Nuclear pulsed propulsion would be even faster. The ship would have to be build in space though, unless we wanted to irradiate the launch area.

Now here is a petition that makes sense! Nuclear powered ion-electric and various forms of nuclear propulsion (e.g., NERVA, nuclear pulse, etc.) represent the next logical significant leap in propulsion tech, beyond today's chemical propulsion and low powered ion-electric.

I will be signing this one.

Scubasteve - you could also utilize nuclear upper stages, as was the plan with NERVA before the program was cancelled under Nixon, so construction on-orbit isn't necessarily required to address your concerns. Although, for missions to the outer planets (or one day interstellar) yes, on-orbit construction will be necessary, but mainly to overcome the large payload and fuel mass that would be required.

Won't the hostile aliens be able to see our "signature" in space bazillions of miles away with all that radiation emission?

I dunno. Sounds pretty risky.

They won't bother with us until we attain warp drive, duh... ;)

Yeah, but what if they follow us home? Who's gonna walk'em and feed'em and take care of them?

(And the first one who answers "Obama" is gonna be in BIG trouble mister)

Why can't we drop the *does my Duck Dodgers of the 21st and a Half Century voice* "In the distant future in a presently unknown galaxy..." crap and work on the things that we have the technology for and a way to impliment them in a real and working manner to benefit the current society in such a way as to make these "In the distant future in a presently unknown galaxy..." crap actually obtainable without going so far into debt as to need to rub to rocks together to generate heat.

Space-Based Solar Arrays. Microwave transmission and receiving arrays. Real energy from a renewable, basically maitenence free, power supply that can have real impacts on our oil dependencies.

I think it's worth mentioning this probably wouldn't cause a bunch of nuclear waste within our atmosphere. The article didn't specify, but I am sure they would use conventional rockets on the way out of the atmosphere then use these once they're free of our atmosphere. Not sure though, anyone know for certain?

Nolan,

For what the article was talking about, you'd be correct.

For Nuclear Pulsed Propulsion (What Cjsks and I mentioned) the size requirements of the ship would make it difficult to launch (in one piece at least) with conventional rockets.

Nuclear Pulsed Propulsion is basically dropping small nuclear bombs behind the ship and riding the shock-wave to accelerate. It would be difficult and expensive to build a working ship, but it's the fastest type of ship we could build with current technologies.

Scubasteve58001, the Nuclear Test Ban Treaty won't allow us to conduct nuclear detonations in space (or anywhere else but but underground on Earth). It has no exceptions for space propulsive purposes.

That's the main thing that killed the nuclear-pulse Orion (not to be confused with today's capsule)...

'Won't the hostile aliens be able to see our "signature" in space bazillions of miles away with all that radiation emission?"

Skip, any emissions from a solid-core nuclear thermal rocket will be immediately lost in the noise of solar and galactic cosmic radiation. If 'they' are close enough to detect it, 'they' are close enough to just plain see you...

mKlRivOwner: Space based solar power doesn't come cheap. You can't talk about that, and staying out of debt, at the same time. (Oh, and will it be competitive with existing and near-term alternatives? If not, won't happen. Period.)

nolan-4517032: Though it's possible to use an NTR as an upper stage, chances are that we wouldn't actually use them closer than LEO.

I support the petition but wish it would have gone a step further and suggested a) the immediate stop-work on SLS b) redistributing 25% of the SLS budget to commercial crew development and c) giving the remaining 75% of SLS funding to in-space nuclear propulsion and power sources.

The Limited Test Ban Treaty specifically uses the word "weapon" within the treaty, therefore nuclear detonations for the purposes of propulsion are fine and not a problem.

There is a new treaty, the 'Comprehensive Nuclear-Test-Ban Treaty' which may actually prohibit it depending on how you view the wording though the premise does state that it's in relation to weapons testing also.

Even if it does ban it, 2 things; First the US has only signed the treaty, since we haven't ratified it yet technically we haven't bound ourselves to it. Secondly Article 7 of the treaty allows for review of any new technologies or scientific endeavours which nuclear detonations are used peacefully, which nuclear-pulse propulsion would fall under.

