NASA to Test Fission Power for Future Mars Colony

By Irene Klotz, Contributor, Original Story on Here


An artist’s impression of a nuclear power system, consisting of four separate fission reactors, for Mars habitats.

Credit: NASA/Kilopower

As NASA makes plans to one day send humans to Mars, one of the key technical gaps the agency is working to fill is how to provide enough power on the Red Planet’s surface for fuel production, habitats and other equipment. One option: small nuclear fission reactors, which work by splitting uranium atoms to generate heat, which is then converted into electric power.

NASA’s technology development branch has been funding a project called Kilopower for three years, with the aim of demonstrating the system at the Nevada National Security Site near Las Vegas. Testing is due to start in September and end in January 2018.

The last time NASA tested a fission reactor was during the 1960s’ Systems for Nuclear Auxiliary Power, or SNAP, program, which developed two types of nuclear power systems. The first system — radioisotope thermoelectric generators, or RTGs — taps heat released from the natural decay of a radioactive element, such as plutonium. RTGs have powered dozens of space probes over the years, including the Curiosity rover currently exploring Mars. [Nuclear Generators Power NASA Deep Space Probes (Infographic)]


The second technology developed under SNAP was an atom-splitting fission reactor. SNAP-10A was the first — and so far, only — U.S. nuclear power plant to operate in space. Launched on April 3, 1965, SNAP-10A operated for 43 days, producing 500 watts of electrical power, before an unrelated equipment failure ended the demonstration. The spacecraft remains in Earth orbit.

Russia has been far more active developing and flying spacecraft powered by small fission reactors, including 30 Radar Ocean Reconnaissance Satellites, or RORSAT, which flew between 1967 and 1988, and higher-powered TOPAZ systems. TOPAZ is an acronym for Thermionic Experiment with Conversion in Active Zone.



A photograph of the SNAP-8 generator from the Lewis Research Center, part of NASA’s Systems for Nuclear Auxiliary Power (SNAP) program. Here, engineers exposed the system to shocks and vibrations expected to occur during a launch into space and subsequent maneuvering.

Credit: NASA

Nuclear power revival

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Irene Klotz can be reached on Twitter at @free_space. Follow us @Spacedotcom, Facebook and Google+. Original article on


118 thoughts on “NASA to Test Fission Power for Future Mars Colony

  1. Power is 2nd. You first need to create an atmosphere to protect you against the sun. Dont go before the atmosphere is there.

    • And don’t try to create an atmosphere until you have created a magnetosphere to prevent the new atmosphere from get blown away.

      • ferdberple. I didn’t know. But Wikipedia (I know…) says: “Unlike Earth, Venus lacks a magnetic field. Its ionosphere separates the atmosphere from outer space and the solar wind. This ionised layer excludes the solar magnetic field, giving Venus a distinct magnetic environment.” What do you think, is it a reasonable explanation? Venus is closer to the sun, so the solar wind should be much stronger than here.

      • Mars’ escape velocity is 5.027 km/sec, while Venus’ is 10.36 km/sec. While surface temperatures for the two planets differ by more than 750 C, their top of the atmosphere temperatures are close to the same, as are their molecular weights. The mean molecular velocities for TOAs of both planets are thus the same. So both need to pick up the difference between the same starting energy and energy to escape the planet’s gravitational field. That difference is more than four times larger at Venus than it is at Mars.

      • CO2 is too heavy to have been blown away.
        I like the idea that in the far distant past, Venus was an outer gas giant and got pin-balled into the inner solar system where the solar wind blew off its lighter gases, leaving only the heaviest ones behind while Earth and Jupiter scavenged what was blown through their orbits. This could also explain it’s retrograde rotation, odd tilt, that it has orders of magnitude more CO2 than Earth and that Earth seems to have more N2 and H2O then can be well explained. Perhaps Venus hit Uranus at a shallow angle and bounced off towards the inner solar system being ‘captured’ by the Sun’s gravity leaving both planets to share unusual axial characteristics.

      • Mars lost it’s magnetic field long before Venus did.
        Venus had much more atmosphere to begin with.
        Venus has a higher gravity.

      • If an object the size of Jupiter had been “pin balled” into the orbit of Jupiter, all of the inner planets would have been tossed from the solar system.

      • Mars would also need a fiarly large stabilizing moon. Currently the planetary obluquity varies chaotically from around 10deg to possibly as much as 60 degrees. A 60 degree tilt would place much of the planet in perpetual darkness for up to 6 months at a time (Local Winter) then in traditional Day – Night cycles for 6 months (gradually increasing the length of day until summer) Then total daylight for 6 monthe durnig the summer.
        Without a stabilizing moon, there would be only a narrow band of permanent habitability near the equator

      • MarkW,
        It depends on when it happened. We see gas giants in close orbits to other stars all the time, yet we believe that they can only form in the outer parts of the planetary disk, so we know that this can happen. If it happened long before solar ignition (shouldn’t the planets have been mostly formed by the time the Sun gains enough mass to ignite?), there would have been plenty of time for orbits to settle into a more stable configuration, although pre-ignition there’s no solar winds so gas giants could form closer in …
        The hard thing to explain is how Venus ended up with a retrograde rotation and a wildly flipped axis. The only other planet close to this is Uranus. Earth was subject to a collision with a Mars sized object which resulted in the formation of the Moon and a small change in axial tile. If Venus suffered a similar collision, where’s its Moon? If two gas giants collided, especially if was not head on, it would seem to be more of an elastic collision since the atmospheres are so dense the solid cores below may never come in contact with each other before the atmospheric compression pushes the colliding planets apart, or it could just be a gravitational slingshot effect from two gas giants in crossing elliptical orbits and they never made contact.

