Discussion A contingency plan for fast return of the U.S. to space.

ISProgram

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I seem to recall the goal for Ares I was to put it at better than 10 times safer than the shuttle, which would put it in the 1/500 to 1/1000 failure rate range.

Not with that thrust oscillation, it wouldn't have. The Ares I was only good because it had a LES, so it could bail out any TO'ed astronauts.

It actually depends on why you mean by "safe". Incapacitated but still alive astronauts might(?) qualify, depending on that.
 

garyw

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Not with that thrust oscillation, it wouldn't have. The Ares I was only good because it had a LES, so it could bail out any TO'ed astronauts.

And there were plans to deal with that. The thrust oscillation of the single SRB was well understood. http://www.nasaspaceflight.com/2008...llation-mitigation-the-current-state-of-play/

It actually depends on why you mean by "safe". Incapacitated but still alive astronauts might(?) qualify, depending on that.

Yes it would have, in fact, one of the requirements for any escape system is to be independent of astronaut action. This is one of the requirements that came out of the CAIB. http://www.huffingtonpost.com/2013/01/30/columbia-shuttle-disaster-space-safety-nasa_n_2577595.html
 

kamaz

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The SRB toric joint failure was unoticed by sensors and even cameras until the disaster happened.

The damaged SRB saw a drop in thrust and chamber pressure 9 seconds before vehicle breakup. Also, it broke loose 0.9 seconds before vehicle breakup, creating an unrecoverable thrust asymetry which ultimately led to disaster.

Both events were detectable by onboard systems - Challenger moved engine gimballs to compensate thrust asymetry - and should have triggered an abort...
 

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Both events were detectable by onboard systems - Challenger moved engine gimballs to compensate thrust asymetry - and should have triggered an abort...

And those same systems gimblaled the SSME's to compensate. Once the SRB thrust fell outside it's limits then yes, an abort should have been initiated but it would have been a lot of stress on the capsule which should have survived but been damaged.

Remember that the crew compartment from Challenger survived the explosion and mach 2 airstream. It probably lost pressure which is why the crew died. All that was needed was the ACES suit and some parachutes and it might have been a different outcome.
 

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Remember that the crew compartment from Challenger survived the explosion and mach 2 airstream. It probably lost pressure which is why the crew died. All that was needed was the ACES suit and some parachutes and it might have been a different outcome.

I call :censored: on that one

Even post Challenger the shuttle cabin had no escape provisions for un-controlled flight. The only way the crew would have survived would have been for this failure to manifest during one of the early test flights when the shuttle was still fitted with ejector seats.

---------- Post added at 08:52 ---------- Previous post was at 08:51 ----------

Even then only those on the flight deck would have escaped, the mid-deck crew would have been SOL.
 
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Urwumpe

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The damaged SRB saw a drop in thrust and chamber pressure 9 seconds before vehicle breakup. Also, it broke loose 0.9 seconds before vehicle breakup, creating an unrecoverable thrust asymetry which ultimately led to disaster.

The drop in SRB chamber pressure (19 psi less than the nominal 900 psi, about 2%) was still within limits of how much the thrust in the SRBs may fluctuate - and the first indication there happened about 1.5 seconds before LOS.

The first anomaly was the LH2 ullage pressure dropping despite all two control valves being open, about 8 seconds before break-up. But that also triggered no warning, since it was until shortly before LOS above the warning limit (Remember, it was 1986 - the booster console did not have the ability to display plots of every thinkable quantity over time and even today, it only does that if requested).
 
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RisingFury

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Remember that the crew compartment from Challenger survived the explosion and mach 2 airstream. It probably lost pressure which is why the crew died. All that was needed was the ACES suit and some parachutes and it might have been a different outcome.

A few pilots have survived ejection from their aircraft at supersonic speeds. They reported that hitting the air was like hitting a wall. Planes like B-1 have escape capsules. As for SR-71, have fun ejecting at Mach 3. The plane gets hot because of the compression of air. So would humans.
 

kamaz

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Remember that the crew compartment from Challenger survived the explosion and mach 2 airstream. It probably lost pressure which is why the crew died.

The investigation showed that someone (probably Resnick) activated Smith's oxygen apparatus, which was depleted, meaning that he breathed normally until the cabin hit the water. It also appears that he flipped some switches in a futile attempt to restore power to the cockpit. I know that the official line says that the crew died due to hypoxia, but that's conjecture which is not really suported by evidence. It is not hard to see why this conjecture became an official line, though.

If you think about it, that's the best argument for an Apollo-style design you can come up with. Without LES, the crew survived the vehicle breakup, and the pilot was conscious, at least long enough to take action. If only he had something to work with (i.e. chutes)...
 

