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NASA Looks At Reviving Atomic Rocket Program (newatlas.com)
Big Hairy Ian shares a report from New Atlas: When the first manned mission to Mars sets out, it may be on the tail of an atomic rocket engine. The Space Race vintage technology could have a renaissance at NASA after the space agency's Marshall Space Flight Center in Huntsville, Alabama signed a contract with BWXT Nuclear Energy to develop updated Nuclear Thermal Propulsion (NTP) concepts and new fuel elements to power them.
Today, with NASA once again considering the challenges of sending astronauts to Mars, the nuclear option is back on the table as part of the agency's Game Changing Development program. Under this, NASA has awarded BMXT, which supplies nuclear fuel to the U.S. Navy, a $18.8-million contract running through September 30, 2019 to look into the possibility of developing a new engine using a new type of fuel. Unlike previous designs using highly enriched uranium, BMXT will study the use of Low-Enriched Uranium (LEU), which has less than 20 percent of fissile uranium 235. This will provide a number of advantages. Not only is it safer than the highly enriched fuel, but the security arrangements are less burdensome, and the handling regulations are the same as those of a university research reactor. If NASA determines next month that the LEU engine is feasible, the project will conduct testing and refine the manufacturing process of the Cermet fuel elements over the course of a year, with testing of the full-length Cermet fuel rods to be conducted at Marshall.
Slashdot reader Big Hairy Ian adds: "At the very least it looks much more feasible than Project Orion."
Today, with NASA once again considering the challenges of sending astronauts to Mars, the nuclear option is back on the table as part of the agency's Game Changing Development program. Under this, NASA has awarded BMXT, which supplies nuclear fuel to the U.S. Navy, a $18.8-million contract running through September 30, 2019 to look into the possibility of developing a new engine using a new type of fuel. Unlike previous designs using highly enriched uranium, BMXT will study the use of Low-Enriched Uranium (LEU), which has less than 20 percent of fissile uranium 235. This will provide a number of advantages. Not only is it safer than the highly enriched fuel, but the security arrangements are less burdensome, and the handling regulations are the same as those of a university research reactor. If NASA determines next month that the LEU engine is feasible, the project will conduct testing and refine the manufacturing process of the Cermet fuel elements over the course of a year, with testing of the full-length Cermet fuel rods to be conducted at Marshall.
Slashdot reader Big Hairy Ian adds: "At the very least it looks much more feasible than Project Orion."
yeah, 20 billion. nasa budget. thats UGE ! that's about 1/1000 th of the DOD's budget.
So what happens if there's a fault and the RSO hits the self-destruct button?
Those political donations from BWX really paid off!
Why else is a company that has had nothing to do with rocketry of any kind doing this instead of NASA, the Air Force or a University?
It's kind of sad because it would be nice to see an atomic rocket instead of vanishing pork money funding a very expensive undergraduate level literature survey.
It's a study into feasibility, not a launch program. Presumably, given Musk's talk of Mars, SpaceX is also doing a study and the can be compared. It's pretty normal to look at multiple options for something so bold, before committing, or taking on faith the first organisation to say they can do it. SpaceX has no track record in deep space (NASA does), so I'd want to see a detailed work up from SpaceX too before signing a contract.
Look at what a horrific disaster all those exploding reactors have been on navy ships and submarines!
When will people realize the horror of nuclear reactors! Radiation! Radiation!
Not to mention the ecological disaster that there would be if evil radiation were to leak in space!
Do people not realize it is the one truly pristine environment left?
Every single ONE of the radioactive RTGs that we have sent up on rockets has caused untold deaths! The chemical rockets on the other hand make rainbows brighter and butterflies more colourful!
The horror..
Come on. You can die even if you strap yourself behind a horse. You remind me of people who said (about 2 centuries ago) that going over 40 km/hours kills a human.
Speed doesn't kill
Acceleration may kill (solution, don't accelerate beyond harmful limits).
Radiation may kill (shield yourself).
Patents Drive Free Software as Hurricanes Drive Construction Industry
I'm replying as AC because I modded-up this and I think questions like this should be answered from time to time, even though I disagree with the apparent sentiments.
