Hannu2

I fear that this is common problem for all western countries. Our politicians see space tech as futile money sink or excuse for subsidizing their hometown's high tech companies and do not take especially India's and China's space programs as serious competition. I do not know what prime minister of India said in his speech after successful landing, but if their highest politicians think that space tech and utilization of extraterrestrial resources is important for their countries development in foreseeable future there may be nasty surprises for western countries in next decades.

Or maybe target was 40 m at early planning but they had to make some trade off to get some scientifically more important. I think that number psychology works better for average consumers than astronomers or professional funders. This is true. They have probably ordered important parts from companies and made contracts. Modifications would cost billions now.

I have understood that worst problem is heat loss from plasma. If you put plasma in container with permanently cool walls it cools down and you have to input more energy than you get out. Energy output goes also through walls. Material which has constant temperature independent on energy flow could not conduct heat. Such material violates known conservation laws and energy produced in fusion would be lost. But as you said, such material would be excellent heat sink for all imaginable purposes.

So, that odd material converts all energy to hydrogen gas at some temperature (less than 1500 C) which metal has when it is activated. I do not see how that would lead fusion any easier than hydrogen gas taken from regular gas cylinder. You should still give hydrogen atoms huge energy somehow, which is the main problem. However, your material would be very nice for perpetuum mobile industry. You can cool it to 4 K and activate. After that it would be practically infinite cold sink. Any industrial power would produce just trace amounts on hydrogen which would be easy to ventilate safely away.

Your assumption is correct. Gravity prevents material losses, but 0.1 g would be more than enough for RC aircraft hobbyists.

They were lucky. I had once a coaxial RC-helicopter. It went sometimes in "LAND_NOW" -mode (usually after rotor had hit to some object) and made autonomic unscheduled landing. My helicopter needed almost always manual repairs after such events.

Do humans know? Humans have unlimited number of assumptions, beliefs and religions what is absolute truth but all of them are philosophical assumptions impossible to prove right (and most also to prove wrong). Humans get information and feedback of that "truth" through senses and AI algorithms have different feedback mechanism. Biggest difference is that humans accept errors and idiotic actions from other humans but they expect machines to work perfectly in all situations. People also want some human who can be accused if something goes wrong. For example examples like which victim AI-car should choose are quite common. But no one ask how humans should interact. It is OK that human make panic braking and no one have time to think to who he choose to hit.

I think that shape of space missile is determined by radar or other detection technology. I would guess that missiles will never be practical weapons in combat between spaceships because they are easy to see in empty space. It is also very difficult to predict what kind of radars or other detectors are possible when there will be space wars.

I think the most important effect is mutual interaction of planets. Solar systems are unstable many body systems during extreme long periods. They may converge to quite stable orbits but for example nearby stars can disturb systems. Also beginning may be chaotic. Some simulations show that outer planets have moved significantly, maybe even changed their order, and one gas or ice giant may have been kicked out of the system. It seems to be quite common that gas giants drift near their stars (and destroy smaller planets in migration) and as far as I know it is not known why it has not been happened in our solar system. Such many body motion can shrink or expand orbits or even cause collisions or kick planets out from their system. Second most important is slow drifting outwards because stars loose their mass during life. Stable stars like Sun lose negligible amounts during main sequence period but after that they begin to loose. Larger stars can loose significant part of teheir mass during main sequence period (which is very short due the extreme radiation power). I think drag or radiation pressure are not noticeable for planet sized objects, except if they are completely swallowed in red giants. However, such effects drop small particles to star in astronomically short time and affect orbits of small asteroids. In thermodynamics perpetuum mobile is a mechanism which does not obey conservation of energy. For example rogue planet can rotate in space whole lifetime of the Universum but it obeys conservation laws and is not considered to be perpetuum mobile.

I agree. It is exactly the same thing every time humans invent something radically new. But do anyone see possibilities to prevent problems without actually suffering and learning when problems are solved? I do not see very realistic that development of AI algorithms would be banned. It would give huge benefit to rogue states, terrorists and criminals if they got head start. I think it is better to let companies develop AI things and people to get used to AI and mitigate its problems. Of course with legal control. But legal control will be behind like environmental control was at beginning of industrialization or safety was in medical industry. It is new thing that threats of new technology are taken seriously form beginning and I hope it will prevent worst case scenarios.

I do not fear but I am worried. AI is like all major development steps. In very long period it increases wealth and well being but in transition phase it causes much problems and suffering before community adapts to it. Just like computer automation, industrial production, democratic governments and so on. And of course, when we begin to adapt AI someone invents new things which repeats the cycle.

I hate crude fixes to complex problems. One part of my job is to sort out researcher's crude fixes to complex problems and make real fixes. Usually every saved minute for them takes an hour of my work time. Sometimes it is unavoidable, if they fix something to continue measurement campaign in distant locations but they do it also in lab next to my office.

I would like realistic thrust curve, like real SRBs. For example Shuttle's SRB begins at full thrust, decreases during max Q, increases again and then decreases smoothly to keep acceleration in limits. https://en.wikipedia.org/wiki/Space_Shuttle_Solid_Rocket_Booster#/media/File:Srbthrust2.svg

3.71 MPa is very high pressure if it affects on large surface. Water nozzle has a diameter around 1 mm. Starship has 9 m. Force is proportional to surface area, i.e. square on ratio. Larger structures able to handle that kind of pressures are very thick walled metal structures. Like gas cylinders, hydraulic cylinders or high pressure parts of powerplants. Concrete is very brittle in those conditions and temperature of exhaust does not make concrete's work easier.

