not "hit the 'ditch button'" to separate early. Hence, I guess that it is considered possible to separate from the SRBs even while they are burning (possibly because safety is a relative thing...). -- John Woods, Charles River Data Systems, Framingham MA, (617) 626-1101 ...!decvax!frog!john, ...!mit-eddie!jfw, jfw%mit-ccc@MIT-XX.ARPA This space dedicated to Challenger and her crew, Francis R. Scobee, Michael J. Smith, Ellison S. Onizuka, Judith Resnik, Ronald E. McNair, Gregory B. Jarvis, and Christa McAuliffe. "...and slipped the surly bonds of Earth to touch the face of God."
henry@utzoo.UUCP (Henry Spencer) (02/04/86)
> > I would be surprised if the SRBs were capable of independent guidance. > > They have no control surfaces, and I doubt the SRB nozzles are on gimbals > > like those of the main engines. > I agree. It would seem the three main engines would exert > enough control. Unfortunately, they don't; that is precisely the problem. NASA would have liked to avoid the complexity of having gimbaled nozzles in the SRBs, but it wasn't avoidable. The SRBs give most of the launch thrust for the shuttle, and the main engines have only a limited gimbal range. It turns out that the main engines cannot exert enough side thrust for adequate control while the SRBs are burning. So the SRBs have nozzle gimbals. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry
barb@oliven.UUCP (Barbara Jernigan) (02/04/86)
> It's my belief that NASA Launch Operations will regret that they > intentionally destroyed the SRBs. As I understand that situation, > there was only a POSSIBILITY that the SRBs could have fallen on > populated areas. That POSSIBILITY is enough. It is one thing to have the Challenger blow up killing seven who knew the risks (I grieve them, how I grieve them) -- it is quite another to have an SRB take out a major section of a city/town. THAT would have put the nails in the coffin. I, too, regret that the SRBs were not recovered -- but I do not criticize NASA's decision. It *may* have been too conservative -- but I, for one, wouldn't want to second-guess Chance. Barb
sean@ukma.UUCP (Sean Casey) (02/04/86)
In article <366@nvzg2.UUCP> bjb@nvzg2.UUCP (Bernie Brown) writes: >...Just like a normal landing, it's >the world's biggest glider. That reminds me what a NASA spokesperson said once. A newscaster said something about the shuttle being basically a glider and the NASA person said "it's more like a flying brick". That statement is not far off base, for the glide ratio of the shuttle is truly awful. -- ------------------------------------------------------------------------------- Sean Casey UUCP: sean@ukma.uucp CSNET: sean@uky.csnet University of Kentucky ARPA: ukma!sean@anl-mcs.arpa Lexington, Kentucky BITNET: sean@ukma.bitnet "Wherever you go, there you are."
swengle@uok.UUCP (02/05/86)
The exhaust nozzles on the SRBs are gimbled and are controlled by gyroscopes
in each SRB. Did you notice that immediately after the explosion both SRBs
resumed their original course for a few seconds?
Steve Engle
University of Oklahoma
{ctvax,ea,okstate}!uokvax!uok!swenglehenry@utzoo.UUCP (Henry Spencer) (02/05/86)
> > It's my belief that NASA Launch Operations will regret that they > > intentionally destroyed the SRBs. As I understand that situation, > > there was only a POSSIBILITY that the SRBs could have fallen on > > populated areas. They surely would have burned for only a few > > more seconds. Would the parachute recovery mechanism have worked even > > after the shuttle explosion? > > It appeared from here that one of the SRBs was heading almost straight > downward, under power, shortly before it was destroyed. The story I hear is that the original message was correct, and NASA does regret the destruction of the SRBs; in retrospect there was little danger of them going anywhere untoward. But the Range Safety people had only seconds in which to make a decision, and I believe NASA has officially stated that their (as it turns out) excessive caution was proper. The recovery system would probably have worked, given that the noses of the SRBs were probably the section least exposed to the blast. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry
ijk@hropus.UUCP (Ihor J. Kinal) (02/05/86)
It occurred to me that the design of the SRB's did not actually necessitate them being totally demolished upon destruct - insted, just blow the tops off - then the exhaust would come out of the top as well, since the SRBs are hollow. This would stop them in short oreder. In today's NY Times, I read that I was correct (except that the destruct mechanism also blows away the nozzles at the base). The parachute that was seen was attached to the cone that was blown off. Of course, since the boosters are no longer connected to parachutes, they hit the ocean at terminal velocity, so it's not clear how intact they still might be. Ihor Kinal ihnp4!houxm!hropus!ijk
greg@nmtvax.UUCP (Greg Titus) (02/07/86)
> According to the Space Shuttle Operator's Manual (a source whose veracity > I can't vouch for), the SRB nozzle's can gimbal six degrees. Not an > overwhelming amount of control, but they are adjustable. I believe the situation is that indeed the SRB nozzles are moveable, but that the control for that movement comes entirely from the shuttle itself. Thus, once the launch assemblage is no longer intact, the SRBs are not steerable. greg -- Greg Titus ..!ucbvax!unmvax!nmtvax!greg (uucp) NM Tech Computer Center ..!cmcl2!lanl!nmtvax!greg (uucp) Box W209 C/S greg@nmt (CSnet) Socorro, NM 87801 greg.nmt@csnet-relay (arpa) (505) 835-5735 ======================================================================
