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The vibratory effect was essentially the basis for the "worm" drill that failed so miserably on a recent lander. It works in fine-grained stuff that is ALL fine-grained. But Mars is not. The worm drill bumped into a rock just subsurface underground, and it could not navigate around that rock. The rock completely stopped it.
My point: the subsurface material on Mars is NOT a uniform material in terms of sizes. This is a mix of stuff from wind-blown dust all the way to house-sized boulders (or larger), because Mars is heavily cratered and covered with ejecta (like the moon. Why? Because of the very long time it has had a very thin atmosphere that cannot stop meteors very well at all.
The bedrock projects up through this in many places all over Mars, usually as craggy-looking stuff. It is both weathered, and cratered. In the northern lowlands, this surface is also overlain by sea bed deposits resembling sands, and maybe some clays. Or maybe not any clays. But that, too, has some cratering disturbance. Just not as much. Which suggests the ocean persisted a bit longer than the atmosphere did.
The "best estimates" I have seen published say that Mars essentially lost its atmosphere down to the thin thing we see today, dried up, and froze, something like 3 billion years ago (1.6 By since formation). Before then, it was supposedly far more Earthlike. The leading contender for "why" it lost its atmosphere is no significant magnetic field to ward off solar winds and mass ejections from stripping it away. But nobody really knows "for sure" what happened.
If life here (as best we understand its history) is any guide, there was microbial life in the Martian ocean and lakes. There may still be vestiges of it surviving underground here and there. But the planet likely went uninhabitable before multi-cellular life could evolve. Life on Earth was single-cell microbial as best we know, until about 0.6 billion years ago (4 By since formation). Our atmosphere was pretty much devoid of oxygen until photosynthesis changed that, somewhere around 2.5 billion years ago (2.1 By since formation).
Assuming similar life would follow a similar gross history there, life on Mars never even had a chance to put much oxygen into its atmosphere, which is thought to be a prerequisite for multi-cellular forms of life, at least multi-cellular animal life.
But if things happened the way I suggest on Mars, that would explain the long-derided supposed microbe fossils found inside the Allan Hills meteorite ALH-84001, which came from Mars.
Whoops, I wandered off topic! Sorry! But what you must deal with, operating upon that surface to build things, depends integrally on the past history that created it.
Screws do not work in soil containing big rocks (6-inch and up), especially close-packed big rocks. I have literally seen that, here in Texas, on the farm as well as out on construction sites.
The microwave idea would require an enormous amount of electrical energy. You literally have to melt ton-class masses of rock and rock dust around your pile.
If you use piles at all, the gas-driven hammer would be best. You must use harvesting dry ice and thawing it confined in a tight space, to gasify it at pressure, in order to compress it. Normal compressors like those here (about 6 to 10:1 pressure ratio) will NOT work in a 6-7 mbar atmosphere! They do not work at 110,000 feet here, either. Compression ratio 10 on 6 mbar is 60 mbar (still next to nothing), and the mass you compressed for the power expended is quite tiny, because the inlet density is so low!
Rather than piles, myself, I would go for some sort of slab construction laid on a well-graded surface. Heavily reinforced, of course. Because of the internal pressures it has to support. Which means we need the equivalents to concrete and rebar. We do not have them!
So that gets down to the piling of rocks for dry-fit masonry, upon a well-graded surface. If the thing is big, it will require a proper "foundation" of close-bedded stones in layers, decreasing in size to gravel at the surface. Road beds, when properly done, use that technique. It will have to be quite massive to resist the blow-out loads of internal pressurization on Mars. And the lower gravity reduces the weights of the stones that produce the friction that resists those blow-out loads!
Let's just say there must be some serious in-situ construction experimentation before real recommendations for building construction techniques can be made, and let it go at that.
But THAT is a big part of why I say that there is an "experimental base phase" between initial exploratory landing, and the building of anything permanent like a city or a colony. Or your colonization effort is doomed to failure.
GW
Turns out there was a glitch. The second stage put the satellite in the wrong orbit. Not just "wrong", completely unusable.
It is hard to tell from reports filed by reporters not technically competent, but it sounds like the second orbit-adjusting burn demanded of the second stage about an hour after it shut down, did not happen.