What is the point of make difficult planet to game and then give tools that makes it simple and easy? Also that kind of properties is not typical to SRB. It can be programmed in game but why they should call it "SRB". In my opinion things does not have to work exactly like in real life but there should be certain consistency between game and real life objects and their operation. If there are real world named like SRB's, liquid propellant engines etc. they should work so that I can guess how they work based on general knowledge of rocket echnology. If game developer wants to give totally fictional ways to work, it can be interesting experience too, but they should be named with more scifi-ish names. Quantum enhanced gravitomagnetic antimatterturbine can do whatever magic or inconsistent tricks. I am sure that there are loads of mods which give more powerful and/or simple ways to visit all bodies in KSP system, if you really want to go to see how planets look without too much experimenting and learning. But on the other hand, if you learn few simple ideas how space flight work it may give much more joy. KSP is quite easy game at default settings, after all. Not anything like real world's terror of rocket equation.

It takes decades before those prjocts are accepted in military bureaucracy and build even to test objects. I do not believe that military givea any adavantage to Starship in this phase. I understand it well. ULA operates discreetly like traditional military contractor and can provide all needs military have in foreseeable future (when they get Vulcan ready). It certaily shows much more reliable business partner to military than eccentric space enthusiast billionaire's strange company which wants to colonize Mars. It is one thing why I said that SpaceX is civilian project. It is not necessary even competition but separation of development and economic to two branches. SpaceX sells cheap launches for civilian companies and research organizations and ULA specialices to special customers like military. I am sure than at this moment no one in military severely counts on Starship. It is very uncertain and there are not anything similar projects in potential enemy countries.

Then military aspect was important. But now there are rockets and launchpads already for military use. Starship is civilian project. It takes probably decades after Starship will be ready before there will be military payloads which need Starship's capacity. Maybe there will be military forces and huge armored space stations with scifi weapons in space in very far future but not any time soon. Estate with coastline from area you can get permission to build is more than one order of magnitude more expensive than average rural land here. I wonder it it is different in Texas. There are probably as more billionaires wanting coastal mansions in Texas than total inhabitants in region I live. And also if someone really want to buy a large area prices increase rapidly. In Finland there are legal ways to force people to sell their land in certain situations to a company or city but I do not know if it is possible in USA. Or is space industry enough severe reason to use such force.

I think practically every meter of coast is privately owned and builded or natural protection area. Estate on coast line is the most wanted and expensive. Owners' rights are much more important thing in USA and other western countries than space plays of nerds. Probably much less that you would expect. Even normal market price of properties with piece of coast line is crazy. And when owners understand that some big and rich company want to have larger continuous area their demands increase to totally ridiculous level and there are always some stubborn individuals who do not sell at any price. It would probably be impossible for even state to buy honestly decent launch complex with safety area around it in optimal place. I do not know if there is legal ways to force owners to sell their land at market price in that kind of situations.

My knowledge is based on Scott Manley's video. FTS explosives are long V-shaped explosives which make long cut to tanks. In some rockets it is placed in bulkhead between tanks so that it mixes propellants anf ignite them in addition to break tanks mechanically. I do not know how metals behave in shaped explosions but stainless steel is much more hard material to cut with normal machinig tools than ratio between tensile strengths are (in compared to aluminium alloys). I think it is easy to make an error if those devices are rarely used for stainles steel objects. Link to Scott's video: https://www.youtube.com/watch?v=yekMWWcpfOA

Who is independent if official state administration is not? As far as I know FAA officials will make independent detailed investigation about detected issues and will give SpaceX list of needed changes and conditions before permitting next launch attempt. I think it will take little more time than Elon expect and printed list will be so heavy that even Starship can not lift it. I guess that they underestimated strength of stainless steel compared to common aluminium alloys. Now they detected the problem, fortunately without any collateral damage, and the next version will have strong enough FTS to break the tank. It is probable very easy thing to fix. Just buy larger explosive elements. Issues with the launch pad will be much harder.

If African countries would try with traditional high risk exploration methods I am sure that they would achieve a lead with very much smaller investments than USA or EU. Chinese has also adapted a western attitude in which failure is official shame to the state and funders and can not get real achievements in manned operations. But I do not think it is very realistic. Space operations can not be economically profitable or support political power of any government in several decades or even centuries and African countries have more acute problems to solve than technopropaganda.

That kind of phenomena is conflicting with conservation of energy. Perpetual motion power generation would be much more profitable application. It may be little bit tricky to find such material but there is no other reasoning for conservation laws (or symmetries behind them) than observations. At Universe level conservation of energy does not necessarily hold. Expanding Universe gets energy for nothing and share of "dark energy" is increasing. We do not know what is behind that but what we have observed is not compatible with conservation of energy in observable Universe.

There can not be detonations with rocket fuel as far as I know. Slow explosions of mixed fuels and oxidizers (like traditional gunpowder) are called deflagration and it needs ready mixed materials which rockets do not have. But as far as I know difference between actual detonation and rapid burning is small kilometers away where supersonic shockwave of detonation has already attenuated. I am not demolition expert but it seems that SpaceX's launch site is quite vulnerable. Tanks are on ground level very near the launch pad. If rocket fails at pad or low altitude it probably flattens and burns the whole place when several thousand tonnes of burning fuel falls on top of structures. Maybe they have thought that it is cheaper to build new simple buildings and tubings when needed than make bunkers which can handle anomalies.

This kind of "explosions" are not technically explosions. Fuel and oxygen have to mix with each other to burn which takes time. FTS has high small charge of high explosive but it only breaks tanks so that air resistance and burning fuel can rip the craft in pieces.

You certainly like well done meat. Booster was almost empty but Starship had more than 1000 t fuel and oxygen on board.