A New Nuclear Rocket Concept Could Slash Mars Travel Time in Half (gizmodo.com) 47
"Engineers from Ohio State University are developing a new way to power rocket engines," reports Gizmodo, "using liquid uranium for a faster, more efficient form of nuclear propulsion that could deliver round trips to Mars within a single year..."
Nuclear propulsion uses a nuclear reactor to heat a liquid propellant to extremely high temperatures, turning it into a gas that's expelled through a nozzle and used to generate thrust. The newly developed engine concept, called the centrifugal nuclear thermal rocket (CNTR), uses liquid uranium to heat rocket propellant directly. In doing so, the engine promises more efficiency than traditional chemical rockets, as well as other nuclear propulsion engines, according to new research published in Acta Astronautica...
Traditional chemical engines produce about 450 seconds of thrust from a given amount of propellant, a measure known as specific impulse. Nuclear propulsion engines can reach around 900 seconds, with the CNTR possibly pushing that number even higher. "You could have a safe one-way trip to Mars in six months, for example, as opposed to doing the same mission in a year," Spencer Christian, a PhD student at Ohio State and leader of CNTR's prototype construction, said in a statement.
CNTR promises faster routes, but it could also use different types of propellant, like ammonia, methane, hydrazine, or propane, that can be found in asteroids or other objects in space.
"Some potential hurdles include ensuring that the methods used for startup, operation and shutdown avoid instabilities," according to the researchers' announcement, as well as "envisioning ways to minimize the loss of uranium fuel and accommodate potential engine failures."
But "This team's CNTR concept is expected to reach design readiness within the next five years..."
Traditional chemical engines produce about 450 seconds of thrust from a given amount of propellant, a measure known as specific impulse. Nuclear propulsion engines can reach around 900 seconds, with the CNTR possibly pushing that number even higher. "You could have a safe one-way trip to Mars in six months, for example, as opposed to doing the same mission in a year," Spencer Christian, a PhD student at Ohio State and leader of CNTR's prototype construction, said in a statement.
CNTR promises faster routes, but it could also use different types of propellant, like ammonia, methane, hydrazine, or propane, that can be found in asteroids or other objects in space.
"Some potential hurdles include ensuring that the methods used for startup, operation and shutdown avoid instabilities," according to the researchers' announcement, as well as "envisioning ways to minimize the loss of uranium fuel and accommodate potential engine failures."
But "This team's CNTR concept is expected to reach design readiness within the next five years..."
Not in our lifetime (Score:2)
But "This team's CNTR concept is expected to reach design readiness within the next five years..."
So not even useful designs yet, just research, which is necessary to move forward I guess. We DO have nuclear propulsion engines that have been fully designed and researched and we aren't even building those as far as I can see. The real key will be if it ever gets cheaper to build and maintain those nuclear engines, since the entire space industry is now being driven by the private commercial sector, which is incredibly risk and cost adverse. Corpo interests would rather the designs be LESS efficient if t
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the entire space industry is now being driven by the private commercial sector, which is incredibly risk and cost adverse
The private sector may be more cost-adverse but it is far less risk-adverse. There is no way a government program would have been allowed to have as many failures as we've seen with Space-X's Spaceship.
The reason nuclear propulsion has not been adopted is because of the huge risks in launching large amounts of fissionable material to orbit. Even far smaller radio-thermal power generators (RTG), such as those used by the Cassini and Galileo missions, lead to significant precautions during launch. A nucle
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Yes, but if it were cost effective and reasonable you'd see SpaceX doing both research and lobbying efforts to allow private sector organizations like themselves to do this. As our current tech chemical propulsion systems can effectively reach Mars at a reasonable cost with limited risk (and re-usable rockets now), and the cost of fissionable material is an order of magnitude higher than liquid oxygen and kerosene, both of which can be negotiated on an international market or produced in-house, it won't hap
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And as soon as SpaceX has an accident and spews nuclear fuel across the landscape we'll see SpaceX claiming it is a job for the Fed. Gov. to clean up. Elmo is a visionary in that sense.
