Columbia's Final Minutes in Detail 494
grub writes "This article on Newsday has an excerpt from 'Comm Check... The Final Flight of Shuttle Columbia,' by Michael Cabbage and William Harwood describing the last minutes of Columbia's final flight in detail."
Hot Gas != Plasma (Score:5, Informative)
While original reports used the term "plasma", there's a good explanation at space.com's Columbia FAQ [space.com] that explains that the hot gas that entered the shuttle's wing was *not* "plasma", as defined by science:Not to be a science nazi, but there's an important distinction between sci-fi-sounding "plasma" and the mundane -- but still deadly -- "very hot gas".
Re:Hot Gas != Plasma (Score:1, Informative)
I'm not sure if you were looking for a more in depth explanation. I don't know much about plasma, but that answered it for me.
Re:May their souls rest in peace. (Score:5, Informative)
Atlantic Monthly (Score:5, Informative)
Definitely RTFA... (Score:5, Informative)
Re:Atlantic Monthly (Score:5, Informative)
Re:I didn't think it was so bad until I read this. (Score:3, Informative)
Re:Hot Gas != Plasma (Score:5, Informative)
We're trending off-topic, but I'm curious. As I understand (imperfectly), a gas becomes a plasma by becoming completely ionized at high temperature. But a Bose-Einstein condensate [wikipedia.org] requires a temperature very close to absolute zero, so that the particles' velocity approaches zero and the atoms superimpose (Wiki make um smarter! Ugh!). How would plasma fit into that phase transition?
Very very sad read... (Score:1, Informative)
Re:Atlantic Monthly (Score:2, Informative)
I'm a budgeteer ... (Score:3, Informative)
Re:I didn't think it was so bad until I read this. (Score:2, Informative)
Re:May their souls rest in peace. (Score:3, Informative)
At least credit Sam Kinison. (Not like he's gonna do anything about it.)
Re:May their souls rest in peace. (Score:3, Informative)
Re:May their souls rest in peace. (Score:3, Informative)
Re:bad management kills (Score:5, Informative)
It's murder by management if the engineers tell management "hey, this part isn't strong enough, we have to use a stronger part or some cars are going to blow up" and management says "nah, that'll cost too much, forget it". Ford Motor Company was in fact indicted for second-degree murder over the notorious exploding Pinto gas tank, after it came out that basically the above engineer-management exchange had taken place.
Similar exchanges took place before the Challenger explosion (engineers didn't want to launch until the O-ring erosion had been fixed, and management overruled them) and the Columbia crash (engineers wanted photos of the insulation damage so if necessary they could make a contingency plan, and management spiked the request). So those also fit the pattern of murder by management.
Re:bad management kills (Score:5, Informative)
Do check out the Columbia Accident Investigation Board report at http://www.caib.us/ [www.caib.us]. Or, after February 1st, go to the main NASA site [nasa.gov] and look for the links to the CAIB report.
Management and political leadership did kill.
Re:Nasa won't learn (Score:2, Informative)
Re:Nasa won't learn (Score:3, Informative)
Also, when a shuttle mission is sent to the ISS they have to carry special equipment in the cargo area to actually connect the shuttle to ISS and transfer crew members. The Columbia obviously didn't have that kind of equipment along.
From what I understand, about the only thing they could have done had they known was a) try and launch another shuttle to evacuate the crew, or b) bring them down in Columbia and hope that the shuttle would hold together long enough for the crew to be able to use an escape hatch and parachute to the ground. The likelihood of getting another shuttle prepped in time was almost nill so it's quite possible that even if they did know they didn't really have an alternative anyway.
-Brian
Definition of plasma... (Score:5, Informative)
To be a plasma, the gas should have many free electrons (or ions) in each Debye length. There could be many more neutrals, just along for the ride, in the same space.
Most molecular gases become more or less fully ionized at around 10,000 degrees Kelvin (give or take a factor of four or so, depending on composition) since that's the temperature at which the collision energy becomes significant compared to valence electron binding energies, so most collisions can make new ions. So anything hotter than that is definitely plasma.
But even a fraction of a percent ionization is often enough to give you the nice bulk behavior of a plasma, because the ionized particles do their thing and drag along the neutral ones by collision. Depending on the density, it's probably reasonable to call the 8,000F (3800K) gases "plasma".
