Nuclear struggle for NASA! - Nuclear flight for Manned flights.

Martian Republic · 2005-03-12 22:39:24

Another view of the planned manned flight from the past from another perspective. Now this is a Larouche Site, but I thought it was interesting. I posted it for anybody else that interested in the subject. I goes over the political battle between the two sides to either kill manned flight including nuclear manned flight and promoting manned flight by the two sides. Kennedy was the champion of both the chemical and nuclear manned flight into space and after his death, only the chemical side of Kennedy plan continued through to the Apollo mission with the nuclear side being squelched by the other side.

http://www.larouchepub.com/other/2004/s … space.html

Larry,

GCNRevenger · 2005-03-13 08:58:02

Or it could be that the latest of your wild conspiracy theories is hogwash, and that NASA didn't use NTR engines because they wern't nessesarry and would have slowed Apollo down (Saturn-V was big enough not to need them), not to mention that they hadn't reached flight readiness by 1969.

Nor do we HAVE to have NTR engines for getting around cis-Lunar space. NTR engines don't provide a sufficently compelling improvement in performance except for very large payloads or high-delta (eg Mars) maneuvers. Liquid Hydrogen engines provide adiquate performance, so long as the rockets are big enough to bring up lots of it.

BWhite · 2005-03-13 11:18:18

There is the underlying issue that humanity has yet to devise a property rights regime for lunar and NEO and Marsian resourecs.

The Outer Space Treaty of 1967 was enacted to discourage the nations of the world engaging in a "land rush" seeking to claim sovereignty over celestial bodies and the US favored that treaty because in 1967 it was not so clear we could win that race.

= = =

Anyway. . .

La Rouche is, well, let's just say off the wall.

However, it is true that humanity has not addressed the legal and geopolitical implications of ownership of celestial resources and some threads of conservative thinking might favor delay in opening that Pandora's Box.

One of the "Great Geo-political Games" of the next 100 -150 years will be jockeying for position in the struggle to write the laws that govern ownership and exploitation of celestial resources.

Edited By BWhite on 1110734347

BWhite · 2005-03-13 11:24:22

Nor do we HAVE to have NTR engines for getting around cis-Lunar space. NTR engines don't provide a sufficently compelling improvement in performance except for very large payloads or high-delta (eg Mars) maneuvers. Liquid Hydrogen engines provide adiquate performance, so long as the rockets are big enough to bring up lots of it.

How efficient would an NTR tug be for moving mass from LEO to the Moon on a regular basis? Large payloads broken into smaller chunks.

Chemical is about 5:1 ratio, right? 100,000 pounds in LEO = 20,000 pounds on Luna? About the same as Mars.

Would NTR be a more efficient way to move mass from LEO to Luna? Obviously, you need the economy of scale to justify the capital costs.

GCNRevenger · 2005-03-13 11:46:20

I would argue that persuing NTR technology for Lunar tugs doesn't make alot of sense, mainly for one big reason:

They only have their superior performance when using Hydrogen as propellant. Even with water ice harvesting on the Lunar surface, Hydrogen will be a precious commodity that probobly wouldn't be plentiful enough to use for NTR fuel. A LANTIR type LOX-boosted NTR engine would mitigate this somewhat, but would still use lots of Hydrogen and cut into the engines' efficency. The added weight of the reactor and LOX systems would probobly eliminate much LANTIR efficency advantage.

With regular cryogenic chemical engines, most of the propellant mass is Oxygen, which will probobly be much more plentiful on the Moon. Refueling at the Moon is probobly superior versus trying to bring round-trip Hydrogen fuel from Earth.

Martin_Tristar · 2005-03-13 20:32:10

GCNRevenger,

Again, more information relating to NTR Engine systems. Again you are against the implementation of NTR Engines in LEO to Moon operations, and marginally better support for Mars missions. Its time to consider the current chemical drive systems are dead for highly frequent and long haul space voyages. We need to develop a new long term drive system for continuous use for years not in frequent burns and low duration systems.

I also agree with the thoughts on the various lobby groups including the anti-technology, anti-nuclear and environmental groups having too much say into development of space. The " what if " scenerios have been work overdrive until you can find a reason not to do something, We could say the same for every piece of technology and we could say many reasons why we should, we need to balance fair risk with fair reward.

