…are being incorporated into Commercial Crew:
There is no way the Columbia crew could have survived the breakup of their orbiter after it lost its left wing to a crack in the thermal protection system caused by falling foam debris on ascent two weeks earlier. But forensic analysis after the catastrophe revealed “survival gaps” in cabin and crew-equipment designs that could give space travelers a better chance in accidents if they are fixed, according to Dr. Michael Barratt, a flight surgeon/astronaut in the NASA Human Research Program Office.
“This is really the only source of high-altitude hypersonic breakup information we have with regard to human response to it,” Barratt says. “It’s incredibly valuable, and it’s obviously information that came to us at a very high price, and something we are obligated to process.”
The data show all but one of the crewmembers died of blunt force trauma, and the nature of their injuries indicated their shoulder harnesses did not lock as the failing shuttle spun slowly in the thin upper atmosphere. That, and head injuries suffered inside the non-conformal helmets all but one of the crew were wearing during reentry, suggested redesigns of both the crew safety constraints and helmets.
None of the crew was able to close a helmet visor. The cabin decompression killed one of them outright, and the rest lost consciousness, which led to a requirement that crews on the remaining shuttle flights practice sealing their suits, Barratt told the annual FAA Commercial Space Transportation Conference in Washington Feb. 5.
It was a very interesting talk, and first time I’d seen those forensic details. I’ll probably incorporate them into a new edition of the book, along with the NTSB report on SpaceShipTwo, when it becomes available. I gave Barratt a copy.
I’m surprised that the helmets don’t close automatically in the event of a pressure loss. Self-closing faceplates were developed in the 60’s.
I’m also surprised (in fact, shocked) that there was not a requirement for astronauts to practice sealing their suits until *after* the Columbia accident. Did no one think, “Hey, these helmets don’t close automatically. We need to make sure the crew knows how to close them manually”?
Automatically closing the helmet would require a spring, a latch, and a solenoid.
On a vehicle that size, I really don’t see a viable survival option without ejection seats and designing the crew cabin as its own escape pod (such as on some early supersonic designs). If you did go with an escape pod, you could use rockets to limit the pod’s maximum G-loads, kind of like inertial dampers, and make the initial break-up survivable. The pod then should have it’s own ablative heat shield so it can survive down to an aerodynamic loading and Mach number were ejection is possible.
In most instances, the best escape vehicle is the one you started with. The escape capsules proposed for the Shuttle were the same capsules used in the B-58, with the addition of a heat shield. There’s a reason, however, why the Air Force never used those capsules on later aircraft. They were very unreliable, compared to ejection seats.
The escape option McDD planned for the Shuttle was a (relatively) small solid rocket motor attached to the base of the orbiter. In an non-emergency situation , it could be used for orbital insertion. That, of course, does nothing for an emergency that occurs during reentry. But then, neither Mercury, Gemini, Apollo, Soyuz, Orion, Dragon, CST-100, or Dream Chaser have an escape pod for emergencies during reentry.
Before you invest a large amount of money in an escape capsule, you should ask if there are other things you can do to make the vehicle safer and reduce the need for an escape capsule. It may be that those changes will save more lives for less money.
After the B-58, the Air Force did use escape capsules on the XB-70A. When one of the two prototypes was involved in a mid-air collision, one crewmember was able to escape but the other didn’t. The F-111 used the whole cockpit as an escape capsule. It worked on many occasions (I used to work with a former F-111 pilot who successfully used his capsule). The B-1A also had an escape capsule for the whole cockpit. In the one B-1A crash (only 4 B-1As were built), the parachutes didn’t deploy properly. The pilot was killed and two other crew members were injured. The B-1B and all other operational aircraft use ejection seats because they’re lighter, less costly, and more reliable.
In the Space Shuttle’s case, I think replacing it with an Orion, Dragon, CST-100, or Dream Chaser is the way to make the vehicle safer. It had a lot of complicated failure modes.
A month or so ago I thought about making the re-entry vehicle as small as possible (everyone packs in like a clown car), and having that re-entry vehicle’s bottom be a segment of a capsule’s outer wall. That would give you a delta-shaped lifting body vehicle with a bottom that’s a conic section. That would allow the rest of the large capsule to be much lighter (no heat shield), filling the same role as the Soyuz orbital module but doing so in a conventional capsule shape. The abort motors would then just push or pull the re-entry vehicle from the side of the capsule instead of pulling away the entire assembly.
