Armadillo Aero One Step Closer To Space

RobertB-DC writes "The folks at Armadillo Aerospace have taken another step toward the X-Prize, dropping their re-entry vehicle from 2000 feet with no major problems noted. As usual, the Armadillo crew documented the event with text, pictures and video, and the story is also covered by Space.com (though without as many cool technical details). It's a bumpy ride, though -- instruments recorded some 10 G's on touchdown."

Comments

10 Gs?

[LeoDV]

Were their inertion dampening fields down?

Re:10 Gs?

[zapp]

Actually, 10G's is just enough to make a human pass out.

This is measured not as a sudden impact, but as a multiple of gravity. IE: when you're in a plane and they pull up sharp, you experience maybe 2x gravity.

Re:10 Gs?

[mlyle]

You, sir, are an idiot.

As you can see from this link, the baseline for federal tests for preventing injury in automobile crashes is 130 G's-- this is after significant portions of the deceleration have been dampened by restraint systems and portions of the vehicle collapsing. Fighter pilots in pressure suits routinely pull 10Gs without even blacking out.

Re:10 Gs?

[RedWizzard]

Ten Gs? That's an insane amount, enough to kill any human, that's for sure

No. Do some research.

I still think the X-Prize starlights belongs to Scaled Composities and their White Knight/SpaceShipOne

Keep in mind that Rutan's project will cost considerably more than 10 million, while Carmack's will cost a few million tops. Even if Rutan does win the X-Prize, if Carmack makes it to space then his will be greater achievement, IMHO.

Re:10 Gs?

[IvyMike]

Wouldn't 10 g's on touchdown cause death by deceleration trauma?

Bah. During the cold war, the air force did studies using a rocket sled, led by Dr. John P. Stapp that showed that 10Gs is nowhere near fatal. From the page:

By riding the decelerator sled himself, Dr. Stapp demonstrated that a human can withstand at least 45 G's in the forward position, with adequate harness. This is the highest known G force voluntarily encountered by a human.

I suppose the "with adequate harness" part can't be stressed enough, but there's nothing automatically fatal about 10Gs.

Dr. Stapp sounds like a pretty unique guy, and his work led to more survivable crashes in both aircraft and automobiles. I'm giving you One last chance to click on his biography, since I really want you to read it. :).

Re:10 Gs?

[Araxen]

Stole from usenet group sci.space.policy:
"M. Scott" wrote in message news:...
> John Carmack wrote:
> > We did the helicopter drop test of our X-Prize vehicle with parachute
> > system and crushable nose on Saturday.
>
> Great video! Congratulations on your progress and I look forward to
> reading about more of your exploits!
>
> I have one question, though. If there had been a man in the vehicle
> during that drop test, would he have been severely injured? The landing
> looked rough-- much rougher than in the SA'03 nose cone test, for
> instance.

The acceleration spikes were only 10G, which is not much of a problem
with a harness and padding. The roll-up-and-fall-back-down behavior
would certainly be pretty rough, so we hope to reduce that
behaviorwith some changes to the cabin top lip, the parachute, and the
tail supports.

The X-Prize could be had with the landing as-is.

John Carmack

Google link: http://groups.google.com/groups?hl=en&lr=&ie=UTF-8 &oe=UTF-8&threadm=c0e0a1dd.0307071735.5f09aa08%40p osting.google.com&rnum=1&prev=/groups%3Fq%3DThe%2B acceleration%2Bspikes%2Bwere%2Bonly%2B10G%252C%2Bw hich%2Bis%2Bnot%2Bmuch%2Bof%2Ba%2Bproblem%26ie%3DU TF-8%26oe%3DUTF-8%26hl%3Den%26btnG%3DGoogle%2BSear ch )

Re:10 Gs?

[GooberToo]

The problem is, those were G's realative to the person horizontally (perpendicular). When talking about vertical G's (parallel to the spine), a human can withstand far, far fewer G's. This is because our body isn't made to compress and the energy has to go somewhere. When taking G's head on, your body is good about bending and flexing to rid it self of the energy. When impacting vertically, pretty much the only mechanism your body has is to compress your spine. Pilots who land harshly often find themselves inches shorter and a life time of back and body problems.

Re:10 Gs?

[Reziac]

Maxing out at 10 Gs under controlled acceleration and deceleration is a far cry from 10 Gs splat on the ground!