GW
Congrats to Blue Origin. It has joined ranks with Spacex in the heavy launch to orbit business, complete with reusable first stage boosters. They still need to establish the same kind of good track record as SpaceX has with its Falcons, but as good as their technology looks, I think that will happen, and fairly soon.
Meanwhile ULA's Vulcan is grounded for a fault in its SRB nozzles, and has yet to demonstrate any reusable anything. So, my conclusion is that "new space" is pulling ahead of "old space" in the heavy launch business. Not to mention several small "new space" launchers out there.
GW
I think the closeup photo is an enhanced version with clearer focus, but a reduced view dimension, of the blurry photo that shows the whole capsule.
I an not at all sure this has anything to do with being "hoisted up". I suspect without proof the blurry photo was taken just before splashdown, still hanging from the main chutes.
Take a good look at the clearer restricted-view photo. This was intended to show the damage near one attachment pad that did not survive. That is what the whitish "stain" is, staining from the melting metal. There is extra erosion there, too.
But, look up at the lateral side near that same place. Do you, or do you not, see exposed and distorted metal, and maybe a burn-through, where the lateral-side heat tiles were thinner? Maybe too thin? Those whitish areas are not windows, they are exposed locations of the metal outer shell to which the heat shield tiles were attached.
GW
Another follow-up to post 89. I finally found enough photos to make a preliminary assessment of the Artemis-2 heat shield.
Both NASA and I were right, in the sense that NASA said that a single heating pulse no-skip re-entry would reduce cratering damage (it did). I said that cratering would still occur, albeit reduced and smaller, without the reinforcing hex (and it did).
I did see something else nobody expected: complete localized heat shield loss and metal distortion or burn-through, on the more windward lateral side of the capsule, while flying at angle of attack to generate a side force for fine trajectory control (something done since Gemini).
It would appear that flow along that side, supposed to be a separated wake zone, was instead at least intermittently attached, with resulting far-higher convective heating than the thinner Avcoat tiles there, could resist. This was the side opposite the windows. That windows side looked to be in good shape.
GW
I put an Artemis-2 mission article up over at my "exrocketman" site, titled "About the Artemis-2 Mission", posted 31 March 2026, search code 31032026. Today (13 April) I added an update with photos, that lead to a preliminary assessment about that heat shield.
Both NASA and I were right.
NASA was right that eliminating the two-heating-pulse skip entry would reduce heat shield damage. It did. I was right in saying that at least some chunk-shedding crater damage would still occur, and it apparently did. The photos I found so far prove that.
Unexpectedly, I also saw heat shield damage to the lateral wall of the capsule, on the side closer to the stagnation point, away from the windows. That is where the Avcoat bonded tiles were thinner. Hex in those tiles would greatly reduce that, but maybe a bit thicker is also needed, too. The damaged metal was the outer skin to which the tiles are bonded. That is NOT the inner cabin pressure shell!
What that means is that if NASA would put the hex into the bonded tiles, less damage would occur, even with a two-heating-pulse skip entry. I have already told them how to do that, without resorting to manual hand-gunning of the Avcoat in the hex cells. They need to do that before flying again to the moon, with a 10.9 km/s entry. Artemis-3 will come back at only 7.9 km/s from LEO. Even what they have now will be adequate for that.
GW
Both SpaceX and Blue Origin are companies that first and foremost have to make a profit, not lose money. SpaceX was profitable with Falcon-9/-Heavy, but has bet its future "farm" on rideshares with Starship/Superheavy. They still have their hands full just trying to make Starship/Superheavy work at all as a transport to LEO. Blue Origin has its hands full trying to make New Glenn into a profit center. Coming up with a contracted NASA lunar lander is a smaller piece of that overall larger puzzle, for both of them. I cannot fault their priorities.
Of the two, I suspect Blue Origin might be a little closer to satisfying the NASA lander contract. That is because SpaceX bit off a much-larger piece of "iffy" technology advancement, trying to do the all-reusable Starship/Superheavy. Plus, my reading of the events suggests the ratio of Musk time to real time (3 to 4) is a bit bigger than Bezos's ratio (2 to 3).
The time from lunar rendezvous being the adopted Apollo architecture in 1964 or 1965, to the Apollo-9 checkout of the Apollo CSM with its LM in LEO in 1969, was only 4 or 5 years! THAT is how long it took Grumman to come up with a workable lander, under a crash program where cost was no object. And higher risk-taking by NASA with its astronauts was "normal".