So at this point neither Treaty would be a problem.

Mitchell

The very minute science can solve the problem of a 100% sure-fire, foolproof, can't-miss nuclear containment solution for the fuel, and I mean one that can be used successfully in the case of a launch accident, failure to achieve orbit, or any of a thousand other "aberrations" that space flight can be heir to, I say "Go for it, and Godspeed."

In the meantime... theorize away, and please refrain from giving some unsuspecting region of the Earth a glowing rain of plutonium or thorium or whateverelseium you care to use.

Thank you.

Good for you gcooper for not even understanding a philosophical view of life. Not even sure how you get out of bed each day given all the things you must worry about. Of course, with all the things that can kill you in bed, not sure how you even get into bed in the first place. What a horrid place to live in...

Mitchell

@F Glover - No, it won't come cheap, but certainly less than building nuclear powered refueling stations on Titan. And with commercial funding (power companies), it's a real possibility. As for competitive, Solar Panels are 144% more efficient in orbit for the exact same solar panels we use today. Add 100% freedom to 3-dimensional arrangement (increases efficiency), increased exposure duration, and the ease of repositioning the panels and the target area, and you can see how this has true potential.

The big obstacles are launch costs and the decreased lifespan of solar cells in the space environment. Neither of which are insurmountable.

Project turn-around is also a big issue. I fully recognize that I'm saying we can have a solar array functional in 10 to 15 years (realistic). Meanwhile, it's pretty easy for someone to say "We can strap i nuclear reactor to the back end of a firecracker by week's end!"

@skip Nicholson - the Sun gives off way more "radiation" than any human built nuclear reactor ever will :). Already aliens could "see" the radiation from our radio, television and radar broadcasts 40-50 light years away.

Don't you think NASA has considered this themselves? NASA exclusively employs technical and mechanical experts who are mostly nerds in one way or another. When they form a nerd committee to choose which alternative is best amongst all the theoretical options, they obviously look at these ones too. Then they decide that it just isn't feasible for this reason or that reason, and go with the best attainable alternatives.

Seriously, this guy wants the future to look like 2001 a space odyssey. That is a fictional work. Fictional. So is star trek. Yes it is beautiful. But while it may be easy to put on the movie screen, there are a heck of a lot of technical challenges involved in even the simplest parts of that show.

I have no beef with suggesting this program. It may actually be a viable idea someday. However, to quote picard: 'wishing for a thing does not make it so'. I became a lot more interested in space exploration when I started to seriously consider the mathematics and logistics involved. There are probably a lot of logistical problems caused by this idea that make it less interesting for the real rocket people.

moteqaze - Nuclear thermal rocket (NTR) and nuclear-powered ion-electric technology are very well understood by those "nerds", and both options have already been researched & developed to a large extent (see NERVA, Project Prometheus, SAFE-400, VASIMR, etc.)

The reason they haven't been fully implemented yet is a combination of cost, political will, and bureaucratic red tape. There is however, no question around the advanced capabilities these technologies would provide.

Not to mention all the advancements in consumer products that are made because of discoveries at NASA. There have been a ton of things invented there that have made it into the consumer market. I think one was that magical mattress with the memory foam. Another one had something to do with air plane or car seats or something. Oh, and my favorite, astronaut ice cream.

nolan: not sure, but I think the air plane seat story you mention came from the crash of a JAARS (a Christian missionary organization) aircraft in Ecuador. The pilot (Paul Duffey) suffered a broken back in a very hard landing, and he was paralyzed from the waist down. In the subsequent accident study, it was realized that if his seat had been a little weaker in the right way, so that it collapsed in the crash, there was a good chance the pilot's back would not have been broken. JAARS and NASA cooperated in designing and testing such a seat, which is now standard in JAARS' airplanes, and the design is freely available. You can read more about it at

Incidentally, the last time I saw Paul, he was "running" in a wheelchair marathon.

He-3 is Fusion fuel, but the moon also has large deposits of Thorium-232.

You could use that as fuel for Molten Salt Reactors to power a moon base.