Also, while controlled accel is not likely to be fatal, it *can* do some damage. I remember reading the story of one of the high-speed rocket-sled experiments, ca.1960 or perhaps a bit before. I can't recall who rode the thing (it wasn't Stapp, tho), but a side effect of the high G was bleeding inside his eyes, so his vision was slightly pinked ever after.

Re:10 Gs?

[Daetrin]

This is the highest known G force voluntarily encountered by a human.

Okay, i gotta know, what's the highest known G force _involuntarily_ encountered by a human, and how exactly did it happen? College prank gone horribly awry or what? Or maybe along the lines of "What's this button do?"

Re:10 Gs?

[UniverseIsADoughnut]

"Okay, i gotta know, what's the highest known G force _involuntarily_ encountered by a human, and how exactly did it happen? "

I belive some race car drivers have experianced 100 G's in crashes. Ones where the slammed into the outer wall at nearly full speed (ala 200mph). I remember some TLC or discovery special investigating how a driver survived such a crash.

10 G's isn't to bad. Jet fighter pilots can pull 4-5 G's momentarily before blacking out. Those 10 G's would be very very short, not like holding a high speed turn for a while. I think some roller coasters pull 3-4 G's in some turns as well.

Re:10 Gs?

[domninus.DDR]

so just rotate the chair? its not like orientation would matter when they were in space.

Re:10 Gs?

[athakur999]

10Gs should be enough for anyone.

Re:10 Gs?

[ncc74656]

Jet fighter pilots can pull 4-5 G's momentarily before blacking out.

They can go a fair bit higher than that. I saw a show on Discovery Wings not long ago that said Deke Slayton used to pull 9 Gs without a G-suit. (The "without a G-suit" part is a bit extreme, but the "9 Gs" part is kinda on the edge where some people will black out and some won't.) You might want to have a look at this page.

Re:10 Gs?

[Galvatron]

He means, having the acceleration start slow, build up to 10 G over a period of, say a minute, then slow back down. As opposed to crashing and instantaneously jumping from 1 G to 10 G. The former is much less stressful on the body than the latter.

Re:10 Gs?

[risacher]

Back in my flying days, I routinely pulled sustained 6.5 G turns without a G-suit or doing the proper Anti-G Straining Manouver. (AGSM) Some people just have a higher resting G-tolerance than others. Some of my classmates reported routinely "graying out" at as little as 4 G. ("Graying out" is where you progressively lose your peripheral vision.) With a proper G-strain (flexing leg and abdominal muscles to force blood up into cranium), pilots can easily do 6-7 G.

I only flew with a G suit once, and it was before I went to flight training (I was a back-seat passenger). We pulled 7 Gs on the sortie. The suit squeezed my legs hard enough that it felt like I would have bruises. I didn't black out.

It does not seem unreasonable at all to me that some trained pilots could pull 9 Gs without a suit.

Slashdotted already!

[Anonymous Coward]

Perhaps they dropped their server from 2000 feet also!

Finally!

[cybermace5]

Now they're getting somewhere. John Carmack finally quit trying to win the prize by running at brick walls and firing a Stinger missile at the ground.

Re:Finally!

[MousePotato]

damn... I wish i thought of that... i was thinking he did one of these:

~GOD
~FLY
~NOCLIP
~GIVE R 500
~GIVE H 200
~IMPULSE 9

Break even?

[grennis]

instruments recorded some 10 G's on touchdown

I'm not sure how much it costs to put this thing up. But, at 10 G's per touchdown, a bunch of more of these and they may get close to breaking even!

What does 10G's have to with bumpiness?

[Anonymous Coward]

It could be a very smooth, fast drop.

Something just occurred to me

[carl67lp]

Lately, we've been hearing more and more about the X Prize and the amateur (and not-so-amateur) aerospace engineers taking part.

I suspect that the recent projects are to the government-sponsored space programs as open source software is to commercial software. True, the fundamental ideas /might/ be different, but the goals are the same: Take something that you can't have general access to, make it your own, and make it better. Then contribute that idea to the general public.

In an era when people are becoming more and more concerned with manned space flight, I think projects and contests like this are the only way possible to get humanity into the heavens. Governments will always be under pressure to reduce spending; it will only be with enthusiasts that we make it to our proper place in space.

