Terwin

I believe I have heard it called cosine losses, so presumably the cos of the angle (0.71 for 45 degrees) should be the effective thrust multiplier(so almost 30% loss at 45 degrees) It would only prevent liftoff if you do not have enough thrust after accounting for the loss due to the angle. Presumably you would switch to the main engine once you were an appropriate height above the surface, so hopefully the total wastage is not too bad.

The fairing would not be for aerodynamics, but to protect the vessel from the heat and radiation. This is not an issue in space because the pusher-plate acts as an umbrella and there is nothing else to redirect it. In atmosphere, the pressure-wave becomes an issue that the pusher plate cannot stop as it will engulf the entire vessel. The pressure wave is also bringing lots of vessel melting heat and any radiation that misses the pusher plate can bounce off air molecules and radiate the vessel. The 'fairing' needs to resist the shock-wave, heat and radiation of many near-by nuclear blasts and likely needs to be even thicker than the pusher plate to do that.

Nuclear pulse propulsion works in space because the pusher-plate works as a shield. In atmosphere, the heat an radiation can bounce off of air in addition to conduction and other methods of heat propagation that are not an issue in space. While a ground-launch Orion is more realistic than a star-trek shuttle, you would need a fairing that probably weighs more than the rest of the ship put together to have anything survive to orbit, and even that would be highly questionable.

Are you suggesting that yelling 'do better' on the internet after an experimental vehicle launch with no crew or payload experienced anomalies that did not injure any of the many many bystanders is an insufficient argument to tear-down and rebuild from scratch every involved agency and organization?!?!??! Clearly every technical failure requires that we abandon all faulty technologies and start over with wood and bone tools!

I expect, that in-theory, with infinite dV and arbitrarily good aerodynamics, you could get just about anything that is able to get off the ground into orbit. Thus far, in the real world, we have not been able to demonstrate any vessel getting into orbit without at least one stage with TWR > 1. Hydrolox is great in space for its specific impulse, but not so good for a first stage due to it's lower thrust. While it can work(see delta IV heavy), it is not common to have a pure hydrolox first stage for this reason.

I thought the 13 billion year estimate was based on calculations related to the microwave background temperature, not visible red-shift. I am pretty sure there was another, independent age calculation as well, and they overlapped in their uncertainties(at least until recently) Also, I think we can also see things that are further away than the calculated age of the universe, mostly because space itself is expanding, so while the light has only been traveling for 13bln years, the observed location would currently be further than that because the distance has increased while the light was traveling.

A SSTO will be out of the usefully dense atmosphere before its condensing equipment could even produce it's own mass in liquid oxygen. As such, you will have a lower launch mass by just starting with all the lox you will need.

Clearly my networks class was a long time ago(IPv6 which is related to #41 on that list only became a draft standard half way through my Senior year), so I'm glad to hear UDP is finally getting some love. Other than TCP, UDP, and IP4/IP6 encapsulation, are you aware of any other protocols currently in use for bulk data transfers?

Sounds like we just need a second line of charges then, to allow a pac-man style chunk to be cut loose and allow the depressurization to happen much more quickly. (or just put it on both sides and cut it in half, which is probably what the FAA would prefer...)

The internet is designed to be a network of networks, so if the networks are connected to the existing internet and they support IP(Internet Protocol, mostly handles routing), then they will just be invisibly incorporated. If they are not IP compatible(or are preventing from interoperating but are still connected), then some sort of interface node may be required for translating between the incompatible networks. This may require minor changes(like connecting to IPv6), it may block all communications that are not white-listed, or the seems might be completely invisible. It all depends on how they are allowed to interact(if at all). If the networks are not connected, then obviously there will be no interactions, but maintaining an air-gap would be very difficult. Edit: The China article is just about adding an additional protocol in top of IP Currently we have UDP(intended for time sensitive broadcasts where missing data is less important than timely data and is never used), and TCP(best-effort protocol that will check for missing bits and re-request them before delivering the intact package to the application, even if the messages are not delivered in the order they were sent, this is the protocol that *everything* is using because losing random parts of your message is generally not considered acceptable). At worse, China will configure internal networks to drop all TCP packets and require only using their internal(and presumably easier to control) 'New IP' packets for in-country usage, and we will need to use(presumably state-controlled) translation nodes for swapping between TCP/IP and 'New IP'. To outside users it will probably just look like an upgrade to the 'Great Firewall of China'.

