kunok

In this post I use we as the Europeans citizens Your 2) point is precisely the job of an engineer. I worked only doing the 1) and 4) , and trust me, when things go wrong is a lot worse, and with the years "the nobody knows why this component was selected instead of this other" is terrible. WUT? I'm nowadays working for a space startup, with politicians involved, and there is lots of them. Can I suggest that you have a very biased view of what is a life changing achievement? In the practice nothing has changed since the apparition of SpaceX, only a cheaper orbit delivery service, and that's only a money problem, it isn't changing anything in any other aspect, even the dragon is redundant with other manned spacecrafts. How is that more life changing that Rosetta and Philae? What about Mars and Venus express? What about the Sentinel program? Have you read about the internal organization of SpaceX? Because you may be surprised. One thing that we should start is stopping spreading the SpaceX's propaganda, and remarking only ours failures, that is exactly what you did (no offense intended), your post is exactly an example of the problem. But I think that this week this would be impossible. This is simply not true. Even if reusing Falcon9 is really profitable, thing still not guaranteed, we need to have rockets, we can't depend of how good we are with usa, russia, or whatever. We have enough problems with the Soyuz. And Arianne 5 is probably the most advanced and most reliable rocket currently, with lots of developments. If we ever do the Arianne 6 or Arianespace rocket reusable it will be better than the Falcon9 because we have better tech, SpaceX is not developing new techs only improving the transferred techs of NASA. We have currently re utilization programs http://www.pldspace.com/blog/en/2016/11/07/pld-space-esa-support-reusable-launch-vehicle-europe/. And this is again a startup with public investment.

We need a "deep space" habitat before doing interplanetary travel. Cislunar space is far outside the magnetosphere, it checks. We need a substitute of the ISS, it also checks It makes a lot of more sense than you think, the part that doesn't make sense is the mars trip, but that hasn't sense anyway with the current budget. I'm sorry to say that any plan for a mars trip is just plain unrealistic without a big increase in budget, the rocket is the smaller of the problems.

First, raptor still doesn't exist yet, so any characteristic of it isn't real. What you are asking is very very complex, but IIRC the most determinant one given a nozzle was the injector type, how good it mixes and spreads both the oxidant and the fuel. My propulsion teacher was a specialist in solid rockets tho, so I may be wrong. That's an engineering question, and yes is already done to some extent, next to the inlet valve you have some regenerative cooling, even if you don't want to. Remember that the mayor focus in automotive industry is to cut cost, to ridiculous extents, this would be very expensive to do properly.

You could change the suborbital capsule in the NS to a second stage with a payload of the same total mass. It won't be in a Falcon9 class but it would be in a Falcon 1 class, but reusable.

What they do with junk when the only option is the dragon? Return it to earth instead of burning in the atmosphere. The interesting part is: how much of the mass that returns to earth is useful? and how much is just junk? Remember that IIRC there wasn't a call about being able to return cargo in the commercial cargo program.

Pss, is more like beyond GEO And yes, basically is what fans expect, to develop a bigger than Apollo program in record time with less resources and forgetting every middle step in the way. BTW I talked the other day with an ablative materials engineer (you will be surprised if you don't know that cork based ablatives are pretty good) and PICAX is an ablative material, is not really a reusable material, nor is proven that could withstand multiples reentries, is this kind of things that make people in industry to have very big doubts in SpaceX claims

The grasshopper doesn't equal the New Shepard at all, the grasshopper only developed the control landing, the other is a full human grade suborbital rocket. Blue Origin has a reusable from the start design, SpaceX has a cheap and easy to manufacture rocket design upgraded to be reusable. In the mid-long term I think Blue origin will be cheaper, because the lower operations cost. Blue origin has already a proven reused suborbital rocket, they know the caveats, all the logistics needed and what to improve in the next design (it's also said that they hired engineers from the dc-x program, and remember that the dc-x was very focused in reduced maintenance and ground support) and they will probably design the New Glenn with this in mind. The joke is that I don't like neither of them. I didn't claimed that it would have been a successful SSTO, but it would have developed the technologies required to have a better rocket tech, and probably would have ended in a good reusable first stage in the 90's or the 00's. DC-X was more a tech and logistics demonstrator, than a real scale model.

The spaceshuttle was also planned that way, that doesn't mean that will be achievable. Time will say, but I think that Blue origin will be far better than SpaceX in this, and that we wouldn't be discussing any of this if the DC-X were funded in the 90's.

We are derailing but Anyway in the actual topic Do we really know what is done to a future reused stage in SpaceX? How much is reassembled?

