Questions tagged [nuclear]

Questions regarding the use of nuclear devices in space exploration, e.g. to power or propel spacecraft.

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1answer
142 views

Dispose Earth's nuclear wastes towards the sun [duplicate]

If rockets are reliable, can we throw our nuclear wastes towards the sun? The sun's gravity and it's internal energy will do the rest.
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1answer
73 views

Is “nuclear electrothermal” a recognized term for a specific technology?

Is the term "nuclear electrothermal" recognized as referring to a specific type of propulsion technology (specifically, the nuclear thermal rocket with heat engine and arcjet afterburner)?
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Options for (high-thrust) RCS with Isp beyond that of chemical?

There are a number of potential options for high-performance engines in the future: nuclear pulse propulsion, NTR, gas-core NTR, nuclear electrothermal, and potentially even fusion rockets. However, ...
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111 views

How do large thermonuclear explosions on the ground affect satellites in LEO?

High altitude nuclear explosions will completely render electronic devices on the ground useless (unless protected, with lead coating for example). How are satellites affected by such explosions? ...
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3answers
146 views

Would capture of a uranium-rich asteroid open new possibilities?

It seems that energy production in space is a limiting factor. We can use photovoltaics, but they're of minimal value past Mars, and many interesting places (like the moon) have very long nights. The ...
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508 views

Could a thermal nuclear propulsion double as a nuclear reactor?

Nuclear thermal propulsion takes hydrogen and introduces it to enriched uranium that then heats up the gas and expels it to create thrust. Could you use also use the uranium to heat up water instead ...
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1answer
98 views

Using recent technology, how much electrical power could a nuclear reactor launchable by a low-level heavy-lift vehicle be developed to produce?

The main purpose behind asking this question is to ascertain the potential power-to-weight ratio of reactors built using modern-derivative technology (i.e. either Generation III derivatives or ...
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Can we re-fuel solid-core nuclear thermal rockets?

Most solid-core nuclear rocket designs seem to have a rather short fuel lifetime (and one that wastes most of the uranium or plutonium) due to the buildup of fission products (combined with the very ...
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Why do nuclear rockets (e.g. NERVA) have such poor Thrust-to-Weight ratios?

Nuclear fission releases far more energy per kilogram of fuel than conventional hydrocarbon sources. However, proposed nuclear rocket engines like NERVA (https://en.wikipedia.org/wiki/NERVA), while ...
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Is the BBC's explanation of nuclear thermal electric propulsion wrong?

The new BBC News item New engine tech that could get us to Mars faster says: Once Orion has been connected to the transfer vehicle, a nuclear electric rocket would be used to get the crew capsule and ...
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Are DUMBO, TIMBERWIND, and other high-thrust NTRs realistically going to deliver on promises of very high thrust/weight?

Nuclear thermal rockets (NTRs) are notable as the most mature technology (the second-most-mature is Project Orion) to provide both high thrust and higher specific impulse than chemical rockets. But "...
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225 views

LANTR has been proposed; why not bilateral CHEMANTR?

Normal solid-core nuclear thermal rockets use a nuclear reactor to heat gas (almost always hydrogen, since higher molecular weights cause miserable performance) and expand it through a converging-...
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Would it be possible to send a nuclear bomb to Europa and make a hole in the ice of more than 11 km?

The idea is to carry an atomic bomb in an orbiter and throw it towards the surface, would it be plausible?
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85 views

What would be the cost of a thorium reactors at the core of a large starship? [closed]

Thorium is a high power substance that can contains large amounts of energy in a small space. How much would it cost to install and maintain one on a large starship? As well as using solar panels, ...
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1answer
138 views

Have nuclear explosions in space produced any debris that was subsequently tracked, or did all of them completely self-vaporize?

This answer to Where in the solar system could a nuke be tested without anybody noticing? has got me wondering if nuclear explosions (nuclear tests) in space above Earth ever produced any chunks of ...
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What is the basis of the new Russian nuclear rocket propulsion?

