Free Republic
Browse · Search
News/Activism
Topics · Post Article

Skip to comments.

Japanese researchers develop 'microwave rocket'
Daily Yomiuri ^

Posted on 04/20/2003 7:23:36 AM PDT by Trailer Trash

Daily Yomiuri On-Line
news
 
SCIENCE

 
Researchers develop 'microwave rocket'

 

Yomiuri Shimbun

A group of Tokyo University researchers has successfully applied electromagnetic waves--normally used to heat food in microwave ovens--as the propulsion force for a "microwave rocket," the first time such an experiment has succeeded.

According to the group led by Kimiya Komurasaki, an associate professor at the department of advanced energy, the development could enable cost and size reductions in rockets as they could use air in the atmosphere as a means of propulsion, rather than having to carry fuel.

The group fired the microwaves at the rocket's base, rapidly heating the air and creating a burst of energy that propelled the rocket upward.

The group used a powerful gyrotron developed by the Japan Atomic Energy Research Institute to heat an international thermonuclear experimental reactor to fire the beam at a dish-shaped metallic object shaped like a round-bottomed pan. The waves reflected off the object and converged, causing the air to reach ultrahigh temperatures and generating an explosive expansion that created the propulsive power.

When the beam was applied for just one-thousandth of a second to a model rocket weighing 9.5 grams, it flew two meters into the air, the group said.

According to the group, the beam could be continually fired from the ground at the rocket powering it to an altitude higher than 100 kilometers where there is no air. Once this altitude was reached, the rocket could switch over to a conventional rocket engine.



Copyright 2003 The Yomiuri Shimbun
 


TOPICS: Culture/Society; Japan; News/Current Events
KEYWORDS: goliath; japan; microwave; miltech; realscience; rocket; science; space; techindex
Less fuel = more cool stuff in the sky.

I want my videophone.....

Only I want mine flavored with broadband, and delivered through a LEO pipe.

Happy Easter.

1 posted on 04/20/2003 7:23:36 AM PDT by Trailer Trash
[ Post Reply | Private Reply | View Replies]

To: Trailer Trash
Interesting, sounds like a microwave version of Leik Myrabo's "lightship" work.

I remember hearing a few years ago about how a microwave version would be better than laser because microwave generators could be scaled up more easily.

2 posted on 04/20/2003 7:37:44 AM PDT by alnitak
[ Post Reply | Private Reply | To 1 | View Replies]

To: Trailer Trash
I dunno about microwaves, but this has already been done here in the US with lasers instead of microwaves. Same principle, energy fired at a light and mirror-reflective dish, except ours went somewhere around 100 feet up. It had to be stabilized by rotation (they would get it spinning with compressed air right before take off).

I believe the discovery channel had a program on them.
3 posted on 04/20/2003 7:37:48 AM PDT by anobjectivist (The natural rights of people are more basic than those currently considered)
[ Post Reply | Private Reply | To 1 | View Replies]

To: alnitak
Well, you beat me to it.
4 posted on 04/20/2003 7:39:01 AM PDT by anobjectivist (The natural rights of people are more basic than those currently considered)
[ Post Reply | Private Reply | To 2 | View Replies]

To: Trailer Trash
"...the development could enable cost and size reductions in rockets as they could use air in the atmosphere as a means of propulsion, rather than having to carry fuel..."
--
Yeah, now that heavy fuel can be replaced by heavy storage batteries.
And, there isn't any 'air' in space to heat up in order to get the propulsive effect.
Just a few of the bugs that need to be worked out, thats all.
5 posted on 04/20/2003 7:45:31 AM PDT by error99
[ Post Reply | Private Reply | To 1 | View Replies]

To: anobjectivist
Early bird catches the worm :-) I saw this on TV too ("Tomorrow's World" here in the UK"), the thing I remember was them having trouble with the wind, and having to be careful to time their "flights" so as not to fry any satellites passing overhead!

Scientific American article here on new methods of spaceflight. (click the "box" link on page 6 of the article for some more details specific to Myrabo's scheme)

6 posted on 04/20/2003 7:47:55 AM PDT by alnitak
[ Post Reply | Private Reply | To 4 | View Replies]

To: error99
The atmosphere is used as the reactant-mass while you're in it. The microwave energy is beamed up from the ground - this is the key point, existing craft have to carry all their fuel, which is heavy, hence step-rockets. Beamed energy solutions let you leave the fuel on the ground - not to mention the power plant. As for when you get out of the atmosphere, well you can carry anything to act as reactant mass, say liquid air or water, though I imagine liquid hydrogen would be best because of its low mass.
7 posted on 04/20/2003 7:51:08 AM PDT by alnitak
[ Post Reply | Private Reply | To 5 | View Replies]

To: alnitak
You should test your links in 'preview'.
8 posted on 04/20/2003 7:51:17 AM PDT by error99
[ Post Reply | Private Reply | To 6 | View Replies]

To: error99
Hmm, sorry about that, must be because I found the article via their search engine. Here's a direct link to the Myrabo article, and a link to the entire issue, which has many space related stories.
9 posted on 04/20/2003 7:58:06 AM PDT by alnitak
[ Post Reply | Private Reply | To 8 | View Replies]

To: anobjectivist
Moties?
10 posted on 04/20/2003 8:00:16 AM PDT by robertpaulsen
[ Post Reply | Private Reply | To 4 | View Replies]

To: Bear_in_RoseBear; JenB
Seems like a microwave powerful enough to send up a serious, payload, say one measured in tons rather than grams, might be a serious weapon in its own right.

