wumpus

They are going beyond that, and bringing in their best lobbyists. https://arstechnica.com/science/2021/09/blue-origin-hires-advisory-firm-linked-to-messy-jedi-contract-process/

Is KSP docking ten or one hundred times as fast as real life? On the one hand the countdown is timed for a straight shot to the ISS (and computer controlled for the right trajectory), but on the other hand the relative velocity of docking is measured in cm/s.

I'd assume that Spacex is only going to the Moon in a NASA program. So it won't happen until all the lawsuits are settled and STS is either ready for the big day or has been replaced in Artemis. Artemis was designed first and foremost as something that Congress would be willing to fund (although much of the lander fun is because they didn't fund it enough to actually do it, but don't tell the Congressmen paid by Bezos that).

Musk sees the Moon as a distraction, but is willing to do it for the money that NASA is waving around. Or are you talking about the tourist "around the Moon" trip chartered awhile ago (poll says "land", so no)? And when is "complete?" KSP (1.x) is "complete", and took over 10 years to get to "final approach". But it only took 4 years from first compile to "1.0 release" (of course, with all the changes rushed in, it took until at least 1.0.3 to be playable again). Star Citizen appears to be what happens when a software project has fuzzy goals (like any game) and a vastly inflated budget. And it doesn't help that the most profitable thing they can do is to produce more DLC starships.

Can we have a full blown Sputnik (and Vostok) style American reaction? Now would be a particularly good time to push science and the rest of STEM in school and industry.

Hubby didn't live long enough to get (or at least die from) cancer. He was run over by a horse carriage.

You don't need a quantum computer AI to run a corporation. People (preferably psychopaths, but that is more a feature than a requirement) do it fine already. Although perhaps the AI will be able to put more effort into maximizing control of the workforce and market and be less concerned with board level politics.

SSTO (from Earth) more or less requires air breathers. With three-digit Isp (or similar "magic"), Earth SSTO becomes a possibility. Of course, it might still be more effective to use TSTO even with an airbreather, moreso with something like a SABER, less so if you get something like a X-43 engine taking you to mach 10. Of course, X-43 only really made it to mach 6.8 under its own power and only barely maintained mach 10 (positive acceleration was in the center of the error bars, not outside them). And "either rocketry or bombs for thrust then they will wreck the launch site"? You really need to try this game called "Kerbal Space Program" (I heard they finally finished development): it will teach you about the difference between thrust and delta-v. You need "magic" Isp for SSTO. Thrust really doesn't enter into the rocket equation (while it helps use a bit less fuel at first as your effective thrust is 1-TWR, big engines are the enemy of SSTO).

Starship has a capacity of 100 tons (at least that's the plan). Dragon 2 is 10 tons. So you need 11 launches instead of 10, and you can bring along 70 people. Somehow I can't imagine riding with 70 people to Mars inside a Starship. Perhaps the Starship will take them to a large cycler (and park with it for decscent/return duty).

Mars Starship requires 10 Starship launches (9 deliver propellant). There is no reason why humans can't be on the 9 non-Mars launches and have a LES. Also at least one Falcon 9 had an explosion that would require an LES to escape (so obviously things designed with the "move fast and break stuff" will break on you. Expect similar safety on Starship, or less). Also with the LES, they prefer to fuel the Falcon while crewed (which involved a second incident during fueling). Including a known technology to greatly increase safety during an extremely dangerous part of the mission appears to be a no brainer.

Musk has thrown around $1 billion in R&D to add reusability to Falcon 9. Most other swags appear to agree with this number. Total Falcon 9 booster reuse is standing at 66 (my quick count on the infallible wiki, 54 block 5, 12 full thrust). That comes to around $15 million for each booster they haven't needed to manufacture, and it would be hard to claim that they can make them for less. I'd put the break even point somewhere around 20-30 recovered boosters. It isn't 10, and it certainly isn't 240 (they've made 24 block 5 boosters). Granted, this also implies that it is worth >$15 million + an expended upper stage + launch costs for every starlink launch, but I suspect that this is true. I won't claim they really want to cover the full $60 million they charge customers. Falcon has had a single event in 124 launches that would require an abort mode (the other destruction of cargo could be avoided by loading fuel before crew). The Shuttle had 135 missions and lost two orbiters. While abort modes are a good idea, I strongly suspect that the rentry and especially landing is where spacex will lose the majority of Starships (there's no reason to avoid riding a Dragon. You really wouldn't want to bet your life on a safe Falcon 9 booster landing). Also note that the issues with the first failure (and presumably the fueling LOEverything) were fixed going from Falcon 1.1 to FT to Block 5 (there were a few fixes in the tiles in post Columbia shuttles, but not much other improvements). I'd be fairly surprised if the first crewed Starship didn't have a separate capsule with ascent aborts and either parachutes or pressure fed retro-rockets. What we are seeing is likely the "minimum viable Starship", not the end product (which may well end up in only 2 parts. But I don't think they will get there in a single step).