There is a big problem cooling the space craft that I am sure can be solved. I'm for it. How do I sign the petition?

@Scuba: Earth has plenty of Thorium (it's about 4x as abundant as uranium, and that's total uranium.)

Also, no need to qualify Th as Th-232. There's only one natural isotope. (Which is one of the benefits of thorium.)

Matt,

Oh I know all about Thorium my friend. If you look through my comment history you'll see sporadic posts trying to convince people that we should build LFTRs to break our foreign oil dependence but I digress...

I was simply pointing out to Joseph that there were other power sources on the moon that we could use. I mean, there's plenty of Thorium up there already, why lug a bunch from Earth?

Oh and added the "-232" because it makes me sound smarter ;-)

Scuba,

I wrote a proposal (that didn't get funded) to do work on thorium-oxide fuel. (More specifically, the phase transformations required it undergoes from Th > Pa > U). I work at a nuke lab.

It could be more dangerous, it could be less depending on the design.

But there is definitely value in space exploration. That's been proven over and over.

Gee, do you have GPS device? Watch the weather channel? Have Satellite TV or radio? That's just to name a few things coming out of the space program.

Not to mention the cost isn't that great. if you boil it down per citizen it's like what.. 60 bucks for a whole year. That's not too bad.

$50 by my rough calculation ($15 billion / 300 million).

I'm in! Who do I write the check out to? And it better goto this effort and not to fund those pesky special interest groups...

Just kidding!

:-)

I believe you make the check out to "NASA Office of the Chief Financial Officer (OCFO)".

Even though it is not a charity, NASA does accept monetary gifts and donations. Here is their policy directive on "Acceptance and Use of Monetary Gifts and Donations".

...Just in case you weren't kidding :-)

Until a real solution to gravity is found, We can limit trips to what we can do in the 3-4 month range. With NTR, we should be able to get to Mars in that time frame...It might not be the same gravity as Earth's, but it is gravity. We can visit the outer planet's moons by taking stops every 3-4 months at waypoint stations that have one form of gravity or another, beit a planetoid or a deep space station that rotates.

But I agree, rotational gravity or artificial gravity needs to be developed/conquered.

In order for nuclear thermal rockets to be worthwhile, they would have to be significantly more efficient than existing chemical fueled rockets, and efficient enough to compensate for the additional weight of the reactor and shielding.

The efficiency of any thermal rocket, chemical or nuclear, is determined by the temperature difference it can achieve, which determines thermal expansion and exhaust velocity. Existing chemical rockets achieve high enough temperatures to melt most substances, they need sophisticated cooling systems just to prevent the nozzle and combustion chamber from melting and failing. To get even higher temperatures from a reactor means risking melting the reactor core and blowing it out the exhaust. In short, a very high risk operation.

Rockets that don't rely on thermal expansion, such as the various types of ion drives, can achieve much higher levels of efficiency and don't require extremely high temperatures, thus are a better choice for advanced rocketry.

Based on the tests of Project Rover/NERVA in the 60s, a solid-core reactor, heating hydrogen fuel could achieve a equivalent of a specific impulse of 825-seconds and they operate at temperatures of 2000 degrees C. This is somewhat better than chemical rockets currently do and it's not even including what advances we might have now in other kinds of cores, materials, etc.

An ion drive will accelerate very slowly which might not always be ideal, even if more efficient, especially if you want to ferry people around quickly.

I believe they use magnetic fields to shield the plasma in fusion reactors. Why can't they use the same magnetic field to protect the ship from said melting temperatures and direct the thrust outward in one diection (ie: thrust)?

I am far from what is called/labeled a scientist. I am just thinking out loud...

This is somewhat better than chemical rockets currently do and it's not even including what advances we might have now in other kinds of cores, materials, etc.

If by "somewhat" you mean 2-3 times better! :)

You could use small Thorium based reactors. Much more difficult to turn into a weapon.

@Scuba: False. Thorium reactors generate U-233. Just as bad for proliferation.

But they can be designed in a way that makes U-233 and U-232 at the same time. U-232 has a hard gamma emitter in it's decay chain so any U-233 contaminated with U-232 wouldn't be very useful for bomb making.