lmc@cisden.UUCP (Lyle McElhaney) (02/08/86)
> I'm willing to believe that NASA _knew_ nothing to tell. Perhaps the news > media would have been deliriously happy had NASA elected to release a stream > of "Well, it might have been X.... No, it might have been Y.... ", but the > problems with this include (1) the vacillation would make NASA look stupid, > because each guess (released only out of curtesy) would be treated as an > Official Explanation, only to have that Official Explanation Officially > Contradicted later, and (2) somewhere the engineers will examine the > possibility that some human (or organization) seriously screwed up, and any > further guesses released which didn't include that human error (like metal > fatigue, etc.) would look like a cover-up, EVEN if the facts later gathered > made the human error explanation unlikely (indeed, the better the evidence > against, "the more thorough the cover-up", right?). Worse than that is the possibility of legal action taken against any person or corporation, the possibility of libel/slander proceedings, etc. Mostly bullshit, right?....until you are the specimen in question, or have been slandered, etc. The day of the accident, Rockwell cautioned its employees not to say anything. One newsperson (so to speak) did collar an employee, who said that it was "obviously the external tank...", which may easily have lost him his job. However, the damage was done, and picked up in several papers that I read later. It was only his personal guess, but it became "Rockwell engineers said.....", thereby laying the blame (in the public eye) on the manufacturer of the ET. At that manufacturer's plant, those were fighting words. They also ultimately seem to have been incorrect. A minor point. The president's select panel (including Armstrong and Ride) has stated that it feels no doubt that NASA's own investigation of the accident will be done in the best possible manner. If they can feel so (and at least one of them has her life on the line with that statement) then I feel that NASA can be trusted to find the problem and reduce its future probability to far less than its current 4% occurance. Lyle McElhaney ...hao!cisdem!lmc
lmc@cisden.UUCP (Lyle McElhaney) (02/08/86)
> In fact, according to the Monday Boston Globe, "James Mizell, a retired NASA > engineer working as a consultant to the space agency, said yesterday that in > a ''thrust termination'' procedure, explosive charges were used to ''cut the > top and bottom off, disableing the rockets.'' [PARAGRAPH] Under the procedure > burning fuel then fires from both ends, Mizell said, stopping the rocket's > forward motion." I think this is highly improbable. The nose cone of the SRB contains all the electronics that the SRB possesses (destruct system, pyrotechnics control, recovery beacon, etc.) and the *huge* parachute recovery system. Thrust from both ends of the SRB would not slow down the SRB; it has already burned out when it is jettisoned, and even if it were, such a tactic would probably result in extreme tumbling of the rocket, making parachute deployment impossible. It seems to me that the top and bottom of the SRB is it's most valuable parts; the rest is *just* stovepipe. Lyle McElhaney ...hao!cisden!lmc
goudreau@dg_rtp.UUCP (Bob Goudreau) (02/10/86)
In article <247@hropus.UUCP> ijk@hropus.UUCP (Ihor J. Kinal) writes: >It occurred to me that the design of the SRB's did not actually >necessitate them being totally demolished upon destruct - insted, just blow >the tops off - then the exhaust would come out of the top as well, >since the SRBs are hollow. This would stop them in short oreder. In >today's NY Times, I read that I was correct (except that the destruct >mechanism also blows away the nozzles at the base). Why should this stop them short? True, blowing the top off allows equal amounts of exhuast to issue from either end, but it is only the *acceleration* that disappears; the booster still has its *velocity*. Air resistance and gravity will eventually bring it to a stop, but it might strike a populated area in the meantime. Blowing the entire booster to little bits will greatly increase its coefficient of friction, stopping it sooner. Bob Goudreau
polish@garfield.columbia.edu (Nathaniel Polish) (02/10/86)
In fact, the SRBs can gimble 8 degrees according to the 1981 NASA News Reference on the Shuttle. There are also gyros in each of the SRBs; however, the data from them are sent to the orbiter which merges the info. As discussed before the commands to gimble the SRBs come from the orbiter and no provision is discussed for the SRBs to guide themselves after separation. There seems to be confusion in the press about the range safty systems. According to the 1981 stuff the RSS has a linear charge down the cable tube which runs the length of the SRB. The press suggests that the nose is popped. This had been discussed years ago but I thought abandoned in favor of the system just described. Does anyone know FOR SURE?
