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Everything posted by sevenperforce

  1. It looked like it came down pretty distant from the centerpoint in comparison to what we usually see. I wonder why.
  2. The fact that they use the same 9+1 configuration as the Falcon 9 probably contributes. Most teensy rockets use numerous stages with a single engine or a two-engine cluster at most on the first stage. Electron (and now Relativity with its Terran 1) are bucking that tradition with clusters.
  3. I am very interested in whatever cycle they’re going to come up with for the Aero R. If I was going to design a methalox engine of that thrust level from scratch, I would go with a dual split bleed expander augmented by a gas generator, but with the gas generator downstream of the bleed with dual heat exchangers. That way you extract ALL the heat from the chamber first, THEN extract precisely as much additional heat as you need from the gas generator, but you are still able to keep your oxidizer and fuel pumps completely separate and you don’t need any nasty shaft seals. The gas generator empt
  4. Maybe that would be part of Congressman Gohmert's new plan to adjust Earth's orbit. In all seriousness I think the typical issue with doing this is that you'd have weird accelerative gradients on the engine gimbal.
  5. They look TINY (like, beer-bottle-sized) in all the diagrams, so I always assumed they were significantly bigger, like at least the size of a 5 gallon bucket. These are more like large wine bottles.
  6. That's what I thought, too, but apparently not: Relativity has completed hundreds of tests on its Aeon 1 engines that will power Terran 1 – but Terran R will feature a “new engine called Aeon R” that the company has begun developing, Ellis said. “We’ve also tested the engine for the upper stage,” Ellis said. “It’s a copper chamber engine ... and it’s actually now the same engine on the upper stage of Terran R as on Terran 1.” The article showed this image, which it said was the upgraded Aeon Vac firing without its nozzle extension. That said, this upgraded Aeon Vac would
  7. Starship physically can't flip in the thick parts of the atmosphere; that's why it has to use engine gimbal. The ITS would have had an easier time doing an aerodynamic flip because it didn't have the heavy header tank in the nose. It would have been more likely to go tail-first. That's where all the heavy stuff (including the header tanks) would have been. It would have been a chaotic tail-first, though, so it would need to fire up the engines for control just after the flip initiated. I'm a little confused by only having a single Aeon Vac engine on the upper stage, though. T
  8. My training was also physics but I worked as a telecommunications test engineer for a while, so I was (at that point) an engineer. I would not call myself an engineer now because that is not my job. IMO if you have education that qualifies you to do engineering, and you work in an engineering field, you are an engineer; if you do not have education that qualifies you to do engineering and you work in an engineering field, you are a technician. If you pass the PE exam, you are a licensed professional engineer regardless of what kind of work you do. Chemistry and physics are trick
  9. And, three rocket science videos back to back.... (okay so this forum embed function is NOT working properly, so I'm going to post links) Rocket Science Sunday 4 (Why Are Mach Diamonds?) Rocket Science Starts Simple From RL-10 to Raptor -- Power Cycles Everyday Astronauts is great and all but I can do it in under two minutes, so.....
  10. A nice little rocket engine primer for anyone who wonders why rocket science is complicated...reposted because the first one didn't load. (Posting here because I’m using the Kestrel and Merlin 1D as inspiration.)
  11. Oh that’s true without question. I think Bezos would be amused to hang out with someone and not tip them off about who he was, and that’s not necessarily a good thing. I think engineers have their own version of Dunning-Kruger that tends to manifest in precisely these situations. I assume multibillionaires must be actively evil to get that much money in the first place.
  12. That’s what I thought about Gates until I heard about the Epstein business. Musk is neurodivergent and overestimates his expertise in some areas but is generally good at the things he understands. Bezos has a lot more sense than Musk but he’s not quite as smart. Strikes me as the sort of person who you could hang out with and never know who he was. Zuckerberg is an evil lizard person escaped from Area 51. It feels like the anti-nuclear lobby has gotten quieter over the past couple of decades. I think a lot of the old guard died out. Chernobyl would have been less da
  13. Agreed. It's not gonna be raw tonnage delivery; it's gonna be niche. Starship can do two things aircraft can't do. First, it can get there a lot faster and doesn't require coordination of refueling assets. Second, it can take larger payloads than an aircraft, though not by any massive factor. It is admittedly hard to come up with a monolithic payload that the US military would need moved halfway across the world and wouldn't already have local assets for. So the speed is going to be the biggest factor. Another possibility we haven't discussed as much is whether they would dispense
  14. The aircraft carrying capacity of a supercarrier is primarily belowdecks in the aircraft hanger. Large carriers have several hangar decks and can hold aircraft in close quarters. So removing aircraft from the flight deck doesn't even come close to halving the number of planes. In reality, you'd barely even notice. Also remember that the purpose of an aircraft carrier is not to "move" planes, but to operate them. It is a floating airport. Starship can land on the flight deck and then move via onboard crawler to an area clear of the main angled flight deck. It doesn't even have t
  15. I suspect that the tiles only snap on one way. In other words, once they’re on, the only way for them to come off is to break them.
