_Columbia_: the preliminary report. (1 Viewer)

[Jack Briggs]

The most accepted model still involves the foam insulation breaking apart from the External Tank and then colliding with the leading edge of the late Orbiter's left wing, setting off the catastrophic chain of events.

Perspective: This feels more like the recovery from the Apollo 1 disaster than the STS-51L tragedy. Maybe that's because we have more compelling obligations in space (read: ISS) than we did at the time of the Challenger loss.

http://www.spaceref.com/news/viewnews.html?id=817

 

[Glenn Overholt]

I don't know, Jack. It read just like any other federal govt. document. I'm beginning to think that the object that was seen in the vicinity of it for a few days might have been a UFO. Maybe they were taking pot shots at us, just for fun!

I know how screwed up the news can get after big stories like this one, but there was talk that the engineers on Earth knew that something was wrong with the left wing while it was in orbit. The report didn't seen to mention that. (I remember now, it's just like the Warren Commission!).

Seriously, I can't wait to see the final report, and I am wondering if they can get away with saying that as a final conclusion they have no idea what did it. - That would really be good news, as there wouldn't be any reason to delay our shuttle program any longer, and we could start sending them up again.

Glenn

 

[Andrew Testa]

Seriously, I can't wait to see the final report, and I am wondering if they can get away with saying that as a final conclusion they have no idea what did it. - That would really be good news, as there wouldn't be any reason to delay our shuttle program any longer, and we could start sending them up again.

Actually, Glenn, that would be the worst possible outcome. If the final conclusion is that they have no idea, there will be no more shuttle flights. Launches will most definitely not occur until it is known exactly what happened and how to prevent it from happening again, or how to rescue a crew if the orbiter cannot be saved.

Since my paycheck depends on this report, I'm hoping they can further narrow down the sequence of events.

Andy

 

[Ray B.]

Since my paycheck depends on this report, I'm hoping they can further narrow down the sequence of events.

You and me both, man. I don't know about you, Andy, but for us flight controllers, there's not much to do if there aren't Shuttles in the sky.

I'm glad the CAIB released something, finally, even though there was no real news in their findings.

O'Keefe sounds optimistic that the October launch date for 114 will hold. I'm not, but the release of this report makes it seem almost possible. It would be good timing, since the Expedition 7 crew will be ready to come home by then. I have my fingers crossed.

 

[Andrew Testa]

Ray,

From what we've been seeing on the robotic side of the return to flight activities the October date isn't very realistic. Even the most basic tile inspection hardware and procedures are going to take longer than that to develop. I'm guessing we won't see a launch until January or February of `04. We're still floating proposals for inspection hardware, and probably won't have clear direction to build something until June, then it'll be probably 6 months for building and integrating the hardware.

For those of you who my have been asking yourselves why NASA has no ability to fix damaged tiles, believe me it's been looked at. Early in the program many concepts were examined to put an astronaut under the orbiter on the robot arm, and they were all rejected as too risky to the tiles or crew member, or too difficult to do with the arm. So they accepted the fact that if tile damage occurred, they were screwed (In NASA speak, Crit 1/1, loss of crew/vehicle). Now that tile damage has occurred with disastrous consequences, this exercise is being done again, only this time "we can't do it" is not an acceptable answer. And we're discovering all over again why it was rejected to begin with. It's a hard problem, very difficult to do with the arm. It's going to require the development of several new pieces of complex hardware that will need to be carried on every flight to allow us to look at the underside of the orbiter. Even more hardware is required to get a crew member under there so that they can do some work without further damaging tiles. The crew can't work EVA without numerous handholds and stability aids, yet none of these things can exist on the belly, and physics (think levers) won't allow them to work off of a long pole held by the arm. It's a hard problem, and we don't have the solution yet.

And if you're further asking why Crit 1/1 situations are allowed to exist at all, the sad truth is that there's no way around them. There are many of them associated with the orbiter. There's just no way around it. Some things just cannot fail, since there may not be any possible way to have a backup or failsafe and still have a vehicle that can get off the ground. This is why space flight will ALWAYS be risky, and why loss of life will occur again, as much as we hope and work to see that it doesn't.

Andy

 

[Ray B.]

It's going to require the development of several new pieces of complex hardware that will need to be carried on every flight to allow us to look at the underside of the orbiter.

Well, not every flight, just non-ISS flights, and those are going to be pretty rare. For ISS flights, isn't the plan to use a Strella boom on the Station arm for inspection and repair?