Not "Insightful" (Score:5, Informative)
When you've got an object traveling very vast what happens? What happens when you move your feet across the carpet? Static electricity. What is static? Electrons stripped from one object to another.
Static charge accumulates when loosely-held valance electrons transfer from less to more electonegative atoms. (Electronegativity is a measure of an atom's tendency to attract electrons.) It is analagous but not identical to dissociation, which occurs in plasma formation. Dissociation is the complete stripping of electrons from the nucleus, even the tightly-held inner shell electrons, which do not transfer when you shock someone by scuffing your feet on the rug. Dissociation, especially of diatomic gases such as O2 and N2, the major components of the atmosphere, requires immense amounts of energy. N2, for example, dissociates around 9000K (~16,000 deg F). For comparison, graphite vaporizes at about 6000K (~10,000 deg F).
Static can be a huge problem in pipes that move large amounts of non-polar fluids. Guess what most gasses in the upper atmosphere are? Non-polar fluids. So, there is your ionized high velocity, high temperature gas. Plasma.
I don't know alot about the shuttle's design, but I'd guess that if you talked with some NASA aerospace engineers they'd confirm this phenomenon. It's got to be a factor with all very fast aircraft.
Static charge is not plasma. Plasma requires complete ionization, and static doesn't even come close.
Static is not a problem insofar as flight mechanics are concerned. It may be a factor for avionics, as much as it is for any electrical system, but that is outside my area of experience.
-Carolyn
Re:Nasa won't learn (Score:3, Informative)
Actually the shuttle for the next mission was already at the pad and mostly prepped, the launch date was about a month away.
Step up the prep rate for that launch and put Columbia into survival mode (minimal power use, ration the consumables, etc) and they might have done it -- assuming they'd realized the problem right after launch rather than after a week in orbit squandering supplies.
some details... (Score:4, Informative)
2. Clarence Dally was Thomas Edison's assistance with Xrays. Here's [psu.edu] a link.
Re:one thing i don't understand (Score:3, Informative)
The leading edge of the shuttle's wing is flat. Over that goes a series of reinforced carbon-carbon (RCC) panels which form a smooth, aerodynamically-friendly shape. These RCC panels are shaped something like a V rotated 90 degrees. This creates a small cavity between the RCC panels and the leading edge spar of the wing, which is where the RCC panels are bolted on.
The bolts that hold the RCC panels to the spar are covered in insulation designed to take up to 3,200 degrees F.
The initial impact created a hole in the underside portion of the RCC panels, but did not go through the leading-edge of the wing itself.
So to detect this you would need to either have sensors on or inside the cavity of the RCC panels OR you detect it by the hole's effects on the wing, such as an increase in left-side drag.
From what bits I've read of the CAIB's final report, I don't believe there are any sensors on the inside of the RCC panels or inside the cavity between the RCC panels and the leading edge of the wing. Reason being it can get pretty hot in there and would probably destroy any sensors that were placed inside. So no direct sensor readings are going to detect the hole, becaue there aren't any.
So now to detect it right away you need to be able to observe the hole's effects in the form of drag. Problem is, this hole was on the underside of the wing. During ascent the shuttle is pointed vertically up so the effects of this 8 inch hole would be minimal at best and went undetected. Once in orbit, drag, for the purposes of this discussion, doesn't exist.
So there really wasn't any way to detect the hole or its effects.
The only way, until re-entry, would be a visual inspection of the area.
The shuttle wasn't carrying any equipment for a space walk, so that wasn't possible. The shuttle's orientation during orbit is to have it's belly facing away from the Earth, so land-based telescopes and cameras would have been useless.
Spy satellites or some other device in a higher orbit with a camera on board might have been able to do this. But I don't believe a request for such a thing was ever put to the CIA or NSA. It was certainly suggested, but I think the request was never pushed forward.
So that's why it was never detected until it was too late.
The only area I'm not 100% certain on is the sensors inside the RCC cavity. I know during tests of the RCC, they had sensors all over the thing. I've seen pictures of the inside leading edge which had some sensors, but I never saw anything inside the RCC cavity itself.
Given the need for insulation of bolts used to hold the RCC panels to the spar, I think my supposition that it's simply too hot inside that cavity for those sensors may be correct.
