zipline tower escape system

[monophonic]

25 minutes ago, sevenperforce said:

Just out of morbid curiosity, exactly what sorts of pad failures would offer sufficient warning to use a zipline and a MRAP?

Fuel leak. There may well be enough time to evacuate before it finds an ignition source. Even if not - well, they still deserved the chance, don't you think?

[Tullius]

29 minutes ago, sevenperforce said:

Just out of morbid curiosity, exactly what sorts of pad failures would offer sufficient warning to use a zipline and a MRAP?

Maybe some overpressure valve locking up or a fuel leak.

But I think it is probably more about having an escape plan "just in case", than any specific danger. After all, needing 2 minutes to get away from the rocket is better than 10 or more minutes (just think of the distance they have to cover from the top of the tower until they are safe).

Edited April 6, 2017 by Tullius

[sevenperforce]

6 minutes ago, monophonic said:

Fuel leak. There may well be enough time to evacuate before it finds an ignition source. Even if not - well, they still deserved the chance, don't you think?

Oh, certainly. No argument there. Even if there was no anticipated failure which could cause catastrophic pad RUD with two minutes of advance notice, it's still a good idea to put it in there just in case.

Overpressure valve block certainly sounds right if you were dealing with cryogens.

[munlander1]

When would ziplines be needed? I understand with the shuttle, it was the best way to get away fast. But with Orion having an les, would that be safer? The only situation where I think this could be useful is if the crew was not secured or if support crew were still around the capsule. 

[kerbiloid]

Fire or smoke on the launchpad.

[max_creative]

HOW DO I MAKE ONE OF THESE IN KERBAL SPACE PROGRAM?! THEY SOUND SO COOL! I WANT ONE!  

[sevenperforce]

1 hour ago, kerbiloid said:

Fire or smoke on the launchpad.

Honestly if the LES is already engaged I'd rather stay in the capsule than risk the zipline.

[kerbiloid]

1. Ten people around the capsule?

2. Fire and smoke near the rocket or inside its non-explosive part?

[DerekL1963]

On 4/6/2017 at 10:22 AM, sevenperforce said:

Just out of morbid curiosity, exactly what sorts of pad failures would offer sufficient warning to use a zipline and a MRAP?

Serious leakage of fuel or oxidiser, a pad infrastructure fire, etc... etc...   Slow disasters or moderate emergencies are uncommon in rocketry, but not impossible.

On 4/6/2017 at 4:05 PM, munlander1 said:

But with Orion having an les, would that be safer?

No.  You subject the crew to some pretty high G's and a potentially fairly rough landing.

[Exploro]

On 4/6/2017 at 11:41 PM, sevenperforce said:

Honestly if the LES is already engaged I'd rather stay in the capsule than risk the zipline.

Not all emergency modes would trigger LES to activate nor would LES be of help. A cabin emergency; say smoke in the cabin, would make using LES option useless. The only escape option would be immediate evacuation from the capsule and quick escape via the zip line.

[Nothalogh]

On 4/6/2017 at 1:22 PM, sevenperforce said:

Just out of morbid curiosity, exactly what sorts of pad failures would offer sufficient warning to use a zipline and a MRAP?

Somebody dropping a wrench, probably.

[magnemoe]

On 6.4.2017 at 7:22 PM, sevenperforce said:

Just out of morbid curiosity, exactly what sorts of pad failures would offer sufficient warning to use a zipline and a MRAP?

Well something as simple as elevator fail after an launch abort would make an zip line useful. 

And why not use an mrap? manmy are in storage so no issue renting one and it could be better than an normal car if the rocket should blow up.

[sevenperforce]

1 hour ago, magnemoe said:

Well something as simple as elevator fail after an launch abort would make an zip line useful. 

And why not use an mrap? manmy are in storage so no issue renting one and it could be better than an normal car if the rocket should blow up.

Oh, I wasn't questioning the validity of the plan; it's a good plan. Just thinking about the very small number of instances where it would actually save someone.

[Nibb31]

I think it's mostly for piece of mind. Any workplace needs contingency plans and NASA's job, as an employer, is to provide a decent effort to secure the workplace. You need an evacuation plan in any workplace, especially in an environment where there are hazardous materials. This isn't just for the crew, but for any workers who will be working in the white room facility at the top of the tower.

So yes, even though most mishaps involving rockets wouldn't allow time to evacuate, you still have to plan for those that do. Failure to do so would be a huge liability.