There was also a lot of politicing in upgrading 911 (or whatever you local emergency phone number is) to get the GPS information from smartphones. There was a lot of push to require dumbphones (mobile, not landline) to include this as well but I'm not sure what they ended up with. I think that they use tower triangulation and that is good enough. If your phone can quickly get GPS coordinates, it either never turns off (great for emergencies, lousy for battery life) or uses tower triangulation to determine a good approximation and lets the GPS start computing from there.

Note that "cost effective" for the Shuttle likely meant sacrificing ongoing costs to lower upfront costs to avoid complete cancellation (like the other 3/4 of the STS program). It was an amazing stretch to cover all the requirements, but the design required to cover them all never really had a chance of being as cost effective as originally planned (not going to happen with Senate micromanagement). I'm not sure why this thread needs to compare Starship to the Shuttle. Falcon 9 was the rocket that took the Shuttle idea and fixed it. The Shuttle made the booster expendable (you got some heavy steel tubes back, but the expensive part was expended) and recovered [all but the fuel tank of] the ".5 stage" and rump 2nd stage (OMS engines needed to circularize). The Falcon inverted this with and recovered the booster (90% of the rocket) and expended the 2nd stage. Starship+booster goes well beyond the both of them to be fully reuseable, although it is definitely clear that the "shuttle half" (Starship) is keeping Musk awake at night. Also from how often Musk says "we're not thinking about that" about things further along than getting Starship into orbit, it is pretty clear that a reliable means of landing a crew isn't likely a current design requirement of Starship. Presumably after a few landings they will even start on that plan (failsafe/failproof landing? Use Dragons? Something else?). SpaceX is building the capacity to build more Starships than you'd expect a reliably landing vehicle to need (he even admits that he can't send that many to Mars thanks to launch windows), so who knows what the final plan is. "The shuttle never launched without a crew" was more a deliberate political decision by NASA to allow astronauts to piggyback on all military/government launches (pretty much *all* US launches until Challenger). They decided to risk 7 lives on every launch, but also got >100 crewed missions. There is a bit in the youtube Everyday Astronaut interview with Elon Musk where Musk contrasts Starship design with Dragon design. Since Starship will initially fly without a crew, there are far less margins and fast iterations where you don't have time to check *everything* like anything flying people would need. Did they need to look at Shuttle history to know this or only compare their experience with Dragon vs Falcon1/9 and realize that the "crewed only" option made no sense (all other NASA crewed launcher/spacecraft were fully tested uncrewed. Only in a fit of insanity did NASA even consider launching the first SLS with a crew, and since recanted). Probably the biggest "lesson learned" needed (by SpaceX) from the Shuttle was how bad the tiles worked out. Starship is clearly using tiles 2.0, after an initial attempt at something more complex to avoid tiles altogether (and might see some use spraying methane out of cracks in the hinges to protect gaps between tiles). Most of the other critical "lessons learned" were about not mounting rockets on the side of a booster and running a government program (although in many ways it was an amazingly successful as a government program in ways that NASA would love to duplicate. Thirty+ years of massive funding is a success, not a failure by any government standard). If you must use airplane analogies, I'd put the Soyuz as the DC-3. One of the first commercial haulers. Rugged, simple, and keeps hauling even after fancier vehicles are available. The Shuttle would be more like the Concorde: hyper advanced for its time (and currently unequaled by anything regardless of my comparisons with Falcon9), unsafe, and only managed a long lifespan thanks to massive government subsidies.

White oak makes good heat shields. It ablates slowly, in layers. I'd be shocked if nobody has used it for a heat shield. I'm not sure of any bit of spacecraft (not the booster & engines) that requires more attention to materials science than the heat shield.

https://www.goodreads.com/book/show/9542311-packing-for-mars A much better source for your "how does space effect the human body" questions.

A bigger issue is with self-guided trains, I'm not sure the human can do much other than get PTSD from an approaching accident. In highly litigious countries (i.e. the USA), this makes sense as a CYA move, and can help the jurors feel empathy for the hapless engineer unable to stop the train in time. Elsewhere, I'm unsure why you would inflict PTSD on the engineer because somebody just *had* to sit on the tracks/beat the train across a road (the train isn't going to stop regardless of whether or not the AI begins braking). Remember that considering a single AI driven death unacceptable sacrifices 30k (-1) Americans (I'm not aware of the international numbers) to the "perfect safety" gods. I'd like better standards comparing the expected number of accidents (and fatalities) per mile in terms of BAC (blood alcohol content) or eventually the numbers of miles (or km) an AI can drive compared to a human with equal safety. An AI with a safety rating of ".8" or better might be vastly safer for a driver with a DUI conviction than a BAC interlock test. Note: In the US, the NHTSA (National Highway Traffic Safety Administration) has its headquarters in Washington DC, home of some of the worst drivers in the nation. Not sure how many of the decision makers work there compared to "regional offices" (which appear to be more any state vehicle/highway department than anything else). PS: the cyberattack issue is much deeper and having AI drivers barely increases the attack surface. Once I learned that Tesla cars had their brakes altered (anti-lock braking fixed) over a pushed wireless update, I just gave up on the hope of any attempted defense against cyberattacks (it doesn't help to work for a defense company that is deliberately removing security under government orders).

