DENNETT@SRI-NIC.ARPA (Steve Dennett) (01/29/86)
The shuttle tragedy has raised some questions (in my mind) about the shuttle, and the effect this disaster will have on the space program. Perhaps the readers of this digest will have some answers or speculation on these questions. - What kind of escape mechanism (if any) does the shuttle have for the crew? - Will this be a setback for the space program, due to public disapproval or the government's need to find (and punish) someone? - Alternately, might it lead to *greater* support of the space program (e.g., if NASA presents a case along the lines of "If our budget were larger, this wouldn't have happened.")? - Might this redirect (to some extent) the focus of the manned space program away from the shuttle (large, complex) back toward simpler or alternative launch systems? Steve Dennett dennett@sri-nic.arpa -------
dietz@SLB-DOLL.CSNET (Paul Dietz) (01/29/86)
> - What kind of escape mechanism (if any) does the shuttle have for the crew? At that point, the only escape mechanism was to detach the orbiter from the fuel tank and hope it doesn't blow up before you get away. I'll add that if they had been able to get away but had to ditch in the ocean they still would probably have died; the shuttle decelerates from 190 knots to zero in 100 yards when ditched and the TDRS would probably have smashed through the cabin. > - Will this be a setback for the space program, due to public disapproval > or the government's need to find (and punish) someone? I was surprised by the immediate and almost universal support for the program expressed by the public and politicians alike. This might change. I doubt it will lead to more money, though. > - Might this redirect (to some extent) the focus of the manned space > program away from the shuttle (large, complex) back toward simpler or > alternative launch systems? It will certainly deflect satellite launching back to unmanned expendable vehicles (mainly Ariane). The disaster has probably soured DOD permanently on the shuttle, so DOD may push for a small TAV. France will go ahead with Hermes, which is smaller and simpler, consisting of a small spaceplane on top of an Ariane-5 launcher.
dhp@ihnp3.UUCP (Douglas H. Price) (01/29/86)
Does anyone out there have a reasonably up-to-date list of all of the currently sitting senators and congressmen? I think it is time to put modern technology to use and swamp Capitol Hill with letters supportive of the manned space program before the vultures on the hill have a chance to even breathe. Everyone is either saying supportive things at the moment or nothing at all, but you had better believe the Proxmires of the universe are cackling with anticipation of what they can do with this unfortunate turn of events. (To paraphrase John Glenn) it is absolutely true that an accident of this type is more or less inevitable outcome of pushing out the frontier. Everyone hoped that we might postpone this day indefinitely. Now that it is upon us, we must look ahead, and not retreat. It is our responsibility as citizens to make our views known, and prevent as best we can the temptation to take the "safe" course. DAMN THE MONEY, FULL SPEED AHEAD! -- Douglas H. Price Analysts International Corp. @ AT&T Bell Laboratories ..!ihnp4!ihnp3!dhp
cja@umich.UUCP (Charles J. Antonelli) (01/30/86)
Some speculations ... In article <12178969201.19.DENNETT@SRI-NIC.ARPA> DENNETT@SRI-NIC.ARPA (Steve Dennett) writes: >The shuttle tragedy has raised some questions (in my mind) about the >shuttle, and the effect this disaster will have on the space program. >Perhaps the readers of this digest will have some answers or speculation on >these questions. >- What kind of escape mechanism (if any) does the shuttle have for the crew? The orbiter can disconnect from the external tank / SRB assembly prematurely and glide to a landing, hopefully at one of the emergency landing sites. Crew members wear life vests and associated water-survival gear. There are no ejection seats; reasons given: (1) not necessary, needed only for initial flight tests; (2) not sufficient, could not be provided for each crew member; (3) not viable, orbiter speed at ejection and/or magnitude of emergency would preclude successful deployment. I am not aware of any other escape mechanisms. >- Will this be a setback for the space program, due to public disapproval > or the government's need to find (and punish) someone? There will be a setback of as yet unspecified duration in the STS program while the situation is investigated by NASA. The extent of public and governmental influence on the STS program cannot be predicted pending the results of the investigation. It has been said that the 1967 fire in the Apollo (6?) command module in which three astronauts lost their lives greatly increased NASA's committment to safety in the Apollo program. Does anyone know details? >- Alternately, might it lead to *greater* support of the space program > (e.g., if NASA presents a case along the lines of "If our budget were > larger, this wouldn't have happened.")? Wouldn't that be a tacit admission of incompetence on NASA's part? If the budget is too small to assure adequate safety for a given number of operations, prudence dictates fewer operations. NASA's `safety first' paradigm absolutely precludes this `larger budget' argument. >- Might this redirect (to some extent) the focus of the manned space > program away from the shuttle (large, complex) back toward simpler or > alternative launch systems? Those missions not requiring human attention, such as the launching of satellites, most certainly could revert to disposable boosters. Does anyone know the status of booster production? I have heard that the existing supply is totally committed to existing projects. However, missions requiring capabilities not provided by unmanned launch vehicles (such as the space station) must still be carried out with manned vehicles. Does anyone know the specifics of the STS vs. alternatives argument?