FWIW, inspection may be done with a "pirouette" manuever that's done as we approach the Station, while guys with spiffy cameras on ISS take pictures of the Orbiter from the nadir-facing Lab window. That's stuff my office is working on, and like yours, Andy, it's all very preliminary right now. I don't like calling it a pirouette, by the way, because it's really a 360 degree pitch maneuver at 600 feet on the Rbar (below ISS). Wait till you hear the official name of this maneuver... you're gonna laugh.

 

[Andrew Testa]

Yep, every flight, including ISS flights. We've been told to be able to do inspection and repair on station as well as orbiter only. The Strella turns out to be useless. It's more flexible than a whip. Any movement of the SSRMS whips the tip all over the place. Really ugly.

There are long term plans for a station-based boom structure that can place an EVA anywhere under the orbiter while docked, but it'll take years to develop. The pitch maneuver you described is a good start, but I'm concerned about the resolution of the images obtained at 600 feet. We were told we need to be able to detect a 0.25" dia. X 0.25" deep hole.

There's a plan to actually have the shuttle arm grab onto a PMA, undock from station, and use the arm to turn the orbiter around so that the belly faces the station, then use EVA on the SSRMS to survey or repair tiles. I don't see it happening, since it's a 5 hour maneuver, and we may not be able to reberth to the ISS.

In the short term, until something permanent is arranged, we've been told to have a method of doing shuttle arm based inspections even on ISS flights.

Andy

 

[Lance Nichols]

Why not resurrect the costly (as in lots of cash thrown at developing it) MMU? This should give the crew a way to go out and eyeball the entire craft when ever they want to.

BTW, why WAS the MMU mothballed?

 

[Andrew Testa]

As I understand it, the MMU was mothballed because there was no use for it and it was dangerous, basically. We have learned over the years that the orbiter is far more nimble at maneuvering and station-keeping than was originally thought (Ray, step in here anytime). So instead of sending someone out in an MMU to grab a satellite (which was a disaster when we tried it), we can fly the orbiter right up to it and have EVA on the end of the arm do the work. Using the MMU made the crewmember a freeflying satellite all on his own. This is mucho dangerous, since you can't fly it according to common sense because of orbital mechanics. If you get too far from the orbiter, your orbit is different, and commanding a jet to push you towards the orbiter may instead make you speed sideways past it. It's just too dangerous to try to fly without guidance.

Currently EVA uses a system called SAFER that has a small emergency jetpack that would allow a crewmember to quickly fly back to the orbiter if a tether snapped. But it's short range only. There have been proposals to tether an EVA to the arm and have them use the SAFER to fly around the bottom. One problem though is how accurately they can maneuver. They cannot touch the tiles, let alone accidently fly into them. It's fairly cumbersome.

I can assure you that the EVA folks are looking at every possible way to get someone under there, including some that you wouldn't believe professionals actually came up with. I won't denigrate any particular plan, since someone from EVA might be reading, but let's just say that no suggestion is left out.

Andy

 

[Malcolm R]

The most accepted model still involves the foam insulation breaking apart from the External Tank and then colliding with the leading edge of the late Orbiter's left wing, setting off the catastrophic chain of events.

Isn't that what the press was saying the day of/day after the event? And were all scoffed at by NASA? "Oh it couldn't possibly have been the foam...the foam couldn't have been that catastrophic." Three months later and we're back at the foam again. Mmmm...okay.

 

[CharlesD]

Isn't that what the press was saying the day of/day after the event? And were all scoffed at by NASA? "Oh it couldn't possibly have been the foam...the foam couldn't have been that catastrophic." Three months later and we're back at the foam again. Mmmm...okay.

What the press did was jump to a conclusion based on very little evidence. Even if "the foam did it" that doesn't rule out other contributing factors such as fatigue of certain parts that otherwise might have withstood the impact of the foam. Also bear in mind that foam had hit the Orbiter on previous occasions without causing major problems.

 

[Win Joy Jr]

Hey guys -

Wonderful discussion. My head is hurting just thinking about some of the stuff you guys are tossing out there.

One thing that I am sure you guys have started to factor in. And my data may be out of date, but, is there not a restriction that you cannot be transmitting off the K-Band antenna when an EVA is ongoing? It has been quite a while since I worked mission ops at NCC or WSGT/STGT... Not to name drop, mind you...

 

[Jack Briggs]

As for the foam, remember that it struck the leading edge of the left wing at a relative-to-the-Orbiter velocity of more than 500 mph. Would you want to get hit in the head by a 2.5-pound piece of foam flying at 500 mph?

