XCOR Makes a Rocket-Powered Touch-and-Go

wronkiew writes "XCOR Aerospace made a touch-and-go with their experimental rocket powered airplane (see their announcement). The pilot was Dick Rutan, of Voyager fame. Aviation enthusiasts may be familiar with the touch-and-go, but for the uninitiated, this maneuver involves landing an airplane and then taking off again while still on the runway. Note that other rocket-powered vehicles require that the engine be dismantled before they are flown again. While their craft is not exactly a spaceship, it is good to hear of some progress in rocketplanes since the demise of the X-33."

Comments

Re:Definition of rocket?

[WolfWithoutAClause]

The main difference is that a jet engine has a rotating fan/compressor down the center. A rocket engine doesn't necessarily have a pump at all; although they usually do, but it's separate. Rocket engines are much more powerful, lighter, and more efficient (bizarely enough.)

A rocket engine consists of a combustion chamber with a nozzle attached (usually a converging/diverging nozzle called a DeLaval nozzle). Rocket engines need not have any moving parts, although in practice they usually do have some for control purposes.

Re:Space next?

[WolfWithoutAClause]

Mainly at the moment I believe its a showcase for their engines and expertise, they are expert rocket engineers. Also, rocket engines have an undeserved reputation for unreliability, so they have a point to make there. They've run rocket engines in a conference center right infront of people before, it has safety features that mean it won't blowup, and if they fail, they have kevlar containment features to catch the bits.

I'm sure these particular engineers would be able to reach orbit if they had sufficient funds- they used to work at Rotary Rocket.

Re:Definition of rocket?

[paganizer]

uhhh. Yeah. A rocket carries it's own fuel and oxygen supply. A jet, even one without moving parts, just supplies one of the components. That's why things like the bussard ramjet, even though they only operate in space, are called jets; they gather the fuel from interstellar space.

Re:Definition of rocket?

[AJWM]

Jet engines, on the other hand, though they superficially make look like a rocket because they have very hot gases coming out from the back, actually use a turbine to push the air;

Some jets do, some don't. Pulse jets and ram jets don't use a turbine -- the turbine is used to suck in and compress air for combustion. Ram and pulse jets use their forward motion through the air to do this (so they need a push to get started). Jets work on the action-reaction principle too.

thus they pull themselves through the air in a way similar to a boat propeller (or, for that matter, an airplane propeller).

One particular type of jet, the turbofan, works this way (partly). Take a regular turbojet and mount a honking big ducted fan on the same shaft as the turbine. Runs a bit quieter and more efficiently than a pure turbojet, but limits your top speed (subsonic).

Jet engines cannot work in space.

Well, they could if you carried a great big tank of compressed air along -- but that'd be kind of silly. The tank would be heavy and the mass of all that nitrogen is unwanted.

SSTO the key to sapce

[davecl]

Its good to see progress from some of the small launch vehicle companies, especially after the failure of Rotary Rocket.

The actual success here, though, is perhaps not as revolutionary as it first appears. The DC-X had a similarly reusable and relightable rocket even though it was in a more conventional vertical 'rocket ship' design.

Getting cheaper access to space is the key to broader space tourism and proper space industires. Other companies trying this include Pioneer Rocketplane, Armadillo Aerospace, JP Areospace and TGV Rockets to name but a few. There's even a UK outfit, Bristol Spaceplanes,
and the European Space Agency is beginning to think in this direction too, according to CNN.
All the companies are small and desperately in need of money if anyone wants to invest. Its probably less risky than Worldcom!

Another useful resource is the Space Access Society. Indeed they've argued that the whole X-33 mess was in fact Lockheed-Martin protecting their lucrative disposable launcher market by messing up the project. Sadly, NASA seems to have been complicit in this.

TSTO vs SSTO Re:SSTO the key to space

[WolfWithoutAClause]

SSTO will probably work. But the big question is whether it will be cheaper or not. It looks right now that the consensus is no, and TSTO (Two Stage To Orbit) is the way to go for lower cost.

However SSTO has advantages too, lower cost isn't everything. SSTO may be more reliable, because there's less to go wrong; and it may have a lower turn-around time because you don't have to reassemble the vehicles each time. But on the other hand SSTO rockets are lighter, and that means the materials can be nearer to the edge and more likely to fail. We won't know how it comes out on balance until both have been achieved and a few thousand launches are past.