Are you trying to say that just the change in outside air pressure between 18 km and 27 km altitude would increase the wall tension stress of the pressure vessel by a factor four? That's not how it works. What matters is the gauge pressure, i.e. the difference in pressure between the inside and the outside. And that would change from 80 kPa - 14 kPa = 66 kPa, to 80 kPa - 3 kPa = 77 kPa, which is only a 17% increase, not a 300% increase. Even going to perfect vacuum on the outside would only be a 21% increase.
Quote from: daedalus1 on 08/18/2023 06:30 amAgain, if Concorde couldn't make a profit and died then no prospect of any other exotic faster than sound transport will be successful. It's fantasy.Concorde might of been profitable if it hadn't been locked out of USA market.
Again, if Concorde couldn't make a profit and died then no prospect of any other exotic faster than sound transport will be successful. It's fantasy.
Quote from: Vahe231991 on 07/06/2021 08:11 pmQuote from: CameronD on 07/06/2021 12:06 amMaybe it isn't as tangible as Concorde, but you have to admit it's still a very pretty paper aeroplane:This rendering is pretty cool. Any hypersonic airliner design capable of Mach 6 and an altitude of 200,000 feet with a capacity for 100 passengers that Boom jointly envisages with the SpaceShip Company would have to use titanium and a minimal amount of titanium carbide ceramics b/c of heat friction at Mach 3.Perhaps you mean unobtainium?? Whatever breakthrough material they use, if it ever actually makes it off the drawing board this will be one incredibly expensive aircraft to build and operate and, perhaps like it's predecessor, that means uneconomic from the get-go.
Quote from: CameronD on 07/06/2021 12:06 amMaybe it isn't as tangible as Concorde, but you have to admit it's still a very pretty paper aeroplane:This rendering is pretty cool. Any hypersonic airliner design capable of Mach 6 and an altitude of 200,000 feet with a capacity for 100 passengers that Boom jointly envisages with the SpaceShip Company would have to use titanium and a minimal amount of titanium carbide ceramics b/c of heat friction at Mach 3.
Maybe it isn't as tangible as Concorde, but you have to admit it's still a very pretty paper aeroplane:
Quote from: daedalus1 on 08/18/2023 06:30 amAgain, if Concorde couldn't make a profit and died then no prospect of any other exotic faster than sound transport will be successful. It's fantasy.The world is 5 times richer than it was when Concorde was released.
Quote from: Robotbeat on 08/21/2023 07:02 pmQuote from: daedalus1 on 08/18/2023 06:30 amAgain, if Concorde couldn't make a profit and died then no prospect of any other exotic faster than sound transport will be successful. It's fantasy.The world is 5 times richer than it was when Concorde was released.Is that in relative money?If so why isn't a supersonic aircraft running and making a profit now?
Two economists are walking down the street and pass by a hundred dollar bill without picking it up. A little while later one turns to the other and asks “was that a hundred dollar bill on the ground?” To which the other replies “nope, if it was someone would have picked it up already.”
Quote from: daedalus1 on 08/21/2023 07:40 pmQuote from: Robotbeat on 08/21/2023 07:02 pmQuote from: daedalus1 on 08/18/2023 06:30 amAgain, if Concorde couldn't make a profit and died then no prospect of any other exotic faster than sound transport will be successful. It's fantasy.The world is 5 times richer than it was when Concorde was released.Is that in relative money?If so why isn't a supersonic aircraft running and making a profit now?that’s in inflation-adjusted dollars. Multiple companies are trying.The “efficient market hypothesis” isn’t magic. It take a long time to do a project like this, there are barriers all over the place.QuoteTwo economists are walking down the street and pass by a hundred dollar bill without picking it up. A little while later one turns to the other and asks “was that a hundred dollar bill on the ground?” To which the other replies “nope, if it was someone would have picked it up already.”https://news.ycombinator.com/item?id=28029044Someone has to actually reach down and pickup that 100 dollar bill on the ground.
Quote from: Robotbeat on 08/21/2023 08:23 pmQuote from: daedalus1 on 08/21/2023 07:40 pmQuote from: Robotbeat on 08/21/2023 07:02 pmQuote from: daedalus1 on 08/18/2023 06:30 amAgain, if Concorde couldn't make a profit and died then no prospect of any other exotic faster than sound transport will be successful. It's fantasy.The world is 5 times richer than it was when Concorde was released.Is that in relative money?If so why isn't a supersonic aircraft running and making a profit now?that’s in inflation-adjusted dollars. Multiple companies are trying.The “efficient market hypothesis” isn’t magic. It take a long time to do a project like this, there are barriers all over the place.QuoteTwo economists are walking down the street and pass by a hundred dollar bill without picking it up. A little while later one turns to the other and asks “was that a hundred dollar bill on the ground?” To which the other replies “nope, if it was someone would have picked it up already.”https://news.ycombinator.com/item?id=28029044Someone has to actually reach down and pickup that 100 dollar bill on the ground.I don't find the 5 times richer statement. However untill someone builds and operates a supersonic aircraft profitably, then hypersonic and even supersonic travel is fantasy.
Reaction Engines is actively pursuing the future of space access through high-speed horizontal launch vehicles with a view to fulfilling critical missions for stakeholders in both the U.K. and the U.S. The project, “Combining innovative UK air-breathing propulsion with US airframe capability for space access” was competitively selected for a Phase 1 award under the UK Space Agency’s new International Bilateral Fund.Reaction Engines is well known for its development of hypersonic technology focused on air-breathing propulsion. By enabling high-speed flight, well beyond the capabilities of current aircraft systems, Reaction Engines offers a step-change in efficiency compared with conventional rocket propulsion.Reaction Engines has chosen to work with Virgin Galactic on this project. Virgin Galactic’s unique, reusable, suborbital spaceflight system allows them to fly aircraft to the boundary between air and space. After extensive development, Virgin Galactic recently began commercial operations with monthly flights to space for private astronaut and research customers.Under the planned bilateral activity, the U.K. and U.S. Companies will explore the combination of their capabilities, potential use-cases, and development paths. Neither Virgin Galactic or Reaction Engines are strangers to the benefits of strong U.S. and U.K. collaboration and this opportunity to engage is in step with Reaction’s strategic mission of developing hypersonic and space access solutions, by harnessing the allied capabilities and a shared vision of the future. This joint undertaking, as supported by the UKSA, elevates this mission to the global stage and has the potential to set the course for future collaboration.Oliver Nailard, Senior Business Development Manager at Reaction Engines said: “Innovation and collaboration has always been key in progressing our technology. Working alongside Virgin Galactic, a Company already operating spaceplanes, fits our company mission and offers an interesting U.S. opportunity for us to explore.”Steve Justice, Senior Vice President, Spaceline Programs & Engineering at Virgin Galactic said: “We are seeing the emergent benefits of what the U.S. and U.K can achieve in the joint pursuit of space access and operations. This collaboration with Reaction Engines, studying advanced airframe-propulsion integration concepts, contributes to building a legacy.”
