Reactionless Space Drive Being Tested

IO9 ^ | April 30, 2015 | George Dvorsky

[Thud]

"Last year, NASA’s advanced propulsion research wing made headlines by announcing the successful test of a physics-defying electromagnetic drive, or EM drive. Now, this futuristic engine, which could in theory propel objects to near-relativistic speeds, has been shown to work inside a space-like vacuum.

NASA Eagleworks made the announcement quite unassumingly via NASASpaceFlight.com. There’s also a major discussion going on about the engine and the physics that drives it at the site’s forum."

... "The NASASpaceflight.com group has given consideration to whether the experimental measurements of thrust force were the result of an artifact. Despite considerable effort within the NASASpaceflight.com forum to dismiss the reported thrust as an artifact, the EM Drive results have yet to be falsified.

After consistent reports of thrust measurements from EM Drive experiments in the US, UK, and China – at thrust levels several thousand times in excess of a photon rocket, and now under hard vacuum conditions – the question of where the thrust is coming from deserves serious inquiry."

[Thud]

NASA and Chinese scientists have done apparently successful preliminary tests of a reactionless space drive, i.e., electrical energy produces thrust without ejecting a propellant of some sort. This could be epochal in a good way, or allow some crazies to destroy civilization in @50 years, or it could be a false alarm. But it really is worth paying attention to. Several links and two excerpts follow.

http://io9.com/new-test-suggests-nasas-impossible-em-drive-will-work-1701188933

“Last year, NASA’s advanced propulsion research wing made headlines by announcing the successful test of a physics-defying electromagnetic drive, or EM drive. Now, this futuristic engine, which could in theory propel objects to near-relativistic speeds, has been shown to work inside a space-like vacuum.

NASA Eagleworks made the announcement quite unassumingly via NASASpaceFlight.com. There’s also a major discussion going on about the engine and the physics that drives it at the site’s forum.”

Quoting from the NASA report:

“The NASASpaceflight.com group has given consideration to whether the experimental measurements of thrust force were the result of an artifact. Despite considerable effort within the NASASpaceflight.com forum to dismiss the reported thrust as an artifact, the EM Drive results have yet to be falsified.

After consistent reports of thrust measurements from EM Drive experiments in the US, UK, and China – at thrust levels several thousand times in excess of a photon rocket, and now under hard vacuum conditions – the question of where the thrust is coming from deserves serious inquiry.”

Also see:

http://nextbigfuture.com/2015/04/magnetron-powered-em-drive-construction.html

http://nextbigfuture.com/2015/04/emdrive-roger-shawyer-believes-midterm.html

”Shawyer sees scaling up the superconducting version of EMdrive to 300 Newtons per kilowatt combined with radioisotope thermoelectric generators or small scale nuclear fission systems to achieve 200 kilowatts for a Alpha Centauri ten year flyby probe. A probe that reaches about 60% of lightspeed and covers 4 light years in ten years.”

http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive

The Wired.UK article should be read in full. Here is an excerpt:

”"[5. Even if it works, how can such a small thrust push a spacecraft?

The thrust was low because this is a very low-powered apparatus. The Chinese have demonstrated a system using kilowatts rather than watts of power that produces a push of 720 millinewtons. This is enough to lift a couple of ounces, making it competitive with modern space drives. The difference is that this drive doesn't require any propellant, which usually takes up a lot of launch weight and places a limit on how long other drives can operate for.

The Nasa paper says "the expected thrust to power for initial flight applications is expected to be in the 0.4 newton per kilowatt electric (N/kWe) range, which is about seven times higher than the current state of the art Hall thruster in use on orbit today."

6. How does this get us to Mars?

The small but steady push of the EmDrive is a winner for space missions, gradually accelerating spacecraft to high speed.

The Nasa paper projects a 'conservative' manned mission to Mars from Earth orbit, with a 90-ton spacecraft driven by the new technology. Using a 2-megawatt nuclear power source, it can develop 800 newtons (180 pounds) of thrust. The entire mission would take eight months, including a 70-day stay on Mars.

This compares with Nasa's plans using conventional technology which takes six months just to get there, and requires several hundred tons to be put into Earth's orbit to start with. You also have to stay there for at least 18 months while you wait for the planets to align again for the journey back. The new drive provides enough thrust to overcome the gravitational attraction of the Sun at these distances, which makes manoeuvring much easier.

A less conservative projection has an advanced drive developing ten times as much thrust for the same power -- this cuts the transit time to Mars to 28 days, and can generally fly around the solar system at will, a true Nasa dream machine."

If this concept works, we will certainly have interplanetary space travel inside the Solar System. See the old Poul Anderson science-fiction short story series, Tales of the Flying Mountains at:

http://www.amazon.com/Tales-Flying-Mountains-Poul-Anderson-ebook/dp/B00PI181F2/ref=sr_1_1_twi_1_kin?s=books&ie=UTF8&qid=1430522988&sr=1-1

On the other hand, nutballs with a reactionless drive spaceship could try to pasteurize the planet with it in a suicide attack a la 9/11. See the John Varley science-fiction novel, Red Lightning for an example of such an attack:

http://www.amazon.com/gp/product/B003WQAIFG/ref=series_dp_rw_ca_2

We may soon live in much more interesting times.

[E. Pluribus Unum]

Sort of like a rail-gun without the rail.

