Comments by "ke6gwf - Ben Blackburn" (@ke6gwf) on "" video.

@BobSmith-zj6lk those are stainless steel tiles however, not ablative. They are designed to be able to handle the heat without damage, unlike the Shuttle that had very fragile one time use tiles. Totally different technology. The only reason that these are hex instead of sheets is that if you have straight seams, you will get heat buildup and flow erosion, and by going hex, it breaks up the flow paths.
6
I suspect that an intern could design a car cover to slip over the rocket once it got to Mars
4
They are stainless steel tiles. Musk said that they are hex to prevent flow erosion from straight seams.
3
If you knew the conditions in rocket engines, and all the other things they are loaded at max ability with no room for failure or mistake this wouldn't really seem like any harder of a challenge! For instance, with regular ablative heat shields, all it takes is a tiny defect or crack or chip, and the plasma eats through it like a cutting torch, or hundreds of other things that just have to be perfect.
2
I hope they retrain you at rocket school, because either you suck at properly explaining how rockets work, or you don't understand how rockets work, but in either case you make no sense in what you just said.
1
@fiveoneecho well, can you expound on what you mean that the diffusers and compressors reverse when the flow is supersonic?
1
@BobSmith-zj6lk , Elon has said many times now that he is going with a stainless steel hot side of the rocket instead of ablative tiles. He said that on the hottest areas where the stainless steel would be damaged from the heat, they will use transpiration cooling, using an outer layer with micro perforations and pumping water or liquid methane out through the pores, and when it evaporates it will absorb lots of the heat, keeping the skin cool enough to not be damaged at all. And remember, this is a much larger vehicle, so the heating is spread out over a larger surface than a capsule. But this is the whole plan, the whole reason Elon is going to a stainless steel skin, and not using ablative tiles, because he doesn't want to have to do any refurbishment between flights, and ablative tiles would require that. Some whatever you think about whether stainless steel could withstand the heating, Elon says that it can.
1
@redpillcoach1855 so basically, reddit says that all that Elon has been saying about not using ablative tiles, and using SS with liquid cooling is false, and they know better? Hmmm
1
@sophrapsune , you mean, after Elon invested his own fortune into developing the first private orbital rocket, and then NASA hired him to build a rocket to meet their needs and provide services for them, those "subsidies"? Or are you talking about how pretty much all the other rocket companies in Europe and Russia and China and the existing ones in the US are all pretty much in existence because of government support, even when no specific services are provided?
1
@sophrapsune , OK then he gets even lower subsidies than any of the other US aerospace companies, or any of the international rocket agencies, so it isn't an unfair advantage, just him having a product that NASA wants to buy. So your point is invalid.
1
@sophrapsune , so some basic definitions are needed here. A subsidy is when an entity pays another entity simply to support them and keep them solvent, such as when farmers are paid not to grow crops, or giving an allowance to a kid, or when someone is given money despite no services or products being exchanged in kind in return. What Spacex did was bid on a government project, and win the bid, and the government gave them money for a product and a service. This is very capitalistic, it is just going after the government market instead of the private market,which makes sense since the government market tends to be more lucrative. And yes, the bid in question was to develop a new system, but it was needed because no one else had the system, and it was something that NASA needed. So it wasn't a subsidy where NASA was paying them to develop something that they could have gotten elsewhere, it was selling their products on their own merit, which is how capitalism works. And again, the government hiring you to do a job isn't government largesse, it is being hired to do a job. Otherwise, any company that does work for the government, down to the janitor service, is receiving government largesse lol
1
@RWBHere , I suppose in a stretched way it is similar lol Basically, when a liquid is heated, it absorbs a lot of heat in order to vaporize, and then expands greatly in the process, cooling the area around it, and taking the heat with it. It would also tend to create a barrier between the metal and the plasma through the expansion process, but under those speeds and pressures, I don't think it would be very thick, so it's mainly the absorbing the heat and removing it that helps.
1
@sophrapsune so which politicians are benefitting from SpaceX? While projects like the SLS, and pretty much all the other aerospace companies are very much driven by politicians, which is why the manufacturing for all the big projects from Apollo to the Space Shuttle and everything else is spread among factories spread across many states, and it is usually the politicians in those states that push the budgets through to keep the money coming to their states, but now SpaceX comes along and is threatening that whole system, because they don't play that game. For instance, the SLS is often called the Senate Launch System, because that's where it was designed! They lobbied the congressman from the space industry states to create a program to return to the moon, and after it passed they told Nasa to hire the usual companies and create this project, and gave them the money to do it. And even with nasa now talking about using commercial rockets to launch the first phase,, you can bet that congress won't be cutting the funding to the SLS, because it is still making a lot of politicians rich, even if it never flies. This isn't the case with SpaceX, because they don't play that game, and the only reason that they are getting so much business is because they are so much cheaper than everyone else.
1
Wesly Stanton nope, you are right, Elon wasn't starting out at the point of Goddard or Van Braun or any of the Soviet or European rocket pioneers. He wasn't even starting out at the level of NASA or Boeing or Lockheed or any of the current leaders in space technology, he started out building off all of that, and taking it beyond what anyone else can do. First private rocket to orbit (before NASA was funding him), first commercial space flight, soon first non-governmental human orbital spaceflight, first full flow staged combustion engine, soon first flying water tower (which is the closest he is getting to Van Braun or Goddard, building and launching primitive rockets out in the field, he just is starting at a slightly larger scale lol) Yes, he would not have been able to get so far without NASA having given him a contract, so they could quit being ripped off by the Russians and American aerospace industry rates, but NASA is on track to save money by giving him the startup capital investment through hiring him to create a product they needed, but none of that reduces how amazing his progress is, because pretty much everything that he is doing, no one else has done, or even thought possible.
1
@sophrapsune , one point that I forgot, SpaceX is certainly unlike any of the other companies working for NASA, because as far as I know, they don't work for Cost Plus (where the contractor can't lose money, because they are guaranteed that all their costs will be covered, plus profit on top of the costs) like everyone does, where the more expensive the contractor can make the project, the more profit they make (see the SLS delays, and all the over budget and behind schedule space and military projects...), unlike them, SpaceX has been working on goal driven fixed price contracts, and has been driving the change for the existing Cost Plus contractors to have to start bidding on fixed price contracts, instead of being able to write their own checks since they have competition now.
1