sevenperforce

Presumably it is pronounced the same as "scouring" and has a similar meaning. My girlfriend keeps getting onto me because I haven't sqaured the circles in the pots left over from dinner last weekend, but I tell her they're just soaking.

If you are far enough away, light from distant galaxies will still reach you, but their light will be too dim to be visible. There are voids a hundred times wider than the distance between us and Andromeda.

The cross-sectional area collapses as you move away, so yeah. But it's gonna come down to photon counts. Those will stack.

I mean... ...no.

I should have put a /s tag on my post

Did it reach orbit? No? Therefore, failure. An explosion is an explosion. SpaceX has never actually launched Falcon Heavy and successfully recovered all of the boosters from a single Falcon Heavy launch. Therefore all Falcon Heavy launches are failures. But if it wasn't for Zuma remaining attached to the upper stage, Zuma could have stayed in space maybe, and so it's the fault of the upper stage that dragged Zuma back down into the atmosphere. Failure. Proving Merlin engines are unreliable. If Falcon 9 was more powerful and more reliable then it could have put them in an orbit where this wouldn't happen. Failure. If it's supposed to be reusable then why don't all boosters get reused? Make it make sense.

In that study, the participants only identified a single-photon exposure correctly 51.6% of the time -- enough to be statistically significant under the test conditions, but certainly not enough to identify anything we would consider visible. The minimum light intensity that would register as a meaningful point of light depends on the amount of energy necessary to fully interrupt the flow of sodium cations in a photoreceptor cell, triggering the nerve signal which is registered by the brain as a persistent point of light. The necessary light intensity, then, depends not only on the number of photons but also on their frequency, which corresponds to the amount of energy they carry. It also depends on the actual wavelength-dependent sensitivity function V(λ) which peaks at 555 nm. Finally, not all light that enters the lens actually reaches the retina. Although studies from the 1940s proved that you only needed 5-7 photons to reach the retina in order to register a visible flash of light, you need far more to actually hit the lens (since 90% of the light which enters the human eye ends up scattered).

That does not seem correct. You might not see it as a galaxy shape but light does travel through the intergalactic voids - so they probably look like stars. (just spitballing here - but even if a galaxy were far enough away that it's apparent diameter was tiny you should see it. Only way I can see not perceiving it would be if the redshift had taken it down below human visible spectra) Light travels through the intergalactic voids, but it's still subject to the inverse-square law. Most intergalactic voids are 30 to 300 million lightyears in diameter, so you can imagine being in the center of the smallest of these voids and being 15 million lightyears away from the nearest galaxy. That's six times as far as we are from Andromeda or Triangulum, meaning that an equivalently-bright galaxy would be 36 times dimmer than they are, thanks to the inverse square law. The human eye can't take long exposures like a telescope; our maximum "shutter speed" is about 1/50th of a second. And the lens of a human eye is only about 1 cm in diameter, so together we get a total light collection area of 1.57 cm2. Our retinas need to be getting a certain minimum number of photons per second or we simply won't see anything. The theoretical limit for the naked-eye visibility in a perfectly dark sky, ignoring atmospheric extinction, is around +8m, or 69.2 times dimmer than Andromeda's +3.4m and 8.3 times dimmer than Triangulum's +5.7m (apparent magnitude is an inverse logarithmic scale). So Andromeda would be readily visible from the center of the smallest intergalactic voids, but Triangulum would not. The most massive elliptical galaxies, like M87, have absolute magnitudes as high as -22, making them naked-eye visible to a distance of 10 million parsecs or 32 million lightyears. The active blazars in certain galactic nuclei can reach brightnesses of over -32, which would be naked-eye visible from as far as 32 billion lightyears, but only if they are pointed directly at the observer (and even then, the brightness is variable). So while the largest intergalactic voids are vast enough to extinguish the light of the brightest galaxies, there is still a chance of catching a glimmer of relativistic fire through the darkness. And of course a moderately large telescope like JWST with a decent exposure time would still be able to see all the way to the edge of the visible universe.

I am pretty sure that you could point a car wash spray nozzle at that concrete pad all week long and not see it pulverized and spread all over South Padre Island. I suspect there is some flaw with your analysis. Water isn't coming out of a car wash spray nozzle at temperatures greater than the melting point of steel.

I don't know if you even need a fusion drive for it to become worth it. There are a lot of materials in the asteroids that are pretty easy to reach compared to Earth, and you can use rather destructive means without worrying about causing environmental damage. You can then use linear accelerator magrails to launch cargo to wherever it needs to go. In a vacuum of space and with some massive rock serving as your anchor, getting a few km/s of delta-V is not hard. Ideally you could have some sort of basic, low-granularity refinery spaceship that does a basic grind-out of low grade ore, removes the dross, and then uses the dross as reaction mass with a linear accelerator to push the whole asteroid closer and closer to Earth. By the time you get to cislunar space or thereabouts, you've already got a lot of workable ore. Some of the other comments have gotten at this, but I think you're just conceptualizing it wrong. The universe is 13.8 billion years old, and the most distant galaxies we see at the edge of the observable universe (like JADES-GS-Z13-0) appear to have formed a few hundred million years after the Big Bang. They are basically just clumpy masses of hydrogen gas with relatively few, cosmically-young stars. A star takes only a million years or so to form from a collapsing gas cloud, and very very large giant stars (like those formed out of giant clumpy clouds of pure hydrogen) only have a lifespan of 10 to 20 million years. So a young galaxy forming shortly after the Big Bang could accumulate a dozen cycles of giant star births and deaths in as little as 200 million years. An observer in JADES-GS-Z13-0 looking in our direction would see the Milky Way region as it appeared 13+ billion years ago...probably looking a lot like JADES-GS-Z13-0 appears to us.