Urwumpe

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So would humans.

Humans would first of all also experience a lot of drag at that speed. Heating would come next.

---------- Post added at 10:49 PM ---------- Previous post was at 10:45 PM ----------

If you think about it, that's the best argument for an Apollo-style design you can come up with. Without LES, the crew survived the vehicle breakup, and the pilot was conscious, at least long enough to take action. If only he had something to work with (i.e. chutes)...

Still, the important reference is the CAIB report, which defined, which safety measures a future manned spacecraft for the US space program must have, which technology must be researched with priority and which then should get included, if possible.

It was already established during Challenger, that the experimental nature of the Shuttle makes it unsuitable for being used much longer than necessary. And it was necessary more than 25 years more.
 

kamaz

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A few pilots have survived ejection from their aircraft at supersonic speeds. They reported that hitting the air was like hitting a wall. Planes like B-1 have escape capsules. As for SR-71, have fun ejecting at Mach 3. The plane gets hot because of the compression of air. So would humans.

There is a documented case of one pilot surviving SR-71 breakup at Mach 3.18: http://www.barthworks.com/aviation/sr71breakup.htm
 

ISProgram

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A few pilots have survived ejection from their aircraft at supersonic speeds. They reported that hitting the air was like hitting a wall. Planes like B-1 have escape capsules. As for SR-71, have fun ejecting at Mach 3. The plane gets hot because of the compression of air. So would humans.

Well that's :censored:, even if it is true. The Russian apparently didn't see this as a problem, since they developed [ame="http://en.wikipedia.org/wiki/Strizh"]a suit specifically designed for just that thing.[/ame] They actually seem to have put serious work into a ecape system for Buran.

I don't see why didn't we have a Strizh.
 

Urwumpe

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Well that's :censored:, even if it is true. The Russian apparently didn't see this as a problem, since they developed a suit specifically designed for just that thing. They actually seem to have put serious work into a ecape system for Buran.

I don't see why didn't we have a Strizh.

Of course, you have to include there, that, despite all attempts to provide a technology for it, soviet-Russian ejection seats had been pretty dangerous even at Mach 2 already (the seats are only certified for 1400 km/h). The US ejection seats had been way more advanced there, but had been only marginally better to improve the odds of the crew.
 

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Well that's :censored:, even if it is true. The Russian apparently didn't see this as a problem, since they developed a suit specifically designed for just that thing. They actually seem to have put serious work into a ecape system for Buran.

I don't see why didn't we have a Strizh.

We do, similar suits were worn by SR71 pilots and the first few shuttle astronauts.

Most of the injuries associated with supersonic ejection are from the sudden pressure change and shock to exposed soft tissue.
 

Urwumpe

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We do, similar suits were worn by SR71 pilots and the first few shuttle astronauts.

Most of the injuries associated with supersonic ejection are from the sudden pressure change and shock to exposed soft tissue.

And the fact that risking to have a 15-30% chance to kill the pilot during ejection in some situations is still better than a 100% chance to kill him by not ejecting at all.
 

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RisingFury B-1A had a capsule but the B-1B does not.

The only "fixed wing" aircraft to go beyond the testing stages with a capsule ejection system was the F-111.

Capt. Brian Udell a F-15E pilot survived, his WSO did not.

A description of his equipment from the linked article.
"His helmet and oxygen mask had been ripped from his head, and his earplugs snatched from his ears. His gloves and watch also were torn off. All his pens and flight suit patches were gone. His wallet and a water bottle had blasted through the bottom of his G-suit pockets, with the zippers still closed. Underneath his flight suit, his T-shirt looked as though someone had taken a razor blade and shredded it. And the laces on his boots were imbedded into the leather."

With the SR-71 Breakup I find this the most telling piece of it (At least on the subject of ejection at high speeds and altitudes.)
"The pressure suit was inflated, so I knew an emergency oxygen cylinder in the seat kit attached to my parachute harness was functioning. It not only supplied breathing oxygen, but also pressurized the suit, preventing my blood from boiling at extremely high altitudes. I didn't appreciate it at the time, but the suit's pressurization had also provided physical protection from intense buffeting and g-forces. That inflated suit had become my own escape capsule."

Another interesting paragraph.

"Extracting myself from the parachute harness, I discovered the source of those flapping-strap noises heard on the way down. My seat belt and shoulder harness were still draped around me, attached and latched. The lap belt had been shredded on each side of my hips, where the straps had fed through knurled adjustment rollers. The shoulder harness had shredded in a similar manner across my back. The ejection seat had never left the airplane. I had been ripped out of it by the extreme forces, with the seat belt and shoulder harness still fastened."
Also the WSO did not survive.

