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sevenperforce

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Everything posted by sevenperforce

  1. It's a common misconception that climate scientists have predicted more frequent hurricanes as the result of climate change. Climate scientists have never predicted more frequent hurricanes, and hurricanes are not more frequent than they used to be. However, climate scientists DID predict more SERIOUS hurricanes as the result of climate change, and there ARE more serious hurricanes than there used to be. Even controlling for larger populations and more coastal property in the danger zone, the damage wrought by hurricanes now is substantially higher than it used to be, even though the number of hurricanes has remained the same. It's kind of like saying that if you take all airbags out of cars, you won't have MORE accidents, but you will have more DEADLY accidents.
  2. This is somewhat surprising. Not because he wanted to leave BO and join SpaceX, but because employees in the technology industry with access to proprietary information usually have non-complete clauses in their contracts. It's known that Amazon has quite a broad 18 month non-compete agreement, and at one time were even enforcing it against temporary warehouse workers. My guess is that he did have a non-compete and that when he notified Blue Origin he was leaving, they got all nasty, and so SpaceX simply bought out the non-compete. Even if a non-compete clause doesn't have an explicit liquidated monetary buyout provision, it is well known that you invariably cannot get specific performance of a non-compete, so it would be bad faith for BO's lawyers to not entertain a buyout offer and negotiate in good faith. It will be challenging for Bezos to dominate the orbital launch marketplace when he has no orbital launch product. This is not like Amazon, where he could create a book warehouse and sell product below market cost until he killed off all the competition. If you're going to kill your competition you actually have to be able to offer products or services. You can't sell paper rockets.
  3. It looks like we have updated imagery which disproves my prior contention about the rail carriage. The black arms are definitely the catching arms. Those hinges make it obvious. We still don't know how those arms will be attached to the tower or how the forces will be handled. We don't know whether the arm we're currently seeing on the ground is in its right-side-up or upside-down configuration relative to how it will be placed on the tower.
  4. Back to the topic at hand.... I think they simply don't need quite as much back-and-forth skew as we might have expected. Having everything pivot around a single point really simplifies the lifting mechanism because you only need to lift on that single axis.
  5. My armchair lawyering opinion is that monetary damages are usually not considered irreparable harm. There's a four-part factor test for injunctive relief: (1) likelihood of plaintiff's success in the underlying case, (2) actual and irreparable harm to the plaintiff without the TRO, (3) lower harm to the defendant if the TRO is granted than to the plaintiff if it is not, and (4) public interest factors. In this situation, Blue Origin has very low chances of success in getting anything overturned, no irreparable harm, serious harm to NASA and SpaceX if a TRO were to be granted, and substantial public interest factors weighing against them. It doesn't mean a federal district judge somewhere might not go along with their argument, as @JoeSchmuckatelli wisely points out, but it's very unlikely. This is intensely and absurdly embarrassing. First: no, it doesn't take 16 launches, that's stupid. Second, LITERALLY EVERY HLS DESIGN requires two Orion dockings for crew transfer. How is that...anything? Third, National Team's design also required launch vehicles that have never flown to orbit and are still being designed. Just absurd.
  6. It's definitely possible that the government could split Starlink off of SpaceX, but it's a fairly high standard. And in this particular case, SpaceX/Starlink would argue convincingly that the service being provided to Starlink by SpaceX has inherent restrictions (rideshare, flat-pack, proprietary payload dispensing, internal payload integration, etc.) which prevent it from being readily compared to other payload+launch vehicle pairings. In other words, "No, we're not monopolizing the market by excluding other entrants! In fact, we launch other communications satellites all the time! They are willing to pay a fair market price, so it's not a monopoly." Not to mention, it depends on the state. E.g. in California they are unenforceable no matter what Also depends on the industry. Legal non-competes are 100% unenforceable, and even entering into one is an ethical violation. You can, of course, disqualify an attorney from working on a case using the courts, but that's via application of ethics rules, not through a non-compete agreement.
  7. IIRC the only way to get injunctive relief from a non-compete would be if there was substantial trade secret overlap and you could make the argument that there would be irreparable harm, incalculable in damages, if your former employee and the competitor company were permitted to work together. And even then the law would favor monetary damages if there was any possibility that the trade secrets could remain protected.