dsmith@HPLABSC (David Smith) (01/30/86)
> - What kind of escape mechanism (if any) does the shuttle have for the crew? None. Columbia had ejection seats for the first test flights, but this happened too fast for ejection seats. Explosions like this were the reason for the escape towers on Mercury and Apollo. The escape tower saved two Soviet cosmonauts from a launcher explosion in 1983, although they had extended hospital stays. > - Might this redirect (to some extent) the focus of the manned space > program away from the shuttle (large, complex) back toward simpler or > alternative launch systems? It astounded me that the orbiter and ET were completely obliterated, while the SRBs flew out of the fireball apparently intact. This suggests that ths SRB-X proposal might produce a good, reliable launcher (for unmanned payloads). SRB-X consists of two SRBs side by side for a first stage, with one SRB on top as the second stage. While solid propellant is more expensive than LH/LOX, a savings would come from not launching the weight of the manned compartment when the mission does not otherwise need to be manned. Manned launches could be via transatmospheric vehicle, which would be much smaller than the current Shuttle, not carrying the heavy cargo and (explosive) propellant for the cargo. Being air breathing through the atmospheric boost phase, it wouldn't have so much LOX to tangle with its LH. Manned missions requiring heavy equipment would use orbital rendezvous. About the press: I am still surprised at how imperceptive the newscasters were. They played the tapes over and over in slow motion, pointing out that the fire started between the orbiter and ET at about the forward attachment point. Finally they discovered the earlier fire at the rear of the tank. These were said to be two separate fires. By Tuesday night, Rather was saying that the fires may have been breaches of the left (nearer) SRB, in spite of the fact that the SRBs didn't have any flame out their sides after emerging from the fireball. The V-2 was solid fueled. Etc., etc. Here's what I think. There was a leak in the hydrogen tank or its connections, as evidenced by the cloud that gathered around the base of the tank unnoticed by newscasters. The short-lived flame plumes near the closer SRB were ignited in the cloud of hydrogen by the rocket exhaust. Perhaps they went out for lack of atmospheric oxygen: the SSME exhaust is hydrogen rich. But before long, the cloud really caught; the fire spread around the back side of the tank (as seen from the camera) to appear between the tank and the orbiter. By this time, more hydrogen was coming out of the tank. The fire climbed the oxygen line to the oxygen tank. The explosion which ripped the vehicle apart was centered at the join between the O2 and H2 tanks. David Smith hplabs!dsmith dsmith%hp-labs@csnet-relay
mcgeer%ji@UCBVAX.BERKELEY.EDU (Rick McGeer) (01/30/86)
> >> - What kind of escape mechanism (if any) does the shuttle have for the crew? > >At that point, the only escape mechanism was to detach the orbiter from >the fuel tank and hope it doesn't blow up before you get away. I'll >add that if they had been able to get away but had to ditch in the ocean >they still would probably have died; the shuttle decelerates from 190 >knots to zero in 100 yards when ditched and the TDRS would probably have >smashed through the cabin. That escape mechanism would only have worked if the external tank exploded first. As far as I know, it's pretty much even money that an internal tank went. > >> - Might this redirect (to some extent) the focus of the manned space >> program away from the shuttle (large, complex) back toward simpler or >> alternative launch systems? > >It will certainly deflect satellite launching back to unmanned >expendable vehicles (mainly Ariane). The disaster has probably soured >DOD permanently on the shuttle, so DOD may push for a small TAV. >France will go ahead with Hermes, which is smaller and simpler, >consisting of a small spaceplane on top of an Ariane-5 launcher. Couple of points. First, the Planetary Scientists have already been banging away on getting rid of manned spaceflight (the argument runs: "neither our missions nor satellite launches require men, hence no worthwhile missions require men, hence we should use only unmanned spaceflight"; the breathtaking arrogance of this has always amazed me). Second, at least one Pentagon official said yesterday that that DoD launches from Vandenberg would probably resume *sooner* than Kennedy's civilian launches, since (I presume) the USAF has a higher risk tolerance than NASA. -- Rick.