Kind of along the lines of the laser powered vehicles in "Footfall."

Wonder if microwaves can be used as guidance systems as lasers can. Perhaps they would not be deflected by smoke.
11 posted on 04/20/2003 8:07:53 AM PDT by Sam Cree (liberals are the axis of evil)
[ Post Reply | Private Reply | To 1 | View Replies]

To: Sam Cree
Kind of along the lines of the laser powered vehicles in "Footfall."

Heh. Was thinking the same thing. And another variation are the laser-powered sails in "The Mote in God's Eye."

12 posted on 04/20/2003 8:29:50 AM PDT by Eala (irrelevant (-rle-vent) 1: The United Nations 2: France 3: CNN 4: Tim Robbins 5: PBS)
[ Post Reply | Private Reply | To 11 | View Replies]

To: *Space; *RealScience; *tech_index; sourcery; Ernest_at_the_Beach
http://www.freerepublic.com/perl/bump-list
13 posted on 04/20/2003 8:36:02 AM PDT by Libertarianize the GOP (Ideas have consequences)
[ Post Reply | Private Reply | To 12 | View Replies]

To: Trailer Trash
Way cool! ...and you can make popcorn with it to boot!
14 posted on 04/20/2003 8:41:37 AM PDT by chilepepper (Gnocchi Seuton!)
[ Post Reply | Private Reply | To 1 | View Replies]

Comment #15 Removed by Moderator

To: error99; Razzz

"Yeah, now that heavy fuel can be replaced by heavy storage batteries."

The microwave generator never leaves the ground. The beam is focused upon the aircraft, and the resulting reaction creates the thrust.

16 posted on 04/20/2003 9:09:15 AM PDT by Trailer Trash
[ Post Reply | Private Reply | To 5 | View Replies]

To: Eala
I'd forgotten about those "sail" ships.

Your essay on the war against the Left on your home page is right on the money, IMO.

I agree that people always seem to be concentrating on the battles instead of the war. Why do you suppose that is? Heads in the sand, fear of sounding crazy? Having the same agenda, but not admitting it (acquisition of power)?
17 posted on 04/20/2003 9:09:50 AM PDT by Sam Cree (liberals are the axis of evil)
[ Post Reply | Private Reply | To 12 | View Replies]

To: Trailer Trash
I want my air car. I want to fold my car into a briefcase like George Jetson. I want to take a Pan Am rocket to the Moon like 2001. Where is all the cool stuff we were promised in the movies and television. Ya, this internet thing is nice, if unpredicted. Of course, future predictions aren't all that great. For instance, in Star Trek-The Next Generation, they cure all disease (including cancer) with a five minute stay in sick bay. Yet the Captain is still bald like a cue ball. Sotty to hear in the year 2300 they stil haven't found a cure for it.
18 posted on 04/20/2003 9:19:08 AM PDT by Lawgvr1955 (Never draw to an inside straight)
[ Post Reply | Private Reply | To 1 | View Replies]

Comment #19 Removed by Moderator

To: alnitak
But wouldn't the microwaves be a hazard to anything between the rising rocket and the microwave generator? Cooked birds, for example?

And if yes, wouldn't this make an excellent missile and air defense system?

If I were America's enemies, I would counter our air dominance by developing new air defense systems -- energy beams of all types or rail guns or whatever. Instead of trying to put together a complex system that took us a half century to achieve in the air, try to leap ahead and make it so that anything that flies, dies. Thus negating our edge and returning it to a ground battle where our edge isn't as huge.

20 posted on 04/20/2003 9:50:42 AM PDT by LenS
[ Post Reply | Private Reply | To 2 | View Replies]

To: LenS
But wouldn't the microwaves be a hazard to anything between the rising rocket and the microwave generator? Cooked birds, for example?

Yes, and anything above it too, due to leakage around the sides (satellites for example).

And if yes, wouldn't this make an excellent missile and air defense system?

I doubt it. The generators are likely to be huge, static things (think airport sized), the beams would be steerable through only a narrow angle, and you would probably situate them away from major population centres.

If I were America's enemies, I would counter our air dominance by developing new air defense systems -- energy beams of all types or rail guns or whatever. Instead of trying to put together a complex system that took us a half century to achieve in the air, try to leap ahead and make it so that anything that flies, dies. Thus negating our edge and returning it to a ground battle where our edge isn't as huge.