GCNRevenger · 2005-03-14 09:42:48

Thats correct, because it is a simple fact that low-temperature NTR engines don't provide a gigantic performance edge, they are expensive to produce, and their fuel is difficult to get/store in space.

For Mars, they make sense, since you need the most amount of payload possible, you won't be using them that often, they need not be too big, and they won't be returning to Earth.

As far as "long haul," I would point out that getting to the Moon is not a "long haul."

And your nonsense babble about "need new long term drive systems, not frequent burns" makes no sense at all, in space there is nothing special about small long burns versus big short burns for systems of similar Isp. Actually, the short burn might get you there faster, since you will spend less time accelerating to Vmax.

I am all for nuclear systems, don't get me at all wrong about that, I am saying that their bennefits should be carefully weighed against their costs and risks. NTR engines for Mars ships or heavy space probe? No problem. Nuclear reactors for Lunar bases, Mars expeditions, heavy probes? No problem...

Its really simple: as long as the reactor stays safely in space or in orbit during and (within a year or two) after operation, its just fine. The only thing I have a problem with is operating a reactor in Earth's atmosphere or on a suborbital flight, which is a much, much bigger risk. In such a case, the risks of operation before reaching/staying in space far outweigh the rewards.

GCNRevenger · 2005-03-14 21:42:55

More thoughts:

I am undecided if it is worth the risk to return a hot reactor back to Earth orbit. The only ways to slow down would be to fire the engine, which will mean it will be highly radioactive if the engine failed & crashed, and would require lots of fuel to slow down... or to aerobrake, which would require intentionally entering the atmosphere with the reactor onboard, iffy safety. The question here is how much radioactivity is too much for safe aerobraking, and would dispursion over an area during an aerobrake "mishap" sufficently mitigate the risk?

If the reactor has just returned from a Lunar cargo tug mission, it will still be intensely radioactive from its last firing a few days ago. If it is returning from a 6-9mo circut to Mars, then that is a question mark...

One nuclear engine that doesn't have any of these problems is, of course, the GCNR engine. The big difference being, that after the engine is fired, you dump the spent fuel overboard into space... problem solved. The drawback being, nobody knows how to build a GCNR engine that wouldn't melt yet, and you would need a pretty big engine to reach criticality.

But if you are looking for a Mars colony ship or manned Jupiter mission without the fuss of building a compact, light weight, and portable fusion reactor... GCNR is it.

SpaceNut · 2005-03-18 06:17:22

Well this article explains some of the struggle Nasa and other face in using some forms of nuclear materials.
The article also goes on to describe how the material is processed for use in RTG reactors such as those slated for the new horizon mission and of the past voyagers as well.

[url=http://www.boiseweekly.com/gyrobase/Content?oid=oid%3A480] From Potatoes to Plutonium
Idaho's most infamous export might be about to change[/url]

Tim Frazier was raised near Dayton, Ohio, and spent his childhood within sight of the Department of Energy (DOE) Mound Site in nearby Miamisburg. Unfortunately, the plant is not only known for working to advance nuclear technology. It also caused extensive uranium contamination of the groundwater aquifer, and soil contamination including radium, tritium and plutonium-238. Despite problems associated with Mound over the years, Frazier grew up to manage the facility.

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#1 2005-03-12 22:39:24

Re: Nuclear struggle for NASA! - Nuclear flight for Manned flights.

#2 2005-03-13 08:58:02

Re: Nuclear struggle for NASA! - Nuclear flight for Manned flights.

#3 2005-03-13 11:18:18

Re: Nuclear struggle for NASA! - Nuclear flight for Manned flights.

#4 2005-03-13 11:24:22

Re: Nuclear struggle for NASA! - Nuclear flight for Manned flights.

#5 2005-03-13 11:46:20

Re: Nuclear struggle for NASA! - Nuclear flight for Manned flights.

#6 2005-03-13 20:32:10

Re: Nuclear struggle for NASA! - Nuclear flight for Manned flights.

#7 2005-03-14 09:42:48

Re: Nuclear struggle for NASA! - Nuclear flight for Manned flights.

#8 2005-03-14 21:42:55

Re: Nuclear struggle for NASA! - Nuclear flight for Manned flights.

#9 2005-03-18 06:17:22

Re: Nuclear struggle for NASA! - Nuclear flight for Manned flights.

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