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Yes, and we saw that recently with the debris from the starship explosion. But with pro-musk forces in the whitehouse all they would need to do is ask and they'd get approval.
My point is they *have not asked* and are not even considering this approach for the colonization of Mars, because its not economically viable, regardless of how efficient or faster it is.
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Yes, but if it were cost effective and reasonable you'd see SpaceX doing both research and lobbying efforts to allow private sector organizations like themselves to do this.
I agree, my point is that the reason it is neither reasonable nor cost effective is because of the huge dangers around launching large amounts of fissionable material to orbit. The technology is actually relatively simple and cheap, at least compared to a chemical rocket, and the cost of the fuel is also not an issue. The problem is getting the fuel to orbit without a risk of causing widespread nuclear contamination.
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Didn't the government pay for nearly all of it anyway?
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Not unless you mean pay for it by paying for payload space or tax credits. Compared to ULA and other companies in the old school military industrial complex they have received almost nothing. Arianespace is also subsidized to be able to operate at a loss, so who cares?
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The US government subsidises Arianespace? Really?
Whether or not SpaceX is a bargain is irrelevant. The fact it they didn't have enough money to develop and launch to orbit on what Musk had and from what he was able to raise from venture capital at the time.
The way the government contracts for services has always been ridiculous and is made worse by lobbyists and corrupt politicians.
That should have been changed long ago.
Musk didn't invent rocket science and a lot of SpaceX early experts were former NASA sta
Re: Not in our lifetime (Score:1)
Re: Not in our lifetime (Score:2)
Is that in the new Blood Bowl rules?
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There is no way a government program would have been allowed to have as many failures as we've seen with Space-X's Spaceship.
I guess you missed the whole NASA space program in the 50's/60's.... Read up on the NASA space progam and you'll see that it also had a lot of accidents, even with deaths, all during designing and testing the hardware, not even counting the deaths during actual 'production' flights.
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Re:Not in our lifetime (Score:5, Funny)
Release the Epstein Drive files!
Launching Nuclear Material (Score:5, Insightful)
I suspect we will not see nuclear rockets until we develop a fusion-based one because, unlike fission-based designs fusion uses light, non-toxic, stable isotopes as fuel and so is likely to be no more dangerous than current chemical rockets.
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I theory you could launch the nuclear material piecemeal as pellets embedded in massively thick explosion and re-entrant safe containers but that would jack up the price so high it would probably make the whole thing unfeasible even with a NASA budget.
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It's just a paper design, at a time when focus needs to be on practical solutions. It's 50/50 who gets back to the moon first now, with the balance tipping in China's favour a little more every day. They will probably be the first to do a Mars sample return mission too. All based on developing well established technology, some of it novel but never pinning their hopes on getting anything too exotic or far out.
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Ah yes, just what the world needs. Another dick measuring who-can-plant-their-flag-first race. Except this time without innovation!
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Re: Launching Nuclear Material (Score:1)
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Tried and tested idea (Score:2, Interesting)
With spectacular results, too.
https://en.wikipedia.org/wiki/... [wikipedia.org]
Re:Tried and tested idea (Score:4, Informative)
The nuclear reactor on Kosmos 954 was not used for propulsion at all, it was purely for generating electrical power, the thrusters on the satellite were entirely conventional. In no way was that an example of nuclear thermal propulsion, much less the proposed centrifugal nuclear thermal design discussed in the article.
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The nuclear reactor on Kosmos 954 was not used for propulsion at all
What difference does it make? It still fell on the ground and hasn't been found, which is bad enough.
All examples of reactor-based propulsion that we know of are even worse, as they pollute profusely while in operation as the propulsion fluid is in full contact with the naked core.
