Questions tagged [nuclear]

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

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43
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3answers
9k views

Did the Galileo spacecraft cause a “blotch” on Jupiter after it crashed?

There's this interesting story: Did NASA Accidentally “Nuke” Jupiter? Long story short: On September 21, 2003 Galileo is deorbited in order to prevent eventuality of contamination of Europa. It ...
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3answers
3k views

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 ...
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1answer
2k views

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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2answers
3k views

Are nuclear-powered engines the way to go for space exploration?

I often think about the future of humanity and how to achieve it. Despite criticism, the USA and USSR achieved significant scientific breakthroughs, such as: putting the first man in space landing ...
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3answers
5k views

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 ...
21
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1answer
779 views

Is there any ongoing research in nuclear pulse propulsion?

Nuclear pulse propulsion seemed to be quite actively researched up until the 1990's, with a few projects that saw some rather promising results (some that could theoretically reach over 4% light speed....
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2answers
4k views

Why does Curiosity use an RTG rather than solar (as Spirit and Opportunity do) for power?

Why did Curiosity choose to go with nuclear power? While solar panels have issues with Martian dust, this was a known factor before the 2004 Spirit and Opportunity mission. Why then did the 2004 ...
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6answers
8k views

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 ...
16
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2answers
718 views

How does the launch risk posed by plutonium compare to the launch risk posed by propellants?

For outer solar system exploration, virtually the only feasible power subsystem are Radioisotope thermoelectric generators (RTGs). These include plutonium, which may carry considerable risks (see ...
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2answers
1k views

What are the economics of Nuclear Thermal Propulsion?

Can anyone breakdown the cost of developing and implementing an upper stage nuclear thermal engine? After development, what could the price be of each engine produced?
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1answer
1k views

How does the launch risk for a plutonium RTG and a uranium fission reactor compare?

I was looking at this answer that talks about how a good alternative to Radioisotope Thermoelectric Generators would be fission reactors. It makes a number of good points, but in the comment thread ...
15
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1answer
2k views

What does it mean for a launcher to be 'nuclear-certified'?

This article says NASA has booked a nuclear-certified Atlas 5 for the launch of the Mars 2020 rover, and says this: currently, Atlas 5 is the only launch vehicle that holds a NASA certification ...
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2answers
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Could we detect a nuclear explosion near Proxima Centauri?

How big would a nuclear explosion in open space around 1 AU from Proxima Centauri have to be for it to be detectable with current technology? Assume best-case scenarios, such as we're specifically ...
13
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2answers
868 views

Has there been any nuclear thermal rocket test program after NERVA?

Has NASA tested any nuclear thermal rocket engine after dropping the NERVA program? Is there any current ongoing mission to use nuclear power to make a rocket fly?
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2answers
4k views

Nuclear Explosion in Space

It is possible to detonate a nuclear bomb in space, if possible then what will happen? In Armageddon movie we watched that, after discovering that an asteroid the size of Texas is going to impact ...
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2answers
1k views

Nuclear thermal rocket specific impulse calculation uses 1 amu, is that wrong?

Following the parameters in the Wikipedia nuclear thermal rocket article, it seems to paint somewhat of a shaky world view. Consider these quotes: Current (2010) 25,000 pound-thrust reference ...
12
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1answer
909 views

Is there an alternative to nuclear reactors for high-power spacecraft?

Many of my favorite ideas for space exploration, such as large outer solar system probes, or the Mars Direct human Mars exploration proposal, require nuclear reactors to supply the high-power ...
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3answers
4k views

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 ...
11
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4answers
5k views

Would it actually be feasible to drop a nuclear bomb from a satellite?

During the Cold War, one of the main reasons for space exploration was military/propaganda purposes. One of the things that the US was worried about was the prospect of a nuclear bomb being dropped ...
11
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2answers
2k views

Is it possible to covertly put an EMP weapon into an ISS-like orbit by masquerading it as a legitimate launch?

I'm writing a sci-fi novel and I need some clarification on some technical issues. An HEMP is an high-altitude EMP. A 400km high, high-yield nuclear explosion over Kansas could "switch off" all the ...
11
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1answer
739 views

Is it possible to use zinc powder as a NTR propellant?

The ISP of a propellant is important when mass is the limiting factor; however, that is not exactly the case when launching a rocket. For the first part of the flight, the density of the propellant is ...
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2answers
2k views

Would a nuclear propelled spaceship still need a storm shelter?

