Nibb31

I don't see what a German WWII propaganda leaflet had to do with the discussion.

It's really down to a question of semantics. Powered flight != controlled flight Clement Ader was the first to succeed in powered flight, although over a short distance. No, it wasn't practical, it had no application, and the whole project was abandoned. When you look at the design of his "Avion", it was more out of sheer luck than sound engineering, but it did achieve a positive lift/weight ratio over a very short distance. There were also plenty of unmanned powered aeroplanes that existed before the Wrights' attempts as well as manned gliders with some form of control. One can't really say that they invented "flight", as there was a lot of research and many different projects going on at the same time. It was only a matter of time before someone would have done what they did. But they definitely capitalized and expanded on that knowledge. The Wrights did invent "controlled powered flight" and the first manned aeroplane based on proper engineering and an actual understanding of physics. They also had a good understanding of business and how to make money with their invention, which is also a large part of their success.

There's this thing called 'reality', which is the environment in which we live. It's made of all sorts of economical, political, social, and engineering constraints. Of course, you can handwave them all away, but in 'reality', the chances of bending those constraints are even lower than bending the laws of physics. My take is that in 'reality', it isn't cheaper to build a 10000-ton rocket out of steel than to build a 1000-ton rocket out of aluminium with modern construction techniques.

A modern workforce requires modern construction techniques. You can't build ships (or rockets) in 2016 (or anything else for that matter) the same way you built stuff in WWII. If Ford reintroduced the Model T today as it was built in 1920, it would cost more than a Mustang. The cost of maintaining a workforce is much higher today, there are safety and evironmental regulations, there are laws, quality standards, accounting, procedures, that are much more restrictive, materials are different and more expensive... Sure, you could outsource to India or China where they don't care when a worker falls off a platform, or where you can have near-slave labour, but what kind of progress is that? Even then, ships are work-intensive things to build. Oh, and I'd like to see the logistics for filling up and launching something that huge. The original plan involved a massive LOX and RP1 plant near the dock and a nuclear aircraft carrier to electrolyse the water into LH2. How is that, in any way, cheap and quick ? And how do you test fire the engine on such a behemoth ? The whole argument also ignores that modern expendable rockets have become less and less expensive to build. They are optimized for expendability and low cost. They are expensive to design and to operate and to test, but the actual material and manufacturing process is easily automated.

It still takes longer to build a submarine than to build an SLS core stage, for example (SpaceX can churn out Falcon cores every week or two). A diesel submarine also costs a billion dollars.

The question is the shape of the curve of that advancement. The actual curve, going 50000 years back, is probably an exponential one, with a few flatter areas now and then. There is no reason to believe that it will remain exponential, or even linear, forever. In fact, much depends on the area. There are many curves that cover the many fields of science. For example, the field of fluid dynamics went exponential in the 1940's to 1960's, but advancement in that field is probably linear or logarithmic now.

That's a pretty bold claim for something that was barely even a paper proposal. The idea was that you would build a rocket using shipbuilding techniques instead of aircraft techniques. The problem with that reasoning is that ships aren't exactly cheap or quick to build. There is no way building a rocket the size of a supertanker in a shipyard, and blow it up in the process (Sea Dragon was not reusable) would be anywhere near economical. It might have seemed that way in the 1950's with the wartime experience of the old Liberty Ships, but with modern shipyards and the cost of a qualified workforce and materials, no way.

Besides the fact that it would take months to prepare those rockets, it would take 3 days after launch for your nukes to reach the Moon. Any hostile "aliens" that have interstellar travel would probably have a good laugh and swat them out of existence. There is no such thing as space warfare, because any technology that allows you to bend the laws of physics enough to make interstellar travel practical will also have corollary technologies that enable insta-kill of just about any threat.

I doubt they will actually go with the orange stripes anyway. The orange foam shifts color under sunlight, heat, age, etc... so they will never be able to match the exact same color paint on the boosters.