Thorium reactors are good for stationary power (on or off Earth), but I don't know if they lend themselves to nuclear thermal rockets...

What is the big hurry. How about this. When I was in HS the world population was 4 billion. It is now around 7 billion. Worst case projections indicate by 2100 the world population at around 17 billion. Unless you plan to kill some people off or implement drastic population control measures (good luck with that), just how how long do you think the earth can sustain unrestrained growth?

pcover: Population growth is indeed a big problem - but we can't solve it by exporting the excess population into outer space. Currently, the population doubling time is about 40 years. That means that in order to stabilize earth population by space colonization only, we'd have to export to space the equivalent of the entire world population in just 40 years, 175 million persons every year. The handful we could house in space colonies with current technology wouldn't even cover a days worth of births.

No, it's going to require bringing down the birth rate. If we fail to do that, then nature will eventually do it for us by raising the death rate.

You could stipulate laws and limits around it... say we only allow fission (and maybe one day fusion) reactors for BEO/deep space missions at first, until safety of systems are proven? You could also limit the size and output of a reactor per launch (say 400kw). LEO missions, satellites, etc., could still be limited to conventional power and propulsion? Some of the same risk would still exist on launch and initial Earth orbit departure, but greatly reduced.

There are many other reasonable precautions that could be taken. Regulate the heck out of it! But there is simply too much upside to just ignore the potential of nuclear power in space.

It forbids nuclear weapons and WMD (not conventional weapons interestingly), but I don't believe nuclear reactors are barred: www.unoosa.org/oosa/SpaceLaw/outerspt.html

In fact, NASA was developing JIMO in the early 2000's (http://en.wikipedia.org/wiki/Jupiter_Icy_Moons_Orbiter) that would have been the first mission of NASA's Project Prometheus, which was a program to develop nuclear fission for spacecraft propulsion.

Unfortunately it also forbids the peaceful use of nuclear weapons of say a Orion type mission in deep space, also if you read the language (It is specified as weapons of mass destruction) it doesn't outright forbid the use of say things like kinetic kill weapons, say using space rocks, probably because it wasn't considered practical at the time, but probably should be updated for that at least.

Burn, could you please cite the exact passage that you are referring to? I see no such language forbidding nuclear reactors for peaceful purposes. It makes no sense, given that NASA has made serious efforts to develop nuclear reactors in space on multiple occassions subsequent to adoption and ratification of this treaty (e.g., NERVA and Project Prometheus, etc.), only being limited by funding and political will.

Not Nuclear reactors, I was referring to the old bomblet propulsion system Project Orion, it gets confusing because they are calling the new NASA mission Orion as well, so the treaty outlaws a Project Orion type mission because a Project Orion type mission uses nuclear weapons for propulsion and those are weapons of mass destruction.

Not Nuclear reactors, I was referring to the old bomblet propulsion system Project Orion, it gets confusing because they are calling the new NASA mission Orion as well, so the treaty outlaws a Project Orion type mission because a Project Orion type mission uses nuclear weapons for propulsion and those are weapons of mass destruction.

Burn2496, do some more research on this subject. UN Office of Outer Space Affairs provides some guidance on this, but as long as it is not a "weapon", a certain safety measures are taken, it is not forbidden by int'l law. You mentioned Project Orion - nuclear pulse propulsion is not a weapon, and would be allowed if properly implemented.

There are some risks, non-binding resolutions, and other political pressures that have scared the US and Russian govt's away from implementing space-based reactors in recent decades (not to mention cost of R&D), but nuclear reactors are not illegal under international law.

I have done research on the topic, and so far the legal opinion is that as long as it uses nuclear weapons it is considered to be a weapon, and I never claimed nuclear reactors were illegal by law, that was a misinterpretation probably because the new NASA mission is named Orion.