Falcon 9 hits Max Q after roughly 70 seconds, this is also shortly after it passes Mock 1 Wikipedia says the fastest air-breathing aircraft is the SR-71 blackbird that hit 2,193.2mph/mock 2.81 in 1976 The falcon 9 first stage only burns for 162 seconds. For a first stage air-breathing engine to work, it would, at best, replace less than half of the first stage. This would cost the use of an extra set of engines, an extra recovery, and lots of extra development. I just cannot see a sufficient increase in efficiency during the first minute of flight to warrant splitting up a less than 3 minute burn across 2 stages.

Hydrogen leaks. Through anything. While doing so, Hydrogen also make the things it leaks through more brittle. Leaking that hydrogen into a LOX tank seems like a good way to get a big explosion.

I figured that a chunk of the reason to do the 'hammer toss' would be to transfer additional energy from the booster to starship. After release, Super-heavy wants to turn around and slow down, while Starship wants to speed up more, so any sort of momentum transfer should save dV for both. Center of mass is probably still inside SH, due to all of the engines at the base, but Starship should have a majority of the remaining weight, so this little maneuver may transfer a significant amount of inertia from one to the other. Even a few dozen m/s transferred might save tons of fuel, and those would be tons of fuel at stage separation that did not need additional dry-mass.

I think you overestimate the rationality of the average activist or dictator. They may not actually be able to do anything(depending on the organization that uses the nuke), but they will still raise a ruckus.

Relationship dramas are very much a Pathos(emotional reasoning) thing. A lot of the most impressive parts of Rockets are dependent on Logos(logical reasoning), in part because the sizes and scales do not make a lot of emotional sense. (a teaspoon and a 5 gallon bucket are easily recognizable sizes, a 5-kiloton rocket is much more abstract, and for the observers, the explosion took up less of the visual field than your average professional firework mortar, so you need a logical understanding of the scales for it to be appropriately impressive)

As far as I am aware, no one has taken a Launch abort pod version of starship off of the table. My understanding is that Elon would prefer to have a starship so reliable that transferring passengers to and from a Dragon capsule for ferrying people to and from the earth would actually increase the total risk of the end-to-end voyage. Like so much else, this is aspirational until it has been demonstrated as possible. My expectation is that the first several 'manned' starships will launch without crew and get a transfer from a Dragon(or possibly SLS) capsule. (probably for a trip to the moon) I also expect Starship to have 100+ flights and probably 50+ consecutive 'norminal' flights before it ever launches with crew on-board, even a version with a LES pod. I consider both launching and landing a Starship design similar to the current one with crew(on earth) to be aspirational as opposed to expected. And just like other Musk aspirations, they will be great if they can be managed, but that is by no means certain. I will be pleasantly surprised if there is never a need for a starship 'shuttle' configuration with a smaller second stage and built-in LES(similar to Dragon) that is only used for transporting several dozen(or perhaps 1-2 hundred) people to and from orbit where it docks with longer-range starships that will actually transport them to the moon/mars/stations outside of LEO. (replacing the more expensive ticket of using a Dragon capsule for this purpose)

Compared to what? Interstellar space(1/10 particles per cc) is a vacuum compared to the solar wind, the solar wind(5 particles/cc) is a vacuum compared to the surface of the moon, the surface of the moon(10^4-10^5 particles/cc) is a vacuum compared to Mars, and Mars(0.02 kg/m^3) is a vacuum compared to earth, and earth(1.3kg/m^3) is a vacuum compared to Venus, and Venus(65kg/m^3) is a vacuum compared to Jupiter(25,000 mile deep ocean of liquid metallic hydrogen). Can it enter the solar system? Can it land on the moon? Can it land on Mars? Can it land on Earth? etc. If you are trying to write a story, spending all your time coming up with rules about the universe is a backwards way to do it. First you come up with the story, then you identify interesting complications that can be added to the story. Only then are you in a position to do general world-building, and it must be constrained by your story. (and every question you ask would need to include the relevant story-beat details so helpers know the constraints) And frankly, anything that involves startrek-style shuttles is science-fantasy at best.