irwin@uiucdcs.CS.UIUC.EDU (02/10/86)
>>/* Written 3:29 pm Feb 7, 1986 by lmc@cisden.UUCP in uiucdcs:net.columbia */ >> In fact, according to the Monday Boston Globe, "James Mizell, a retired NASA >> engineer working as a consultant to the space agency, said yesterday that in >> a ''thrust termination'' procedure, explosive charges were used to ''cut the >> top and bottom off, disableing the rockets.'' [PARAGRAPH] Under the procedure >> burning fuel then fires from both ends, Mizell said, stopping the rocket's >> forward motion." >I think this is highly improbable. The nose cone of the SRB contains all >the electronics that the SRB possesses (destruct system, pyrotechnics >control, recovery beacon, etc.) and the *huge* parachute recovery system. >Thrust from both ends of the SRB would not slow down the SRB; it has >already burned out when it is jettisoned, and even if it were, such a >tactic would probably result in extreme tumbling of the rocket, making >parachute deployment impossible. It seems to me that the top and bottom >of the SRB is it's most valuable parts; the rest is *just* stovepipe. >Lyle McElhaney >...hao!cisden!lmc >/* End of text from uiucdcs:net.columbia */ Lyle, in your response to lmc@cisden.UUCP, I do not think you absorbed what you read! Note "thrust termination". This is an abnormal abort, BEFORE the SRBs have burned out, and YES, it will stop the forward motion of the "stovepipe". Ever thought what would happen to a four wheel drive vehicle, if you put the front wheels in reverse and the rear wheels in a forward gear, (not that it can be done) and let them have a tug of war? ["I think this is highly improbable" (Lyle)]. This is EXACTLY what is done. The nose and tail of the SRB are blasted loose, and no consideration is given to the parachute deployment, they are trying to stop the flight of the SRB, not RECOVER it. CBS showed a strip of animated film the other day, which explained the proceedure that the Range Safety Officer had taken. It showed the nose and tail of the SRB being separated from the rest of the SRB, and as it happened, one of the separated nose cones of one of the units had the chute deploy, carrying down only the nose cone. By the way, on the news last night, it was stated that NASA had decided to give up on the search for the remainder of the SRBs (stovepipes). They could have verified the blown seal theory had they found them, but it appears they will not be found. Al Irwin puree!uiucdcs!irwin irwin@a.CS.UIUC.EDU
jer@peora.UUCP (J. Eric Roskos) (02/11/86)
> The story I hear is that the original message was correct, and NASA does > regret the destruction of the SRBs; in retrospect there was little danger > of them going anywhere untoward. But the Range Safety people had only > seconds in which to make a decision, and I believe NASA has officially > stated that their (as it turns out) excessive caution was proper. > > The recovery system would probably have worked, given that the noses of > the SRBs were probably the section least exposed to the blast. What happens if you deploy a parachute on a rocket that is headed almost straight downward? Won't it get tangled in the parachute? -- UUCP: Ofc: jer@peora.UUCP Home: jer@jerpc.CCUR.UUCP CCUR DNS: peora, pesnta US Mail: MS 795; CONCURRENT Computer Corp. SDC; (A Perkin-Elmer Company) 2486 Sand Lake Road, Orlando, FL 32809-7642 xxxxx4xxx
klr@hadron.UUCP (Kurt L. Reisler) (02/12/86)
Before the discussion gets totally out of hand, and not to shed doubt on the knowledge of our TV news personallities... From the February 10 Aviation Week and Space Technology article entitled "Solid Rocket Motor Designed with Conservative Margins" (page 53-57). On page 57... "The range-safety destruct system on the motors had to be used Jan. 28 when one of the boosters began flying back toward the Florida coast following explosion of the external tank and orbiter. That destruct system is a linear-shaped charge that runs down the side of the motor and when fired splits the moter open extinguishing combustion in the motors."