Not sure why, but subs are classified as "boats" in the US Navy. That's odd. They can't get a gearing to match the engine speed to the propeller, or the engine simply refuses to run at the right speed to enter/navigate harbors?

From the ULA discussion, but really belongs here: Just out of curiosity, does anybody know how much NASA (or other potential customers) paid for Falcon 1 design? I'm assuming something, because the friction between the "reckless new hotshots" and NASA existed before the Falcon 9 CSA contract, but I don't think much of the money came from NASA. That and that's the type of thing NASA would throw some change at, if only expecting whitepapers or powerpoint as a deliverable item. - as a disclaimer, I should note that every single "good job" I've ever had either was directly for the military industrial complex or was closely associated with it.

Except there is a long history of using other renewable energy sources to move ships. Namely wind. While entirely wind [commercial] ships appears unlikely, it seems foolish to avoid mounting a modern "sail" on board a shipping container ship. I'm equally perplexed on the idea of an electric ship (ship being something that crosses oceans. I live near Lake Ontario, and I suspect an Electric ship-sized vessel to Toronto might make sense). Trains might work with the diesel (or whatever) engine using the generator-motor combination as some sort of transmission, but a propeller hardly needs such a thing. I'm not aware that ship-sized engines need anything moderating their propellers. Probably the only critical thing (assuming you can't get them to mount sails) is to try to keep them from using the dregs from a refinery. Electricity (like hydrogen) isn't a fuel source. It is a means of transmission. And you don't have very far to transmit in a ship (or more specifically a ship's engine room).

I'd still want to flip the SH, although it might take some serious fins fore and aft (remember dry weight isn't that big a deal on the first stage). While the landing record of Falcon 9 is great (recently), the landing record for Falcon Heavy (center) isn't, and I'm reasonably sure that getting more delta-v from SH than the Falcon 9 booster provided would be better. I'm fairly certain the Falcon 9 booster was designed around the "expended" delta-v amount. Of course a company as in love with "iterated design" may well choose SH 1.0 to be as close to F9 as possible, with SH1.x morphing into something else (which might surprise everyone).

Another old space tradition. Then again, workers who keep working long weekends aren't too likely to become old employees (at the same firm) with the long institutional knowledge. They'll splat "impressive new space company" on their resume and find a more family friendly company to raise a family.

Note: "shorter lived waste products" also means "nastier and higher radioactivity" without further description, but I'll admit that the "ultra long lived waste" problem of fission is mostly a still strong myth (yes, it lives long. But long lived isotopes tend not to be radioactive. Glassify it and store it somewhere in an old mine and don't worry about it.

Quick googling implies that for SLS, the idea is to clear the SRBs without cutting them. Shuttle had plenty of impossible abort modes, but I don't think they even pretended that there was anything they could do in the case of a SRB failure. Even if they could blow the panels, it would have required an ultra-fast reaction to blow the panels to save the Challenger. And then you get to detach the SRBs and try to fly the Shuttle?

Dawn was shot to escape velocity under chemistry even though she had 10km/s of non-chemistry delta-v. Part of this might have been the issue of just how much time it takes (the team involved might want to have more papers in their entire career than the ones produced by Dawn), and some of it because it was untried tech (for NASA, there was a British experiment that went from LEO to the Moon without chemistry). I'm a huge fan of non-chemistry propulsion, and can't recommend chemistry for anything without a crew beyond LEO unless you have an unexpectedly shortened schedule (like a GPS satellite going out of commission and needing replacement immediately). They also appear relegated to low-visibility NASA projects (granted, anything without a crew that isn't a huge telescope qualifies) as it doesn't fit in the "complete during the current president's available terms" timeline.

Blowing up the nozzle would only reduce thrust by a large fraction, I think 50% or so (possibly a lot less, if you also took out the throat and realized that the expansion chamber had grown to near the edge of the fuel). Pretty sure you'd need the top as well. But I think that is overthinking a LES. You just ride it out till it runs out of fuel and then parachute down. You can either design the parachutes to handle the entire range of possible escapes (more or less necessary, as you'd want it to work from the launch pad up to out of the atmosphere) or add the ability to cut the SRBs. I'd guess that cutting the LES doesn't buy you much but plenty more complexity. Remember that parachutes are a lot more complicated than what is shown in KSP. You might want additional retro-rockets for more abort coverage, and I'd expect these to be able to cut the thrust. No idea if Dragon's draco engines can do this role.