4 thoughts on “Alan Bond”

  1. I think the whole concept about Skylon is neat. I remember reading about LACE engines several years back and wondering why all development in the area stopped. His team is probably the only team seriously working on this stuff. However I doubt doing an SSTO with it like the design he shows in is concepts will be easy. Not to mention that they still do not have a complete working and tested engine let alone the entire launch vehicle.

    1. The big problem, as we touched on in another thread recently, is that they need at least ten gigabucks to build the first Skylon, and I’d expect the final cost of developing such unproven technology will turn out to be far higher than current estimates. SpaceX could build an expendable launcher and actually be making money before they worked on reducing cost through reliability, but Skylon needs huge wads of cash well before we even know whether it will work. It’s pretty much the Underpants Gnome launch vehicle, because only governments can throw kind of money at such a risky endeavour, and most of them are broke.

    2. Governments are not broke when it comes to saving banks. Rather curious.
      I know full funding of something like Skylon is not forthcoming. Neither should it be. Not until they have an actual working engine. A lot of people back in WWII also wanted large government funding for jet engines and to a large degree they did not get it until late in the war and even then it was given a low manufacturing priority. The powers that be on both sides of WWII knew the war would end before the kinks on jet engines could be worked out.

  2. “LACE engines several years back and wondering why all development in the area stopped. ”

    You can kind of see from the depictions of Skylon the Rube Goldberg arrangement of pumps and heat exchangers, and the thing only works in air-breathing mode to some small fraction of orbital velocity.

    Orbital velocity is multiples of the exhaust velocity with known and usable chemical fuels. You can reach orbit with a rocket, but it requires a very high “mass fraction” of the fuel and oxidizer. Conversely, if you scoop air near orbital velocity and decelerate it to stagnation, you will well exceed the combustion temperature of any of those fuels, probably exceed the temperature of atomic disassociation.

    The scramjet approach is the proverbial drink from the firehose. You don’t even attempt to decelerate to stagnation, but then you have to sustain combustion in a supersonic air stream. And you need to generate thrust in excess of your inlet drag under these conditions.

    LACE requires decelerating to stagnation. What you have to do there is accumulate oxygen liquified from air at the lower speeds and then operate in rocket mode to achieve orbit. If I understand the thermodynamic cycle of Skylon, they chill the scooped air without liquifying it to get some kind of advantage at the upper speed range of a turbojet with ramjet effect (Mach compression in the inlet), so they are not scooping liquid oxygen for the rocket portion of the flight?

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