It was recently retired program manager Ron Dittemore who was quick to dismiss the foam as culpable. Yet the evidence continually supports the foam-strike theory. And Gehman was careful to stress that it appears as if this is the most likely scenario, not that it definitely is. The investigating board is being scientific here. Its members won't say it absolutely was the foam impact because it cannot be proven beyond all doubt (presently, that is).

Andy, Ray: Do you even think February 2004 is realistic? STS-114, as noted, will have to benefit from a lot of changes to the vehicle as well as in mission preparation. This fall, of course, seems hopelessly optimistic.

 

[Ray B.]

Andy, Ray: Do you even think February 2004 is realistic?

Yeah, maybe. I wouldn't bet my lunch money on it, though. Just my humble opinion.

 

[Jack Briggs]

I hope your "humble" (I would call it "informed") opinion is on the money! Again, this feels more like the aftermath of the Apollo 204 tragedy than STS-51L. There's a greater sense of urgency in getting the fleet back into action. After Challenger's ninth and final flight, it was as if the nation had to experience its collective grief first and then go into a mode of self-doubt, browbeating, and equivocation.

Advances aren't made without taking risks, and our society has become far too risk-averse. I remember Apollo 7 astronaut Walter M. Cunningham saying just this during a Discovery Channel documentary years ago. As he was speaking, there was a visual in the background showing the LZ-129 Hindenburg flying against the backdrop of the New York cityscape. It was quite inspiring, actually.

 

[Ray B.]

There's a greater sense of urgency in getting the fleet back into action.

Thankfully!

I wasn't here for Apollo or Challenger, but I can tell you this: the way this matter was handled by Ron Dittemore in the weeks following the event was simply amazing. I'm told that NASA was very tight-lipped after Challenger and it's the exact opposite this time. I'm impressed with mostly everything (on NASA's side) so far, including the debris recovery operation (in which I participated for two long weeks in the mud).

Again, JMHO.

 

[Glenn Overholt]

Wow! This is fantastic! Nice having people that really know.

I am wondering though. But before I get into that I can honestly state that I wouldn't want to get hit by anything going 500 mph.

Ouch!
Now, They never really explained how the foam broke off in the first place, and as I thought it was just used for packing stereo equipment, what was it doing there? If it is prone to breaking off then wouldn't it be more practical to remove all foam before any flights?

Next, if this new 'rig' had been set up before this flight, would we still have known that something was wrong under the left wing, or are they planning on checking under all of the leading surfaces on future flights?

Last, I thought they would have had more cameras on the launch pad, recording digitial images as the crafts took off. Ok, maybe there are more that they haven't told us about.

Anyway, thanks all!
Glenn

 

[BrianW]

Glenn, the foam is there to insulate the tank, which contains pressurized fuel. As the fuel is expended, the pressure in the tank(s) drops, This causes the temperature of the remaining fuel to drop (PV ~ T) to the point where ice can form on the outside of the fuel tank. And ice can do much more damage than the foam ever could. So the foam is intended to prevent ice from forming by providing an insulating layer around the exterior of the fuel tank.

Next, if this new 'rig' had been set up before this flight, would we still have known that something was wrong under the left wing, or are they planning on checking under all of the leading surfaces on future flights?

That's an excellent question. If whatever solution they invent to inspect the orbiter while it's on orbit wouldn't have been utilized or effective enough to have detected Columbia's mortal wound, what would be the point? Once they have an inspection procedure in place, it makes sense to me that the policy would be not to inspect unless there was a reason to suspect damage. After all, inspection itself is not without risk and may, in a worst-case scenario, result in mortal damage to a shuttle that was undamaged prior to the inspection taking place. A policy like this would make perfect sense to me. But the next time an accident occurs on a picture-perfect mission in which inspection did not take place because no damage was suspected, NASA will be drawn and quartered for having the inspection procedure in place and not taking the risk to employ it. But if they inspect on every mission, then every mission will become more complex and invite more opportunity for disaster.

In a high-risk endeavor in which accidents almost surely cannot be avoided forever, I think this is a no-win situation for NASA. I'm confident they will employ any inspection procedure appropriately and judiciously, minimizing - but not eliminating - risk as much as possible. But the media and the general public may feel differently once tragic events are again viewed through hindsight.

 

[Jack Briggs]

I know. The agency is damned if it does and damned if it doesn't. "Your assignment: Carry out the opening steps of humankind's most daring and most dangerous effort ever undertaken and do not allow for anybody getting hurt in any way whatsoever. Ever. And you have $15 billion a year (and change) to do it with."

 

[Andrew 'Ange Hamm' Hamm]

This is the coolest thread ever, despite its sad subject matter. And I really like this "Dork in Space" program. Sign me up.