Safety system designed to destroy the shuttle?

[ElPelado]

I read on Space.com that the Shuttle has a [FONT=&quot]"safety system designed to help destroy the shuttle if it strays off-course"... is that right???
What does this system do? Won't something like this kill the astronauts?
Does anybody have any info on this systems?
I've never heard about it...
Thanks!
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[MeDiCS]

AFAIK, all launchers have this kind of system. It's better to destroy the playload/kill the astronauts than risking a flying bomb that is a rocket to plummet into somewhere populated.

But the Shuttle has some kind of abort mechanism (RTL abort, I think), allowing the shuttle to separate from the main tank and boosters and glide back to safety.

 

[Woo482]

I think the shuttle only has a range safety system in the SRBs, but I'm not entirely sure

 

[Urwumpe]

I read on Space.com that the Shuttle has a [FONT=&quot]"safety system designed to help destroy the shuttle if it strays off-course"... is that right???
[/FONT]

Like all western launch vehicles, it has a range safety device on some parts of it, the SRBs and the ET. The orbiter of the NSTS has no range safety system.

http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/srb.html

It is not for killing the astronauts, it is for destroying parts of the Shuttle after an contingency abort, for preventing they fall on populated regions. 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. Note that the contingency abort is executed first - an destruction of the whole stack is possible, but not the first option... it would appear somewhere on page 20 of all possible options.

The system had been used during the STS-51L incident for destroying the SRBs.

 

[orbiterguy]

The shuttle has an instrument that if you push the button the command capsule will rip off and deploy parachutes keeping the astronauts safe, then as they leave the remaining shuttle self destructs.
Just like off the t.v programes lol.

 

[Woo482]

The shuttle has nothing like that on it...

 

[T.Neo]

The shuttle has an instrument that if you push the button the command capsule will rip off and deploy parachutes keeping the astronauts safe, then as they leave the remaining shuttle self destructs.
Just like off the t.v programes lol.

Sorry, WHAT?

I do hope you are kidding. "Off the t.v programes lol" and reality are two different things.

 

[Urwumpe]

The shuttle has an instrument that if you push the button the command capsule will rip off and deploy parachutes keeping the astronauts safe, then as they leave the remaining shuttle self destructs.
Just like off the t.v programes lol.

That is utter nonsense. The Space Shuttle has no "command capsule" at all. The Apollo spacecraft had a command module that could be separated by an launch escape system during the early phases of ascent.

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

The only parachutes in the Space Shuttle orbiter are the parachutes of the astronauts, you need to leave the orbiter by jumping out of it.

 

[Linguofreak]

I read on Space.com that the Shuttle has a [FONT=&quot]"safety system designed to help destroy the shuttle if it strays off-course"... is that right???
What does this system do? Won't something like this kill the astronauts?
Does anybody have any info on this systems?
I've never heard about it...
Thanks!
[/FONT]

Any course deviation big enough to necessitate the use of the range safety system would likely spell death for the astronauts anyways. The purpose of the range safety system is to make sure that if the shuttle stack (or part of it) comes down in pieces, it comes down in little pieces and not big ones.

 

[T.Neo]

you need to leave the orbiter by jumping out of it.

Is this also not possible without having the orbiter in more or less level flight seperated from the stack?

 

[Urwumpe]

Is this also not possible without having the orbiter in more or less level flight seperated from the stack?

Exactly and also at relatively low altitude.

You can find information about it here:
http://www.nasa.gov/centers/johnson/pdf/383441main_contingency_aborts_21007_31007.pdf

 

[garyw]

Is this also not possible without having the orbiter in more or less level flight seperated from the stack?

Yes. There is a GPC mode for this and it's designed for bail out conditions so that the GPC can fly the shuttle whilst the crew exists via the mid deck escape pole.

As for the explosives, there are charges placed on both SRB's which have two settings - ARM & FIRE. When the ARM signal is sent a light shows on the flight deck. when FIRE is set the explosive charges detonate destroying the SRB's and potentially anything attached. Prior to STS-51L the ET also had a charge but it is no longer used.

SRO (Safety Range Officer) is the person who has authorisation for sending the ARM & FIRE codes. These people are military and obviously trained to handle such situations and the commands to the explosive devices are, of course, encrypted.

There has been talk about an escape capsule and/or the crew module seperating but the amount of work required and weight required would negate being able to carry a payload so one has never been installed.

 

[Urwumpe]

As for the explosives, there are charges placed on both SRB's which have two settings - ARM & FIRE. When the ARM signal is sent a light shows on the flight deck. when FIRE is set the explosive charges detonate destroying the SRB's and potentially anything attached. Prior to STS-51L the ET also had a charge but it is no longer used.

That is wrong - there is no such light for indicating armed RSS. The two modes are also safed and armed. The safed mode means the connection between igniter and NSD is physically blocked and the main shaped charge can't be ignited by accident.

 

[garyw]

That is wrong - there is no such light for indicating armed RSS. The two modes are also safed and armed. The safed mode means the connection between igniter and NSD is physically blocked and the main shaped charge can't be ignited by accident.

Source: Riding Rockets by Mike Mullane, page 155.
"If the RSO ever transmitted the flight termination system ARM command, a red light on Hank's instrument panel would illuminate as a warning. I wondered what sick engineer had thought that would be helpful".

 

[Urwumpe]

Source: Riding Rockets by Mike Mullane, page 155.
"If the RSO ever transmitted the flight termination system ARM command, a red light on Hank's instrument panel would illuminate as a warning. I wondered what sick engineer had thought that would be helpful".

Have this light also in the SCOM on the commanders panel right below the sun shade, but there is no explanation of what it actually indicates. Since the RSS S&A system is "armed" always between lift-off and post-separation, it makes no sense to display this.

 

[garyw]

I think there is a difference between the explosives being primed (as in ready for usage) and the system itself from being ARMED by a particular coded signal.

Where is daves when you need him?

 

[Urwumpe]

I think there is a difference between the explosives being primed (as in ready for usage) and the system itself from being ARMED by a particular coded signal.

Could be the state of the electronics then, if it follows older Airforce Range Safety standards (ARM/DETONATE). But I still can't find how the light state is evaluated. Would need to be coming from the SRB MDMs.

 

[orbiterguy]

That is utter nonsense. The Space Shuttle has no "command capsule" at all. The Apollo spacecraft had a command module that could be separated by an launch escape system during the early phases of ascent.

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

The only parachutes in the Space Shuttle orbiter are the parachutes of the astronauts, you need to leave the orbiter by jumping out of it.

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:

 

[Shadow Addict]

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

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.

By the way, on this forum you are talking to a lot of people who know a lot about the shuttle. Don't pretend to know what you're talking about just because you copied the Wikipedia article.

 

[orbiterguy]

Ok,Ok watch it i was only making a contribution to the topic, I infact watched a whole 2 hour programe about the challenger incident, Im sorry but its late of here in the u.k