Firstly, "paying down the national debt" isn't necessarily as useful as one might think. Certainly, avoiding indebtedness to foreign powers may be of strategic importance, and rapid expansion of national debt for big spending programs might stoke high inflation that drives economic instability. However, most of the national debt (along with most money in the economy) is funded with money that has been created from thin-air by private-sector banks, and perhaps laundered through the economy to look more real than it is. Paying-off the original debts that created the money causes it to disappear with the debt but it provides profit in the form of interest for the banks that created the money in the first place. Very little actually goes to cover capital and interest for the deposits of any real investors, and even those originated mostly in debt to generate new assets that have been laundered and liquidated into cash for deposit. This is the world of fractional reserve banking, where almost all money in the system is born out of debt and inflation.
Now to the main point about why do this instead of "more worthwhile things we could be doing, such as curing cancer, solving world hunger, or reducing our impacts on climate change". Of course those are important and, quite rightly a good deal more money –many billions of dollars– already goes into those things than the 19 million dollars going into this project.
But blue-sky technology and pure science reap huge benefits in the long term and that simply can't be foreseen. Copernicus, Galileo, Tycho Brahe, Kepler and Newton were concerned with the motions of planetary bodies and the moon. They paved the way for the foundations of the science of mechanics which is one of the pillars of all of modern engineering and science. Franklin, Faraday and many others tinkered with electricity and magnetism, and Maxwell synthesised a theory from their experiments which gave another of pillar foundations of everything we have now. Even the highly abstract theories of Quantum Mechanics and General Relativity, formulated a century ago, now have a big impact on our everyday lives.
Everything I've described (albeit in a very brief and shallow manner) is the basis for things like MRI, CT and PET scanners, computational drug discovery, understanding climate change, GNSS/GPS and countless other technologies that have the power to benefit everyone. There are bigger political decisions to be made that will have more impact than anything gained by switching funding from atomic rockets to feeding the starving. Consider the cost of building a 2000-mile wall. And if you want another perspective, consider that, in the US alone, about $200 billion is spent each year on advertising.
Personally I have no desire to move to Mars; it's way more hostile than America would have been for early settlers, but that doesn't mean we shouldn't invest a relatively small amount. One can't imagine the long-term benefits that humanity might eventually reap from the effort.
I haven't bothered with references but if you're curious and if you really care you can easily find plenty to read about any of this.
"Instead of going to Mars, let's use our resources to do things that actually benefit people, such as stopping global warming. "
Mars is rather cool and could benefit from a bit of global warming.
Even SpaceX admits that for more distant missions (far outer planet destinations, oort cloud, etc), scaling chemical rockets is not sufficient. Nuclear rockets are also interesting for Venus, delivering crew and payload between the habitable layer (~54km) where breathable air is a lifting gas that can loft a colony, and orbit. Some of Venus's great advantages, like having nearly Earthlike gravity and thus no concerns about wasting like exist for the moon and (to a lesser extent) Mars, are also disadvantages, in that it's also nearly Earthlike difficulty to get to orbit. Furthermore, unlike Mars where your rocket rests on the ground, with Venus you have to support its fully fueled mass. While it's possible to get out with two-stage chemical rockets and re-dock the returning stages, you get much better mass fractions with nuclear. Even though nuclear pretty much only works with hydrogen propellant (the ISP drops in linear proportion to the atomic mass of the propellant), and hydrogen is not particularly common on Venus, the low propellant requirements mean that a nuclear rocket can use less hydrogen than most low-hydrogen rocket propellants that could be used were the ascent vehicle a two-stage chemical rocket.
I'm sure lots of people are going to be discussing NERVA in this comments section. It's important to realize that NERVA is obsolete technology, and there are much better designs available at present. NERVA's biggest problem was its awful thrust to weight ratio. One of the first realizations since then was that you can make a nuclear rocket with a LOX "afterburner"; at liftoff, you use LOX to vastly augment the thrust (the resulting ISP, while nothing like pure hydrogen nuclear-thermal, is still well above that of normal hydrolox). Once the high liftoff thrust requirements are no longer needed, the rocket transitions to pure hydrogen thrust for much higher specific impulse.