The New York Times' Russia Confirms Radioactive Materials Were Involved in Deadly Blast discusses the potential nuclear aspects of the recent missile test and references several time the possibility ...
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208 views

Would a nuclear turbojet with a chemical afterburner be a suitable intermediate between a pure nuclear turbojet and a nuclear thermal rocket?

NOTE: This is not the place to question the fundamental viability of nuclear propulsion in aircraft and spacecraft. For context, in a spaceplane, the higher speeds you can attain under air-breathing ...
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35 views

Have nuclear reactors been used in space [duplicate]

Have nuclear reactors ever been used in space as a way for power, instead of solar panels? If not, have any plans for one ever been made?
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144 views

Can rocket engine like NERVA be used to get into low earth orbit or higher?

I have heard of nuclear propulsion, however I wonder that is it possible for it to launch into space, and if so, how much fuel would it need?
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386 views

Could a “nuclear turbo-jet” be built?

Being familiar with jet engines myself, I wonder whether a similar device could be built to provide high $I_{\text{sp}}$ and high thrust in vacuum and space. Using the tried-and-true turbojet formula ...
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1answer
271 views

Efficiency of a nuclear thermal rocket

I am trying to calculate the specific impulse and thrust of a nuclear thermal engine, given the thermal power of the reactor, the maximum working temperature and the propellant. I'm calculating the ...
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The problem of low level nuclear waste on Mars

How is it planned to handle low level nuclear waste on Mars produced by the use of Kilowpower reactors? Nothing is mentioned in the Wikipedia article about the resulting waste or spent fuel.
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1answer
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Most recent launch of a nuclear reactor, and current barriers to launching the next one?

This question about Kilopower nuclear reactors got me thinking. Answer(s) to How many nuclear fission reactors have been launched into space? How many are still there? suggest that most nuclear ...
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347 views

What happened to Kilopower generators?

Why are we still using solar power for spacecraft? Would it be possible to replace the giant solar arrays and batteries on spacecraft with Kilopower generators?
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Is there enough energy in a rocket nozzle for fission?

How much more energy does the rocket exhaust atom have to have to be before fission can occur to create more thrust? Which exhaust byproduct atom would be the easiest to split? I understand in ...
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1answer
126 views

Bombing the Moon: how much debris would there be in stable orbit?

If someone had actually nuked the Moon (e.g. here or Bombing Moon and Mars: What would it look like? ), what's the probability of some debris reaching a stable orbit around the Moon? This would not ...
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How much CO₂ could the wind through a tunnel within the deposit near the south pole of Mars sublimate?

Within the CO₂ deposit near the south pole of Mars, according to this article 3 subunits have been found with one having the top CO₂ layer of about 300 meters thick covered by a water ice layer with a ...
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Will the sinking of a nuclear reactor into the CO$_2$ deposit on Mars cause a huge explosion? [closed]

Within the CO$_2$ deposit near the south pole of Mars, according to this article 3 subunits have been found with one having a top CO$_2$ layer of about 300 meters thick covered by a water ice layer ...
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1answer
165 views

Why didn't the NERVA rockets use a higher neutron flux?

One of the big problems with NERVA was that the T/W ratio of the engine alone was hardly above one, making it impossible to use for getting into orbit. Since the power of a nuclear reactor is directly ...
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In what ways could a US-based commercial space company legally use nuclear power?

At the moment, commercial usage of space seems to be the next big 'thing' in space exploration. Much of this (tourism, commercial launch companies, etc) will likely use solar power or fuel cell ...
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1answer
418 views

How many nuclear fission reactors have been launched into space? How many are still there?

I remember @Hobbes's answer mentioning that the US has put one nuclear fission reactor in space, and that not much was known about Russia's program. The Bloomberg article NASA Is Bringing Back Cold ...
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1answer
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How similar are nuclear ramjets to nuclear thermal rockets?

Russia is currently developing nuclear powered cruise missiles. These presumably use nuclear ramjet propulsion in the same way that the US's Project Pluto would have. Is there enough similarity ...
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Using Kilopower without shielding

The KRUSTY reactor (the first actual test under the Kilopower project) is shown in this image. As can be seen, about half of the mass is shielding. Suppose we were using the reactor on an umanned ...
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Is it true that nuclear rockets cut the journey to Mars in half?

