Ares 1-X First Stage Damaged

http://www.nasa.gov/pdf/283154main_AresIXHighLevelDrawingCMR.pdf

Maybe as the stages scissored on the sep plane, the pilot chute cone on the skirt extension was clipped, affecting main chute deploy?

Well there we go! Some darn good data coming in!

From what I saw of launch replays it seemed that separation was not totally "clean"; that the first stage may have "bumped" the Dummy second stage because it was still firing, thereby sending the second stage off track a bit and its apparent loss of expected forward momentum.

If the pararchutes come out of the top of the first stage, that area may have taken some damage
as a result of the "bump" and hence the chutes didn't deploy as anticipated.

Oh and btw, you can tell that I have NO expertise
in this area but I'm just giving my thoughts. :)

I'm not a rocket scientist either but I can see a video-and it appears that the upper stage impacted the top of the booster.

I dunno about re-contact after separation, but the booster definitely lights up pretty good just as the separation occurs. More plume pretty much always = more thrust, so I bet that provided a re-contact, or an asymmetrical thrust pulse, creating unplanned yaw to the second stage while it is still in contact with the first.

I know SRBs have been damaged on splashdown before, and there have been chute failures. I think an SRB sank on at least one occasion. I don't know more than this though. Does anyone know if damage this serious has happened before?

There was a high-speed ChuteCam onboard:

http://www.advancedimagingpro.com/publication/article.jsp?pubId=1&id=5673

So if that was operating properly, it should clarify the issue of any chute malfunction. Maybe also provide pics of the separation? Or maybe it's blocked until the chute deploys...

I'm no expert, but that dent looks too far down the length of the booster to be direct impact damage from the presumed re-contact. It is possible that the off-axis force from a lip-to-lip contact between sections of the vehicle caused the casing to crumple a bit like an empty soda can. However, given TitanLakes's comments about previous 'chute failure-related damage to SRBs, we'd better wait until an official line emerges before jumping to too many conclusions.

I think that incomplete separation is more likely than recontact. If the sep charge didn't completely severe the connection, you'd see the upper stage and first stage "hinge" and behave similar to the way they did on the video.

Dave

Even if thre was a slight (and it would've been slight) recontact, I doubt that would affect the deployment of the main chutes. The top of the booster was the forward extension which houses the pilot chute. There was a "second separation" whereby that ring was jettisoned and then the main chutes deployed. The USSS may have contacted and damaged that ring, which maybe could've prevented deployment of the chutes, but all three chutes did deploy. One of them collapsed afterward and tangled in another chute that may have only been partially deployed. Still, I don't see how that could've been caused by recontact with the USSS after burnout. But then again, who knows. Probably the hardest thing to do with spaceflight is a prachute recovery. It LOOKS simple enough, but it is not.

But before anyone maligns I-X and tries to use the parachute failure as "yet another reason" to ditch Ares I and go with a commercial option, keep in mind that SpaceX has so far failed in every attempt to recover the Falcon 1 first stage on the 4 flights out of 5 where they attempted to do so.

There's an article at Spaceflight Now with some more details about the splashdown:

http://www.spaceflightnow.com/ares1x/091030recovery/

It looks like all the chutes made it to the 50% open condition, but after only a couple seconds one chute deflated and was useless. A second chute was damaged while disreefing to the fully open position, and only partially inflated. The third chute was good.

All the damage is being attributed to the hard splashdown. The dummy fifth segment was apparently 15% overweight - maybe it was matched to the weight of a real fifth segment at launch, but not to the weight after burnout. Anyway, the extra weight didn't help.

Bob Ess also said recontact at staging wasn't seen. He says that the tumbling of the upper stage simulator did come up on some of their simulations, and that the simulator was "inherently unstable." For a real Ares I, he said "the upper stage engine and thruster system would keep the rocket under control."

I would think that with all the sensors on board, that there should be some accelerometer data or something that would resolve the issue of whether there was recontact.

If there's any future for a five segment SRB, whether on Ares I or on something else, the chutes will definitely need some more work, though even the chutes on Shuttle SRBs have a less than perfect record. I'm not even sure whether recovering SRBs saves that much money anyway, though examination of recovered SRBs can yield useful engineering data, and helps to deal with problems like the O-ring problem.

That article is partially correct about the parachutes. The main problem was that the SRB was 15% heavier than what the parachutes were designed for. The Ares I-X SRB was heavier than the Ares I because the dummy 5th segment was filled with something like concrete. You can see it's influence in the video of reentry. The second problem was with release of the parachutes, and I don't know yet if maybe there was some contact after separation and it damaged something in the chutes. All the tests of the parachutes have been perfect. You can find video online.

There are sensors and accelerometer data and it's being looked at soon. The first stage only just returned to shore, give it time.

IMO, this is a minor issue that can/will be easily explained or fixed.

I am MUCH more interested to see how we're looking when it comes to the oscillation issue.

"I am MUCH more interested to see how we're looking when it comes to the oscillation issue."

The models used to initially recognize that there might be a TO problem had some conservatism built into them. Word "on the street" is that these models have been (and are still being) refined using data from the recent 5-segment test by ATK. Some of the preliminary (i.e. unofficial) results are indicating that the TO problem is significantly lower than initially feared.

Dave

So how does one model thrust oscillation from a 4 segment booster and extrapolate to a 5 segment booster with different chemistry? and maybe having the dummy segment weigh 15% more won't dampen the oscillation, or change the volume and having a stack that doesn't have the same compliance as the real vehicle should negate all that great information. How many years was this same motor flying on the Shuttle, and they don't have the data yet?

Parachutes that don't open properly: what's the statistics on that, big and small, and how will it apply to Orion?

Don't confuse manned spaceflight with booster return, and don't confuse rocket science with photo ops.