Assume you have a sophisticated nuclear (thermal or whatever comes to mind) propelled spaceship for your summer vacation on Mars. Half way there Houston calls and informs you about an inbound solar ...
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1answer
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How does propellant flow work in a nuclear thermal rocket?

I assume a nuclear thermal rocket with a solid core first. The principle of operation seems simple enough: Bring your propellant close to your nuclear fuel, start a reaction and wait for some heat/...
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2answers
1k views

Dangers of launching a nuclear thermal rocket

Nuclear thermal rockets may have great benefits for Solar system exploration. But one consideration is that the launch of a nuclear engine from Earth's surface, as the payload on a chemical rocket, ...
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2answers
746 views

Orion Project (NPP) Pusher Plate computer models and survivability?

Does anyone know of any modern (1990's - present) computer modeling of the Orion pusher plate and its reaction/survivability to repeated plasma impacts? Regarding the 1950s/1960s Orion Project using ...
10
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1answer
338 views

What are the unique design considerations for space bound nuclear reactors (TOPAZ, SNAP 10-A), and their respective dangers?

While the US has claimed only sending one nuclear reactor (SNAP 10-A) into space, Russia has sent many. Here on earth we've adopted a Defense in Depth strategy to design for safety controls. Though, ...
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How could a fast powerful rover on Mars be powered electrically?

Background The rovers on Mars are slow and weak. If I am to believe what I read, MSL Curiosity only produces 1/6th of a horsepower electric effect, 125 watt. In order to perform tasks like deep ...
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2answers
525 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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2answers
478 views

Will Roscosmos et.al attempt to revive nuclear-engine space technology violate the OST?

This article dated. 2013 writes to say After a multi-decade hiatus, both NASA and the Russian Federal Space Agency (which developed many of its own NTRs during the Cold War but never physically ...
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3answers
331 views

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 ...
8
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1answer
325 views

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 ...
7
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2answers
660 views

For a hypothetical high-power nuclear spacecraft, where does the waste heat go?

It seems that all nuclear propulsion concepts extract fission energy as heat, and somehow convert a portion of that heat to energy in the desired form, such as electrical (e.g. to power an ion ...
7
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1answer
410 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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2answers
847 views

What happens to a spacecraft crashing into the Moon?

When planning a new architecture for lunar missions, one always faces the potential of nuclear thermal engines. Having a much higher $I_{sp}$, they offer a much higher propellant efficiency, causing a ...
7
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1answer
644 views

Is nuclear fusion a viable means of powering spacecraft?

Today while studying about nuclear reactions, I found that we can produce a large amount of energy. So, why not introduce this energy in our space exploration rockets? It may decrease the time of ...
6
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2answers
274 views

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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1answer
259 views

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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0answers
188 views

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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4answers
1k views

Why is comet deflection so hard (and how does a fusion rocket help)?

I just read an article arguing that we need very fast rockets for the deflection of comets, since we will probably detect them just several months before impact. So we need to hurry in order to pick ...
5
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2answers
492 views

Detecting a Nuclear powered vehicle from outer space (at least 8 AU or further out) feasible?

I sometime see this quote in forum arguments against "Klingon/Romulan-style" cloaking in video games that tries to be close as possible to real-life. It is quite difficult to ascertain where the ...
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3answers
538 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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3answers
2k views

Could a spacecraft take off from Earth using nuclear thermal rockets?

If enviromental concern was not taken into account, could you use a nuclear thermal rocket such as NERVA or Pewee to take off from Earth's surface into low Earth orbit? If not why? Is a launch ...
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4answers
1k views

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?
5
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1answer
612 views

Are nuclear thermal engine designs limited to about twice the Isp of existing chemical rocket engines? If so, why; what's the limiting factor?

Discussion below With Ultra Safe Nuclear engines and hydrogen propellant, how far to Mars could you get and still be able to return to Earth in an emergency? including a comment that suggests that the ...
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1answer
472 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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2answers
222 views

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 ...
5
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1answer
733 views

Was a nuclear device detonated over Earth's Moon?

Apropos Project A119 Wikipedia writes to say The aim of the project was to detonate a nuclear bomb on the Moon which would help in answering some of the mysteries in planetary astronomy and ...
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5answers
1k views

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 ...
4
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2answers
118 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
763 views

Nuclear powered engines with LFTR technology?

According to this YouTube video which starts with a 5 minutes summary the Liquid Fluoride Thorium Reactor is an extremely safe alternative to the current ones. Not only Thorium is abundant on Earth, ...