  16. Carriers are designed to have giant flying bombs plummet toward them at terrifying speed and slam onto the deck violently. They’re also designed to easily absorb surface explosions. A nuclear supercarrier can easily produce LOX from seawater and is already accustomed to tanking large amounts of fuel for a number of different vehicles, but it could also just take the empty Starship back to land. Existing carriers can easily be equipped with cranes capable of unloading cargo rapidly from a Starship as soon as it has safed. I suspect most military equipment can handle plenty of stres
  17. Here’s a thought. Where are they intending to land Superheavy again? That’s right, on a floating platform. If they can land the boosters on a floating platform, they can readily land Starship on a floating platform. If they can land Starship on a floating platform, they could readily land Starship on an aircraft carrier. It should be quite safe. I assume that with a negligible payload penalty, starship can perform the same off-target maneuver that the Falcon 9 boosters perform, correcting for a landing burn at the last second. A landing failure wouldn’t necessarily do much damage to a car
  18. This is very accurate. It is trivial for the United States to set up complete air superiority when we are dealing with tiny insurgencies. Not so much in a hypothetical battle with another superpower. [snip]
  19. I'm not sure what the current state of prediction is regarding the eccentricities of gas giant exoplanets very close to their stars. If I had to guess I would say that tidally-locked exoplanets are likely to be more eccentric, while exoplanets that are far enough out to not be tidally locked would be more circular. Yes, eccentricity is only constant in a two-body system.
  20. Is that assuming that the limiting factor is gross liftoff thrust? Cost is the limiting factor, of course, but it's difficult to tie that to something specific. The major drivers of cost (all other things being equal) are dry mass and gross liftoff thrust.
  21. All accurate answers so far, but since it hasn't been discussed yet.... During the formation of a solar system, there are two driving forces that tend to circularize a planetary orbit. The first is the clearing of the local neighborhood. Objects which cross the orbit of a growing protoplanet due to high eccentricity are more likely to have high-energy collisions, while objects which orbit more or less circularly are more likely to have low-energy collisions. Since low-energy collisions are more likely to cause the growth of an object, objects will tend to grow larger in circular orbits.
  22. Hmm. This makes me wonder...given basic assumptions about engines and propellant choices (and avoiding an inordinate number of staging events), is there an ideal vehicle configuration for any given orbit? Assume gross liftoff thrust is the limiting factor. Hydrolox would perform better in comparison to kerolox for certain large LEO payloads, but methalox typically beats them both. One of the great things about methalox is its high O/F ratio means its bulk density is not much different from kerolox but its specific energy is much higher.
  23. Yeah, this makes a lot of sense. Use the spin-gravity to acclimate, since you have a long coast period anyway. Of course a cycler tends to be a shorter coast period but still. The mission was said to be two years so I’m assuming they’re on a single Aldrin cycler where they launch from Earth to catch it, then drop off on Mars, then launch from Mars again to catch the same cycler on its return leg. Here are the mission patches for all the prior operational launches in this universe... Some interesting Easter eggs here.
  24. Uh, what? The first FH launch went to Mars. The second went to supersynch GTO. The third was a multi-orbit mission that ended up in direct-MEO. The future FH contracts are, in order: direct-GEO, direct-GEO, heliocentric (asteroid belt), an unknown USSF orbit, heavy GTO, heavy GTO, TLI, TLI, TLI, and TLI. So of the dozen known FH contracts (not including the also-beyond-LEO test flight), there is only one that **might** be LEO. And that one might use Falcon 9 since it hasn’t been confirmed as Falcon Heavy. It’s a Vandy launch anyway so it’s definitely not a normal LEO flight rega
  25. All this talk of trying to 3D print Starships on Mars seems absurd to me. Yes, if we want colonies on Mars, we will eventually need manufacturing on Mars. However, Starship is not a rocket that would be built on Mars because a rocket built on Mars would not necessarily look anything like Starship. By the time we have a functioning colony on Mars that is developed enough to need its own manufacturing capabilities, we are going to be well beyond Starship. Therefore, there is absolutely no purpose to doing something more expensively on Earth just to learn how to do it on Mars when we wi
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