Launch News (FAILURE) Proton-M/Block-DM-03 launch with triple GLONASS-M, July 2, 2013

[boogabooga]

It took 300 microL/L nitrogen tetroxide for Vance Brand to pass out.

How far downwind would have that concentration after perhaps several tones is released?

 

[Urwumpe]

It took 300 microL/L nitrogen tetroxide for Vance Brand to pass out.

How far downwind would have that concentration after perhaps several tones is released?

Depends on the wind and temperature of the fire. If you assume conservative danger zones by the fire departments here for train accidents with similar amounts of dangerous liquids, you would have about 1500 meters of urgent evacuation zone and few kilometers more of "keep the windows closed and don't leave your house" in any case.

 

[MaverickSawyer]

Plus, the hydrazine fuel will eat your lungs.

When I went to the Titan II Missile Museum a few years back, they said that one of the fuels would kill you on the spot, and one would kill you overnight while you slept. Not sure which was which, but both of them are nasty stuff.

 

[Urwumpe]

Plus, the hydrazine fuel will eat your lungs.

When I went to the Titan II Missile Museum a few years back, they said that one of the fuels would kill you on the spot, and one would kill you overnight while you slept. Not sure which was which, but both of them are nasty stuff.

Most Hydrazine fuels are a very potent neurotoxin, which kills you pretty quickly. N2O4 is slightly less toxic, but since it reacts violently with everything based on carbon, you can imagine what N2O4 vapors do to your lungs. It already caused a very bad pneumonia to three Apollo astronauts during one accident during landing at relatively low concentrations.

 

[N_Molson]

If the rocket gets close enough to you that you can inhale the smoke, I think you won't have time to die of poison gas inhalation.

Not at all. If the wind rains it down in your direction, that's enough.

 

[MaverickSawyer]

Most Hydrazine fuels are a very potent neurotoxin, which kills you pretty quickly. N2O4 is slightly less toxic, but since it reacts violently with everything based on carbon, you can imagine what N2O4 vapors do to your lungs. It already caused a very bad pneumonia to three Apollo astronauts during one accident during landing at relatively low concentrations.

Ok, got 'em mixed up... again. :facepalm: Thank, Urwumpe.

 

[Urwumpe]

Ok, got 'em mixed up... again. :facepalm: Thank, Urwumpe.

I am also not sure if N2O4 wasn't even more toxic than hydrazine, I only know that hydrazine smells like fish and if you can smell it, you are already poisoned and likely due for bad cancer already.

 

[Linguofreak]

The recent SpaceX incident got me looking through YouTube for other range safety firings, which got me looking at rocket mishaps in general, which led me to a video of this flight (think of it as a less extreme version of xkcd 214).

Reading up on the causes of the failure of this flight got me thinking: Might there be a case for building launch vehicles to failover from internal guidance to command guidance from a human operator on the ground if the guidance system shows signs of malfunction?

 

[boogabooga]

The recent SpaceX incident got me looking through YouTube for other range safety firings, which got me looking at rocket mishaps in general, which led me to a video of this flight (think of it as a less extreme version of xkcd 214).

Reading up on the causes of the failure of this flight got me thinking: Might there be a case for building launch vehicles to failover from internal guidance to command guidance from a human operator on the ground if the guidance system shows signs of malfunction?

A very Orbinaut idea. We do it all the time!

 

[RisingFury]

Reading up on the causes of the failure of this flight got me thinking: Might there be a case for building launch vehicles to failover from internal guidance to command guidance from a human operator on the ground if the guidance system shows signs of malfunction?

If the internal guidance fails, it's likely not because of a bug in the software, but failure of sensors. If you lose sensors, you lose the information about where you're going anyway and a human operator does you no good.

More than that, while we all fly rockets in Orbiter, I think piloting a real rocket would be much more difficult. You also have to consider that the handoff from on-board guidance to remote guidance would take at least 1 second for the operator to really start controlling the rocket. And in that 1 second, a lot can go wrong.

 

[Linguofreak]

If the internal guidance fails, it's likely not because of a bug in the software, but failure of sensors. If you lose sensors, you lose the information about where you're going anyway and a human operator does you no good.

It all depends which sensors you lose, and what type of failure they experience. If a sensor is installed in such a way that its readings get sign flipped, a human is likely to be able to recognize and correct for the error, whereas an automatic guidance system is likely to fail catastrophically. At the very least, a human is more likely to be able to keep the correct end pointed towards space based on visual reference from cameras alone.

More than that, while we all fly rockets in Orbiter, I think piloting a real rocket would be much more difficult.

Sure. But given the choice between a human stretched to the limits of his abilities but aware of what he's doing and a guidance system that is well within its limits but hopelessly confused by bad data, I'll take the human.

You also have to consider that the handoff from on-board guidance to remote guidance would take at least 1 second for the operator to really start controlling the rocket. And in that 1 second, a lot can go wrong.

In situations where the guidance software is receiving incorrect data from sensors, it is likely to be making control inputs that exacerbate the situation (if a sensor input is sign flipped, control inputs that depend on that sensor are likely to be sign flipped as well). In such situations, during the interval between the end of internal guidance and the beginning of remote guidance, while the operator is not yet doing anything to correct the situation, the on-board guidance is at least no longer acting to make it worse.

 

[Urwumpe]

Also... the human factor was already addressed at assembly. The sensors had a notch to indicate their proper alignment and make it hard to install the sensors upside down. This did just not prevent somebody from using force to put the sensor upside down into its socket and was not detected by quality assurance.

You can't prevent everything, you can only make it much harder to happen.