Fuel Efficient Five-Gear Rocket Engine Designed

Roland Piquepaille writes "Georgia Tech researchers have had a brilliant idea. Rocket engines used today to launch satellites run at maximum exhaust velocity until they reach orbit. For a car, this would be analog to stay all the time in first gear. So they have designed a new space rocket which works as it has a five-gear transmission system. This rocket engine uses 40 percent less fuel than current ones by running on solar power while in space and by fine-tuning exhaust velocity. But as it was designed with funds from the U.S. Air Force, military applications will be ready before civilian ones. Here is how this new rocket engine works."

Comments

Re:Solar?

[bky1701]

In *SPACE* you need very little. Ion drives work fine.

Say what?

[ottffssent]

IANAAE (aerospace engineer), but obviously this is only applicable if either

1. high-thrust mode is hugely less efficient than low-thrust mode, or
2. there is a considerable fuel cost to starting and/or stopping the motor.

If neither applies, then you would simply run the motor at high thrust for shorter periods of time, without the added expense of a low-thrust mode.

The article wasn't what you might call detail-oriented, but this is some sort of electric ion propulsion scheme, which achieves high specific impulse (~3000sec, accd. wikipedia) and so optimising for efficiency makes sense. But it's still an ion drive, so there'll be no takeoffs in its future. At least not takeoffs from anything with a gravitational well deeper than an asteroid.

So we have an article about a thing. Only the article doesn't say what it is or what it's good for. I think I'll keep getting my space news from not-ZDnet, thanks.