(This isn't to say, of course, that a non-government-sponsored flight will be the first to Mars. This is simply to say that it will be the space enthusiasts who shed the light on the important facts about space and its wealth of knowledge.)

Re:Something just occurred to me

[RocketScientist]

(extremely off-topic reply follows) Governments aren't under pressure to reduce spending. Governments are under presure to increase spending to things like invading other countries, giving money and food to people who don't work, figuring out new and different ways to screw citizens out of natural resources, "saving the environment", and studies to make sure that we're all aware that drinking beer is bad for us. So they have to simultaneously tax the crap out of anybody that makes money and cut a lot of things that are really worthwhile, like pure research and rocket science.

Private enterprise really is the best way to get to space. I just hope when they colonize mars they remember exactly why a government that that could get to the moon can't even reliably send people into orbit and bring them back anymore, and set up their government with the additional checks and balances to keep from repeating those mistakes.

I'm not bitter or anything though. Just because it's right after the end of a quarter and all.

Re:Something just occurred to me

[fname]

It's a very good point. The government resources clearly outmatch any private company at this point, and probably will for some time. The big problem is, space stuff is risky and expensive, and no one can really see the return on capital that they need to take the risks. Boeing, Lockheed, et.al. always need some government contracts to pay for the development before it makes sense to build a new rocket.

Of course, the engineers at NASA, Boeing, Lockheed, etc., are brilliant, and I'm sure they'd love to be doing this stuff. But that's not what Boeing pays them to do. and real rockets are a lot more expensive than computers. Plus, you can try new things and let them fail fairly risk-free in the computer world; not true in rocket science.

So while these "amateur" (quotes is b/c none of these groups are really amateurs. They are professionals doing this on the side) will come up with some very clever ideas, the government may be in the best position to exploit them. Which is fine, and I bet these guys would be happy if that were there legacy. And if Armadillo, or more likely Scaled Composites, comes up w/ a sustainable business propoisition, then this will get a lot more interesting.

[ Warning: Rocket Science humor ahead. ] In fact, if things go right, after the X-prize is won, this space thing will take off like a rocket-- and more like a Delta II-heavy than a Delta IV medium, if you know what I mean!

Re:Something just occurred to me

[cheesybagel]

Rockets got where they are today because some government decided it was neat to have a high-speed, hard to defend, way of killing people.

The V2 was not done by private enterprise. Or Saturn V. Sorry to bust your ultra-liberal bubble.

FWIW I agree with you that for space to be explored properly it must ultimately be done by private enterprise. Competition and diversity are key. The launch market should be liberalized and regulations for space launches should be relaxed.

PS: Giving food for people who do not work is good for everyone unlike what you think. It may not be 100% fair for those who work but it is a compromise. If food was more scarce this would be an issue. Food is abundant in our present Western societies. The fact is people are paid not to produce and food is sent to the trash. Giving some away to improve social stability is good policy.

Re:Something just occurred to me

[stmfreak]

In an era when people are becoming more and more concerned with manned space flight, I think projects and contests like this are the only way possible to get humanity into the heavens. Governments will always be under pressure to reduce spending; it will only be with enthusiasts that we make it to our proper place in space.

Government is not under any real pressure to reduce spending, they are under internal pressures to maintain control. Enthusiasts are possibly the only ones that will ever find a way for humanity to get into space. Governments are only funding space projects to appease the curiosity of the masses and maintain control of the technology.

Look around the world today at the way government is actively acquiring a monopoly on force. Do you think anyone in government looks forward to an easy way for terrorists with rocks to obtain Earth orbit?

Re:Something just occurred to me

[Larsing]

Usually an anti-government, pro-business standpoint is not so much liberal as it is conservative

No, that's liberal. Liberal as in free. Free from regulation. Market/capitalist liberal. As most countries/economies are quite heavily regulated (even the USA), an anti regualtion stand-point is (market/capitalist) liberal.

As for conservativism, it depends on what you are conserving. In Soviet Russia, comunism was conservative. With a "middle way" government, getting attacked by opposition from both sides, what one side would find conservative, the other would find liberal or socialist (or what ever...).

Just my 0.2c

ROFLOL

[matth]

From the website:

Too many users... blah blah blah

Probable cause: http://www.slashdot.org

Try again in a few seconds...

-xian@idsoftware.com

Google cache...

[Anonymous Coward]

Is armadilloaerospace.com already down?