Artemis is NOT a crash program where cost is no object, and NASA (I hope) has learned not to take such extreme risks with its astronauts! Expecting SpaceX and Blue Origin to come up with anything workable as a lunar lander in only 4 years or so, is actually quite unreasonable! SpaceX started only 2-3 years ago, and Blue Origin "in earnest" only last year.
You CANNOT count the proposal and contract-win time, as real hardware development time! That only sets the concept they will focus upon. REAL development only starts AFTER contract award. And coming up with a concept has NOTHING to do with its development into something real! That's just life. Ugly, ain't it?
NASA projecting schedules that have no reality tells me there is no one there anymore that understands the difference between company time and real time, and that the ratio varies from company to company. I would expect that, after all the former traditional contractors agglomerated into monopolies that no longer really compete (with the government making no anti-trust moves to stop it). THAT is why "new space" has had such a hard time getting established. The game was rigged.
GW
With Spacenut's photo of the fiberglass hex with the hand-gun tool inserted, I an now sure that the hex's resin was phenolic. I saw a lot of electrical and electronic board materials in the 60's and 70's made of this very same stuff. The color is the key to identifying it: that orange is commercial phenolic resin, on plain white fiberglass cloth. Cures at modest heat and only some pressure between mold platens, if you are making flat panels. I do not know what tooling was used to make hex.
The type of phenolic that went into the glass and silica phenolic materials was different! It cures under greater heat and a lot of pressure, and is tan in color. I used a lot of silica phenolic in ramjet nozzles, and in rocket nozzle assemblies. It is tough, dense, slow-ablating, and very heavy. The fiber is in woven cloth form, and you must be very careful to orient the cloth layers correctly relative to the flow direction.
GW
Avcoat is a thick, not-quite-liquid, paste that is more like a dry mortar or cement material, comprised of epoxy-novolac polymer heavily loaded with silica fiber and phenolic microballoons. The polymer contribute the carbon to the char layer, with the silica fibers contributing some silica content. But the char is largely porous amorphous carbon. I do not know the standard percentages of the components, but I do know they can vary, especially the microballoon content. Porous amorphous carbon char handles to the touch about like a piece of charcoal from the BBQ grill that is burnt-through but not yet consumed to ash.
The microballoons contribute the porosity required to get the pyrolysis gases out from the pyrolyzing layer through the char. That is a serious issue in inch-plus thicknesses, not very much in fractional-inch thicknesses. And that is because the lower the permeability letting the gas out, the higher the driving gas pressure must be, to get out. And carbonaceous char is a very structurally weak material, especially in tensional loadings.
The microballoons lower the density, to around sp.gr = 0.51, instead of slightly greater than 1. That also increases the ablation rate (which is both pyrolysis and erosion of the char from the surface as fine grit). Higher microballoon content is lower density, higher ablation rate, and higher char permeability. It's a tradeoff, and can be varied from place to place on the heat shield, if desired.
The heat shield on Apollo and on Orion EFT-1 was hand-gunned with what amounts to an air-powered caulking gun into each and every cell of a fiberglass hex bonded to the capsule structure. I think it was probably fiberglass-phenolic, but I do not know for sure that it was phenolic. I am sure of the fiberglass. These cells are on the order of at most hlf an inch in dimension. There were almost 300,000 of them on Apollo, and nearly 400,000 of them on Orion, in part because the lateral sides also needed the protection. That glass fiber hex reinforcement provides tensile strength to retain char from breaking off, and acts to limit cracks propagating from cell to cell.
The enormous time and cost of the hand-gunning is why they decided to cast Avcoat blocks and machine precision tils from them. These were bonded to the capsule structure the way that PICA or PICA-X tiles would be bonded. The bonds and gap-fillers worked fine on Artemis-1, but the retention of the char did not. Without the reinforcing hex to hold it down and limit crack spread, several large chunks and bunch of small ones spalled off during that entry. Complicating that was this was a skip entry, with 2 heating pulses separated by a modest cooldown. A lot of these materials, particularly silica, suffer a solid phasa change at about 2300 F that causes shrinkage by around 3%, and embrittlement to the point of no strength at all: they just crumble at a touch.