Only if you want to SSTO from a large body. Demios has an escape velocity of only 20kph, letting you both land and launch with only about 12m/s/s of thrust. This would let a MMU land and liftoff twice before running out of fuel, and any 'real' rocket could probably do a lot more. But for earth? Any realistic rocket using less than 50% of it's wet-mass as propellant to get to orbit is pure fantasy. (the real number is probably above 80%, but I am willing to allow for new technologies like rotating detonation engines getting that number lower, just not *that* much lower)

The placement is random, but once you have surveyed a biome, you can edit the resources remaining in a specific biome in your save file.

To keep things cryogenic you would need larger radiators and a lot more power. Radiators are more efficient the hotter they are, and it takes more power to move heat from lower temps to higher temps. It is not just Styrofoam and a mini-fridge. It also means that any temporary power loss could let your fuel boil off. Also, long-term storage of hydrogen is not really a thing as far as I know, between embrittlement and and just seeping through solid materials, hydrogen just does not like to stay in place. It might be easier to take up water and just use electrolysis(adding a delay before any burns as the fuel is produced). Hypergolics are also much easier to ignite as they are hypergolic, greatly simplifying the engine, and reducing points of failure.

Going by Steam telemetry sure, but if you ever used mods in KSP1 you know that you do not play with mods in the steam directory, so anyone playing with mods or otherwise not using the steam launcher will not be in those statistics as an active user. (and at this point of the dev path, there is a lot of need for mods) I got errors launching through steam, so my 'play-time' is all of 2 minutes back on release day. I 'landed' on the Eve seas before the patch and did a mun-minmus tour after the patch. (my 'landing' was about as stable as the game-ball at a NBA game, but the vessel was still intact...)

If you only need 'gravity' for people, then just use steel plates on the floor and magnets in your boots. Simple, practical, and the energy requirements are low enough that it can be provided by the muscles of the person(mostly for lifting your foot away from the floor) You should even be able to tune the strength of the magnets to minimize or eliminate muscle atrophy in the legs(even if the muscles are likely to re-allocate a fair bit over time). This may even act as 'training wheels' for people not accustomed to microgravity for long duration flights on large vessels(like a starship to mars).

Looking at the roadmap, he might be putting a lot of it into the core KSP2 game. It might be more enlightening to ask if he intends to migrate his LS mod, as it sounds like that is less likely to be integrated into the core. That said, it may be a while before he has the free time to work on mods, as he is probably putting a lot of extra hours towards his day-job. I hear they just released a large product in early access and are working hard on supporting it.

"How many groups do you get if you take away zero at a time from your starting set?" Divide by zero is also something of a bug in math, as anything other than 0/0 is nonsensical. Computers operate on math, so when they try to perform an operation that should produce a nonsensical result, they have a problem because they cannot handle said nonsense. Computers are also not able to calculate infinity, and any attempt to do so will also result in problems due to limited computation/storage space. Division of floating point numbers is also the most difficult and time-consuming operation that computers perform, so optimizing those operations, especially pathological cases, can shorten the cycle time of the processor, allowing for an increase in clock speed. (that MHZ or GHZ number that they list for the CPU or GPU)

Steam says I have 2 minutes of play-time and I last played on Feb 24th. Why? Launching through steam does not work for me, so I run it with a short-cut to KSP2_x64.exe in my games folder. Remember all the advice about not playing from your steam directory because it will mess-up your mod installs? I expect that is also having quite a large impact on the steam statistics, even if there is not much in the way of mods just yet. Old habits die hard I can tell you that I have played KSP 2 a lot more than steam thinks I have, even if I am not playing as much as I will once there is some form of progression. I suspect that the launcher is having problems because of my multiple monitor set-up(3 monitors with two different sizes), but as the KSP 1 launcher did not work for me either, I just shrugged and created my own short-cut a few minutes after downloading the game. While I will likely leave a review once KSP 2 is more feature rich, I am not expecting any of my future play-time to be reflected on steam, especially considering how frequently I used mods in KSP 1. Edit: I got KSP1 from the squad store, so my only 'KSP' activity on steam shows me downloading KSP 2 and abandoning it in less than 5 minutes. Not sure how many hours I played KSP1, but my hours played would be at least 4 digits.