Anyone care to correct me on this?
Re:one thing i don't understand (Score:3, Informative)
For the same reason they don't make entire planes out of the material they use to make the "Black Boxes:" weight and cost. If you put sensors all over everything, your ship suddenly weighs much, much more, thus takes more fuel to launch, thus increasing the cost considerably. Besides, it's not very often that you experience catastrophic structural failure, and when it does happen (such as in the case of Columbia), it can usually be determined by existing sensors. Such as the spar-stress sensor and wheel well temperature sensors mentioned in the article.
if you level your course, instead of going down into the atmosphere will you just gradually burn up? I'm thinking, skim the outter atmosphere,
Orbit is a very sensitive thing. They started out in a stable orbit. Once they aimed themselves a little lower, they'd have entered an elliptical orbit, were it not for the braking effect of the atmosphere. If they'd instead pulled back up or tried to level off, they'd have skimmed off the atmosphere back into space, but at a different angle than the one required to resume a stable orbit. In short, they'd be heading out into space. They'd have needed substantial fuel to get back into orbit - fuel which they did not have (since this was literally the last few minutes of the mission, and they'd burned all their fuel, save for some maneuvering fuel). The shuttle actually lands with no thrust at all. It is effectively a glider. It needs very little fuel to re-enter.
although if your travelling at 1,568 mph
If they'd only been traveling at 1,568 mph, it would have been almost survivable (at least the breakup portion). RTFA - they were traveling at 15,800 mph (I think you missed a zero there), and that was almost 10 minutes after beginning their descent.
at what point of re-entry is it too late to do any sort of constructive abort?
From everything I've read, it was "too late" the instant the foam hit that panel. They couldn't have launched another shuttle in time, and they didn't have enough fuel to make it to the ISS's orbit, nor the equipment to dock anyway. I suppose it might have been remotely possible for another nation (Russia) to launch a rescue mission, but there wasn't much hope at any point after the impact event.
Re:one thing i don't understand (Score:5, Informative)
Re:I didn't think it was so bad until I read this. (Score:1, Informative)
Re:May their souls rest in peace. (Score:3, Informative)
Re:Nasa won't learn (Score:2, Informative)
Did you read the CAIB report? (Score:5, Informative)
Essentially this is a myth circulated by some NASA management apologists.
Bose-Einstein Condensates (Score:3, Informative)
Re:Nasa won't learn (Score:5, Informative)
No. Columbia was the oldest orbiter, and even though it had been refit and upgraded in many ways, it still had it's original airframe. Columbia was the heaviest of the orbiters, and unable to achieve the high orbit of the ISS. It was the only shuttle unable to make flights to the space station.
Even IF Columbia were able to achieve the altitude needed for docking, it was in an orbit that would take it nowhere near ISS. And IF it had been able to make it to ISS, Columbia did not have the docking module needed to dock to ISS. Without the docking module, the crew would need to EVA to get to ISS. Columbia did not have the spacesuits needed for this.
Columbia's ONLY option would be to wait for Atlantis, and Atlantis would have to be preped for launch in such a hurry that it's crew would be at extreme risk.
Columbia should have been retired a long time ago. We should have been using a 2nd gen shuttle by now. It may be sad to think that the shuttle fleet is to be retired with NASA's Mars goals, but in truth it was time.
I'm a big fan of the Space program, but NASA's claims that the shuttle fleet was designed to fly for 50 years should fail anybody's smell test. We don't use school buses for 50 years. Are we supposed to believe that they accounted for 50 years of metal fatigue when designing the shuttle fleet?
After Challenger NASA placed the odds for loss of a shuttle at 1 in 100. Those are risky odds. You wouldn't fly on an airplane with those odds.
The Shuttles never made the price of lauching satelites cheaper (it's primary goal) and it never made the turnaround cycle shorter than disposable launch systems.
It's time for NASA to get out of the trucking business and back to science.
The CAIB Report (Score:3, Informative)
It's worth taking a look at, as it gave a lot of insight into how they used the recovered parts to determine exactly what happened. The graphs that show where each tile fell on the ground makes it very clear where the problem started. The sensor timelines also give clues about how the fire spread inside the wing. Internal emails are included to show how the problem was acknowledged but played down, and how many missed opportunities there were to have discovered the problem while still in space.
