Questions tagged [nuclear]

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

Filter by
Sorted by
Tagged with
44 votes
3 answers
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 ...
user avatar
  • 52.4k
29 votes
1 answer
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 ...
user avatar
27 votes
3 answers
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 ...
user avatar
  • 118k
22 votes
2 answers
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 ...
user avatar
21 votes
3 answers
6k 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 ...
user avatar
  • 227
21 votes
1 answer
799 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....
user avatar
  • 2,013
18 votes
2 answers
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 ...
user avatar
  • 5,969
17 votes
2 answers
762 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 ...
user avatar
  • 11.1k
16 votes
6 answers
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 ...
user avatar
  • 323
15 votes
2 answers
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?
user avatar
  • 366
15 votes
1 answer
2k 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 ...
user avatar
  • 20.8k
15 votes
1 answer
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 ...
user avatar
  • 20.8k
13 votes
4 answers
4k views

Nuclear Explosion in Space

Is it possible to detonate a nuclear bomb in space? If possible, then what will happen? In the Armageddon movie we watched that, after discovering that an asteroid the size of Texas is going to impact ...
user avatar
  • 443
13 votes
2 answers
2k views

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 ...
user avatar
  • 392
13 votes
2 answers
893 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?
user avatar
  • 18k
12 votes
2 answers
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 ...
user avatar
  • 16k
12 votes
1 answer
928 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 ...
user avatar
11 votes
3 answers
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 ...
user avatar
  • 218
11 votes
4 answers
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 ...
user avatar
  • 17.8k
11 votes
2 answers
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 ...
user avatar
  • 283
11 votes
1 answer
286 views

How much is known about those liquid metal droplets orbiting the Earth? (e.g. sizes, composition, orbits...) Are any actually tracked?

The question Orbit Guardians - bs, right? mentions a company proposing a smallsat that will capture then give a roughly 200 m/s retrograde "kick" to liquid metal NaK alloy droplets in LEO ...
user avatar
  • 148k
11 votes
1 answer
815 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 ...
user avatar
10 votes
2 answers
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 ...
user avatar
  • 2,373
10 votes
1 answer
1k views

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/...
user avatar
  • 2,373
10 votes
2 answers
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, ...
user avatar
  • 26.2k
10 votes
2 answers
792 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 ...
user avatar
  • 1,699
10 votes
1 answer
348 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, ...
user avatar
  • 649
9 votes
9 answers
1k views

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 ...
user avatar
  • 26.2k
9 votes
2 answers
553 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 ...
user avatar
8 votes
2 answers
484 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 ...
user avatar
  • 13.5k
8 votes
3 answers
352 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 ...
user avatar
  • 26.2k
8 votes
2 answers
912 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 ...
user avatar
8 votes
1 answer
347 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 ...
user avatar
  • 1,308
7 votes
2 answers
703 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 ...
user avatar
  • 17.1k
7 votes
1 answer
425 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?
user avatar
  • 71
7 votes
1 answer
653 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 ...
user avatar
  • 381
7 votes
1 answer
280 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 ...
user avatar
  • 148k
6 votes
3 answers
1k 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 ...
user avatar
6 votes
1 answer
581 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 ...
user avatar
  • 148k
6 votes
2 answers
195 views

Legality of nuclear debris field on the Moon?

A while ago, I asked about what happens to a nuclear engine that gets smashed into the Moon. While not conclusively answered, it's likely that the contaminated area would be of significant size. But ...
user avatar
6 votes
2 answers
298 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 ...
user avatar
  • 18.9k
6 votes
0 answers
213 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 "...
user avatar
  • 7,726
5 votes
4 answers
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 ...
user avatar
  • 2,373
5 votes
2 answers
518 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 ...
user avatar
  • 153
5 votes
3 answers
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 ...
user avatar
  • 121
5 votes
1 answer
797 views

What is the relationship (if any) between NASA's Kilopower project and its request for 40 kW reactor designs?

Gizmodo's NASA Wants to Put a Nuclear Reactor on the Moon begins NASA is teaming up with the U.S. Department of Energy’s Idaho National Laboratory to develop a non-solar power source on the Moon by ...
user avatar
  • 148k
5 votes
1 answer
780 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 ...
user avatar
  • 148k
5 votes
4 answers
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?
user avatar
  • 51
5 votes
2 answers
226 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 ...
user avatar
  • 1,319
5 votes
1 answer
744 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 ...
user avatar
  • 13.5k