Or, better yet, HTP! Here we go Black Horse!

I wonder if transporting them by barge would even have been viable. Unlike the external tank, which could be transported by barge quite readily because it weighed less than 27 tonnes empty, the SRBs had a mass of over 700 tonnes each. The Pegasus Barge just barely had enough draft to maneuver up the canal by the Saturn Causeway and into the Turning Basin to drop off the tank. A barge holding a booster that was narrower than the external tank but 25 times heavier would have a much greater draft.

Was it ease of transport, or possibility of transport? As I understand it, there literally would not have been any way to transport the SRBs to the pad if they were constructed and filled with propellant without segments.

I believe that you can set thrust curves for KSP SRBs using the KAL controller. It would also be cool to be able to construct thrust curves using multiple segments in your booster with different burn rates.

Looks like some possibility of differently-sized spray holes: I cracked up when I saw someone calling it a "launch bidet".

The milkstool creates a circumferential flame trench. They just need to make sure the surface underneath doesn't go all pyroclastic rock tornado like it did last time. Interested in running some numbers on this upside-down showerhead idea. Raptor yeets 650 kg/s of exhaust out the back end at 3,210 m/s. Assuming all the exhaust plumes generally merge under the 10.3-meter base of Starship, that's a dynamic pressure of 3.71 megapascals. Really quite shockingly low if you think about it -- less than the water pressure in the output of your typical coin-operated car wash spray nozzle. The coolant loops in a pressurized water reactor run 4-5x higher. I wonder if the holes at the center of the showerhead will be larger than the holes near the circumference, to create a sort of virtual cone of water. That kind of design might also help relieve internal pressures that could otherwise cause it to expand in the center. Water fountains have been built with higher pressures than this already. King Fahd's Fountain in Jeddah, built in 1985, continuously pumps sea water through a single nozzle at 4.2 megapascals to almost twice the height of the OLT. Building something at slightly lower pressure which fires for only a few seconds should be straightforward despite the much higher flow volume.

A launch pad is a proper test stand. Why would you need a separate facility to do the exact same thing? The pad at Boca Chica does have an exhaust trench. A milkstool creates an open-air exhaust "trench" in place of a physical one. That's what the Apollo Milkstool did for the Saturn 1B and that's what the OLM does for Superheavy. Engines won't burn each other due to proximity when they are actively cooled. These aren't RS-68s. I'm reminded of From the Earth to the Moon by Jules Verne. Tackled this exact problem and came up with almost the exact same result.

Defer to @Meecrob on the rest of the answers, but I will note that for aerospace applications a 40% safety margin is fairly standard.

To lower the takeoff weight. And possibly spare a runways destruction. Although I don't know the specific values enough. I'm looking at a vehicle weighting different amounts depending on the fuel used and which way to use it. In this case air breathing at takeoff and then fills up with a lot of oxidizer. I was hoping to spare cargo space by using a single tank for fuel. What you're describing is LACE, the Liquid Air Cycle Engine. The problem with LACE is that you have to carry a coolant to liquefy the air as you collect it. Basic physics should tell you that the mass of coolant you need to liquefy a given mass of air is going to be on the order of mass of air you're liquefying, so you might as well start off with liquid oxygen in the first place.

There is more hydrogen in a gallon of liquid gasoline than in a gallon of liquid hydrogen. Shockingly deep. SRB has low isp so they are not very practical as upper stages. In real life, there are plenty of vacuum SRBs. The Star 48 is one of the most popular: Vacuum-optimized nozzle which gives it 286 seconds of specific impulse -- better than the sea level impulse of a Merlin 1D. Because they are so dense, they work well as terminal kick stages to fit inside a fairing with a payload. The Star 48 was the final stage of the Delta II launch vehicle and it was also used on top of the Centaur on the Atlas V 551 that launched New Horizons to Pluto. These kick stages can either be spin-stabilized or they can have TVC. I've always thought it would have been cool to have segmented SRBs in KSP. Choose a segment size, a number of segments, and a nozzle size/design. That way you could have a dense, low-thrust, high-efficiency kick stage, if so desired.

While it's on paper. Once it starts flying, it will be a military project as well. Orbital lasers, orbital maneuvering sat depots, orbital hypersonic maneuvering reentry vehicles. Nothing such capable can be just civilian. Your Kremlin is showing.

The perforated steel pancake idea is very Elon but I don't see any clear reason why it wouldn't work.

Well, begrudgingly to @Spacescifi's credit, this is one of the only workable magic solutions he's come up with so far. And it matches most of the depictions of levitation and spaceflight in science fiction.

Why not just give the middle stage a hinged fairing and have the third stage inside that fairing? If it's not coming back to Earth EDL for a landing, then it won't need flaps or a heat shield or anything, really -- just tanks and engines. What space debris? If you have an orbiting propellant depot that is refilled with reusable tankers, there's no space debris left over at all.

Yes, correct; I said tempered glass but I meant laminated glass. Good catch. Ok, gotcha. So this would still be a reusable two-stage-to-orbit design, just with a third stage that is reusable BLEO.