[sevenperforce]

9 hours ago, Nibb31 said:

I think it's mostly for piece of mind. Any workplace needs contingency plans and NASA's job, as an employer, is to provide a decent effort to secure the workplace. You need an evacuation plan in any workplace, especially in an environment where there are hazardous materials. This isn't just for the crew, but for any workers who will be working in the white room facility at the top of the tower.

So yes, even though most mishaps involving rockets wouldn't allow time to evacuate, you still have to plan for those that do. Failure to do so would be a huge liability.

Indeed. This is one of those things where even if we cannot come up with a situation where you'd need this particular sort of evac, it's still better to have it and not use it than need it and not have it.

[DerekL1963]

18 hours ago, sevenperforce said:

Oh, I wasn't questioning the validity of the plan; it's a good plan. Just thinking about the very small number of instances where it would actually save someone.

In reality?  It's the same reason that nuclear submarines (which 99% of the time operate in areas where the bottom is far below crush depth) have escape hatches, and provisions for a rescue submarine to latch on.   They keep congresscritters, mommas, wives, and girlfriends happy.

None of us were under any illusion as to their actual usefulness.   If we couldn't reach the surface and stay there, it was game over.

[Exploro]

2 hours ago, DerekL1963 said:

In reality?  It's the same reason that nuclear submarines (which 99% of the time operate in areas where the bottom is far below crush depth) have escape hatches, and provisions for a rescue submarine to latch on.   They keep congresscritters, mommas, wives, and girlfriends happy.

None of us were under any illusion as to their actual usefulness.   If we couldn't reach the surface and stay there, it was game over.

True all safety contigencies are viable under certain circumstances; outside of which such measures would fail or be of no use. That does not mean they exist only to give piece of mind.

About 15 years ago or so I recall seeing a TV program on British Royal Navy submariner training. One escape method that was demonstarted in the program was the use of the Submarine Escape Immersion Equipment. It is water tight suit that supplied air to the submariner to breath and bouyancy to ascend. Further it helps prevent the onset of hypothermia. Lastly it would help the submariner stay afloat on the surface until help arrived. The suit is designed to keep a submariner alive from a depth of 600 feet. Obviously modern military submarines can go further down than that; 1200 feet or so. Thus that method of escape is only viable to a certain depth as you point out. But a mishap or accident at 600 feet can be just as perilious as one happening at 1200 feet. So even if SEIE is useful for limited regime, having that means of escape is still of tangiable benefit.

[hugix]

Don't forget that ingress into the capsule isn't just like getting into your car. It takes a team of people to help the astronauts to get into the vehicle. If something where to happen during ingress, the only fast way out is the zipline. 

[munlander1]

On April 6, 2017 at 10:37 PM, max_creative said:

HOW DO I MAKE ONE OF THESE IN KERBAL SPACE PROGRAM?! THEY SOUND SO COOL! I WANT ONE!  

I think a mod would be your best bet. 

[DerekL1963]

21 hours ago, hugix said:

Don't forget that ingress into the capsule isn't just like getting into your car. It takes a team of people to help the astronauts to get into the vehicle. If something where to happen during ingress, the only fast way out is the zipline. 

Um, the two are not related...  because you have to exit the capsule before you can use the zipline in the first place.

[sevenperforce]

21 hours ago, munlander1 said:

I think a mod would be your best bet. 

I bet you could use end-to-end struts with something that would slide on it, and attach a chair to it. A decoupler would give the initial push. It couldn't be as long as the real one but it should work. Maybe use separatrons to slow the landing.

[Tullius]

1 hour ago, DerekL1963 said:

Um, the two are not related...  because you have to exit the capsule before you can use the zipline in the first place.

I think the "if something where to happen during ingress" is relating much less to problems that astronauts might have to get into the capsule, but to a mishap with the rocket happening during that procedure, which would force the astronauts (who cannot yet use the LES, since they are not yet secured in their seats with the hatch closed) and the support crew to get away from the rocket as fast as possible, i.e. to use the zipline.

This is relevant, because in case of the Shuttle, the external tank would already be fully fueled before the astronauts and their support crew would access the tower. And it is quite likely that it will be the same for SLS.

In short, the zipline is the rescue plan for those people that will access the tower with a fully fueled rocket sitting next to them on the pad.

Edited April 12, 2017 by Tullius

[DerekL1963]

22 hours ago, Tullius said:

In short, the zipline is the rescue plan for those people that will access the tower with a fully fueled rocket sitting next to them on the pad.

In short, we already knew that.