NASA tests crazytech flying saucer thruster, could reach Mars in days NASA has tested an "impossible" electric space drive that uses no propellant – and found it works even when it is designed not to. EmDrive space motor The EmDrive space engine ... a long time coming This has sparked immediate skepticism of the technology. The system is designed to use microwave energy reflected along a …
I agree, this would need to be tested in a "Hard Vacuum" with to eliminate the possibility that you are just microwaving the gas particles in the air, also some method of testing that ablation of the chamber walls is not contributing reaction mass to the engine.
"it is still a very useful technology that should be pursued to reduce the cost of getting mass into space."
No, it won't work to get mass into space, way too feeble. But once it's lugged into space by a conventional rocket, it would be great for getting mass around space
Damnit, Scotty!! I need engines if we are going to get to our rendevous with the nubile green space women of Coitus 5!!! Is there anything you can do!?
Well Capt'in, I can try to set up a propulsive momentum transfer via the quantum vacuum virtual plasma, but it will take 12 hours!
You have 6 hours, Mr. Scott!!
Aye Capt'in!!
(Yes, I watched WAAAYYYY too much Star Trek as a kid)
There seems to be some bits missing from this version. It needs more stuff. See this science article for more information.
I too will take this with lots of grains of salt until it is proved out a lot more. However, I would like to contribute another reactionless drive scheme for you all. :-)
Make a smallish particle accellerator. Accellerate particles from one end to about the half-way point. Then decellerate the particles. Reverse, and send the particles back. Keep them going back and forth. No resulting momentum is imparted to the structure of the chamber because it all cancels out. But, make the thing strong enough to accellerate the particles to close to the speed of light in the middle. Now you get a mass increase in the particles. Still no big deal.
Now use two different waveforms - one to accellerate and one to decellerate, such that the particles spend different amounts of time at different near-speed-of-light speeds. Do both phases contribute the same momentum to the the chamber's structure? We would assume so, but I'm not good enough at math to actually do the calculations to prove it.
If its not balanced, you have a reaction-less drive. If this actually works, some theory as to why it works would be needed, and this "quantum vacuum virtual plasma" stuff doesn't seem to be involved.
(I first had this thought in my undergrad days, which is a loooong time ago.)
But the center of mass of the system as a whole is not affected. It is like running up and down a small boat. The boat will move backwards and forwards a little but you can't do more than oscillate the boat around an average position and the center of mass of the whole system does not move.
I hope this is not redundant. The first time I tried to post it seems to have evaporated.
Before anyone calculates trip time with an "assumed" acceleration, some simple calculations should be done (and shame on the headline writer for not doing them).
The key number is specific power (W/kg).
F=ma (Force equals Mass times Acceleration so....
a = F/m
From a slightly old source, the "long term goal" for specific power of solar panels on spacecraft was 300 W/kg, and this was at Earth orbit, It will decrease on the way out. If we use the optimistic 300 and the optimistic Chinese data with .72 Newtons/2500 Watts we get:
a = (0.72 kg-meter)/(2500 Watt-second^2) * 300 Watt/kg
a = 0.086 m/s^2
1 g is 9.8 m/s^2 so we have less than 0.01 g (without any spacecraft body or payload).
There is a rule of thumb that the power source is 25-35% of a satellite's dry mass, which means we get (assuming the optimistic-for-payload smaller number) less than 0.0025 g acceleration.
Based on previous calculations by Pet Peeve, this gives us a 14 month straight line to Mars time and (if I read it correctly) that is straight acceleration without slowing down. This is an impressive number, but no big improvement over what we can do now.
It may be possible to better this if the craft takes a slingshot journey near the sun, since it will be able to greatly increase the acceleration while it's in close.
Don't look towards nuclear power to improve on this. The now cancelled ASRG was supposed to improve on present RTG (Radioisotope Thermoelectric Generator) technology and it would still have had a specific power of only 7 W/kg. This is useful out around Jupiter, where sunlight is dim, but not for the topic under discussion.
Finally someone demonstrated how the microwaves are generated. Depending on solar activity this could be highly variable. If the one designed to fail worked, perhaps the actual enabling mechanism is not the one theorized. Totally useless for Deep Space(beyond our solar system).