I am sure plenty of regimes would like to leap ahead of American military technology, especially air defense, but it's easier said than done :-)

21 posted on 04/20/2003 10:01:20 AM PDT by alnitak
[ Post Reply | Private Reply | To 20 | View Replies]

To: LenS
You might want to read the "StarFIST" series. Portable rail guns that strike at spacecraft, etc.

Fun read with a USMC "worms eye" view, The authors are ex-grunts.
22 posted on 04/20/2003 10:36:16 AM PDT by ASOC
[ Post Reply | Private Reply | To 20 | View Replies]

To: LenS
But wouldn't the microwaves be a hazard to anything between the rising rocket and the microwave generator? Cooked birds, for example?

Yes, high flux microwaves are hazardous to living things and electronics. However, missiles and military aircraft can be shielded against microwaves.

I've been doing some research into this field. I believe that microwave beamriders hold the key to low-cost SSTO. Here is a summary of my conclusions.

The transmitter antennas should not sit on the ground. They should be composed of several linked hexagonal airships, totalling about a kilometer in diameter, operating at about 10km of altitude, tethered by a long power line supported by intermediate balloons.

The effective range of the antenna would be less than 500km, therefore a full orbital launcher would probably have three transmitter antennas spaced about 600km apart. This would allow the spacecraft to accellerate to orbital speed over a 1800km trajectory

Although using liquid hydrogen as propellant would give the maximum ISP (about 1200), liquid ammonia is a much better choice, with its high density, low cost, and easier handling. Ammonia's ISP of about 800 would also be close to the ideal for minimum energy required for GTO.

Links for related information can be found here.

23 posted on 04/20/2003 10:47:15 AM PDT by Mr170IQ
[ Post Reply | Private Reply | To 20 | View Replies]

To: Sam Cree
Your essay on the war against the Left on your home page is right on the money, IMO.

Thanks! (Would that it were otherwise, or that I was mistaken...)

I agree that people always seem to be concentrating on the battles instead of the war. Why do you suppose that is? Heads in the sand, fear of sounding crazy? Having the same agenda, but not admitting it (acquisition of power)?

That is a good question. I think maybe there is a general perception that there is a general war, but that it gets forgotten for the local battles, or ignored for fear of fighting on too many fronts. And there is really no organization, no coordination, and worst of all, no support for each other.

All too often, for example, we adopt the, er, linguistic practices the Left forces on us. Why? Because to refuse gets one singled out for attack (even if only verbal) from the Left. And the rest of the Right doesn't often rally to the poor soul's defence.

And the attack may be worse than merely verbal. The Left has so greatly infiltrated the judiciary that all sorts of bizarre takes on laws (not to mention the laws themselves) abound these days -- singling out and punishing the poor soul who broke their code, or law. And remember, to the Left the law (a straight code) is not a necessary component of civil life, it's just another tool to be twisted into a weapon against those who stand in the way of their all-out war for power.

24 posted on 04/20/2003 3:32:18 PM PDT by Eala (irrelevant (-rle-vent) 1: The United Nations 2: France 3: CNN 4: Tim Robbins 5: PBS)
[ Post Reply | Private Reply | To 17 | View Replies]

To: anobjectivist
dunno about microwaves, but this has already been done here in the US with lasers instead of microwaves.

Before there were lasers (Light Amplification by Stimulated Emission of Radiation), there were masers (Microwave Amplification by Stimulated Emission of Radiation).

I don't know, but I suspect this is technically a maser beam, and is absent a light component.

25 posted on 04/20/2003 3:46:16 PM PDT by Semper911 (For some people, bread and circus are not enough. Hence, FreeRepublic.com)
[ Post Reply | Private Reply | To 3 | View Replies]

To: Trailer Trash
So every time a rocket is launched, there's a chance the ascent to orbit will turn into a multi-multi million dollar skeet shooting misadventure?

Is there a known substance that can withstand the huge forces of concentrated microwaves on the reflector dish of a satellite launch?

26 posted on 04/20/2003 5:50:25 PM PDT by JerseyHighlander ()
[ Post Reply | Private Reply | To 1 | View Replies]

To: alnitak
Dr. Myrabo also did research on microwave versions of his lightcraft. I'm sure this is follow on research based on his work
27 posted on 04/20/2003 10:29:40 PM PDT by anymouse
[ Post Reply | Private Reply | To 2 | View Replies]

To: tricky_k_1972; KevinDavis
Blast from the Past!
28 posted on 03/09/2006 8:40:29 AM PST by SunkenCiv (Yes indeed, Civ updated his profile and links pages again, on Monday, March 6, 2006.)
[ Post Reply | Private Reply | To 1 | View Replies]

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.

Free Republic
Browse · Search
News/Activism
Topics · Post Article

FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson