Safety system designed to destroy the shuttle?

[DaveS]

You rang?? The shuttle that "blew up" was Challenger, on mission STS-51L. And it didn't "blow up", despite what popular belief will have you believing. It rather was destroyed by out-of-tolerance aerodynamic forces. The "command thingie" you're talking about is called the Orbiter Crew Module. It is housed inside the two forward fuselage halves.

What happened was that the Orbiter(Challenger) got broken up in several intact sections that have been positively identified on long-range camera footage. The intact sections that was identified was the left wing with its two elevons, the Orbiter forward fuselage and the aft engine compartment with the SSMEs still thrusting.

The Challenger accident happened 73 seconds after lift-off from Launch Complex 39B on January 28 1986. It was the first shuttle launch from Launch Complex 39B which had spent several years being converted from supporting Apollo/Saturn launch vehicles to supporting the Space Shuttle.

 

[Urwumpe]

I mean by where all the astronauts are and infact it does exist when one of the shuttles blew up on take-off (can't remeber which one) they tried to find the command thingie that had been jettisoned because they saw it tear away but sadly the parachutes didn't go up:dry:

It didn't jettison, the orbiter broke into pieces, with the strong pressure hull of the crew module forming one large piece of debris among others. It was never intended to be jettisoned. It didn't even remain intact - the pressure hull had many leaks that allowed air to vent out in seconds.

The parachutes didn't open, because the parachutes don't exist. Simple. There had been absolutely no means of separating the crew module and land it intact.

Also, it was STS-51L.

And what ever 2 hour program you saw, I can name you many one hour long programs that don't contain such nonsense.

 

[tblaxland]

Thread re-opened following clean up.

Please keep the discussion civil and on-topic

 

[Dambuster]

. For example, it is possible to separate the SRBs already about 30 seconds earlier in emergency, the separation system is designed for this extreme case.

The Space Shuttle has no abort option until 89 seconds into flight and no acceptable one until 125 seconds into flight.

Do you know of any documents which talk about these? I'd be interested to learn more about them - I tried searching, but found nothing.

 

[Urwumpe]

Do you know of any documents which talk about these? I'd be interested to learn more about them - I tried searching, but found nothing.

Two reports: First of all, there is a report about the separation system and the conditions under which they should be operating.(Have it printed somewhere here, need to find it again for telling you the ID)

Second, there is a technical report of NASA about using liquid rocket boosters and how they affect safety. This contains the 89 second figure as comparison to a 50 second abort option with LRBs. (NASA-CR-183601)

 

[Donamy]

FYI,

When the Challenger accident occured, I remember the reporter who was covering the launch, wrongly stated that the crew cabin had a parachute, for just such an occurance.

 

[supersonic]

You rang?? The shuttle that "blew up" was Challenger, on mission STS-51L. And it didn't "blow up", despite what popular belief will have you believing. It rather was destroyed by out-of-tolerance aerodynamic forces.

From what I heard, the flame from the SRB burnt though the O rings then, small bits of something used in the fuel blocked a gap in between two parts of the SRB. Soon after STS-51L flew though a powerful gust of wind that blew the bits out of the gap. The plume of fire came out of the SRB, burnt thought the ET and started to burn the fuel from the ET. Soon after the bottom of the ET fell away, instantly the fuel ignited, and that was the end of STS-51L.

This is what I have heard, of course I might be wrong.

 

[Ark]

This thread may be the nerdiest flame war I've ever seen.

 

[Urwumpe]

The plume of fire came out of the SRB, burnt thought the ET and started to burn the fuel from the ET. Soon after the bottom of the ET fell away, instantly the fuel ignited, and that was the end of STS-51L.

This is what I have heard, of course I might be wrong.

The underlined part is wrong, the rest is fine with the reality.

The fuel did only partially combust, since it needs oxygen to react and must be gaseous and hot for ignition. Most of the fuel just spread by aerodynamic forces, since it was cold and liquid. The end was already reached when structural integrity failed and the ET disassembled itself below the orbiter at Mach 2.

The acceleration of 22g when the orbiter separated from the ET connections is pretty much caused by aerodynamic and mechanic forces, by the hydrogen tank shooting forward by tons of fuel under pressure rushing out of the end, like a large bottle rocket.

 

[RisingFury]

I mean by where all the astronauts are and infact it does exist when one of the shuttles blew up on take-off (can't remeber which one) they tried to find the command thingie that had been jettisoned because they saw it tear away but sadly the parachutes didn't go up:dry:

Okay what on earth gave you that idea? For one, I don't really think anybody who can't remember "which shuttle blew up" should think he's qualified to talk about it from any standpoint of expertise. Second, nothing in that post indicated there is any sort of command module on the shuttle because there isn't.

I actually recall that as well, from a documentary that I watched on Discovery Channel quite a few years back. Of course, I can't pass a comment if such a system really exists, but the documentary stated, that in case of emergency, the cabin is seperated by explosive bolts and is brought to the ground by parachutes. I remember the documentary mentioning failed chutes.

The documentary also mentioned that the cabin remained somewhat intact until it hit the ground and that there is evidence that a few of the crew did not get killed by the initial desintigration.

Again, so there's no misunderstanding... I'm not saying that such a system exists, I can just recall the documentary mentioned it. This documentary might be the source of the misconceptions.

 

[dougkeenan]

At STS-131 launch all systems were go in the final minutes except RSO. With minutes to go (in actual time) he announced he could receive "String 2" but not "String 1." That apparently was sufficient and she left on schedule. What kind of string? Anybody know?

 

[Urwumpe]

At STS-131 launch all systems were go in the final minutes except RSO. With minutes to go (in actual time) he announced he could receive "String 2" but not "String 1." That apparently was sufficient and she left on schedule. What kind of string? Anybody know?

The strings of the Range Safety System - there are two sets of receivers, decoders and Igniters, one to decode is enough to trigger it.