Here's the google cache

In case of Slashdotting

[PhysicsGenius]

This links right to the video and the pics are here

Full text, posting as AC

[Anonymous Coward]

Helicopter Drop Test

http://www.armadilloaerospace.com/n.x/Armadillo/Ho me/Widget`s Corner?news_id=214

We finished up all of the prep work for the vehicle on Tuesday. We welded in strapping points to hold 600 pounds of passenger sandbags in the cabin area, and we mounted five 45 pound Olympic barbell plates on a peg at the end to simulate the weight of the final engines, plumbing, and backup recovery system that will be on the full size vehicle. We mounted four 2 throat engine shells as placeholders. Total weight is just under 2400 pounds. We use a combination of multiple chain hoists, a palette jack, and a forklift to move the full vehicle around and get it up on the trailer, but we did wind up breaking one of the castor wheels that we had mounted on our tank cradle. If we wind up having to use the 1600 gallon propellant tank (the current one is 850 gallons), we arent going to be able to stand the vehicle up under the main girder inside our shop, which will be inconvenient.

On Saturday, we headed out to our test site for the drop test. There were quite a few stares on the road in transit We had a few spatters of rain, and the wind occasionally gusted to 12 knots, but we were able to perform the drop in relatively calm 6 knot winds.

Anna rented a big RV for the day, which was very worthwhile. It was nice to be able to take a break in an air-conditioned space.

5 State Helicopters arrived with a big Sikorsky for the lifting. It was very convenient that they were based close by, and didnt have a problem with our unusual application (although they did have us contact the local mayor and sheriff for explicit permission). We were very impressed with the precision that they were able to do the lifting we were afraid that the vehicle might get dragged or bounced on the crush cone, which could buckle it before the test even started, but they were able to perfectly pivot it up on the nose, and gently lift it off the ground. If we had known they were that precise, we probably could have skipped renting the forklift truck for recovery and just had them lower the rocket back onto the trailer after the test.

We made several 18 diameter test parachutes that were weighted to drift at about the same rate that the full size parachute was expected to fall. We did the test drop from 1500 AGL, under the assumption that the big vehicle would fall several hundred feet before the main chute was fully deployed. The landing point for the test parachute was satisfactory, so we planned the full vehicle drop for 2000 AGL. Neil rode in the helicopter to do the parachute releasing, and Anna hung out the side of the helicopter (with a safety strap) to get aerial footage.

We had to abort our first attempt to drop the vehicle, because the line that we ran from the helicopter to the Sea-Catch toggle release above the rocket had wrapped itself around the chain so many times that Neil couldnt pull it hard enough to trigger the release. This was fixed by tying loose loops of plastic every few feet along the chain, which kept the pull-line in place.

On the second try, the release worked perfectly. You can clearly see the naturally unstable aerodynamics of the vehicle, as it starts to tip over almost immediately after release. We all held our breath as it started to fall, but the drogue immediately inflated and started pulling the main canopy out. It was nine seconds from release to full canopy inflation. The opening shock was negligible, barely hitting 2Gs. For high altitude flights, we are aiming for a 200 mph terminal velocity under the stabilizer drogue at the time of main canopy deployment, so opening shock will be much greater then.

The wake of the main canopy is so great that the deployment drogue just rests on the canopy during descent, without any inflation at all. The real deployment system will have a much longe

Re:Full text, posting as AC

[dbrutus]

Why is it that I always read about 1 or 2 X Prize competitors. Armadillo joined the race at the same time ARCA did but just because slashdot people like quake Armadillo gets all the glory.

Re:Ever see a dead Armadillo?

[PD]

I've seen a dead armadillo, but I've never seen a dead armadillo cooked in rocket fuel. That would be new.

Slashdotted?

[Snoe]

Is the site slashdotted already or did they drop the vehicle on their web server?

10 Gs

[Wyatt Earp]

Crash rated seats for military helicopters are rated to take 50G down to 20G so I wouldn't think 10G would be a problem to deal with.

Re:10 Gs

[twostar]

except that they've only fallen 2000ft, any guesses as to if the test vehicle made it to terminal velocity?

Re:10 Gs

[thebigmacd]

No guess...an answer. The article at space.com shows the craft PARACHUTING to the ground. I'm sure terminal velocity was attained quite quickly. Ewwww...10 Gs upon landing, WITH a parachute.

