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View Full Version : Orion Parachute Test, or, Oops - Never Mind



Jim
2008-Aug-26, 08:39 PM
NASA conducted a test of the Orion capsule's parachute system, designed to bring the capsule and its astronaut occupants safely back to earth. It didn't go quite as planned.

http://gizmodo.com/5039573/nasa-tests-orion-parachute-result-spectacular-failure?autoplay=true

As that site says, the failure was not in the capsule's parachute system.

Here's a snippet of a response from the engineering team... which makes things seem far less bad than you might otherwise infer:

All but one of the 18 parachutes inflated (10 to get the mockup in the proper position; eight on the mockup). The parachutes that extract the mockup from the vehicle inflated and performed correctly. The pyrotechnics that separate the mockup from the pallet it sits on inside the plane successfully fired. However, the programmer chute that gets the mockup facing the correct direction and slows it down to the correct speed did not inflate when it was deployed. The engineering team will be looking into why that is.

All the parachutes that are actually part of the parachute assembly system continued to deploy and inflate as planned. There are three types of parachutes in the parachute assembly system: drogues that are designed to stabilize the spacecraft; pilots which pull out the main parachutes; and mains, which are the large parachutes that actually lower the spacecraft to the ground. However, because the programmer chute did not inflate and slow down the vehicle and get it turned in the correct direction, the vehicle was going much faster than it would normally have been, and those parachutes were exposed to much heavier loads.

The two drogue parachutes deployed and inflated as planned, however because they were experiencing increased loads, they separated from the mockup almost immediately. The three pilot parachutes then pulled out the three main parachutes successfully, however, two of the main parachutes also separated from the mockup - again because they were experiencing loads they weren't designed to handle. Those two probably slowed the vehicle down enough that the third main parachute was able to stay attached until the vehicle reached the ground. The test vehicle did flip end over end during its descent.

The hardware was damaged, but some parts of it may be reusable.
NASA does not plan on issuing a formal statement -- this was a test of a system and it has not yet been declared a "mishap."

Summary: the positioning chute (that gets the capsule into the proper attitude) and spinnaker failed to get the capsule slowed down enough or in the correct attitude so all other chutes experienced load that exceeded their design tolerances. They did deploy, but failed due to excessive capsule velocity.

IOW, a learning experience.

Larry Jacks
2008-Aug-26, 08:50 PM
That's why they do these tests - to find and fix problems before putting people on board.

Trebuchet
2008-Aug-26, 11:12 PM
I'm not quite understanding -- is the "programmer" chute part of the test equipment only, and not part of the projected capsule equipment?

Nowhere Man
2008-Aug-27, 12:32 AM
the programmer chute that gets the mockup facing the correct direction and slows it down to the correct speed
From this, I infer that it was part of the test equipment and not part of Orion.

Fred

Ara Pacis
2008-Aug-27, 12:57 AM
Maybe they should start using hang-glider wings like I recommended. :-)

timb
2008-Aug-27, 08:26 AM
Maybe they should start using hang-glider wings like I recommended. :-)

Maybe they should contract out the work to the Russians. They've been successfully landing spacecraft on terra firma for four decades.

stutefish
2008-Aug-27, 04:18 PM
Maybe they should contract out the work to the Russians. They've been successfully landing spacecraft on terra firma for four decades.
Isn't "four decades" also the amount of time that's passed since the Russians have successfully designed, built, and tested a new spacecraft?

JohnD
2008-Aug-27, 05:54 PM
That's what paratroopers used to call a Roman Candle.
Could never understand why, but now I see!
Most parachutists only get one star - this effort got dozens.
JOhn

cjl
2008-Aug-28, 06:45 AM
Maybe they should contract out the work to the Russians. They've been successfully landing spacecraft on terra firma for four decades.
All of the parachutes on the capsule itself worked perfectly though. The failure was in the test equipment.

slang
2008-Aug-28, 07:19 AM
I still have the image of Genesis plummeting down on my retina (down to the ground, not to my retina). Not something I'd want to see repeated, especially not with any manned capsule!

timb
2008-Aug-29, 01:08 AM
Isn't "four decades" also the amount of time that's passed since the Russians have successfully designed, built, and tested a new spacecraft?

I assume you're talking about manned orbital spacecraft. The Soyuz capsule has undergone several generations of development. The latest being a modification to accommodate heavier and wider American passengers :-) Has NASA produced a spacecraft that gets people into orbit cheaper than Soyuz in those four decades? Who spent more over that period?

ravens_cry
2008-Aug-29, 01:13 AM
Yeah, the Soyuz is about the closest we have to mass-produced manned space travel.

clint_dreamer
2008-Aug-29, 03:53 PM
Hey, if it ain't broke, don't fix it. I don't think anyone can question Soyuz's track record at this point...well as long as they work out the ballistic reentry problem.

zerocold
2008-Aug-29, 08:36 PM
The parachute is deployed, but it does not open..it might not be only test equipment-timing problem

IMO, even with very high loads these parachutes should not have separated

NASA is learning from 0, after decades out of the capsule landing technology, the problem is that now they must re-learn much faster , because this is not a Geminis capsule....