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Hmm. Ignoring the many bits I don't understand (I'm no rocket surgeon), I am minded of what I wrote on these very forums two weeks ago:
"Or a fantastic new means of propulsion (that doesn't involve lots of mass to weigh the rocket down at launch) so you can accelerate the rocket at 9.8M/s^2 for half the distance and flip it around and decelerate it at the same rate for the other half. (And back again)."
Okay, we're not talking 9.8M/s^2 in this case, but still. Neat. If it really works.
(Also, on the bonus side, if microwaves are involved, that's a handy way to heat up the astronauts' meals: Just hang 'em out of the back of the ship. Job's a good 'un.)
Hmm I remember reading about this when it came out, at time it was relatavistic effects causing photons to exit different ends of the cavity with non matching momentum thus exerting a force without propellant.
And I seem to remember at the time a lot of people looked at it and came to the conclusion that yes the device was capable of generating a force BUT only if it didn't move in the direction of that force. So you can generation 10 newtons of force to counteract gravity but you can't generate 20 and go up, something about the relative movement of the inertial frames. So if you get the efficiency up you may get a hover board but not a starship.
I wonder if anything has changed or whether this is just a repackaging. You always have to worry when gen 1 produces a barely perceptible effect that even it's existence can be debated, but the gen 2 that's in development (just need a bit more seed capital) will produce a floating building.
Still I'm not saying I wouldn't want to live in a universe where it worked.
This engine uses microwaves to accelerate a pair of virtual particles in the opposite direction of it's vector, thus transferring momentum from the resting virtual particle pair into the rear-facing direction of the device, and due to conservation of momentum, the device is moved 'forward' while the particles move to the back, but because of their virtuality the particles (annihilate?) / seize to exist before they'd impact the back-wall of the device and thus will not accelerate the device in the opposite direction again, leaving the momentum of the thrust-device intact?
In dumb terms: It's creating a 'stone' inside it's hull 'throws' the 'stone' in the direction of the back of the device and thus gains momentum (equal and opposite reaction and all), but lets the 'stone' disappear before it hits the back-wall.
At least that's what my imagination says whats happening. Unfortunately I'm not very well versed with technical terms so, yeah.
Actually, I was thinking of dropping them an email to ask if they had cloud chambers to mount at either end. If virtual particles are being produced it should be a pretty straightforward(!) matter to calculate the energies and see if they appear in the trace. Maybe even synchronised.
Just a thought...
P.
Photons have momentum if the thing broadcasts microwaves the existence of thrust is not a surprise. The size of the thrust is it should be the power divdided by the speed of light but is two big. but there are lots of possible explanations like the vaccum not being perfect and it causing ionsation and acceleration of ions or an unintended interaction with the test chamber.
I'm sure they had an article about the problems of long distance space travel, and someone suggested a drive based on heating metal up. The glow of photons would create a tiny thrust, which - over time - would accelerate to quite a speed. IIRC the artists illustration (OMNI had some stunning sci-fi fantasy artwork) showed something like a car cigarette lighter in space ....
Brilliant!
Good going NASA for testing this out, I am really surprised they proved it really works, but very pleased of course! When no sound came out of china after they started research on it, I expected it was either they failed and didn't want to loose face or they succeeded and decided to not publish...
A pint for the British boffin thinking outside the box (or should I say thinking inside the box considering how this works)
Now we just need to get a decent mini nuke reactor to power it!
Not only does this make manned interplanetary travel more practical, but interstellar travel becomes possible with constant acceleration!
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No, they didn't. And that is a potential problem - until that thing is tested free-flying in space there will still remain a possibility that the thrust might be caused by some unaccounted for conventional factor.
Having said this, they have done some elimination tests - like putting one of the devices backwards and replacing the "thruster" with a dumb load.
... if they tested it in less-than-perfect vacuum (a bit hard to avoid) and were measuring the force exerted by the device on the test rig (and not the force exerted by the sealed test rig on the environment) then certainly more likely mechanisms for transfer of momentum are available.
Is this not just another tap off the planet's magnetic field and is hence useless for propulsion outside of said field?
I remember another system that tapped the power of the planet's field via creating and collapsing magnetic fields that disappeared due to perpetual motion scepticism again minimal power output the result of the energy recovered from collapsed EM fields. So yes this standing wave thruster will work here within the Planet's magnetic field but outside of our relatively strong bubble this drive will have nothing to push a
gainst
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