That's what I was trying to say. And I think that is very easy to misquote that wording, and I think is very naive to think that easy to misquote wording wasn't done in purpose. Nowadays most people believe that SpaceX had developed the first private orbital rocket ever.

It's also claimed that Falcon1 was the first privately funded rocket rocket to reach orbit, apparently Pegasus never existed. Welcome to the posmodernism

The "idea" is to just land the zeppelin, and the atmosphere above the stratosphere IIRC is not that turbulent.

Somewhat related: What about a "big" telescope in a high altitude blimp? To overcome atmosphere extinction, overcome seeing and be able to see in wavelengths impossible in the surface, without the need to be in orbit and the capability to have maintenance be upgradeable. It maybe is stupid, I'm very tired today.

Clearly he also wants the team fortress 2 market

That was for a defined goal, that is to develop the landing capabilities of the Falcon9. (And it was already proven what grasshopper did) You are basically suggesting to design a new service module, that is exactly one thing that SpaceX has opposed to do. You are really oversimplifying the engineering in that.

Because it's very expensive to design and build the hardware just to test that.

Well now here goes a cynical note about SpaceX loosing their place as the rock star For me not only the ones steering the ship are sailors. The scientists in a boat researching fish or whatever in the ocean are also sailors, the fishers that doesn't nothing in the navigation of the boat, the workers in a cruise, etc.

A tourist in a cruise is not a sailor, the people working in it are, a passenger in a ferry is still just a passenger. Why would be different with the astronauts? If you are working you are an astronaut, if you are making tourism, you are a space tourist, if you are a passenger you are "only" a passenger. PD: At least in Spanish makes sense this way

I think we also need an official distinction between principal moons and moonlets (or other name, that's not the problem). Something like Jupiter has 4 moons and at least 63 moonlets

I'm an engineer I suffer the marketing and commercial department overpromising things. (I don't currently have that kind of job but in the past...) You develop a sixth sense for this kind of things Yeah, that's true, they now have a cargo spacecraft that isn't really that modular, but that's not necessarily a problem, I suppose that have common manufacturing processes with the crew version, look at Progress and Soyuz (in the other hand Roscosmos have plans to change the Progress to something non soyuz based because it could be cheaper...). But that's because the lack of mid/long term technical plans in SpaceX, nothing new. And here you can see how they were overclaiming since at least 2012. The Falcon have extra room, not really the Dragon, and because that they announce they can launch extra secondary payloads capacity so they could claim that the dragon has that cargo capacity. Falcon is pretty overpowered for this cargo.

NASA is the client, is SpaceX who needs to adapt to the NASA cargo not the other way, more when the dragon was designed to meet NASA's needs. Of course is overpromised, and also an unproven claim. And the capacity to return cargo IIRC wasn't a requisite With is also higher that the cygnus. Dragon is a good modular spacecraft, which probably make it worse than any specialized design for any given mission, but very versatile, just not as good like SpaceX marketing claims. You could see how little I like marketing

No, mercury also have craters of the same age, and there is more info out there. But today I'm sleepy and lazy, so I won't search for you.

https://en.wikipedia.org/wiki/Five-planet_Nice_model#Notes_on_Planet_Nine There are models derived from the Nice model that could somewhat explain that planet

Bro, what machine tools you have? You won't be able to do this with manual machine tools, and high temp alloys are a pain to machine even with very expensive tools. And seriously you wont get high temp aloys from old trailers, and scrap, unless you have aircraft engines scrap, and that even being scrap is very expensive and valuable. And for safety, just put a mirror at 45º so you can see behind a corner, far from the test engine and in no direct line of the possible shrapnel

Is just that the cargo capacity of the dragon advised by SpaceX, like in the picture posted by @tater, is not realistic. Useful things are usually a lot less denser that what dragon will allow in the little space it have. In this dragon it was only 2389kg, and only 1492kg are pressurized. That's less than half the announced payload. Dragon in theory could have 3300 kg of pressurized cargo in 10m3 and the enhanced cygnus for a similar cargo capacity (3300kg using an Antares, 3500kg with an AtlasV) has 27m3, that's almost 3 times the space for the same cargo. The unpressurized extra cargo capacity of the Dragon is mostly unused and has never flown to more than half the advised capacity (and that time was because it was used to send the bigelow beam module), but the cygnus has already flown at full capacity. We could also compare with the now retired ATV that had 48m3 for pressurized cargo or the good old Progress, both have the capacity to deliver propellant, and both have flown at full announced capacity. I will admit that I have little knowledge of the HTV, but looks like it also was launched with it theoretical full cargo capacity. Dragon is a good cargo spacecraft, with it's limitations, but please, stop repeating the over-promising claims of SpaceX