bdw@chinet.UUCP (Bill Wisner) (01/30/86)
DENNETT@SRI-NIC.ARPA (Steve Dennett) writes: >- What kind of escape mechanism (if any) does the shuttle have for the crew? None. Once the orbiter gets very far off the ground, how could the crew get out? Five miles is a long drop.. >- Will this be a setback for the space program, due to public disapproval > or the government's need to find (and punish) someone? There WILL be a setback; it is inevitable. NASA will suspend most regular activities, including even training, until the cause of the explosion is determined. The public might set the program back even more, but it is always hard to tell. >- Alternately, might it lead to *greater* support of the space program > (e.g., if NASA presents a case along the lines of "If our budget were > larger, this wouldn't have happened.")? I personally don't think that NASA would be offer a comment in such poor taste. Also, one of the reasons NASA's budget is too small is the extensive safety precautions that are taken with everything they do. >- Might this redirect (to some extent) the focus of the manned space > program away from the shuttle (large, complex) back toward simpler or > alternative launch systems? There is a chance; but I would say that if it DID happen that way, a big factor would be congress -- that wonderful body of elected officials who think they know what is best for us. This body also controls NASA's budget -- at the whim of a majority of representatives/senators, NASA could even cease to exist. -- Bill Wisner "All that wander are not lost." The Computer Connection --- J.R.R. Tolkien UUCP: ihnp4!chinet!bdw CIS: 76474,1213 USNail: 6290 Highway 44 Star, ID 83669
mrgofor@mmm.UUCP (Michael Ross) (01/30/86)
In article <12178969201.19.DENNETT@SRI-NIC.ARPA> DENNETT@SRI-NIC.ARPA (Steve Dennett) writes: >The shuttle tragedy has raised some questions (in my mind) about the >shuttle, and the effect this disaster will have on the space program. >Perhaps the readers of this digest will have some answers or speculation on >these questions. > >- What kind of escape mechanism (if any) does the shuttle have for the crew? > Did you see the explosion? What kind of escape mechanism would have helped? --MKR
space@ucbvax.UUCP (01/30/86)
In article <12178969201.19.DENNETT@SRI-NIC.ARPA> you write: >- What kind of escape mechanism (if any) does the shuttle have for the crew? To my knowledge, none. >- Will this be a setback for the space program, due to public disapproval > or the government's need to find (and punish) someone? From Reagan's speech, I would think not. >- Alternately, might it lead to *greater* support of the space program > (e.g., if NASA presents a case along the lines of "If our budget were > larger, this wouldn't have happened.")? I have seen something to this effect on the net, and heard people on the news refer to this. >- Might this redirect (to some extent) the focus of the manned space > program away from the shuttle (large, complex) back toward simpler or > alternative launch systems? Possibly, we'll just have to see. Interesting observation: 30 minutes after the loss of the shuttle, pictures were carried on Soviet TV... -- -- Carl Kuck (apply all standard disclaimers to the preceeding babble) UseNet (west) : {wherever}!sdcsvax!ncr-sd!se-sd!cbk (east) : {wherever}!ihnp4!ncr-sd!se-sd!cbk PacBell: (619) 450-6271 (w), 944-1705 (h) Quote #1: Only those who attempt the absurd can achieve the impossible. Quote #2: 55 mph isn't a good idea, it's just the law...
henry@utzoo.UUCP (Henry Spencer) (01/31/86)
> There are no ejection seats; reasons given: ... > ... (3) not viable, orbiter speed at ejection and/or > magnitude of emergency would preclude successful deployment. If you listen to recordings of one of the early test flights, when the pilot and copilot did have ejection seats, quite early in the mission you'll hear a comment "negative seats". That means the shuttle has passed Mach 3 and the ejection seats are no longer considered useful. I'm not sure just how fast Challenger was moving when it blew, but it was at least close to Mach 3 based on the position-and-velocity calls earlier. And even a fully automatic ejection system probably wouldn't have helped, considering how quickly it happened. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry
al@vger.UUCP ( Informatix) (01/31/86)
In article <12178969201.19.DENNETT@SRI-NIC.ARPA>, DENNETT@SRI-NIC.ARPA (Steve Dennett) writes: > > - What kind of escape mechanism (if any) does the shuttle have for the crew? Only the orbiter itself, plus various ways of getting out of the orbiter on the ground or in the water. For the accident that occured, no imaginable safety device would have been even slightly useful. > > - Will this be a setback for the space program, You bet it is. 25% of the fleet, half of TDRSS, 6 astronauts, the first passenger, months (at least) of delay, a launch schedule blown completely away, customers who won't launch on time ... > due to public disapproval > or the government's need to find (and punish) someone? I doubt that these will be major issues.
carroll@uiucdcsb.CS.UIUC.EDU (02/04/86)
Challenger was going very close to 2,000 mph, which is above Mach 3. I doubt anyone is going to survive ejection into a windstream that's moving that fast. I can't really see surviving much over Mach 1.
henry@utzoo.UUCP (Henry Spencer) (02/09/86)
> Challenger was going very close to 2,000 mph, which is above Mach 3. I doubt > anyone is going to survive ejection into a windstream that's moving that fast. > I can't really see surviving much over Mach 1. Most ejection systems are spec'ed for a limit circa Mach 1. Mind you, that's where they are officially supposed to be usable, not where you might survive if you were desperate and had no choice. Capsule-based systems have been built for Mach 3, but that's a slightly different story. I don't *think* anyone has ever tried a Mach 3 ejection. There have been supersonic ejections, which usually result in serious injury but have been survived. (Not that a *subsonic* ejection is all that safe, mind you... things like spinal injuries are not uncommon.) -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry