NGCR Engine

Boris_Badenov · May 29, 2006

Is anybody aware of work being done on Nuclear Gas Core Rocket Engines. <div class="Discussion_UserSignature"> <div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div> </div>

vogon13 · May 29, 2006

I can never remember which is which. Is Boris asking about NERVA or Pluto. {and do we attract the attention of Homeland security for posting it?} <div class="Discussion_UserSignature"> TPTB went to Dallas and all I got was Plucked !!So many people, so few recipes !!Let's clean up this stinkhole !! </div>

qso1 · May 30, 2006

The last that was still being actively pursued that I'm aware was VASIMR. That program was investigating the use of nuclear electric propulsion. Gas core reactors to my knowledge are still largely theoretical. That is, nuclear thermal designs were tested in actual rocket engine firings during the 1960s at Jackass flats Nevada IIRC. The VASIMR was near the point of full scale testing on a space vehicle when apparently the program was shifted to private enterprise, current status unknown. No actual full scale gas core reactors were built or tested to my knowledge. <div class="Discussion_UserSignature"> My borrowed quote for the time being:There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened. </div>

qso1 · May 30, 2006

vogon13: I can never remember which is which. Me: NERVA was a nuclear thermal design. This in general involves liquid hydrogen as the propellant which is passed through and superheated by passing through a core of fuel rods not unlike that in a nuclear powerplant. The reaction mass exhausted as a gas with an ISP approaching 1,000. Variable Specific Impulse Magnetoplasma Rocket or VASIMR is a nuclear electric engine which involves utilizing a fuel such as hydrogen but not limited to that. Heating it via radio waves in a process similar to how microwave ovens work, to the point of making it a plasma which is then exhausted as a reaction mass through a magnetic field in the exit nozzle with an ISP that can be varied between 10,000 to more than 200,000. <div class="Discussion_UserSignature"> My borrowed quote for the time being:There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened. </div>

tap_sa · May 30, 2006

"ISP that can be varied between 10,000 to more than 200,000." These figures represent estimated VASIMR exhaust speeds in m/s. Isp numbers (in seconds) are about an order of magnitude lower. Still very good though.

qso1 · May 30, 2006

Correct, I should have pointed that out. Actual numbers may vary as the saying goes, thanks. Even a system with an ISP or 10,000-25,000 would be one major improvement. <div class="Discussion_UserSignature"> My borrowed quote for the time being:There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened. </div>

webtaz99 · May 30, 2006

VASIMIR was never intended for atmospheric use. The tested NGCR units all suffered from problems with the vibrations and shockwaves resulting from the supersonic flows in the core. Although they amply proved the basic feasability of the concept, the engineering of the day was not able to build a unit capable of real-world use. With modern materials and CFD software, this could probably be done, but the Great Unwashed will never stand for it. This is another reason we need to develop the Moon. If we built and launched nuke rocket from there, it would not even show up on the environmental whackos' radar. <div class="Discussion_UserSignature"> </div>

vogon13 · May 30, 2006

And as I recall, VASIMIR hasn't been proven to work in space yet. {exhaust might arc bark around and reattach to the vehicle} <div class="Discussion_UserSignature"> TPTB went to Dallas and all I got was Plucked !!So many people, so few recipes !!Let's clean up this stinkhole !! </div>

Boris_Badenov · May 30, 2006

On NuclearSpace.com, Anthony Tate wrote an article that talks about an HLV with a GCNR engine, he states that testing was done in the 1970's but does not say where, or what kind of reactors were built. <div class="Discussion_UserSignature"> <div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div> </div>

Boris_Badenov · May 30, 2006

The original GCNR research was part of NERVA, what was PLUTO? (BTW, I just read your Bio, you are really WEIRD) <div class="Discussion_UserSignature"> <div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div> </div>

nacnud · May 30, 2006

I think pluto was part of the Rover program, another NTR.