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It demonstrates the issue though. You have to get the reactor up into orbit, and make sure that if and when it comes down it doesn't pollute. There isn't enough research on non-nuclear satellites re-entering the Earth's atmosphere and burning up to really be sure what the environmental impact of that is, especially with the new mega constellations.
It's probably doable, but
1) The cost will be high.
2) The tech will take time to develop and prove safe.
3) Maybe your country can do it safely, but do you trust ev
Just Use Solar (Score:2)
It seems my response to anything nuclear ends up being, "Just use solar." And so it is, yet again.
You can build a type of rocket called a solar moth [projectrho.com] that can achieve similar specific impulse (Isp) as a liquid core NTR (which is what is being described here) but is much lighter than any NTR because it doesn't require heavy neutron shielding (you can only really shield neutrons with high-Z atomic nuclei, and thus mass; that's why lead is a great neutron shield). Using non-Hohman trajectories, i.e. dropping i
Re: Just Use Solar (Score:2)
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No, low-Z materials act as a moderator, lowering the temperature of the neutrons. High-Z materials reflect the neutrons away from the shielding. The main reactor shield isn't concrete and water; it's a big steel containment vessel.
And if it does not work.... (Score:3)
Nuclear Salt Water Engine (Score:2)
The idea of having a nuclear liquid fuel rocket is not new: do a web search for "nuclear salt water rocket" and read up on the Wikipedia article that appears. And that rocket doesn't seem to have any startup or shutdown problems, just valves.
Re: Nuclear Salt Water Engine (Score:2)
When it fails. (Score:2)
liquid Uranium? (Score:2)
the article is really skimpy on details, like exactly what the "liquid Uranium" is. Is it actual molten metallic Uranium or some kind of Uranium salt?
How is this engine different from the NERVA and other Nuclear Thermal Rockets engines NASA was developing in the 1950's through the 1970's?
One question (Score:2)
Mars and Earth have wildly different distances from each other. If an actual scientist were to speak of time, they'd probably note "as little as" and "depending on opposition"
"As little as" would require the least amount of extra explanation.
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I always get a bit skeptical when I see statements like "You could have a safe one-way trip to Mars in six months, for example, as opposed to doing the same mission in a year,"
Yikes! I'm a dumbass. I corrected what I wrote to:
Mars and Earth have wildly different distances from each other depending on where they are in their respective orbits.
it generated buzz. Mission accomplished (Score:2)
It generated buzz for the university.
Sure you can get to Mars twice as fast, but that just get you closer to death twice as fast.
Look up all the ways space tries to kill us, or conversely, how we try not to die in space / Mars.
You could have a rocket ship that'll land there tomorrow. Everybody still gonna be screwed when they try and get off the planet or survive for more than the rations allotted.
maybe just maybe we should stop shitting in our own backyard and continue to make this planet habitable. After
There are issues... (Score:2)
There also is an issue whereas radiation causes molecular dislocations which cause embrittlement cracks in metals. Unlike Wigner effects the carbon in reactors, you just can't run a bake cycle during the flight to fix it. Metal cracks would be a problem w
Why this design? (Score:2)
Deceleration energy increases with speed (Score:2)
It seems like this is just some research group noodling on advanced rocket concepts, not whether they are practical or not. Any increase in SPEED to destination results in an EQUAL need to decelerate at the destination. Deceleration can occur through gravity assisted capture or aerobraking, but none of the more complex strategies for getting rid of velocity at the destination is really used because they're very inaccurate compared to a capture burn.
That's why I'll always be skeptical of these sort of promis
Great news for Whitey on the Moon (Score:2)
"Instabilities" (Score:1)
"Instabilities" = that giant boom that Marvin the Martian always wanted to hear.
Correction: kaboom (Score:1)
Correction: kaboom
A reason (Score:2)
If I understand this correctly, it requires you to toss out the uranium, so an ongoing requirement for still more uranium. Nuclear thermal keeps the reactor fuel.