That hex-reinforced Avcoat worked just fine on every Apollo and that Orion EFT-1. Something similar flew on Gemini with the hex cell thing on only the heat shield (the lateral sides were bare superalloy), but the polymer was a Dow Corning silicone, and I do not know what solids it was loaded with.
The problem was that Artemis-2's heat shield was built and shipped for assembly before Artemis-1 ever flew. The spalling of chunks caught everyone by surprise. Their thermo-structural models and arc jet data did not predict this. So was it the lack of hex, or the two-heating pulse skip? NASA spent a year convincing its management that it was the skip, so they flew Artemis-2 back with almost no skip at all.
Myself, I think it's actually both effects. They need to put the hex into the tiles, but they need to do it without hand-gunning, or they might as well go back to the Apollo and Orion EFT-1 technique. I figured out a way to load all the cells at once in a chunk of hex, using an extrusion press, in order to make hex reinforced blocks for machining the bonded tiles. And I gave that to NASA, although so far they have ignored me.
I have seen one blurry photo of Artemis-2 being hoisted out of the sea. Everybody comments on the weird-looking but expected damage near one of the four hold-down pads. I thought I saw some missing-chunk craters, fewer and smaller than Artemis-1, but there! But, the photo was blurry, so I as-yet know nothing for-sure! I did see some localized outer-layer burn-through damages on the lateral side, low down, close to the heat shield, in some of the photos of the crew standing next to it. The Avcoat is very thin there.
GW
There are 2 "credible" lunar lander candidates, the SpaceX HLS, which is still nothing but a paper design, and the Blue Origin "Blue Moon" landers, the smaller uncrewed version being under construction. I do not know if the larger crewed form has seen any construction yet.
How those undeveloped statuses blend with some sort of Artemis-3 mission in LEO in 2027, is beyond me to understand! That mission is publicly said to be about docking with, and maneuvering with, one or the other or both landers, as prep for a landing mission (or two landing missions) in 2028.
Sounds like BS to me. I must conclude that there is no one left alive at NASA today, who is competent to distinguish between Musk time and real time, or Bezos time and real time.
GW
A follow-up to post 88.
I saw a NASA news conference where they indicated that the recovery divers took underwater photos of the Artemis-2 heat shield while the astronauts were being extracted. None of these were shown at the news conference, and I cannot find them on-line.
You would think that if these showed no char chunk-shedding cratering, they would have been posted quickly, to quiet critics like me, former astronaut Camarda, and many others. But THAT has NOT happened!
I have to wonder what those photos really show!
GW
Forgive me, but why is the Artemis-2 stuff listed under "unmanned probes"? There were 4 people aboard!
GW
The Navy does not operate Sikorsky Skycranes. The Army did fly a few, but most of them serve commercially now.
GW
Well, Artemis-2 made it back with 4 astronauts safe and sound. I am very glad about that. I have seen no images of the condition of their heat shield yet. Sure would like to see one! I am expecting to see chunk-shedding cratering, similar to Artemis-1, maybe reduced, maybe not.
Meanwhile projecting an Artemis-3 flight to dock with a lunar lander in LEO in 2027 is nonsense, until there really is a lunar lander to dock with. So is projecting lunar landings in 2028. Not until there is a lunar lander!
GW
I see that SpaceX has pushed the next Starship/Superheavy launch off into May. No reason has been given that I know of. But I suspect this one is different enough from the block 2 version that flew previously, that it is taking them longer to make sure they think it is ready to fly. THAT is why Musk time and real time differ by about a factor of 3.
GW
Today's "Daily Launch" from AIAA finally brings up the heat shield issue facing Artemis-2 as it heads to re-entry. The link was to a Scientific American article of some kind. Not all the supposed facts quoted in it were correct, but the concern over char cracking leading to the shedding of chunks of char was correctly pointed out.
Myself, I think the odds are good that the crew will come home just fine. Where I differ with NASA is that I think the same damage seen on Artemis-1 will happen to Artemis-2's heat shield, despite switching to a non-skip, single heating pulse entry. It might be less than what happened to Artemis-1, or it might not. But if ANY chunks at all get shed, then NASA was wrong and I was right!