“This is really the only source of high-altitude hypersonic breakup information we have with regard to human response to it,”
This is not correct. An SR 71 broke up at Mach 3.18 at 78 thousand feet.
http://www.916-starfighter.de/SR-71_Waever.htm
Well, maybe he meant “fatal” one.
One of the two guys in the SR-71 died from a broken neck.
Hypersonic is generally defined as being greater than Mach 5. If you count Mach 3+, you need to include Mel App who was the first to break Mach 3 but died when he lost control of the X-2 he was flying. He activated the plane’s ejection system (breakaway nose) but was unable to escape it to parachute to the ground.
There was also an X-15 crash that killed Major Mike Adams:
Adams was in a relatively high altitude dive and had a good chance of rolling upright, pulling out, and setting up a landing. But now came a technical problem that spelled the end. The Honeywell adaptive flight control system began a limit-cycle oscillation just as the plane came out of the spin, preventing the system’s gain changer from reducing pitch as dynamic pressure increased. The X-15 began a rapid pitching motion of increasing severity. All the while, the plane shot downward at 160,000 feet per minute, dynamic pressure increasing intolerably. High over the desert, it passed abeam of Cuddeback Lake, over the Searles Valley, over the Pinnacles, narrowing on toward Johannesburg. As the X-15 neared 65,000 feet, it was speeding downward at Mach 3.93 and experiencing over 15 g vertically, both positive and negative, and 8 g laterally. It broke up into many pieces amid loud sonic rumblings, striking northeast of Johannesburg. Two hunters heard the noise and saw the forward fuselage, the largest section, tumbling over a hill. On the ground, NASA control lost all telemetry at the moment of breakup, but still called to Adams. A chase pilot spotted dust on Cuddeback, but it was not the X-15. Then an Air Force pilot, who had been up on a delayed chase mission and had tagged along on the X-15 flight to see if he could fill in for an errant chase plane, spotted the main wreckage northwest of Cuddeback. Mike Adams was dead and the X-15 destroyed.
I was glad to see “engineering creep” discussed.
The original concept of the shuttle; a low cost fast turnaround space truck, as IMHO an excellent one. Where the shuttle failed abysmally was in the man hours needed to turn it around (making for both long turnaround times and insane costs).
As for the breakup, I too am shocked that, pre Columbia, training on how to close the helmet visor wasn’t mandatory. What’s the point of safety gear if they aren’t trained to use it?
What’s the point of safety gear if they aren’t trained to use it?
That’s what I was just about to say. Why wear pressure suits on re-entry unless a) they aren’t already sealed, or b) they can’t be sealed rapidly in an emergency?
It sounds like a failure you’d see in a very poorly written movie. “The astronauts didn’t know to close their helmets when the cabin depressurized! Who wrote this stuff, George Lucas?”
What about Soyuz flights? Do they usually fly with their visors down or not?
There was a lot of information in the shuttle crew survival investigation report. It’s online, maybe at the CAIB site. Among the interesting bits, IIRC, was that the shuttle’s life support system wasn’t capable of handling the exhaust from the crew launch and entry suits for the duration of re-entry. They weren’t able to close everything up for re-entry because of that.
The crew didn’t seem to be practicing good suit discipline, as not everybody had their gloves on, though they were supposed to. But it wouldn’t have made any difference. The violence of the accident caused grievous injuries even before the heat and aero forces took over. Even if everybody had been buttoned up, it would have made no difference.
After Challenger, NASA implemented the launch and entry suits; they never made any difference, as it turned out. There will be a lot of good yet painful lessons learned after Columbia, but who knows if they’ll make any difference next time.
I was always under the impression that the launch and entry suits were a mere gesture to make it look like they had a viable solution when there wasn’t any.
Even worse was the “bailout pole” (or whatever they called it), a very bad joke.
An engineer once told me that the Shuttle bail out pole would work just fine during every conceivable escape scenario that occurred while the Shuttle was horizontal, stationary, and parked over an air mattress.
Other than that, however…..
Yeah, the trampoline didn’t work out so well.
@ Edward Wright
The B-70, 58 type escape pods were proposed AFTER the Challenger accident. There are numerous references to a “pod” type crew escape capsule design which was deleted due to cost considerations in the literature but no actual drawings that I can find.
During one period in my career, I had a fleetingly small window of opportunity to fly on Shuttle as a payload specialist. Had I really pressed it, it might have been possible. But when it comes to entry accidents, I would rather have a helmet visor that opens if the vehicle breaks up. I’ve sustained some pretty severe burns in my life, and can extrapolate to perishing from them. I’d much prefer to go the peaceful, painless, blissfull way of anoxia.