They picked the RL10 years ago.

I think it's a hell of a leap to go from an up-and-down landing demonstrator to the third largest rocket in History. I would have felt more comfortable if he had gone for a Soyuz-class orbital launcher before going full-scale. It's in total contradiction with "Gradatim Ferociter". But I wish them luck.

The Soyuz tower arms use a lever and counterweight balance system. The rocket weighs down on 4 pads, which push the 4 strongback arms against the rocket. As the rocket lifts itself, it no longer weighs on the pads and the arms are pulled back by their counterweights. Clever.

You would probably need lots of stages.

It all depends on what you call "real-time". Telemetry has resolution in the ms range, and that timestamp metadata is important when you are dealing with an event that takes lasts less than a second. If they have 3000 channels, that is a lot of data to transmit in real-time.

Where did you find that info ? It all depends how those 3000 channels were transmitted. The info could be buffered somewhere on the pad, or it all could have happened much faster than the time resolution of their sensors...

I'm starting to wonder if they had even one rolling at the time of the test.

I found that extremely odd too. You would think that Elon has folks from NASA, USAF, and FAA on speed dial. He shouldn't have to use Twitter to request their help...

A leak would be detected by a pressure differential, volume pumped wouldn't match volume in the tank, etc... To get a fireball, you would need two leaks. LOX alone doesn't combust. F9 is supposed to be reusable. The Merlin engines are supposed to be rated for over 50 burns. Not applicable in this time, because the Merlins didn't even get lighted.

It's desperate in the sense that they seem to now be relying on amateur footage from miles away to find the cause of the mishap, while they should have actual close-up footage and telemetry. They supposedly have data from instruments (including accelerometer data, pressure sensors, valve positions, etc...), on board the rocket and GSE, as well as their own cameras, and monitoring equipment from CCAFS (including sismological and meterological data, radar...). Unless maybe that is another area where they cut corners to save money, and don't record data for tests, only for launches... The fact that the data they have isn't helping them figure out what happened when an anomaly did occur makes you wonder what use there is to actually do these static-tests in the first place.

Yeah, but the plea for recordings on twitter does sound a bit desperate. You would think that they would have cameras pointed at every inch of the rocket as well as all the telemetry they would need. It looks like they are stumped.

Wow, I'm amazed that they don't seem to have the slightest clue about what happened. A bang before the explosion could come from anything, including a COPV failure inside the LOX tank, or something snapping. However, their telemetry would have recorded any pressure variations. LC40 is well inside KSC, with a radius of over 15 km being off-limits to civilians. Sniper rifles typically have a range of 1000m. Breaching several perimeters and trekking 15 km through a swampland that happens to be one of the most heavily restricted and patrolled military areas while carrying a sniper rifle isn't going to be easy... Similarly, you would need a pretty heavy drone to be able to fly over 15 km from outside of KSC. Civilian drones have a max range of 1 or 2km. A drone that big couldn't have gone undetected. So basically, either a sniper or a drone couldn't operate without the USAF being involved, which puts both of those hypotheses seriously into wacky conspiracy territory.

It wouldn't necessarily be that big or expensive or complicated. It would basically be Project Echo on steroids: Echo 2 was 41 meters diameter and weighed about 250kg. It flew on a Thor-Agena. You could probably extrapolate the weight for a 1500m diameter equivalent.

You wouldn't want it to stay up there forever anyway. Ad campaigns don't last more than a year or two. You want it to come down eventually.

I think the inflatable sphere is probably the best idea, with a huge video projector in the center, projecting on the side that faces Earth. I wonder what the amazonian tribes or the Sentilese would think about it... as well as the astronomy community. I think most people would consider it a major nuisance and would probably generate more bad publicity than actually urge people to drink a Pepsi.

After watching The Island (real TV show), I think I'd go with a Leatherman or a swiss knife, a Zippo lighter, and a mosquito net.