Re:10 Gs

[child_of_mercy]

thats a drogue design issue, and comes back to weight questions, its easily done if weight is no object (as with most things in spacecraft design)

but 100 yards of kevlar ribbon will bring terminal velocity down a long, long ways.

and there are better designs still.

Re:10 Gs

[Guppy06]

I think the weak link here for most people here would be their own posteriors. I've personally only experienced maybe 3 Gs or so on various carnival rides, and with those I'm pretty much on my back. Nobody this side of a fighter pilot does anywhere near 10 Gs, especially in a near-sitting position. Heck, not even astronauts do that any more.

Re:10 Gs

[Magila]

A 10G jolt isn't as bad as it sounds, figher pilots only have to worry because they experiance high Gs for relativly long periods of time. People can take 20Gs or more over a fraction of a second without too much trouble assuming they're well restrained.

some 10G's???

[Anonymous Coward]

It's a bumpy ride, though -- instruments recorded some 10 G's on touchdown.

Good thing they only recorded some 10 G's. If those 10 G's had been present all over the craft, who knows what kind of complications could have arisen. I'm sure the design team will find a way to spread those 10 G's throughout the craft, reducing the overall readings to a manageable 2 or 3 G's.

The Problem is...

[Frodo2002]

..The problem with these people is that their movie clips are waaaay too large. They could reduce their movie file sizes by a factor of 5. I am sure that would alleviate some of the pressure on their server... Has noone pointed this out to them?

Re:10 g's? So what!

[charnov]

Depends on many milliseconds of duration. Humans have been shown to take 35 G's for very short durations (belted head on collision at 50 mph for example), but anything over about a 100 milliseconds and your organs (and bones) tend to go a little mushy.

Info direct from the armadillo's mouth . . .

[Darth_Foo]

John Carmack is a semi-regular poster to sci.space.policy on usenet; he's posted several times today with details of his test plans and schedules. Even if the company site is slashdotted, go do a Google Groups search on him and the sci.space.* groups and you'll get all his publically-available info, straight from the source.

I want Doom 3

[Anonymous Coward]

Stop playing with those rocket thingys and go finish your job!

Obligatory Physics snob comment...

[Anonymous Coward]

It should actually be written "10 g's", with 'g' in lower case, as this refers to 10 times the normal acceleration, while "G" the capital letter refers to something entirely different.

Re:Obligatory Physics snob comment...

[Anonymous Coward]

Yeah, 'G' as in 'Geek.'

I Smell A Rat

[wbav]

Anyone else think this is wrong? When touching down 10 G's? The most G's would be on lift off, not touch down, and 10 is just plain nuts. Come on. If you think of a plane, and touchdown, you are going in the same direction of gravity, not against it.

I mean conceptually, the article doesn't make sense, and I hope people will realize that.

Re:I Smell A Rat

[Tmack]

uhh ever take physics? g forces are a measure of acceleration in reference to the standard acceleration of freefall on earth. Since they are saying 10g's at touchdown, that means the acceleration at tuchdown is 10*g(9.8M/s/s), or about 98M/s/s. Since mass*acceleration=force, your mass*98m/s/s==the downward force you would create on this landing. Using g's, you remove the unit dependance, making it easier to create estimates such as "at 10g's a person weighing 180Lbs would feel like they weigh 1800Lbs". What is also important but not mentioned is the duration and delta of this acceleration.

tm

You're absolutely right.

[DaedalusLogic]

Visit www.scaled.com and you'll see who's going to win the X-Prize. Burt Rutan designer of the famous Voyager, the plane that made the first non-stop flight around the world.

This guy has been engineering exceptional aircraft for years. Father of one of the most radical and popular homebuilt aircraft designs ever.

J.C. has an interesting background and obviously the mind of an engineer, but no one is going to catch up with Rutan's design which resembles the X-15 project of the 1960's.

If someone at Scaled Composites is reading... Can I have a job? Yeah, like that will happen...

Re:You're absolutely right.

[RedWizzard]

but no one is going to catch up with Rutan's design

No one outside of Rutan's organisation really knows how far advanced Rutan's project is, so it's a bit hard to say if he's in the lead or not. Certainly when it was first announced and the website went up there were several pictures that had been doctored to make it look like things where more advanced than they actually were. Rutan lost some credibility in my eyes with that.

Re:You're absolutely right.

