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NASA Will Man Destruct Switch Just In Case
Ant writes "Popular Mechanics reports if the looming Discovery mission or any other between now and the spacecraft's retirement loses control, National Aeronautics and Space Administration (NASA) is prepared to ditch it in the Atlantic ocean — or blow it up. The article also shows complete no-fly-zone maps and a photograph of the switch."
I don't understand why there are four switches. I mean, I understand "Arm" and "Destruct", but why "test"? Does that blow up just a small section of the shuttle? I would have thought that turning off the "Arm" would be the same as "Safe"
... it's the engineers having a laugh. Getting a kick out of the confused looks on stupid people like myself.
I know, I know
I looked at TFA, and I gotta tell you, it's an exciting picture of the switch. Actually, it looks like FOUR switches and FOUR buttons. Well worth going to the site to see it.
This is such a non-story. NASA has a Range Safety Officer for every single launch, manned or not, and always has.
Give a man fire, and you warm him for the night. Set a man on fire, and you warm him for the rest of his life.
...would be pretty nasty if someone if someone figured out how the radio comms for this function worked.
-- Even if a god did exist, why the fsck should I worship it?
Yes, they are. They always have. *Every* NASA rocket launch includes a self-destruct to prevent ground casualties. This includes the manned missions. In such cases where it would be used, the crew is either dead or will unavoidably be dead very shortly, and the lives on the ground must be saved.
You know, if you are going to have destruct switches... they really should look like that. A big turn key, solid, metal, single function panel that does nothing else. Heavy clunky switches that tell you you've done something. Yep, if you're going to have what is essentially a "big red button" that's how it should look. There's no mistaking that for the coffee dispenser switch. Putting modern "iPhone" styling on that would be a sin.
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When our name is on the back of your car, we're behind you all the way!
According to NASA documentation, the SRB Range Safety system is operated by encoded signals.
;)
From the description in the document, it sounds like one coded signal to 'arm' and a second coded signal to 'fire'. I'd bet that due to the nature of the system, it's transmission method will be so simple that it rarely needs to be tested and as such gives little opportunity for homicidal black-hat analysis.
Finally, I'll also bet that the codes are as top-secret as to-secret can be (as in: Get caught with this and you'll disappear forever). It wouldn't surprise me if the codes are created and handled by just one person on the day of use and never used again. Or perhaps two people where only one person knows the arm code and the other the fire code before the system is finally set.
However it's done, I'd like to think that a hell of a lot of thought went into system security
Ripping an new rectum in the fabric of spacetime.
And if you need an example of why those destruct systems are required, watch this.
I've met at least one of the Range Safety Officers while working out at Cape Canaveral. It's not something they like to talk about much, when it comes to the Shuttle.
The other issue, just as important as the explosives, is all the other chemicals on board - many of which are highly toxic. This includes chemicals like monomethyl hydrazine (MMH) used in the Orbital Maneuvering Subsystem (OMS) and in the Solid Rocket Boosters (SRBs) for control. It is great stuff, you mix it with nitrogen tetroxide (N2O4) and they ignite with no spark or air required. At the same time, by the time you can smell it, you have been exposed to ten times the lethal dose. Remember when Columbia crashed and they told everyone not to go near the wreckage? this was one reason why.
As the parent said, remote destruct capabilities are simply par for the course when your strapping things to that much explosives and toxic chemicals. Really it should make us feel safer that NASA is honest about the risks and is willing to do what it needs to do to insure (as best as possible) public safety.
The Solid Rocket Boosters can't be stopped once they are started, but they have their own navigation system (rate gyro assemblies, and inertial measurement units) that are considered as/more reliable as those on the orbiter due to the rigidity of the SRBs. So the reason this "self destruct" button exists is because there is no "off" button for the SRBs, but, as far as I know, it is only an issue if its quad-redundant navigation system fails and somehow its thrust gets stuck in an unsafe vector, and that is very unlikely.
More detail, including why you can't jettison the flight deck with all the crewmembers: http://en.wikipedia.org/wiki/Space_Shuttle_abort_modes
Test: ping
Arm: login root
Destruct: rm / -rf
Safe: logout
For the technical details on how this works, check out an old Risks article here. They put a lot of thought into the system.