Boeing patents hybrid fusion/fission engine

originally posted by: Bedlam

originally posted by: mbkennel

Uh, this stuff has plenty of fissioned ex-U238 trailing behind it. It's not going to pass a EPA smog test.

This. Also, the liner will be thermally hot as well as radioactively hot, since the daughter products you'll get will be decaying in there. In fact, you MIGHT be able to get a meltdown of the liner. It would sort of depend on how thick it was...

By the way, this means that even if your tokamak can't get breakeven in fusion power, if you use DT it would be great for precisely making Pu-239 if one were Doctor Evilish and would the IAEA ever know?

I think I brought this up on one thread or another and was ignored. It's a great way to start your day with some nutritious Pu239.

So Tom, is Planet Dirt getting fallout exhaust clouds like you'd expect from them damn dirty Romulans? And that's why it's so SCI? Fear of lawsuits from xenoenvironmentalist lichen-huggers?

This isn't a workable design. It's a bad joke.

But in space...can the vacuum provide a heat exchanger? Could this be being testing on the space ship flying up there for 12 months? Could we leave a long range space ship attached to the ISS fuelled to fly around, a trip to the moon or Venus in a sports ship!

originally posted by: Forensick

But in space...can the vacuum provide a heat exchanger?

No. If anything, it makes it tougher to be rid of heat. You'll need a really big set of heat sink fins.

a reply to: punkinworks10

Your link appears to be broken.

a reply to: TheLotLizard

This makes me think that it's intended to use in space.

a reply to: Bedlam

but in the atmosphere couldn't you make a stupid powerful 511 powered ram jet via heat conversion?

one ram jet to rule them all?

originally posted by: BASSPLYR
a reply to: Bedlam

but in the atmosphere couldn't you make a stupid powerful 511 powered ram jet via heat conversion?

one ram jet to rule them all?

If you don't mind spewing U238 fission byproducts across the countryside...

a reply to: Bedlam

no I'm saying get away from the whole fission thing altogether. just have a annialation chamber like a hollow rod running lengthwise down the middle of the tube and convert the 511 to heat....a bunch of heat. the outside of the annialation rod gets really hot and air expands rapidly. replace spent rod from time to time as normal wear and tear maintenance.

a reply to: BASSPLYR

Oh. Well, if you're going to use positrons, you can just use air as a working fluid and dribble some into what would be the combustor in a more sane setup. But the gammas are harsh and tend to kill pilots, I'd guess.

a reply to: Bedlam

wouldnt the gammas be contained inside the annialation rod though and only bthe heat transfere through. basically using the 511 to heat up an element which would be the outside of the hollow aniallation chamber.

a reply to: BASSPLYR

Gammas are sharp and pointy and hard to contain.

a reply to: Bedlam

sheilding for the cockpit? like a fire wall but instead a gamma wall.

Also as an exhaust product for the gammas that get loose. are they long living and a hazard to the environment or as long as some reasonable distance from people is maintained its basically safe to use.

originally posted by: BASSPLYR
a reply to: Bedlam

sheilding for the cockpit? like a fire wall but instead a gamma wall.

Also as an exhaust product for the gammas that get loose. are they long living and a hazard to the environment or as long as some reasonable distance from people is maintained its basically safe to use.

Gammas are really blue light. So don't pull up or you'll be pointing some nice gamma searchlights at the ground...

originally posted by: Bedlam

originally posted by: Forensick

But in space...can the vacuum provide a heat exchanger?

No. If anything, it makes it tougher to be rid of heat. You'll need a really big set of heat sink fins.

Forgive my lack of knowledge of thermodynamics, but isn't the heat going to be radiated by the cooling system that will line the chamber? Isn't that how this whole design is going to generate power?

a reply to: chuck258

It's going to use SOME of the heat to generate electricity to run the laser side. But that's not the problem.

The issue comes when you run it for a while. Then you will end up with really hot low half-life daughter products in your uranium liner. And you'll have lots and LOTS of waste heat to dispose of.

Unfortunately, vacuum doesn't make for a good way to do that, as you're limited to radiating it. You can manage it, but you're going to end up with the SS Heat Sink if the liner's very big.

Lasers and nuclear reactors zipping around in the skies, what could possibly go wrong?!

use a direct conversion type fusion engine to eliminate or greatly reduce radiation problems combined with a droplet curtain type radiator. use some excess power to power cryo-coolers. periodically dump part of the heated coolant into the exhaust stream. put strategically placed thermo-electric converters all over the place.

So would this make space travel to say mars much faster? I am thinking if these engines were produced we could see a whole new era in space travel.

originally posted by: FormOfTheLord
So would this make space travel to say mars much faster? I am thinking if these engines were produced we could see a whole new era in space travel.

yes. depending on the design details. generally 1st generation fusion drives are considered capable of 3 percent c (maximum.) and often a percent of a percent. but even then they would be much faster than anything we have now because of advantages in acceleration if they are used to superheat an exhaust material and act like an NTR. in actuality idealized steady state fusion reactor engines (these would be 4rth or 5th generation tech) can top out at over 30 percent c.

a reply to: stormbringer1701

Is their a working fussion reactor?

originally posted by: Hyperia
a reply to: stormbringer1701

Is their a working fussion reactor?

Officially not that I know of..


however the X-37 was up in space for almost 2 years. What powered it for 2 years?