A variety of airbreathing modes have also been investigated which can strongly increase thrust and/or specific impulse further - thrust augmentation, nuclear scramjets, nuclear-driven turbojets, etc. Also, there have been general improvements in nuclear technology to allow for transferring higher energies to the hydrogen steam since then, as well as a number of yet-to-be-proven concepts. For example a fission fragment reactor can theoretically get the hydrogen much hotter than the reactor itself; in such a system, the goal is to (as much as possible) capture only neutrons in the fuel and only thermalize fission fragments (which carry most of the energy) in the hydrogen. But you definitely wouldn't pursue a fission fragment reactor with LEU....
He's really very... gentle... and fuzzy. We're becoming fast friends.
No. This sounds like a solid core nuclear rocket. Like NERVA or Dumbo. It's not that different from a plain old nuclear reactor. There's a core with the uranium rods in the middle inside an enclosed metal shell which heats the liquid hydrogen or liquid ammonia reaction mass outside that then gets ejected outwards. The only way it would leak radiation is if the metal containment failed and even then it would be a much lower level of radiation than a nuclear explosion. It would be more akin to a nuclear power plant venting over like what happened in Chernobyl.
I've heard of no plans to use these in the atmosphere. From the sounds of it they're basically planning to make a nuclear engine similar to Dumbo so that has too low a thrust-to-weight ratio to even consider using as a first stage and would only be used in upper stage application (i.e. only fired in space) to propel probes or spacecraft to far away planets.
Tu pang, what?
I believe that's Klingon. Damned trekkies...
Ezekiel 23:20
For high-mass, Hohmann-transfer spacecrafts bound to Mars, nuclear really isn't the best propulsion option even in the long run. It's basic physics. At the low delta-Vs required for the flight, the mass ratios and volumes required are disadvantageous for nuclear, as is mined mass usage from all hydrogen sources with the exception of perhaps mining hydrogen directly from Saturn or one of the other smaller gas giants.
Ezekiel 23:20
- Tungsten Cermet Reactors presentation.
- Dumbo: A pachydermal rocket motor paper.
Exactly.
What could go wrong ?
Rockets have, at best, 98% reliability (Using old and proven tech, new one is muuch wooorse.).
that means that 2% of the time, they explode and get dispersed in the atmosphere, low or high, soon or late.
So it's a very very very very very very bad idea to send fissile material to orbit and then to escape velocities.
(the small quantities of the mars rovers and similar RTG powered probes are only comparable to a very weak Hiroshima in mass)
aaaaaaa
WHAM! WHAM! WHAM! WHAM! /Why not vacation in beautiful Bellingham, Washington?
.
Airbreathing modes? In open space nuclear designs could be the kings of specific impulse, but getting to LEO with one is going to be a lot more difficult, especially politically.
Fission designs have the advantage that a crew could be 'shaded' from solar flares by the heavy-isoptope fuel load. The ship's safe room would be positioned to exploit this effect.
Just takes a lot of people with BIG BRASS BALLS!
love is just extroverted narcissism
FINALLY !
It's been about 50 years that the NERVA program has been on hold - mostly because of the atmospheric nuclear test ban treaties of the time, and also the space nuclear bans related to those test bans.
Check out these 2 sites / articles for some history of a WORKING nuclear powered rocket engine - - -
NERVA testing - https://www.youtube.com/watch?...
and - http://www.daviddarling.info/e...
I was in high school, and missed out on actually seeing one of the tests at Jackass Flats in early 1967 because I was underage and couldn't get the security clearance needed - really sucked.
redneck geek
Even SpaceX admits that for more distant missions (far outer planet destinations, oort cloud, etc), scaling chemical rockets is not sufficient.
Well, on the Falcon Heavy page they list payload to Pluto and escape velocity is only 0.39 km/s (0.03+0.02+0.11+0.20+0.03) more delta-v than that so anything inside the Sun's gravity well like the far outer planets is quite reachable by chemical. If you do ITS-style fueling in orbit or slingshot around Jupiter probably with a decent size payload too. The Oort cloud is a lot further out though, Voyager is at 139 AU and the lowest estimate for where it might begin is 2000 AU so like 500+ years even with all the gravity slingshots Voyager got. Since you won't get the same slingshot again until 2151 and the chemical propulsion is only a small part of Voyager's total speed I think you're looking at centuries even with a massive efficiency boost through fission.
Live today, because you never know what tomorrow brings
Even better, you shouldn't need to lift the fuel from Earth's gravity well.