Below news article

http://www.naplesnews.com/news/2008/feb/23/ben-bova-outer-space-law-it-exists-and-restricts

Harvard law article:

Quote:

"However, nuclear propulsion by means of detonating atomic bombs (ORION) is, in principle, banned under the 1963 Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space, and Under Water"

http://adsabs.harvard.edu/abs/2002iaf..confE.410P

Below quote:

"""""

States Parties to the Treaty undertake not to place in orbit around the Earth any objects carrying nuclear weapons or any other kinds of weapons of mass destruction, install such weapons on celestial bodies, or station such weapons in outer space in any other manner."

from the full outer space treaty below, nowhere does it make a exception for peaceful uses:

http://www.oosa.unvienna.org/pdf/publications/STSPACE11E.pdf

Oh it's not just the outerspace treaty but the outer space test ban treaty that disallows it:

Below book review from George Dyson's book:

"""""""Dyson traces the history of the project's many twists and turns, from its beginnings in 1957 as a government-funded project at General Atomic (a division of General Dynamics located in La Jolla, California) to its death in 1965, a victim of interagency squabbling and the nuclear test ban treaty. He interviewed many of the scientists and engineers who worked on Orion and quotes extensively from the documents they wrote. Dyson had an inside
track in his research; his father is Freeman Dyson, the well-known physicist at the Institute for Advanced Studies in Princeton, who worked on Orion for two years.""""""""

http://scibooks.org/orion.html

This is better a direct quote fromt the book:

http://books.google.com/books?id=r_Gu4f0QxrkC&pg=PA266&lpg=PA266&dq=project+orion+the+true+story+of+the+atomic+spaceship+space+treaty&source=bl&ots=F4a-3vQ_83&sig=7yNoE81PZ-3z1yM4cdL_yJD9ad4&hl=en&sa=X&ei=_ufsUKT5LYWy9gT0wYDoBw&ved=0CEYQ6AEwBDgK#v=onepage&q=project%20orion%20the%20true%20story%20of%20the%20atomic%20spaceship%20space%20treaty&f=false

List of relevant treaties dealing with the topic below:

http://www.un.org/en/globalissues/atomicenergy/agreements.shtml

Below a good description of the treaty, and note nowhere does it state a exception for Project Orion:

http://www.au.af.mil/au/awc/awcgate/au-18/au180044.htm

And yes most nations would consider the pulse units in Project Orion weapons, they are just used differently.

There has been a attempt to redefine them as serving propulsion purposes, however so far it hasn't made it into the treaty. the various test ban treaties themselves are even worse, as they define based on all nuclear explosions, thus Project Orion would be explicitly banned under those treaties.

Burn and Lee -

Neither of you are wrong with regards to Nuclear Pulse propulsion (good research Burn btw). The legality under international law is definitely debateable, because it is a basically a series of "nuclear explosions" propelling the vehicle (though not a "weapon"). Still if the US gov't really wanted to implement such a system, I doubt any existing treaty would have the teeth to stop them ("in the light of the mutability and evolution of international law"). However, we are far from needing to have that debate, the expense alone puts nuclear pulse spacecraft a little further down the road...

In the relative near-term, we are muuuch more likely see nuclear thermal rocket engines (as the petition calls for), or preferrably nuclear fission reactors for the purposes of providing electricity to ion-electric drives and other systems. These are not prohibited.

Really? When/where did this happen? Provide your source.

Is it true fools can comment too?

Sadly, the 1st amendment allows them to comment anywhere they wish. The true meaning of intelligence is choosing not to listen.

Good morning, Burn. I would agree. Solar power is roughly cut in half once you get to Mars, so even using solar on a shuttle to/from Mars is not a great choice. A 200MW VASIMR could get to Mars in 39 days. A 200kW version will, hopefully, get tested as early as 2014. The 200MW version obviously needs lots of electrical power. If it ever gets built, it is likely to be nuclear powered.

NERVA is not a starship nor has anybody who actually knows anything ever claimed it was, so the issue of "travel time to another star" is rather pointless.

What NERVA or its derivatives give us is shorter trip times to the other planets in our own solar system and larger payloads to those planets.

I could be wrong, but isn't acceleration rate with ion propulsion insanely slow? Could they use a mix of chemical for the thrust then ion for the distance? Launch from the moon with lower gravity could reduce the chemical mass required for thrust. That sounds so dirty..