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Key Test For Skylon Spaceplane Engine Technology
Ogi_UnixNut writes "The Skylon spaceplane is an ambitious project to develop a single-stage-to-orbit craft that can take off and land like a normal airplane. Part of this project requires an engine that can work both as a rocket engine and a normal air-breathing engine (a hybrid approach, essentially). This would reduce the amount of oxidizer required to send stuff into space, and thus greatly reduce the cost. Now, some key experimental parts of the engine have been built, and are to be tested in public at the Farnborough Air Show in the UK in July. The BBC has video of the cooling system being tested."
I've been following the guys down at Reaction Engines and their SABRE engine concept for a few years. These are the same guys who came up with the HOTOL concept at Rolls Royce in the 1980's. No word on what they'd use for thermal protection on re-entry but they're a clever bunch and if I came into a billion pounds I'd shove a fair chunk of it at these guys to build me a fleet of spaceships to rule the world ;-)
If they could get government funding we could lead the world in launch capabilities. However, what would probably happen is that we'd end up handing it over the the USA as our leaders are too short sighted and too cheap to fund anything truly visionary or world beating.
At high speeds, the Sabre engines must cope with 1,000-degree gases entering their intakes... Reaction Engines' breakthrough is a module containing arrays of extremely fine piping that can extract the heat and plunge the intake gases to minus 140C in just 1/100th of a second.
That is... impressive, to say the very least. It sounds from Wikipedia like they are even using the heat energy to power the turbo compressor (wondering if it was possible to convert the heat to useful energy was one of my first thoughts). I'm curious how efficient the jet is at low speeds, though. Typically, most jet engines work well at either low or high speeds, not both.
These kinds of engines are definitely needed to make space travel cheaper. Much cheaper, potentially, than solid-state rockets.
"None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
Just thought I'd point you in the direction of Reaction Engines ideas for a mission to Mars. Take a look at the detailed PDF and the movie.
http://www.reactionengines.co.uk/troy.html
it's the coming home part that is the problem.
Capt. Malcolm Reynolds: Just get us on the ground!
Hoban 'Wash' Washburn: That part'll happen pretty definitely.
Faster! Faster! Faster would be better!
The issue isn't necessarily protecting the bulk of the spacecraft, it's protecting those parts that have openings to the outside world. It's easy to design an ablative thermal protection system, or a ceramic-based one, but the tough part is sealing the air inlets, docking ports, etc, etc, etc, such that superheated gasses can't melt the turbine blades or fuel nozzles within the engines. Yeah, you can have moveable doors that would swing open to block the ports, but you've got to make sure they're SEALED, and you've got to make sure that they can open again, reliably, after re-entry, so that you're able to start up your engines on the air cycle and make a safe landing.
STS didn't need to have air intakes that hang out in the breeze... that simple difference makes the engineering problems a whole lot more difficult.
I've worked in commercial and government space for nearly 30 years, and one thing I've learned is that most, nay almost every, new launch system idea that sounds promising and brilliant in the concept stage runs aground on shoals of engineering problems with the result of either grossly inflated cost and schedule, or catastrophic failure. Layman frequently underestimate how much of the technology space has been explored and found to be dead ends due to either unsurmountable technical difficulties or simple economics. Incremental materials improvements are the most common route to innovation, but they can only do so much to open up new avenues.
In other words, it's not always possible to identify technical risks early on. The history of launch systems is full of "oh, shits." The cliche "the devil is in the details" may very well have been coined by a rocket scientist.
That said, I wish them luck and good fortune. If there's a way that we haven't yet achieved of bumping up the payload fraction of conventional launch systems, this is it. Hybrid jet/rocket engine approaches are also one place where I believe the introduction of improved materials can be disruptive. REL may have found a new route to orbit, and I hope it works for them.
I can see the fnords!