ijk@hropus.UUCP (Ihor J. Kinal) (02/14/86)
References: <4270@mhuxd.UUCP> <8500024@uiucdcs> <261@hadron.UUCP> Everyone has stated that the SRB's have charges down the length of them, and that the news media who claim that only the tops were blown of don't know what they're talking about. Yet in this week's TIME (Feb 17), they state: "While both rockets had been reported blown up by radio signals within 30 seconds of the accident, NASA belatedly explained that only the nose cones and nozzles were detonated. With the boosters thus opened at both ends, they lost their exhaust thrust and fell to the water." Has anyone seen the NASA statement to confirm this???? If this happened, was it a failure of the destruct mechanism. DID ANYONE THERE (Cape Canaveral) OR ON TAPES ACTUALLY SEE THE BOOSTERS ALL THE WAY (and can one tell if the destruct mechanism really works). Still puzzled. Ihor Kinal ihnp4!houxm!hropus!ijk From ijk Fri Feb 14 09:07 EST 1986 Subject: followup failed postnm: line 8: No colon on header line Did you remember to leave a blank line after the article header? postnm: line 9: No colon on header line Did you remember to leave a blank line after the article header? postnm: line 10: No colon on header line Did you remember to leave a blank line after the article header? postnm: line 11: No colon on header line Did you remember to leave a blank line after the article header? postnm: line 12: No colon on header line Did you remember to leave a blank line after the article header? postnm: line 13: No colon on header line Did you remember to leave a blank line after the article header? postnm: line 14: No colon on header line Did you remember to leave a blank line after the article header? postnm: line 15: No colon on header line Did you remember to leave a blank line after the article header? postnm: line 7: you changed the references line but I fixed it Exit status 1 from postnm Your article follows: Command: followup Newsgroups: net.columbia,net.space To: klr@hadron.UUCP (Kurt L. Reisler) Subject: Re: Challenger SRBs Keywords: SRB Destruct Mechanism Distribution: References: <4270@mhuxd.UUCP> <8500024@uiucdcs> <261@hadron.UUCP> Everyone has stated that the SRB's have charges down the length of them, and that the news media who claim that only the tops were blown of don't know what they're talking about. Yet in this week's TIME (Feb 17), they state: "While both rockets had been reported blown up by radio signals within 30 seconds of the accident, NASA belatedly explained that only the nose cones and nozzles were detonated. With the boosters thus opened at both ends, they lost their exhaust thrust and fell to the water." Has anyone seen the NASA statement to confirm this???? If this happened, was it a failure of the destruct mechanism? DID ANYONE THERE (Cape Canaveral) OR ON TAPES ACTUALLY SEE THE BOOSTERS ALL THE WAY (and can one tell if the destruct mechanism really works)? Still puzzled. Ihor Kinal ihnp4!houxm!hropus!ijk
garym@telesoft.UUCP (Gary Morris @favorite) (02/18/86)
> ... By the way, on the news > last night, it was stated that NASA had decided to give up on the search > for the remainder of the SRBs (stovepipes). In the newpaper it stated that recovery ships have now found what they believe to be the right SRB in about 1200 feet of water and that they will try to bring it up. --GaryM -- Gary Morris -- seismo!s3sun!gould9!telesoft!garym decvax!ucbvax!sdcsvax!telesoft!garym telesoft!garym@sdcsvax.ARPA "Always listen to experts. They'll tell you what can't be done and why. Then do it." -- Lazarus Long
henry@utzoo.UUCP (Henry Spencer) (02/22/86)
> What happens if you deploy a parachute on a rocket that is headed almost > straight downward? Won't it get tangled in the parachute? With a gradual-deployment system like that of the SRBs (small chute comes out first, pulls out bigger chute, which pulls out still bigger chutes), one of the major purposes of the early stages in chute deployment is to get the thing pointing the right way. It needs attention but it's manageable. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry