Comments on: Plasma Thruster

By: Cyborgman

Cyborgman — Wed, 12 Oct 2011 20:08:17 +0000

It is so much easier to prove a person wrong in theory than it is to prove them correct in theory. In the Canary Islands in the late 1950′s until the early 1960′s the US Navy began to research microwave particles as a viable energy source. This research was due to the fact that a group of radar outpost operators set fire to the sea by inadvertently directing the microwave emitting radar dish at the sea and just like when a fork sparks when placed in the microwave oven the metal salts in the sea minerals sparked enough to ignite HYDROGEN released by streaming microwave particles. Do not take my word for it. Google Hydrogen Sea fires. Not that I agree with Phive’s Physics or even the spelling of his Peace prize any more than I agree with you or anyone else believing that mistakes demonstrate low intellect. I in turn believe mistakes reveal only that we are human.

By: Quintin Davis

Quintin Davis — Sun, 29 Mar 2009 21:56:12 +0000

Matthew,
Have you gotten a chance to test this out in a vacuum chamber yet?
If you were operating the device as an MPD as opposed to an arcjet, will there be a decrease in total thrust in exchange for greater specific impulse? (as I understand it, MPD operation requires low injected propellant pressures as well as near-vacuum operation)
Lastly, how much Isp/thrust variability wiggle room do you have to match mission constraints along the lines of the VASIMIR concept, within reasonable limits of electrode lifetime?
Cool build, hope to pursue something similar for my senior design.

By: Andar

Andar — Wed, 14 Jan 2009 22:34:30 +0000

@Phive

That would be amazing if you didn’t use words like thingie…

And if it wasn’t complete BS.

Prove me wrong, anyone can say ‘I was thinking about using a microwave oven to make plasma particles to use in my superluminal propulsion system’

By: Phive

Phive — Tue, 13 Jan 2009 15:01:40 +0000

* Using the electrons spinning around an atom
for a method of invincible shielding (I was
thinking that if everybody got those, people
would get tired of shooting at each other
and I would get the nobel piece prize for
world piece) — Started saying that, but I
accidentally skipped ahead (I was thinking
about the lightspeed thingie) And, guess what
(this is kick-ass, because nobody my age would
probably have these ideas) I am 17.)

By: Phive

Phive — Tue, 13 Jan 2009 14:57:33 +0000

Hey! speaking of space engines, I’ve got a
doosie. I thought this up when thinking about
the plausibility of using the equivelant of
the electrons spinning around an atom (at the
speed of light) but if you could get the atoms
to go foreward and around, you wouldn’t be limited
by rocket engines. (E=mc2 just use another
source of controlled energy to stimulate the
atoms) I warn you that he who tries this WILL
die and be atomically disentegrated (not to mention BECOMING A NUKE!!!). But, I was thinking
about the ability to control the stimuli and
accelerate to any speed, not limited by any other
internal force (except gravity and friction)
but hey, what happens in space stays in space.

By: sora

sora — Sat, 10 Jan 2009 03:27:49 +0000

simply said, let F-Zero projects commence

By: Sol

Sol — Thu, 08 Jan 2009 19:22:22 +0000

@james d
don’t forget, it would be controlled using a wii and everyone has to complain about how it’s not a real hack

By: MC screwdriver

MC screwdriver — Thu, 08 Jan 2009 15:34:11 +0000

So you need 14 MW for 40 N thrust- or 350 KW for 1 N. Hm… If we suppose you are using solar cells with 350 W/m2, and 1 m2 of cells is only 0.1 kg mass, you need 1000 m2 of cells to produce 1 N thrust, and weight of cells is 100 kg. Then your acceleration is a=F/m=0.01 m/s. Not bad at all for an electric thruster, and with solar cells, working time is unlimited. In ~1 day you would achieve 1 km/s speed, in 100 days 100 km/s. That’s excellent! Even with solar cells weighing 1000 kg, design is still very good and useful, for example for asteroid belt exploration.

By: K.

K. — Thu, 08 Jan 2009 05:24:38 +0000

Thanks, Matt. That’s a sweet bit of kit there. I’ve got a megawatt stack I could try, but previous experiments found tungsten melting like butter on a hot griddle. How’d the nozzle hold out?

By: ex-parrot

ex-parrot — Thu, 08 Jan 2009 00:57:46 +0000

aztraph: it really is very similar, insofar as I can see. this is essentially a rail gun with the metal projectile replaced by a conductive cloud of plasma.

By: Matthew Krolak

Matthew Krolak — Thu, 08 Jan 2009 00:31:50 +0000

Some comments from guy who designed and built that beast:

1) This thruster operated at about 14 Megawatts peak.

2) As shown, this device is actually an arcjet thruster. The operation is similar to a chemical rocket where hot gases are expanded in a nozzle to get thrust – except here the gas is heated by an electric arc.

3) In order for magnetoplasmadynamic effects to generate the bulk of the thrust, the device must be operated in a near vacuum. I couldn’t get a hold of a large vacuum chamber so I went with arcjet operation instead.

4) Total thrust of 20-40 N is respectable, but not a good performance measure. You could probably get 20 N by throwing a few bowling balls. A much more useful measure is thrust per unit of propellant mass. This is know as the specific impulse (measured in seconds. Yes, seconds. That’s just how the math works out.) The space shuttle’s main engines operate at about 450s. Arcjets operate around 2-3,000s. MPD thrusters operate upwards of 30,000s. My thruster was probably somewhere around 2,000s, which puts it at the low range of an arcjet. Not too shabby. Results probably would have been much better with a proper nozzle.

By: icefox

icefox — Thu, 08 Jan 2009 00:17:03 +0000

The real question is when do we get to see this tested in space?

By: mad.hephaestus

mad.hephaestus — Wed, 07 Jan 2009 23:14:55 +0000

I saw the development of this thing from start until its current state. A video would be awesome except the discharge takes place in 6ms. That is MUCH less that one frame of standard video, so it would need a high speed camera. The further challenge to that would be convincing someone with a high speed camera to allow it so close to such a large EMP. And it actually IS much closer to a rail gun then a Jacobs ladder. The Lorenz forces of the current flowing through the ionized argon accelerates the argon generating the thrust.

By: amk

amk — Wed, 07 Jan 2009 22:41:01 +0000

so how long does it take to recharge a 28kj capacitor bank in the darkness of interstellar space?

By: chris

chris — Wed, 07 Jan 2009 22:36:59 +0000

An upside down jacobs ladder will just arc across the spark gap until it melts. The heat from the plasma is what causes the spark to rise from what I’ve read and seen with my own jacobs ladder. Yes, I melted the hell out of one while not paying attention while it was in a non-vertical mode (it fell over…oops!). Killer hack tho!