GW
The lowered static temperatures obtained in the supersonic expansion of a De Laval nozzle are intimately associated with the supersonic speed. As soon as the stream slows down by any means whatsoever, it rewarms. If dead still, it is at its stagnation temperature. Unlike pressure, you ALWAYS recover the full stagnation temperature, no matter what. Ttot = Tstatic * (1 + const * Mach^2) where constant = (gamma - 1)/2, and for air, gamma = 1.4 is usually a very good model.
I ran into that many years ago with ingested cooling air for the electronics in a towed decoy. Once we started looking at supersonic speeds, the cooling air started getting hot. You may capture it at high speed relative to the decoy, but you must slow it down very slow relative to the decoy in order to use it for anything at all.
The missile seeker guys also ran into this decades ago, missiles being mostly supersonic, even by the early 1950's.
GW
They probably have enough on their plate trying to get Starship working acceptably well at all, plus they have a contract that is all-but-in-default for an expendable version that is to be a lunar lander. It's too early in the flight tests to be criticizing their decisions about what to spend their money and their efforts upon.
None of the projected numbers (masses, dollars, anything) are "real" until those tests are successfully completed, and they are actually still somewhat bogus, until actual operational experiences have been obtained. That's just real life!
My guess is that they will have at least another test loss or two, before Block 3 Starship and Block 3 Superheavy are actually flying into orbit and fully-recovering. That's what you get when you operate with youngsters under age 40 and no "old hands" to impart the engineering art.
The art is the undocumented knowledge passed-on, on-the-job, one-on-one, from old hand to newbie. It is about 50% of the essential knowledge in production work, and much more than that, in development work, which this Starship stuff is. Art is the stuff not documented in project reports, because nobody wanted to pay for all that writing. SpaceX's youngsters have to learn that art the hard way, by failing a lot, in tests. Their track record is not hard to understand, at all. It was the same with the Falcon series, starting with almost going bankrupt before they got Falcon-1 to fly.
GW
Too bad nobody is looking at MCP anymore. They are choosing habitat and suit pressures too high for it. Some are approaching 8 psia in the oxygen suit! Such are not necessary.
Paul Webb's MCP test prototypes in the 1960's amounted to vacuum-protective underwear with an oxygen helmet plus a small backpack that had only oxygen plus a CO2 absorber in it. No need for cooling equipment, you just sweat right through the garment into vacuum. Cooling by evaporation guaranteed! The whole shebang weighed 85 pounds., although you would need protective outerwear over it, for the thermal and mechanical hazards, maybe another 5 lb. 10 lb at the very most.
His final prototype was very limber, even more than the SpaceX suit. It operated near the old Apollo suit pressure of 3.2-3.5 psi (170-190 mmHg in his reports), although that gas pressure is only in the helmet and tidal breathing bag! The clothing is unpressurized by gas at all, just a tight fit exerting mechanical pressure upon the body. The old partial pressure suits worked the same way, but they did not apply pressure as evenly, and they did not pressurize hands and feet at all. Webb did.
I've seen the film of the test subject wearing Webb's MCP rig, pedaling a bicycle ergonometer inside at vacuum tank at a simulated 87,000 feet, which is more than 4 miles above the vacuum death point! He was in there for 30 minutes and had no problems, unlike the old partial pressure suits, which were limited to 10 minutes max before fluid edema into uncompressed zones started hands and feet swelling.
Think about it: vacuum protective underwear, over which you wear whatever mechanical/thermal protective outer you need for the job at hand. Easily launderable, too!
And if you run your two-gas habitat atmosphere as 43% (by volume) oxygen (the rest nitrogen), at 43% of a standard atmosphere, the fire danger oxygen concentration driving chemistry rates is the same as sea level pressure air at 70 F, the oxygen partial pressure is equal to air somewhere below 8000 feet (2500 meter) for no risks of chronic altitude sickness and no risks to childbirth, and the nitrogen pressure is low enough compared to oxygen suit pressure that you need zero pre-breathe time, all the way down to suit pressures of only 3.0 psia (155 mm Hg)!