  8. Believe it or not it's almost virtually impossible to get specific performance of a non-compete. There's almost nothing that you can't simply buy out.
  9. Ooooookay now THAT is some memelord-level trolling. Well, if they took it to court they could try to get a temporary injunction, but their chances of succeeding at THAT are about as slim as the odds of Bezos asking Elon to loan him Raptor engines.
  10. Yes, we're talking about EVA suits here, but it's not just a design issue; there's a fundamental challenge because in order for the suit to work, it has to exert quite a bit of counterpressure. And that means it must be literally too small to put on, which means putting it on is always fundamentally challenging...like a grown adult trying to put on a child-sized wetsuit. Add microgravity and it gets even more challenging. It also has to be much, much more exactingly tailored to each person's body and cannot accommodate any changes in body shape. Hybrid suits, in comparison, are not new; there are plenty of them in production. Probably one of the best is the MK-III: This suit can support a full atmosphere of internal pressure, meaning you don't need to prebreathe to transition. The core of the suit is a completely solid torso with sealed rotating-bearing joints at the shoulders, upper chest, navel, hips, thighs, and ankles. It avoids ballooning at the upper arms, elbows, wrists, and knees by using multiple layers of extremely thick fabric, which makes these joints stiff enough to stay at nearly constant-volume, but of course also makes those same joints puffy and difficult for the wearer to articulate. However, if the solid portions didn't have to be airtight -- if they were basically just a suit of armor overlaid on an internal pressure suit -- then the whole thing would become much smaller, lighter, and easier to doff and don. It would be almost like the Master Chief armor: The outer armor has tons of gaps but provides mobility at all the joints; the inner suit liner is the airtight part.
  11. Mechanical counter-pressure suits are nice and all, but the required pressure is quite high, meaning that they are extremely difficult to put on and take off and have to be precisely form-fitting. They also tend to impede certain bodily functions and can cause soft tissue injury (for example, regions like the armpits tend to become distended). That's a feature, not a bug. The sublayer would have no joints at all; it would be flexible . The outer layer, however, would have joints which maintain constant volume. The thing that makes it difficult to bend your arm in a conventional spacesuit is that bending your arm reduces the total internal volume of the suit, which means you are mechanically compressing air. The NASA EVA suits get around this by using pure oxygen at low pressure so that there is less exertion required to mechanically compress the air, but it's still a significant amount. To avoid this, you try to design joints which can be opened or closed without changing their internal volume. Constant-volume joints in a flexible suit are possible, but they are bulky and extremely ungainly: And since a hard suit must have seals between each of its joints, the only constant-volume joints possible for a hard suit are rotating ones, which leads to this horrific nonsense: However, if you DON'T have to have an airtight seal on the hard portion of the suit, designing a constant-volume joint is trivial. Consider the shoulder pauldron on a traditional medieval suit of armor, where the overlapping plates can slide over each other to move the joint easily: For a more modern aesthetic, consider this guy, who built a fully flexible metal Mark V Iron Man suit that actually folds up like a briefcase: Full video here: You can have a completely flexible outer hard suit because all the surfaces can slide over each other. Of course, it is impossible for those surfaces to seal, but the point is they don't have to -- gaps are fine because the outer suit's only job is to keep the flexible undersuit from ballooning and ensure it maintains constant volume so that there's no extra exertion required to move the joints.
  12. Apparently there are 27 different subcontractors for the current Artemis suit. I still want to see SpaceX make an Iron Man spacesuit. A flexible airtight undersuit next to the skin and a lightweight, open-gap titanium exoskeleton that provides MMOD protection and prevents the undersuit from ballooning. I have yet to see any reason why it wouldn’t work.
  13. Any proof? Proof? Are you asking me for proof that a cylinder moving with its axis perpendicular to the airstream will have a L/D ratio of zero? Or are you asking me for proof that a cylinder with a nonzero angle of attack will have an L/D ratio greater than zero? Because Falcon 9 is a primitive circular cylinder which attains an L/D ratio of approximately 1 by flying at a high angle of attack. I mean, you can literally watch it glide. Yes, because neither Starship nor Superheavy nor Falcon 9 are spaceplanes. If Soyuz has a breach in its HTP tank at any point in the flight, everyone dies. What's the difference? The wings are flat for purpose. Are you making a claim? At <2 km/s speed? 8 km/s is 4 times freater. Drag and heat flow ~16 times. It's not like anyone has ever devoted any time studying hypersonic L/D ratios in wind tunnels, right? The drag should be controlled. This is the main purpose of the flat-bottoms. No, the main purpose of the flat bottom on a capsule or the planar heat shield on a spaceplane is to increase the effective radius of curvature of the plasma sheath and produce a greater stand-off from the heat shield surface.
