A New Nuclear Rocket Concept Could Slash Mars Travel Time in Half (gizmodo.com)
- Reference: 0179249468
- News link: https://science.slashdot.org/story/25/09/15/0322251/a-new-nuclear-rocket-concept-could-slash-mars-travel-time-in-half
- Source link: https://gizmodo.com/new-nuclear-rocket-concept-could-slash-mars-travel-time-in-half-2000658084
> 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 [2]new research published in Acta Astronautica ...
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> 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, [3]said in a statement .
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> 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 [4]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..."
[1] https://gizmodo.com/new-nuclear-rocket-concept-could-slash-mars-travel-time-in-half-2000658084
[2] https://www.sciencedirect.com/science/article/abs/pii/S0094576525002838
[3] https://news.osu.edu/ohio-state-scientists-advance-focus-on-nuclear-propulsion/
[4] https://news.osu.edu/ohio-state-scientists-advance-focus-on-nuclear-propulsion/
Launching Nuclear Material (Score:3)
Nuclear rockets are nothing new but the reason they have not seen significant use is because first you have to launch them to orbit. Rockets have a not-insignificant chance of exploding or crashing during launch and when you have them loaded with lots of fissionable material the effect is like a dirty bomb that has a good chance of scattering highly toxic, radioactive debris over a large area.
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.
Tried and tested idea (Score:3)
With spectacular results, too.
[1]https://en.wikipedia.org/wiki/... [wikipedia.org]
[1] https://en.wikipedia.org/wiki/Kosmos_954
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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.
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 [1]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
[1] https://www.projectrho.com/public_html/rocket/enginelist.php#solarmoth
And if it does not work.... (Score:2)
...fallout will slash humanity in half!
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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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?