A grand applause
A grand applause. And a very well deserved one.
The fifth flight of Blue Origin's New Shepard rocket saw a successful blast-off for the crew capsule, as the company simulated an emergency escape for future crews. That is one hell of a booster. #InFlightEscape #GradatimFerociter https://t.co/7ZRRe2HnMO — Jeff Bezos (@JeffBezos) October 5, 2016 The rocket rose up over the …
If there had been any astronauts in that "escape" capsule, they would be dead. It was so out of control the rapid change in acceleration forces would have incapacitated the crew in seconds. I'm not a rocket scientist but I know from my aviation experience and training that that was not a survivable "escape".
Also, when it left the main rocket with that much thrust, what would the G forces be that were applied to them during the escape phase? It's not like it was a gentle bang seat ejection. :-)
Well acceleration of a mass with a force is Newtons second law. I'm going to assume it's that simple.
70,000lbf against 8000lbs (from the article) = 8.75g acceleration
A typical flighter plane ejection is around 20g (mostly because the seat and pilot don't have much mass and you have to get out quick enough to avoid the tail of the aircraft hitting you) and bones break around 25g, it's not excessive. You might well be incapacitated for the time you're under that much g but that doesn't exactly matter.
With the capsule bouncing around that much, the crew will need helmet restraints to avoid some serious neck/head injuries.
The proximate cause of the Columbia's crew's death was depressurization, followed by head and neck injuries as the crew cabin tore away and tumbled. See p. xix-xx in the executive summary. (Surprisingly, there was very little heat damage inside the cabin.) I'd like to think the aerospace industry learned from that.
Interestingly, the Orion capsule is not only getting tested with crash test dummies, but has used cadaver testing already
Formula 1 drivers routinely walk (or at least limp) away from 50+g crashes, fighter pilots can sustain extended periods of 9g with training, and I believe the record for surviving an impact is something like 214g (though luck did play a big part in that one). Provided the crew are securely strapped down (and why wouldn't they be?) that kind of tumbling is most definitely survivable. It wouldn't be very pleasant though, but given the alternative is being blown all over the local area I think most astronauts can live with it.
All professional race series mandate the use of a HANS device (Head and Neck Restraint System.) This device sits on the shoulders and is held down by the shoulder belts and prevents the neck injuries that rapid deceleration or the violent tumbling described in the article can produce. I doubt the occupants of this capsule would be wearing one.
According to the commentary, there was supposed to be a brief firing of retros just as the capsule hit the ground. I didn't spot that happening. There was a puff of dust, but it looked to me more like the result of the impact.
However, that was all pretty impressive. Not sure if I'll tire watching those boosters land.
From the article: "Once the capsule's three parachutes had deployed, the hardware slowed to just 16mph. The capsule is equipped with retro rockets that slow the rate of fall to just a few miles per hour – but they failed to fire"
(You probably missed that last bit of the sentence.;)
Seems like they need to take another stab at the aerodynamic stability of the capsule, that sort of swing is just too wild. I wouldn't want that to happen during the decent in a normal launch either, but the capsule seems less than stable in any orientation. (Check out the SpaceX Dragon V2 pad abort test footage for comparison, that thing is stable as a rock once it flips)
Same is true of ejector seats, oil rig evacuation systems, parachutes, emergency egress systems from test aircraft... That is kind of the nature of emergencies though. You design and test the best you can, but every emergency event is unique, and will pose unique challenges.
Did you know, for example, that for an uncontained rotor failure on a passenger plane, the manufacturer should calculate the percentage change that the plane will be lost. The recommendation is that there should be a 1 in 20 or lower chance of catastrophic loss. But that's only a recommendation, not a requirement, and is only based on a desk-top analysis. No testing is ever done, and when these things happen in the wild, it frequently is extremely destructive, in ways that nobody really imagined.
So, yes, if things go badly wrong, then things have gone badly wrong.
> The recommendation is that there should be a 1 in 20 or lower chance of catastrophic loss. But that's only a recommendation, not a requirement, and is only based on a desk-top analysis. No testing is ever done,
Maybe there is a business opportunity for really cheap flights there? Advance the state of human knowledge *and* get a 19 in 20 chance (if all goes to plan) of eventually making it to your destination, all for the price of an extremely affordable ticket.
Or free for commentards without an engineering (or physics) degree who insist on bothering electrons with their inane "contributions".
Just like any other capsule then, with the notable exception of Apollo. During a test of its launch escape system the test rocket (a Little Joe) broke up, triggering the escape system to fire for real. That was entirely a lucky accident, however, and would be difficult to repeat intentionally.
And for those who'd like to see that Apollo launch abort test, you can find it here.
It would have been interesting to listen in on the phone calls back to NASA after that test, "Well, the bad news is that the rocket broke up before it had reached the test speed, the good news is the abort mechanism worked perfectly anyway"
"Well, the bad news is that the rocket broke up before it had reached the test speed, the good news is the abort mechanism worked perfectly anyway"
That could sum up a couple of the N-1 flights. The only thing that worked well was the escape system, which pulled away the dummy capsules as designed.
It was so out of control the rapid change in acceleration forces would have incapacitated the crew in seconds.
Apologies, poorly worded post by me.
I was referring to the lateral acceleration forces caused by the unstable "wobbling" movement and not the vertical force. The rapid lateral movement changes would cause necks to fail under those conditions. I would assume stabilisers will be fitted to the capsule to avoid oscillations like that in the future.