[MtViewGuy]

I'll give it to Rutan's Scaled Composites group, too. =)

Mostly because unlike most of their competitors, Rutan's extensive experience with highly-advanced aerospace materials and unusual aircraft design shows he has the expertise that can build a successful X-Prize competitor. Besides, the research from SpaceShipOne could evolve into something that people long for: relatively cheap access into Low Earth Orbit (LEO).

There were proposals to build a small spaceplane in the late 1980's that could fly into space from the back of a modified 747 that has been fitted with a rocket motor that provides the initial boost before the spaceplane launches from the 747 and flies on its own power to LEO; Rutan has the expertise to build such a vehicle, one that could carry as many as seven crew or its equivalent cargo load to the International Space Station.

Missin the Point

[Blastus]

The X prize is about paving the way for paying customers to get to space. It's about developing a cheap re-usable space craft to do it. Lighting off hair chemicals for launches and crashing for landings? You gonna pony up for that? Go ahead. I'll call Rutan for my flight, thanks.

K.I.S.S.

[jayrtfm]

That X-15ish engineering may be Scaled's achellies heel. Remember that the well financed front-runner for the Orteig prize crashed the day before Lindberg took off.

I'm hopeing that both teams get their first launch within days of eachother, so that a media frenzy occurs before the winning launch.

Late again

[apsmith]

RocketForge had a link to this posted 3 days ago! So I got to see the video before you guys slashdotted the server :-)

Armageddon

[KU_Fletch]

I choose to base my logic on the movie Armageddon where people can cheerily pull 18 G's on the backside of the moon.... before landing on an asteroid... and blowing it up...

perhaps i need to find a new base for my logic...

Re:10Gs?

[The Dobber]

Yeah, but they are probably in pretty good physical condition. Your average geek gets woozie just bending over to pick up that stray cheese doodle.

Video Torrent

[heli0]

BitTorrent of the Video here:

http://www.bytemonsoon.com/download.php/11286/Drop Test.mpg.mpeg.torrent

as the old saying goes...

[SuperBanana]

It could be a very smooth, fast drop.

As the old saying goes about leaping off a bridge, it's not the trip down that sucks- it's the ending.

The joke among some pilots, after a hard landing, is the term "unintentional ground contact."

Armadillo first in space?

[dogfart]

seems like a lot of trouble to squach an armadillo. Usually speeding cars do just fine.

Jerk

[Baldrson]

"10Gs" isn't really that informative. In addition to meters per second squared, the key units to report for the landing are meters per second cubed or "jerk". That tells you how much destructive load is imparted by the acceleration. If they published the accelerometer output it should be easy to figure.

Re:Jerk

[evilWurst]

Well, m/s^2 *was* given - that's what gees are. One gravity is, what, 9.8m/s^2? So ten of them would be 980m/s^2. The jerk ratings would be nice, though. If they put up a pretty graph of gees vs time, we'd be able to figure it out.

Re:10Gs?

[GooberToo]

I keep seeing people quote those high g numbers from historic tests of days past. One of the most critical factors in determining how fatal a g rating is on a human, is not only the g's, but the duration the g's were sustained. For example, a human can take insanely high g's over a very finite duration. Those same g's which may of only bruised and bloodied your body may have killed you if the same g's were sustained for twice the duration.

I am counting they will all fail.

[cheesybagel]

Some are too amateurish and do not have enough experience and/or money.

Others are simply pie-in-the-sky.

Rutan is trying to do things in the hardest way possible and you know what that means... However there are rumours there could be a possible government money source behind this interest by Rutan. Remains to be seen.

BTW a suborbital flight is nothing fancy. The problem is getting something in orbit or returning something back to Earth in one piece. Cheaply.

SCALED COMPOSITES will take the prize

[Orre]

It seems that most voters at XPrize believe that the SCALED COMPOSITES, LLC have a better chance to take home the XPrize than Armadillo Aerospace.

Soyuz = up to 8.1G

[hughk]

According to this report, the Soyuz recent TMA-1 that went off track sustained 8.1G. The crew were unharmed. Normally Soyuz, which makes a hard-landing pulls about 3-4G during descent.

With shock absorbing crash couches and a reclined position, higher vales should be possible. The issue is failed parachute depolyment. Single parachutes may deploy incorrectly or not at all increasing the G load. Normally a cluster of parachutes are used hence the margin needed for error. Without access to the web site, I can't see how many chutes were being used.