China's Radical New Space Drive 419
First time accepted submitter Noctis-Kaban writes "Scientists in China have built and tested a radical new space drive. Although the thrust it produces may not be enough to lift your mobile phone, it looks like it could radically change the satellite industry. Satellites are just the start: with superconducting components, this technology could generate the thrust to drive everything from deep space probes to flying cars. And it all started with a British engineer whose invention was ignored and ridiculed in his home country."
I'm pretty sure it doesn't work (Score:5, Interesting)
The principles behind the EmDrive have serious theoretical problems, and the original builder and designer never tested it in a vacuum chamber.
Taking a sealed container and pumping a few kilowatts of microwaves into it, chances are any thrust developed is actually air that's getting heated up and expanding out of the container. Unless the EmDrive has been put in a vacuum chamber where this can be demonstrated to definitely not be the case (i.e. low enough that their couldn't be enough reaction mass) then it's not actually working.
Re:Devil's (angel's?) advocate: (Score:5, Interesting)
The thrust is reported to be from the large end towards the small end. The entire body of this thing that's heating up from a few kilowatts of microwaves would be warming air that flowed over the surface and thus imparting energy to it and providing a source of thrust. It would easily provide continuous thrust.
Re:Doesn't work (Score:5, Interesting)
Conservation of momentum is extended in relativity to conservation of 4-momentum, basically a combination of momentum and energy. In a rest frame this means that standard Newtonian momentum is conserved, it just makes conservation also work when you are observing a system that is moving past you at relativistic speeds.
Re:I'm pretty sure it doesn't work (Score:5, Interesting)
No, it's not like that at all. Ford didn't choose Phillips over Robertson because Phillips was better, he did it because Robertson wouldn't license the patent and wanted to be the sole supplier. Phillips, on the other hand, did license it, and the rest is history.
On the other hand, this crackpot was so desperate to find someone to license his "drive" to he gave up trying to sell it to any American companies and tried out China...
Re:I'm pretty sure it doesn't work (Score:4, Interesting)
No, given their nature, if it worked they would be producing glossy brochures showing spacecraft flying to Mars or where-ever.
While that might be true for Boeing in general, for true black project departments, this is a no-no. For example, at Perkin Elmer, which was doing the engineering for the KH-9, one of the engineers had a heart attack on the job and died. The other engineers were not permitted to tell the guy's widow even how he died (e.g. peacefully, etc.) until after the project was declassified some 25 years after the last KH-9 was decommissioned. That's how secretive they can be.
There is no reason why they would keep this a secret;
Once again, I think you underestimate just how deep and dark these projects sometimes are.
the spy satellite world is not suffering from a lack of reaction mass.
Most KH satellites don't just go around in a fixed [polar] orbit. Their orbits must be constantly adjusted so they can observe a trouble spot in real time (e.g. they can't wait 5 days for the orbit to pass over the spot naturally--they must burn fuel to change the orbit so it's in the right place on the next pass). Considerable mathematical effort is expended in the orbital adjustment calculations, designed to minimize the fuel cost of adjusting the orbit. Sometimes, compromises have to be made, to conserving fuel cost against getting there ASAP. Having a satellite that has no such downside, would be a [closely guarded] strategic advantage.
If they even thought it possibly could work, they would hire Shawyer.
Given that he's a U.K. citizen, it's unlikely he could get the security clearance necessary. Or, the Phantom Works people had reservations about him specifically, for whatever reason (e.g. either his general ability to work well with others, or his desire to keep his work public--to name just a few).