Ezekiel 23:20
If Humans were logical creatures we'd stop funding all military, form a planetary government, and stop all talk of Martian colonization since that's not required and diverts resources from social programs and science.
Can the engines run on reprocessed spent fuel rods from nuclear reactors?
Nuclear thermal is a nice technology for some missions (but probably not Mars where the delta-V isn't all that high). The problem is that I don't see it as political realistic. There are political issues with radioisotope generators on deep space probes - for example the proposed Europa lander will have a very limited lifetime because it will only have chemical batteries.
I think a NTR could be launched safely if it hasn't been turned on yet, but I also think that there is not a snowballs chance in hell of it being politically acceptable.
Its also not all that useful. You can do Mars and Venus without nuclear propulsion. The outer planets are probably better served with electrical propulsion since the travel time is so long that multi-year acceleration isn't out of the question. As long as that acceleration is not too far from the sun, solar will work.
I'm personally a big fan of developing space nuclear technology, I just don't think its likely to happen.
However, they work much better for non-Hohmann transfer orbits. Or non-lowest dV Hohmann transfer orbits. There are advantages to getting to Mars more quickly. Keeping the crew alive being one of them.
Sure you can put a lump of metal anywhere in the solar system with chemical rockets. When you've got people riding along how long it takes tends to become more of a concern.
When I took Intro Chemistry at San Jose State University (before they kicked me out for playing too much Magic: The Gathering into the wee hours), we had a tour of the research reactor in the basement of the science building. We were reassured that the reactor was completely safe. If it ever did go kablooey (extremely unlikely), it would only blow up the building. Rest assured that I went into computers instead of nuclear science.
"Paying-off the original debts that created the money causes it to disappear with the debt but it provides profit in the form of interest for the banks that created the money in the first place."
If you could direct me to this bank that only makes money in interest if you pay off a loan, I would be most appreciative.
True, but even slight increases (1-2 km/s in case of Mars) cut off most of the time; afterwards, there's only diminishing returns. And we can do extra 1-2 km/s chemically just fine. Not to mention that arrival speed increases much more sharply than departure speed (and you don't want to crash into Mars at 20 km/s). However, in case of nuclear thermal propulsion, the use of asteroid-mined propellant only breaks against chemical propulsion after reaching like 10-12 km/s (that's from LEO, so about 18-20 km/s of Earth departure speed, about 47-49 km/s of heliocentric speed after leaving Earth's sphere of influence, and about 35-37 km/s in infinity). So unless you're going for the Oort cloud, it doesn't seem worth it. It's marginally better if you're lifting pure hydrogen from Earth's gravity well, but that's as unsustainable as lifting any bulk material from Earth, and the payload volume issues are still there (remember, it's only 70 kg per cubic meter for liquid hydrogen).
Ezekiel 23:20
See my comment above.
Ezekiel 23:20
Should have read "only breaks even..."
Ezekiel 23:20
If Humans were logical creatures we'd stop funding all military, form a planetary government, and stop all talk of Martian colonization since that's not required and diverts resources from social programs and science.
That makes sense if you look no farther than your navel, and plan for no later than next week. But on a long enough time scale, a rock is going to come along and wipe out our species, and we also develop ancillary technologies while figuring out how to explore space which pay dividends right here on Earth. Unfortunately, much of our leadership is just as short-sighted as you are.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
The one I replied to? Saw it, thanks.
Why is thorium never consider. It is a safer fuel, liquid in reactor use, easy to contain when things go bad, being a liquid you can drain it off into several containment vessels and the waste product much easier to contain as most of it is lead.
Why? Same reason we use uranium; can't make a bomb. Almost all thorium byproducts are at the end of the fission scale, but Thorium is fairly easy to find in nature; easier than uranium.
Hell the lead might make good ejection mass for a ship in flight. Solar wind would in time drive it out of the system, just don't point your exhaust at a planet. That would be rude.
So the truth. uranium mining has stopped in the USA since the second Russian revolution. We have been processing their nuclear bombs in our reactors; we paid well for the privilege but we've used up all they are willing to part with. We are out of fuel. This was all discussed two years ago in Wall Street Journal. Yes I am well read.