vogon13 · May 30, 2006

Pluto was a nuclear ramjet. Probably would have worked pretty well. A reactor, bolted to the ground was test fired a few times; got hot, produced thrust; everything you want a nuclear ramjet to do. {Unlike most of you puny humans, I do not need to pad my resume} {bwa, ha, ha, ha, ha} <div class="Discussion_UserSignature"> TPTB went to Dallas and all I got was Plucked !!So many people, so few recipes !!Let's clean up this stinkhole !! </div>

scottb50 · May 31, 2006

In Space I don't care what you do to yourself, but I would be one of the first to oppose Nuclear launch vehicles. I just have a hard time seeing the mass of the Hydrogen tanks that you would need to run such an engine for even a few minutes. Then you have an extremely hot core with no coolant, not a good thing. Why you would want to do it bolted he floor I don't know? <div class="Discussion_UserSignature"> </div>

qso1 · May 31, 2006

Correct, there were plans to test a subscale unit on an unmanned probe but I don't recall what probe and do not recall that this demonstrator ever flew. <div class="Discussion_UserSignature"> My borrowed quote for the time being:There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened. </div>

qso1 · May 31, 2006

Correct, VASIMR was for use in space. I'm not a big fan of launching nuclear propelled vehicles endoatmospherically myself. Launching from the moon would be something I'd encourage although I suspect there be a few extremist types who'd find some reason to sensationalize and protest it. <div class="Discussion_UserSignature"> My borrowed quote for the time being:There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened. </div>

vogon13 · May 31, 2006

A nuclear ramjet is an engine for an aircraft. That flies in an atmosphere. Like air, you know. The Pluto reactor was stationary because it was being tested to see if it would work. If it didn't work, and was over, let's say, your house, you probably wouldn't be too happy. As I recall, the reactor put out 500 megawatts. The vehicle that this might have been used on was a largish cruise missle type thing. It's mission, would have been to fly around the Soviet Union, dropping nuclear weapons on multiple cities. Since the exhaust of this thing is radioactive, it was planned for the cruise missle to just fly around the Soviet Union after it dropped all its' bombs just to contaminate everything. <div class="Discussion_UserSignature"> TPTB went to Dallas and all I got was Plucked !!So many people, so few recipes !!Let's clean up this stinkhole !! </div>

vogon13 · May 31, 2006

Found some pictures: <div class="Discussion_UserSignature"> TPTB went to Dallas and all I got was Plucked !!So many people, so few recipes !!Let's clean up this stinkhole !! </div>

vogon13 · May 31, 2006

And this: <div class="Discussion_UserSignature"> TPTB went to Dallas and all I got was Plucked !!So many people, so few recipes !!Let's clean up this stinkhole !! </div>

vogon13 · May 31, 2006

Found a really cool one, but the file is too big, youse gets this instead: <div class="Discussion_UserSignature"> TPTB went to Dallas and all I got was Plucked !!So many people, so few recipes !!Let's clean up this stinkhole !! </div>

Boris_Badenov · May 31, 2006

I have no problem with a nuclear powered launch vehicle; if it is launched in a suitably unpopulated area, like say Omelek Island. The power available is too great to pass up. With efficient engines, your entire ship can be reusable. As for the large liquid hydrogen tanks, with efficient engines you can get the mass fraction down to around 55%, all the fuel tanks would be internal. How big is that external tank on the Shuttle anyway. Vogon, do you have the link for those pics. <div class="Discussion_UserSignature"> <div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div> </div>

Boris_Badenov · May 31, 2006

Check out this website www.nuclearspace.com <div class="Discussion_UserSignature"> <div align="center">. </div><div align="center">Never roll in the mud with a pig. You'll both get dirty & the pig likes it.</div> </div>

scottb50 · May 31, 2006

I don't object too strenuously to Nuclear in Space, but I would be completely against it for a launcher. Nuclear electric would work also but I don't really see the need for it with constant Solar power. I haven't tried to find the coolant flow numbers for a comparable reactor but I'm sure a lot of coolant goes through it and the hotter you run it the more coolant is needed. Just a guess but most Nuclear plants seem to be near bodies of water. With the density of Hydrogen I would think the amount needed would be an order of magnitude higher just to cool the reactor. The biggest problem would be getting rid of the waste heat while the reactor is just powering the ion engines and the vehicle electrical system, recirculating the Hydrogen rather than dumping it out the back. Look at how big the radiator system is on the Shuttle. I remember driving into the abandoned cooling tower in Washington, I think it was to be for a 500 or 1000 MW. reactor, which never got built. Huge and a lot of steam still escapes into the air from those. I'd rather have big solar panels and good old rockets to slow down and speed up with. A small reactor, over in a corner might be nice to have though. I think it would be much simpler to use water, brought up to LEO with dirt cheap throw away boosters. We need a lot of it for biological use and safety anyway, so why not use it to provide electricity, using solar power, and propulsion, using LH2/LOX. The Falcon 1 can take 1200 pounds and the cost will come down dramatically once they start flying. <div class="Discussion_UserSignature"> </div>