The biggest challenge of our Mars journey is the journey time (9 months). Now I have seen news coming stating that atomic or nuclear rockets would cut the journey time in half. Is that right? When I ...
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109 views

What is known (or can be deduced with a high degree of certainty) about the distribution of uranium on Mars?

How difficult should we expect it to be to find minable uranium on Mars? What regions of Mars would we most expect to find it in? Is there anything we know about the geology of Mars that would present ...
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Would the EMP from atmospheric polar nuclear detonations on Mars felt by orbiting spacecraft be larger or smaller than (if it were) on Earth?

Gizmodo's Watch Elon Musk Describe Terraforming Mars to Stephen Colbert links to the video (shown below). Their second article Elon Musk Clarifies His Plan to "Nuke Mars" quotes Musk from a ...
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Can people be in orbit around Mars were they to blast the poles with Nuclear bombs? [closed]

IF we launched a series of nuclear strikes on the polar ice caps on Mars, would it affect anyone in orbit around mars (assuming we could have them in orbit around Mars in such circumstances)?
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What will be the best way to convert nuclear fusion energy into thrust for a rocket?

Best means maximum thrust, safest, easy to maintain. And it's not opinion based because I'm looking for a way that's theoretically feasible and may be practical in a few years. However, if you have an ...
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How can a nuclear spacecraft be in compliance with the Test Ban Treaty? [duplicate]

Specifically, a nuclear fusion rocket. And no pulse propulsion, because I know doing that will be very hard.
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Are fission thermal engines more expensive to develop than chemical engines?

Is there something inherent in the technology of a fission thermal rocket engine that makes it a more expensive endeavour than developing yet another chemical engine? For example because of the ...
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Mining lunar thorium for building nuclear rockets on the Moon

Has there been any research on what lunar in-situ processes would have to be developed to mine and process thorium to build nuclear thermal rockets on the Moon?
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Nuclear thermal rocket working fluid performance

After reading an announcement about NASA restarting NTR (nuclear thermal rocket) research I was wondering about how a working fluid would be chosen. For clarity, the working fluid is the gas that is ...
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Are there any designs for fusion engines with similar performance to a nuclear lightbulb?

Are there any fusion thrusters with a twr > 1 and an isp of a couple thousand seconds?
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What are the non-technical barriers to creating a practical nuclear propulsion system?

You can carve it however you want - it can be purely extra-orbital, it can be NERVA, it can be Orion. What are the specific legal and political barriers that prevent it from being implemented?
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Tritium as energy source for probes?

There's this ingenious little hack video: "How to make tritium nuclear battery at home". The idea is very simple: "tritium keychain lights" - tubes with tritium and luminophor - placed between solar ...
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What was the result of the propellant predictions in the last chapter of “Ignition!”?

In John D. Clarke's Ignition! (1972), the author spends the last chapter making predictions about the future of liquid rocket propellants. I thought these were very interesting, but I realize the book ...
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What kinds of nuclear reactors are suitable for operations in space? (Beyond thermionic and RTG)

If we want a nuclear power plant in space with a capacity similar to that of a conventional water boiling turbine nuclear power plant on Earth today, what kinds of fundamental design changes would ...
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238 views

What “high-tech fission-powered mission” almost “killed” New Horizons?

When reading the Discover Magazine article How New Horizons Survived the 40-Year-Glitch and Made it to Pluto while writing this question I saw "...the new NASA administrator tried to kill New Horizons ...
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Can a nuclear detonation on Moon destroy life on Earth?

If a nuclear weapon is detonated on the moon it would launch debris into space. The debris would then fall to earth like asteroids. Would this impact wipe out life on Earth? In other words, are our ...
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Why are RTGs different colors?

This is an image of the radioisotope thermoelectric generator (RTG) for Cassini: This one was for one left on the Moon: And this one is for the Multi-Mission RTG, used by Curiosity on Mars: One is ...