A M-21 crew has also survived a mach 3+ ejection (all though the Launch Control Officer drowned after landing)

Most pilots do not survive supersonic ejection.

From what information I can find, Ejecting at supersonic speeds with out adequate protection, in the form of a pressure suit, is going to kill you unless you are really lucky and even then you are going to have a whole lot of other problems. With an operational Pressure suit and equipment your odds are probably 50/50.

It is my opinion that space flight has got past the experimental stage as far as getting in to space. And that we have to do our best to ensure crew survivability. Soyuz has proven that it is possible to create a safe and reliable launch system (true after some early problems) and any competitor or replacement should be able to provide a better survival probability.
 

garyw

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The investigation showed that someone (probably Resnick) activated Smith's oxygen apparatus, which was depleted, meaning that he breathed normally until the cabin hit the water. It also appears that he flipped some switches in a futile attempt to restore power to the cockpit. I know that the official line says that the crew died due to hypoxia, but that's conjecture which is not really suported by evidence. It is not hard to see why this conjecture became an official line, though.

It wasn't Oxygen. It was a PEAP which provides AIR. It wouldn't have been enough to keep him alive.

The separation of the crew compartment deprived the crew of Orbiter-supplied oxygen, except for a few seconds supply in the lines. Each crew member's helmet was also connected to a personal egress air pack (PEAP) containing an emergency supply of breathing air (not oxygen) for ground egress emergencies, which must be manually activated to be available. Four PEAP's were recovered, and there is evidence that three had been activated. The nonactivated PEAP was identified as the Commander's, one of the others as the Pilot's, and the remaining ones could not be associated with any crew member. The evidence indicates that the PEAP's were not activated due to water impact.

http://www.spaceacts.com/howdied.htm

There were no switch throws on Challenger post accident. You are thinking of Columbia where McCool tried to restart the APU's.
 

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The only "fixed wing" aircraft to go beyond the testing stages with a capsule ejection system was the F-111.

What? The B-58 Hustler had one, and I'm pretty sure it was operational.

Later versions gave each crew member a novel ejection capsule that made it possible to eject at an altitude of 70,000 ft (21,000 m) at speeds up to Mach 2 (1,320 mph/2,450 km/h). Unlike standard ejection seats of the period, a protective clamshell would enclose the seat and the control stick with an attached oxygen cylinder, allowing the pilot to continue to fly even "turtled up" and ready for immediate egress.

B-58_Escape_Capsule.jpg

Convair_B-58_Ejection_Capsule_3-4_front_view_061101-F-1234P-012.jpg


Interestingly, the images refer to a "ejection pod" and a "ejection capsule", so this might be a moot point if the two are distinct. Also moot if a delta-wing is not "fixed-wing".
 

Urwumpe

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There were no switch throws on Challenger post accident. You are thinking of Columbia where McCool tried to restart the APU's.

There had been switch throws in Challenger which can't be explained by water impact or the 22g load factor during breakup. Some of the switches on the right side panel (R1) had been moved, which require the crew to pull them up with quite some force to release, had been moved into a new position - the switch itself is too light to have been moved by even the 300 g impact by its inertia (According to Mike Mullane).
 
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kamaz

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There had been switch throws in Challenger which can't be explained by water impact or the 22g load factor during breakup. Some of the switches on the right side panel (R1) had been moved, which require the crew to pull them up with quite some force to release, had been moved into a new position - the switch itself is too light to have been moved by even the 300 g impact by its inertia (According to Mike Mullane).

Indeed, that's even in the wikipedia article:

At least some of the astronauts were likely alive and at least briefly conscious after the breakup, as three of the four recovered Personal Egress Air Packs (PEAPs) on the flight deck were found to have been activated. Investigators found their remaining unused air supply roughly consistent with the expected consumption during the 2 minute 45 second post-breakup trajectory.

While analyzing the wreckage, investigators discovered that several electrical system switches on Pilot Mike Smith's right-hand panel had been moved from their usual launch positions. Fellow Astronaut Richard Mullane wrote, "These switches were protected with lever locks that required them to be pulled outward against a spring force before they could be moved to a new position." Later tests established that neither force of the explosion nor the impact with the ocean could have moved them, indicating that Smith made the switch changes, presumably in a futile attempt to restore electrical power to the cockpit after the crew cabin detached from the rest of the orbiter.[23]

Also, there is actually no hard evidence that the cabin even lost pressure.
 
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