qso1 · Jun 1, 2006

You are correct in that nuclear plants are typically located near bodies of water to access it for cooling and emergency use. IIRC, the hydrogen fuel was used or to have been used as the coolant for nuclear thermal engines thereby eliminating the requirement for water as a coolant and in nuclear engines designed for space use, the engines themselves are far smaller than the reactors in nuclear plants meaning less surface area to require cooling. Water would be required for the crew life support of course and possibly as radiation shielding. Nuclear power/propulsion is not necessary for operations near earth (LEO, lunar). The main reason for utilizing nuclear power/propulsion in space is manned mars missions and unmanned missions to Jupiter and beyond. Nuclear thermal designs were studied for mars flights during the 1960s. NTR ultimately offers probably only a marginal advantage over chemical systems for the same job. Both are restricted to Hohmann transfer orbits meaning six to eight months tranist times to and from mars. Nuclear electric offers transit times on the order of three months and a wider option for transfer orbits to mars which in turn allows wider options for length of time spent at mars. In general, there are also big differences in nuclear propulsion systems for spacecraft as opposed to that used for power generation here on earth. Nuclear power systems on earth are not constrained by mass limitations. Nuclear propulsion systems for space operation have to be compact enough for delivery to orbit and use on a spacecraft that is also limited by the amount of launches it would take to get the craft to orbit. Transporting water to LEO has been an issue (Crew usage) in mars craft design which implies a significant amount of water is required. Dirt cheap boosters have yet to be proven and until they are, water will remain a significant challenge as to getting it to LEO economically. <div class="Discussion_UserSignature"> My borrowed quote for the time being:There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened. </div>

josh_simonson · Jun 1, 2006

Falcon 1 is comparable to EELVs in price/lb to orbit, and since the payload is so small the payload fraction (water) would be very low if you include the support structure and service module/tug fuel to get it where it's going. Falcon 9 is the rocket that offers the cheapest rate/lb for domestic launches.

SteveMick · Jun 1, 2006

qso1 wrote: "Nuclear thermal designs were studied for mars flights during the 1960s. NTR ultimately offers probably only a marginal advantage over chemical systems for the same job. Both are restricted to Hohmann transfer orbits meaning six to eight months tranist times to and from mars. Nuclear electric offers transit times on the order of three months and a wider option for transfer orbits to mars which in turn allows wider options for length of time spent at mars" There is no electric propulsion system that can come close to this that I've heard of due to the mass of the electric power generation system required. If you have a specific design in mind please provide more details and/or a link as I'd love to be proven wrong on this. The recent JIMO fiasco needed two years using electric propulsion just to get from LEO to escape velocity. NTR's(and solar thermal rockets) are a little faster than you think and all beat the Hohman ellipse transfer which is a specific trajectory BTW. Admittedly they are hard pressed to cut the time in half vs. chemical, but that is still signifigantly faster. Solar has much higher specific power than any nuke because concentrator type PV cells produce approx. 1KW/kg which beats any available heat to electricity conversion system (which nukes require)and the concentrator mirror required is much less massive than nukes proposed so far at Mar's distance. For unmanned to the outer planets, solar thermal/electric using a sun approaching trajectory can easily beat NTR's to Saturn although a well designed nuke(unlike the one for JIMO) could probably beat its specific power for elec. production at this distance for only a thousand times the cost. What a bargain! Steve

NGCR Engine

Boris_Badenov

Guest

vogon13

Guest

qso1

Guest

qso1

Guest

tap_sa

Guest

qso1

Guest

webtaz99

Guest

vogon13

Guest

Boris_Badenov

Guest

Boris_Badenov

Guest

nacnud

Guest

vogon13

Guest

scottb50

Guest

qso1

Guest

qso1

Guest

vogon13

Guest

vogon13

Guest

vogon13

Guest

vogon13

Guest

Boris_Badenov

Guest

Boris_Badenov

Guest

scottb50

Guest

qso1

Guest

josh_simonson

Guest

SteveMick

Guest

Similar threads

TRENDING THREADS

Latest posts

Share this page