  14. I know you weren't talking about me personally, but for my part I was very disconcerted by both the AMOS-6 disaster and the exploding crew capsule. Doing WDRs and static fires with the payload integrated is exactly the sort of unforced error I'm talking about (even though the spontaneous combustion of solidified crystalline oxygen and carbon fiber had never happened before in history). They learned their lesson, yes, but that was not a "test to failure" scenario, so they don't exactly get credit for it. I was slightly less worried about the exploding crew capsule once I learned that it WAS a "test to failure" scenario -- that they were intentionally subjecting it to stresses well outside the flight envelope in order to look for that exact kind of unknown failure mode.
  15. I think it is a fundamentally different question. Willingness to fail is great when you are working with dev articles. You design a test that will push a disposable test article to its limits in order to figure out the unknown failure modes. Repeated unforced errors in a system that’s supposed to be in its final configuration, ready to fly human beings? Particularly when the company claimed more flight tests weren’t needed because they had validated everything on paper? That’s...disconcerting.
  16. Looking closely at the tile inspection process on SN20. Many of the tiles with red-orange tape are visibly cracked or damaged. None of the tiles with green tape are visibly damaged but many look misaligned. If you blow up the image you can see “OK” scrawled on many of the other tiles. My guess is that red means broken and green means loose. It does seem like a lot of inspection work. But when you consider that it took sixteen hours to replace a single Shuttle tile.... Agreed. Unwillingness to fail is unwillingness to succeed.
  17. It is true that for a blunt body experiencing re-entry with 0° angle of attack, the body cross-section is the only thing that has any effect on drag and heat distribution. A sphere functions the same way as a cylinder (assuming the cylinder’s axis is perpendicular to the airflow). A delta-wing aircraft with a flat bottom and rounded fuselage functions the same way as a capsule with a flat bottom and a rounded top. But this is only if there is no angle of attack (or, depending on your frame of reference, a 90° AoA). With a nonzero angle of attack, lots of things start changing. And that is what someone seems intent on ignoring.
  18. Peroxide is, incidentally, hyperbolic. It is also what the Mercury capsule used. And of course Dragon 2 vents its residuals while descending under chute as well. All capsules do. Less than 1 tonne or more than 1 tonne, it doesn’t matter how much. Any hypergolic propellant tank breach in a capsule’s RCS or propulsion system, even a modest one, is a catastrophic LOCV. Always. Besides, while we are talking about hypergolic fuel tanks on a crew vehicle, what about the Shuttle? Well, this is still just hypothetical in terms of configuration. We don’t know anything for sure yet. One advantage of the design I’ve put together above is that the lift block interfaces directly with the hinge points on the arms, so the cantilever moment is provided by interface with the carriage in tention.
  19. You are correct that a primitive cylinder moving with its axis at 90° to the direction of flight will have the same L/D ratio as a sphere—zero—and will descend ballistically. You are incorrect in supposing that Starship will perform re-entry with its long axis at 90° to the direction of flight. Starship will fly with a significant angle of attack and have an L/D ratio significantly greater than a capsule like Apollo.
  20. Heaven forbid that a crew capsule would have hypergolic fuel tanks inside of it!! That has only ever been done with Mercury, Gemini, Apollo, Orion, and Soyuz! Indeed. In fact, the Shuttle specifically had too much lift for reentry and had to do lengthy and complex S-curve maneuvers to survive.
  21. Ignoring this ongoing war and back to the main topic... I’ve been discussing the catching arm structure with the folks at NSF and this looks fairly promising. Also, here’s a solution for precise positioning.
  22. You realize SN8-SN15 were all gliding tests, right? You understand how body lift works, correct?
  23. A glider that could neither have functioned in space nor survived re-entry from space. Because Shuttle docked to Skylab so many times, right? Oh, wait, it didn’t, and so they had to change the entire docking structure for Mir and ISS.
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