It's definitely worth downloading and at browsing through if you have any interest at all in the space program.
Re:Space Shuttle - too fragile for manned spacefli (Score:2, Informative)
Re:Space Shuttle - too fragile for manned spacefli (Score:2, Informative)
Then why not compare with Soyuz? Or Gemini/Apollo/Soyuz combined? The last fatal Soyuz accident happened in 1971. More than a hundred launches since, no fatalities or injuries. There *were* two accidents in which the escape system saved the crew: Soyuz 18-1 (1975 -- in-flight failure) und Soyuz T-8 (1983 -- rocket exploded on the pad). Both these accidents would have been pretty much "unsurvivable" had they happened with the Shuttle.
The Shuttle is inherently less safe than Soyuz/Apollo designs. You have lots of completely useless structures like wings which only add complexity. You only have a few airports to land on in case of emergency, instead of, say, the whole ocean. There is no escape system like Soyuz's or Apollo's. The crew compartment is not mounted on top of the rocket, but strapped to the side of it, which means that in case of any serious failure of the rocket, you're pretty much doomed, where on Soyuz or Apollo you would have activated the escape system. And remember -- with the capsule mounted on top, foam can fall off the rocket all it wants -- it can't do any harm.
Re:Nasa won't learn (Score:3, Informative)
Soyuz rescue isn't a bad idea, but you'd be better off launching a fresh one as opposed to trying to undock from the station (which, on top of the propellant problem, you're also violating a flight rule for the station by leaving that crew without an escape vehicle). But the problem with launching a fresh Soyuz, assuming one could be scrambled quick enough, is that the Cosmodrome is at 51.6 deg N latitude. Due to that physical location, your orbital inclinations are restricted to 51.6 deg or higher (unless you waste fuel flying to 39 deg N then east) -- so you can't reach the 39 deg orbit that the shuttle is currently parked in. Did that make sense?
Re:Hot Gas != Plasma (Score:3, Informative)
Your memory fails you. IAAPP, and in physics at least, 'plasma' always refers to partially or totally ionised gasses.
chl
Re:Not "Insightful" (Score:2, Informative)
Yes. No. Yes.
Plasmas are more or less gases of electrically charged particles, so statically charged solids are not plasmas. But for a gas to be a plasma, it is neither necessary for every atom to be ionised, nor is it necessary for any atom to be fully ionized. I used to work with magnetically confined Argon plasmas (http://www.ieap.uni-kiel.de/plasma/ag-stroth) where about 10--30% of the Argon atoms were ionised. At temperatures of several ten thousand kelvin, most of the Argon was only singly ionised, i.e. it still had most of its electrons left. And yet, the system was dominated by the plasma effects, with the room temperature neutral gas just forming a background against which the charged particles rubbed.
chl
Slight Inaccuracies in the article. (Score:2, Informative)
Remember, back in the 1970's when the shuttles were designed, Computational Fluid Dynamics didn't really exist and they didn't have the techniques or the brute force computational power to solve the Navier-Stokes equations to see if it was going to be a turbulent flow or a laminar flow. So as a result the RCC panels are actually about two times as thick as they need to be.
So, basically the other panels were handling the temperature and aerodynamic loads just fine, it was the stream of super heated gas that got inside the wing that did all the damage. In fact if you read the CAIB report it says that the shuttle could have survived if the RCC panels had not been breached and instead had only been damaged. It was the breach that caused all the problems, not the rough surface nor the turbulent flow.
I know this because when the Columbia accident occurred my incompressible aerodynamics professor pulled out copies of some of the actual analysis of the shuttle from back in the '70's. They were pretty cool to look at and were using some of the same techniques we were learning.
Anyway, thats just my slight nit pick. On the whole it was a very moving article.
Re:Hot Gas != Plasma (Score:3, Informative)
Well, no.
First, Bose-Einstein condensates only occur at low temperatures when a significant fraction of the atoms sit in the ground state of the system. Second, Bose-Einstein condensates only occur in Bosonic systems. Particles that obey Fermi-Dirac statistics (e.g., ionized Hydrogen) are forbidden by the rules of quantum mechanics from forming Bose-Einstein condensates. There is no way that plasmas could be a precursor to Bose-Einstein condensates.
-JS (Yes, IAAP)