[sasquatch]

Cold fusion.

[equaviator]

Food for thought only! Thanks a f*cking lot...We should have been to Mars and back 15 years ago.

[9thLife]

Not sure NASA has as much credibility as it used to.

[GeronL]

remember this was not a NASA device, although the media reports make it sound like they invented it

[max americana]

“the question of where the thrust is coming from deserves serious inquiry.”

In an interview of a retired Skunkworks engineer years ago, he blurted out ‘whatever gizmo and engine you saw on Star Trek, we already made it’.

[sasquatch]

Is this a PJ Comics site??

[marktwain]

The reactionless drive attack would have to be a pretty heavy machine to pasturize the planet. Defenses would also be available. It is somewhat analogous to car bombs today.

[marktwain]

This drive looks potentially cheap enough for private ownership. Given a private gateway to space, a spaceship made with this kind of drive could be cheap enough for many private entities to start to econimically develop space.

Everything from tourism and mining to colonies becomes possible.

[bigbob]

Pair this up with that warp drive someone posted a while back and we’ll really have something. Need a dilithium mine...

[sasquatch]

We should have been to Mars and back 15 years ago.

We did that. Where were you? /s

[BenLurkin]

It’s the same thing isn’t it?

[BenLurkin]

Any apparently reactionless drive is treated with skepticism by the physics community because a truly reactionless drive would violate the law of conservation of momentum.

Shawyer claims that his drive does not violate conservation of momentum and is not reactionless.[9] Shawyer has posted an updated theory paper (version 9.4) for the EmDrive.[17] Shawyer's paper includes the fundamental assertion underlying the theory: "[t]his force difference is supported by inspection of the classical Lorentz force equation F = q(E + νB). (1) If ν is replaced with the group velocity νg of the electromagnetic wave, then equation 1 illustrates that if vg1 is greater than vg2, then Fg1 should be expected to be greater than Fg2."

This statement makes two assumptions which Shawyer does not substantiate and which may explain the discrepancy between Shawyer's predictions and those of conventional physics. First, Shawyer assumes that radiation pressure is the result of the Lorentz force acting on charged particles in the reflecting material. This is analyzed by Rothman and Boughn[18] who point out that the standard theory of radiation pressure is somewhat more complicated than the simplified analysis suggests.

Second, Shawyer asserts that quantum energy is transferred at the group velocity, and thus momentum of the photon and the consequent radiation pressure must vary with group velocity. Photon momentum varies with phase velocity. Group velocity measures the rate of propagation of information. The phase velocity is constant throughout the frustum resonator, consequently radiation pressure would not be expected to produce unbalanced forces.

http://en.wikipedia.org/wiki/EmDrive

[PastorBooks]

“Pair this up with that warp drive someone posted a while back and we’ll really have something.”

And where’s my working lightsaber???

(Ok, mixing Star Trek and Star Wars is bad...)

[BenLurkin]

Various hypotheses and theories have been proposed explaining the underlying physics for how the EmDrive and related designs might be producing thrust. Shawyer claims that thrust is caused by a radiation pressure imbalance between the two faces of the cavity caused by the action of group velocity in different frames of reference within the framework of special relativity.[19] Yang from NWPU calculated the net force/thrust using classical electromagnetism.[12]

Harold G. "Sonny" White, who investigates field propulsion at Eagleworks, NASA's Advanced Propulsion Physics Laboratory, speculated that such resonant cavities may operate by creating a virtual plasma toroid that could realize net thrust using magnetohydrodynamic forces acting upon quantum vacuum fluctuations.[20]

Likewise, the paper describing the Eagleworks test of the Cannae drive referred to a possible interaction with a so-called "quantum vacuum virtual plasma".[14] This reference has been criticized by mathematical physicists John Baez and Sean M. Carroll because in the standard description of vacuum fluctuations, virtual particles do not behave as a plasma.

http://en.wikipedia.org/wiki/EmDrive

[Axenolith]

1 gram of matter converted to energy yields about 21+- Kt.

Even if the efficiency is crap, say travelling at 20 or 30% C, a couple 10's of pounds is going to yield a shitaceous bang.

Something travelling toward the planet at an appreciable fraction of C can also not be "broken up" without the aggregate mass still carrying pretty much the same yield but over a wider area. Particles the size of sand would transit the atmosphere as if it weren't there, like a cosmic ray and impact solid matter like artillery rounds.

You'd better watch out
You'd better beware
'Cause Albert says that E
= MC²

[Thud]

Look at the first book in the John Varley series, _Red Thunder_:

http://www.amazon.com/Red-Thunder-Lightning-Book-ebook/dp/B00AFXGSRG/ref=sr_1_3?s=books&ie=UTF8&qid=1430528449&sr=1-3

[The Antiyuppie]

Sounds great, but any trips to stars might be tricky. Hitting ANY object - even something much smaller than a grain of sand - at those fractional light speeds might release spectacular amounts of energy that no physical shielding can protect the ship from. We THINK that interstellar space is “empty” but it certainly isn’t COMPLETELY empty. So, now we need “shields”.

[Axenolith]

What you’d probably have to do to open this up to general space travel in the solar system is to have some type of failsafe or deadmans switch in every manufactured craft that either automatically alters course from earth inside a large limit (like more than a million miles) or initiates a large self destruct device that essentially ionizes the craft if it passes the million mile limit over a certain speed.