Somebody, like in the old days, NASA, needs to get the ball rolling again. This time not for weapons. We have all those old nuclear power plants without fuel rods. We can't ship them to France (they have a nice breeder reactor), hell you can hardly ship them at all as people scream 'not in my backyard!' I want the power, not the clean up. I can't understand what the issue is. We have aircraft carriers with two to six reactors on board. What is the issue with them transporting fuel rod? Not safe enough?
So what is likely to happen (mining->refinement->new weapons=more job), (old weapons->conversion industry->power plants=more money) NASA pays for pie in the sky. Same thing that created the ICBM; we called it the Apollo missions which ended when the last of the ICBM programs were done. Congress is hiding their under the table support for the the nuclear power industry via NASA and pie in the sky. So is China by the way.
All right I admit the technical expertise to make nuclear weapons is going away and creating and maintain reactors is too. With idiot nations (Iran,N Korea, India, Pakistan) all working on bombs we should still have the ability. Just don't hid it under NASA's skirt.
It seems that less enriched fuel would require a larger, heavier engine. They may actually build one, but up front after thinking it out, or eventually after seeing the practical problems, they will discard the LEU engine concept.
E Proelio Veritas.
as in, how many million tons of chemical fuel to boost the reaction mass (water) into low orbit?
Nuclear engines do not have higher specific impulse than LH2-LOx and thus, the reaction mass will be GREATER and require a larger chemical rocket to hit LEO.
Thus a nuclear engine will have to be a low delta-v ion/magnetic drive.
So, reaction mass will go up separately, on Chemical rockets and will be even MORE expensive.
Is less than what it cost to refuel a shuttle SRB
There are existing reactors in the hundred-kilowatt range and potential for development of megawatt range reactors, which are feasible for space - spent about 3 hours today just reading up on VASIMR and MPD engines, which - when combined with modern designs for nuclear reactors - will open up speedy access to the entire solar system, and far beyond. Check this list of reactors - old, new and potential - and the energy outputs we've already achieved: http://www.world-nuclear.org/i... The future of space exploration, is through nuclear reactors and advanced ion engines. This could have been done decades ago - the technology is more than ripe enough, to actually go ahead and do this - now.
Go watch the Boondocks, most black people know all about the lunacy of the left and the contradiction between modern money-making black "pop culture", and Martin Luther King's noble and righteous motives and goals.
MLK envisioned a future where people would be judged by the quality of their character, rather than the colour of the skin. A "colour-blind society" where people would succeed based on hard work, honesty and justice for all. He never said anything about silencing people who were white from speaking the truth, he just wanted black people who were at the time segregated, sent to the back of the bus and many other social restrictions to be treated the same as everyone else!
MLK will be spinning in his grave right now, worrying his little heart out about where BLM and BAMN could lead black people in the future, namely civil war or an SJW cult regime, under which many (mainly white people) will suffer; all in his name and on the back of his achievements; the complete antithesis of his goals.
This tagline was transcoded to result in at least one smirk. If you experience failure to smirk, please consult your Gen
NERVA was designed for operation in the atmosphere (it doesn't exhaust radioactive material). Also, Earth is not the only body in the solar system with an atmosphere.
He's really very... gentle... and fuzzy. We're becoming fast friends.
Certainly, but 'airbreathing' implies an oxygen-rich atmosphere. There is only one of those in the solar system.
It's true, but the benefits are questionable then. Hell, they're somewhat questionable even with hydrogen, since solar thermal propulsion has slightly higher Isp because of the heat exchanger being inert. But maybe a nuclear rocket would be good for jumping around Mars, using CO2 as a working fluid.
Ezekiel 23:20
No, the one you didn't reply to.
Ezekiel 23:20
You be the judge...
https://www.opensecrets.org/pa...
Just another day in Paradise
It's logical that we have divergent interests and therefore benefit from having more than one government, also as fallback when one fails.
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Airbreathing does not in any way, shape or form imply an oxygen-rich atmosphere. The most important aspect of air to a nuclear rocket is not oxygen, it's simply reaction mass.
He's really very... gentle... and fuzzy. We're becoming fast friends.
Getting married could kill you, too. If your wife is a serial killer. :/
"It is no measure of health to be well adjusted to a profoundly sick society." - Jiddu Krishnamurti