Below 3.0 psia suit pressure, there are tissue dry-out and bleeding problems in the airway and lungs, although cognition can be maintained down to about 2.0-2.5 psia (100-130 mm Hg). You just don't want more than a few minutes' exposure, that low! I have a similar, not-as-easily-remembered, habitat atmosphere that will do no pre-breathe down to 2.9 psia (150 mm Hg) suit pressure, and yet still meet the life support and fire danger criteria.
MCP suits at 180 plus or minus 10 mm Hg, and "rule-of-43" habitat pressure. Easily-launderable space suits. Lightweight backpacks. No heavy cooling systems. Very flexible allowing almost any human activity. And it worked fine in ground tests, more than 6 decades ago. Looks like a match made in heaven to me!
GW
Spacenut: what I am looking at is only nominally two 8 ft x 8 ft x 40 ft containers. These could be rescaled a little bit.
GW
I'm not using a standard shipping container, they are too heavy, designed for ship-handling loads a space delivery item will never see. I'm looking at something the size of a standard shipping container, which is 8 ft x 8 ft x 40 ft.
GW
My letter to Isaacman should be in a staffer's hands by about today. The handout I sent him is already posted over at "exrocketman".
GW
update 3-13-2026: the handout on ramjet ablatives overlapping with heat shields is titled "Ramjet Data Re: Heat Shields", posted 1 March 2026 at http://exrocketman.blogspot.com. Search code 01032026.
From the AIAA "Daily Launch" email newsletter for 3-10-2026:
Space
Incoming! 1,300-pound NASA satellite will crash to Earth on March 10
NASA's Van Allen Probe A will crash to Earth on Tuesday (March 10) after nearly 14 years in orbit, according to the Space Force's current best estimate.
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The window USAF projects is + or - 24 hrs from about 7 PM (not sure if eastern or central or what).
GW
Update 3-11-2026: It came down this morning early, reportedly over the "Eastern Pacific region", which does not pin it down very well. There is a second up there, not expected to enter until the 2030's, although that was the original expectation on this one. The pair was operated until out of attitude control/maneuvering fuel, with no way to safely dispose of them. THAT has to change!
Update 3-12-2026: today's "Daily Launch had this AP News headline summary:
AP News
Old NASA science satellite plunges back to Earth
An old NASA science satellite plunged uncontrolled from orbit and reentered over the Pacific on Wednesday. The U.S. Space Force said the Van Allen Probe A came in west of the Galapagos Islands.
GW
From the AIAA "Daily Launch" email newsletter for 3-10-2026:
SpaceNews
First Starship V3 launch slips
SpaceX is pushing back the first launch of the latest version of its Starship vehicle even as NASA is asking the company to accelerate work on a lunar lander version of the vehicle. In a social media post early March 7, Elon Musk, founder and chief executive of SpaceX, announced that the first flight of version 3, or V3, of Starship would be “in about 4 weeks.” Four weeks from March 7 is April 4.
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GW
From AIAA “Daily Launch” email newsletter 3-9-2026, just the summary of an ARS Technica article:
ARS TECHNICA
With Gateway likely gone, where will lunar landers rendezvous with Orion?
Last week, NASA Administrator Jared Isaacman unveiled a major shakeup in the Artemis Program. The changes focused largely on increasing the launch cadence of NASA’s large SLS rocket and putting a greater emphasis on lunar surface activities. Days later, the US Senate indicated that it broadly supported these plans. Which lander will be used to take astronauts down to the lunar surface from an orbit around the Moon and back up to rendezvous with Orion?
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My take:
The rumors have proved to be true. Gateway is essentially out, SLS Block 1B and Block 2 are out, and there will only be a slight upgrade to SLS Block 1 with the Centaur-5 replacing the Interim Upper Stage (the second stage of Delta-4). Artemis will rendezvous with landers and do its landings from some lunar orbit that the SLS Block-1 can reach with Orion atop it. That is likely some elliptic capture orbit, but nobody is talking about that yet. We will see whose lander “gets there” first. That will be the one they use.
Isaacman is trying to do it “right”. We will see if he can change the NASA culture back to crew lives valued more than schedule and money. He has made noises like that, but as yet I have seen no change at NASA. Artemis-2 will fly with the same flawed heat shield that surprised everyone on Artemis-1. Artemis-3 is already being built to the same flawed design. Sooner or later, the odds will bite them with that, just like they did with the flawed SRB O-ring joint design with the space shuttle.
GW