Anyway these test are done for that, to check failures and success, but really the video was hilarious :D,it reminded me some of the Coyote misshappen adventures, specially the end of the video :D

Larry Jacks
2008-Aug-29, 08:52 PM
IMO, even with very high loads these parachutes should not have separated

Every parachute has a maximum load that it can withstand. If the Orion chutes were designed to open at a speed of say 350 MPH and the test capsule was going much faster, something is going to give. Since the test rig parachutes failed to orient the capsule properly and establish the proper speed, everything went downhill from there (literally).

The drogue chutes failed (probably going too fast), so the test article began to tumble. When the pilot chutes tried to open the mains, they weren't able to get the mains open. It's hard to tell but it appears the main chute lines were tangled. That happens a lot when you try to open a chute while tumbling.

zerocold
2008-Aug-29, 09:22 PM
Well, the stabilization parachutes failure is just an effect, not the cause, don't know if these are released inflight, so that could be the reason why are so weak, anyway i still think that even with the test chute failure, the main should have worked, is probable that this is telling us the design tolerances are a bit tight

slang
2008-Aug-29, 10:29 PM
Huh? Now the design needs to take into account failures of testing equipment too? How much more expensive would you like space travel to be?

cjl
2008-Aug-30, 03:53 AM
Well, the stabilization parachutes failure is just an effect, not the cause, don't know if these are released inflight, so that could be the reason why are so weak, anyway i still think that even with the test chute failure, the main should have worked, is probable that this is telling us the design tolerances are a bit tight
The stabilization parachute is not part of the normal reentry process. It was for the test, and only for the test. Also, the stabilization parachute failure is absolutely the cause. Testing equipment failed, therefore the test occurred in conditions different from the conditions anticipated (and different from the conditions in an actual reentry)

djellison
2008-Aug-30, 03:09 PM
i still think that even with the test chute failure, the main should have worked,

You're still wrong.

zerocold
2008-Aug-30, 04:16 PM
cjl, i was not talking about the first ones, i meant the little yellow ones that broke apart.

I understand, that this kind of topics are subjet for a lot of doom prophets (not about you guys), so that is the reason why i don not want to go further in this kind of threads (like in the Ares thread)

At the end of the day is just a test, and things should improve, yet i still think im right, but well, let see the new tests, i also think it will be improved

djellison
2008-Aug-30, 05:05 PM
You have a specification, and you do tests to ensure things can perform to that specification with an appropriate margin.

These were parachute tests - but the test, because of a failure of the test itself, went outside of the expected regime and thus the chutes failed.

If you are coming here telling us that you and you alone, better than NASA, know that this test put the parachutes into a testing regime that they should have passed - they you will have to provide evidence and sound reasoning as to why that is the case.

zerocold
2008-Aug-30, 06:39 PM
Well, the parachute issue has happen before, is a well known issue that has plagged not only space capsules, but other kind of stuff, sometimes is related with the parachute design itself, sometimes related with the weight distribution of the cargo, sometimes with the arrange of the chute-pack, aerodynamic interaction, etc, im just telling that IMO, the main chute would have open at least a bit even with these test chute problems

If you see the video the stabilization chutes did open very well, even in such unstable state, but just did not had enough strenght , well, anyway are just for stabilization, i just was a bit surprised how easely went out

Was not my intention to begin a polemic about the issue, this is just my opinion, anyway

cjl
2008-Sep-01, 06:01 AM
Well, the parachute issue has happen before, is a well known issue that has plagged not only space capsules, but other kind of stuff, sometimes is related with the parachute design itself, sometimes related with the weight distribution of the cargo, sometimes with the arrange of the chute-pack, aerodynamic interaction, etc, im just telling that IMO, the main chute would have open at least a bit even with these test chute problems

If you see the video the stabilization chutes did open very well, even in such unstable state, but just did not had enough strenght , well, anyway are just for stabilization, i just was a bit surprised how easely went out

Was not my intention to begin a polemic about the issue, this is just my opinion, anyway
If you're talking about the drogues, it may seem like they failed easily, but the truth is that they were under phenomenal loads. Even if it was only going twice the design speed (a perfectly reasonable guess, considering the fact that the chutes designed to initially stabilize it were completely failed), it would have encountered around quadruple the design load when the drogue chutes opened. They cannot afford to overdesign them for these kinds of loads - the extra material would be well over the weight constraints.

Solfe
2008-Sep-03, 03:11 PM
<light comedy><br/>This is why the aliens put anti-gravity modules on the flying saucers.<br/></light comedy>