Skylon Spaceplane Design Passes Key Review 136
gbjbaanb writes "A revolutionary UK spaceplane concept has been boosted by the conclusions of an important technical review. Skylon is a design for a spaceplane that uses engines that work as normal jets near the ground and switch to rocket propulsion in the upper atmosphere. The concept means the plane will not have to carry as much fuel and so will not need disposable stages. It is estimated (by its developers) that the Skylon will drop the cost of delivering payloads to orbit from $15,000 per kilo to $1000."
Re:Skeptical without any numbers (Score:5, Interesting)
From what I learned in physics class, the cheapest way to get through the thick atmosphere is to go straight up.
That's only true for conventional rockets. The longer you remain in the lower atmosphere, you more rocket fuel you must carry. The more fuel you must carry, the larger the rocket you require. The larger the rocket you require, the larger the engine. The larger the engine, the more fuel you must carry. This is a nasty spiral simply because you obtain 100% of your lift from thrust.
With the skylon design, you are obtain a lot of your lift - from lift. Its only after you're passed through the lower atmosphere, where you don't get much lift and where you now need an oxydizer for your fuel, that you need to start a rocket engine. Thusly, they've side step a massive problem with traditional rockets.
Furthermore, its the first stage on traditional rockets which requires the most fuel to obtain orbital velocities. By using a plane's features, a massive weight burden (and associated size) is removed from the design.
Re:Hate to rain on the hype parade (Score:4, Interesting)
Skylon is effectively a development of the HOTOL spaceplane project that was proposed by Rolls Royce and BAE way back in 1986, and was cancelled by the UK government in 1988 - I'm not sure where this 1982 date you mention fits in.
From what I understand the funding for this project has, since then, been very minimal, and only comparatively recently have they managed to attract the attention of ESA. From what I've read ESA only got involved because some real tangible hardware has been produced by Reaction Engines.
That real tangible hardware is in the form of coolers. That's arguably the most difficult part of their engine design, and the part that had doomed the HOTOL project. ESA seems to think that Reaction Engines are making good progress and that nothing about the SABRE engine, on which Skylon relies, is unachievable. So there is some more to this than concept art and promises.
Please get your facts straight (Score:4, Interesting)
This is Skylon, not HOTOL, so no it hasn't been in development since 1982. Different vehicle, different engine (the original one was classified by the UK government).
The statement 'they are not planning to build it until the 2020's' is flat out false. They are planning to have it operational in 2020. This may be optimistic, but what you said does not accurately reflect their statements.
Environmentally friendly is not a touchy-feely issue either; if spaceflight is going to go from long-term experiment to routine flight, its emissions need to be taken into account. Concern has already been raised about the effects of releasing particles from hybrid motors at high altitude. Right now it doesn't matter, but IF we are entering an era of mass spaceflight, it will.
A review isn't the same as the test, no, but I can tell you from first hand experience that ESA engineers are not easily impressed. They will have given REL a proper grilling before coming out and saying that they think this concept is viable.
Whilst I have no doubt the mostly US-based /. audience will probably not have much respect for ESA, please bear in mind that despite a budget half the size, and a lack of manned capability for political reasons, its cooperates with NASA on engineering matters as an equal these days.