    • You can resolve that issue by stationing near a Lava Tube Skylight. Just cover the opening adding an airlock, seal off any internal tunnels with additional airlocks (for further potential exploitation), and pressurize the sealed tube. The soil itself supplies the radiation protection that the lack of magnetic field creates the need for.

    • A planetary magnetic field would be #1 but neither this or an atmosphere is going to happen.
      Any gasses you put into the atmosphere will pretty much get blown off the planet by the solar wind in time.

      • “Time” in this case is millions of years.
        If you have a power source and manufacturing capability, you can flood Mars with CFCs. They are inert, heavy (so they won’t be lost), and act as a greenhouse gas with different absorption bands from CO2 to help warm the planet. If Mars gets warm enough then water vapor will add to the atmosphere too.

    • You wouldn’t put a suitable atmosphere on the whole planet!! Just within artificial habitats. Geesh. You see “The Martian” movie?

  2. Horrors? Mars should be powered only by renewables — Wind and Solar can power a Mars station without imperialist nuclear weapons.

    • Hopefully, the Imperialists can stay ahead of the Barbarians, whose nuclear weapons are the real problem.

  3. Anything associated with nuclear power will cause a reflexive reaction by the green blob. Expect a great deal of objection from anti-nuclear activists.

    • We do need to launch the nuclear material from Earth and I remember when we launched the plutonium based reactor the greenies were hyperventilating that the rocket may blow up on launch and contaminate a large area. Dodged a bullet on that one !!

      • I remember that. The greens’ hysterical reaction to nuclear power is just that they are frightened by unseen things. Grief, they are even opposed to fire.

      • Any natural phenomenon that cannot be observed and largely understood with the use of our five natural senses has every likelihood of becoming the object of fear and/or superstition that takes on aspects of religion. Just look at the religion that has been developed from those mysterious physically non observable, barely present atmospheric gaseous compounds, CO2 and CH4. And, then of course, since water vapor molecules are non observable, they have been easy to just ignore.
        And then there are the Koch brothers and others who can be caste into the role of the devil and his minions. Though quite primitive, and totally dependent upon applied simplism, the religion has all the pieces that are necessary for it to be a complete and self-sustaining religion.

    • Thorium could by utilized and is fairly abundant. Unfortunately though the highest concentrations are a fair distance from any potential lava tube settlement

  4. Manned exploration of Mars is a big waste of money. There are a number of techically near insurmountable issues. Electricity is only one. Water, food, oxygen, enough fuel for the return trip? There is supposed to be a return trip, right? Plus, isn’t necessary. We are exploring Mars right now–robotically.
    Classic example of bureaucratic mission creep. Philosphically NO different than EPA linear no threshold model used to justify pushing diminishing marginal return ongoing study and regulation into negative return territory.

    • Ristvan, humans are curious. If all humans had your attitude, they would all look at Mount Everest and say, “Climbing up there is a big waste of money.” But….a lot of humans have wasted a lot of their own money to climb the mountain. Why go to Mars? Because it’s there.

    • Disagree. Once electricity problem is solved, it solves all the other problems. I think the biggest factor will be the production of food instead of growing. Once we produce food, we can live anywhere and do anything. Electricity and food is the basis for everything and anything. It’s worth doing.

      • Just need to invent Star Trek “replicators” – energy to any form of matter you want including Earl Grey tea. Just have to deal with that pesky E = MC^2 issue. Maybe there’s a dilithium crystal deposit on mars.

      • There is no doubt that with nuclear power, all other problems of development on Mars become manageable.

      • Star trek replicators did not convert matter into energy. They restructured matter into what ever they wanted.

    • Well said. Even if the numerous insurmountable issues could be overcome, what would it achieve?
      It would be little more than a prison colony with a built in death sentence. Sure, some would volunteer for it because people are willing to do almost anything for fame or money.

      • Reg,
        That’s what they said about Australia at one point. But it turned out pretty well, don’t you think?

      • All “impossible” explorations of Earth are done within the life saving blanket of earth’s magnetosphere. Without it, life as we know it could not exist on Earth. So from the comfort of that blanket, mankind dreams up how wonderful space adventures are. Keep in mind that the ISS and other orbiting earth objects are within the confines of that protecting blanket. When you dream of Mars, dream not from an earth perspective, but from the perspective of an environment that is constantly being blasted by solar winds and cosmic rays.
        If people want to live where no one tells them what to do, go to the wilderness of Alaska, where there isn’t anyone for 200 miles. Or go live in Antarctica, where you can find places where your nearest neighbor may be 1,000 miles away. Alaska and Antarctica both are essentially infinitely more realistic places to live than Mars.

    • “Classic example of bureaucratic mission creep.”
      I’m pretty sure that unlike much of NASA’s activity Congress has explicitly told NASA to start planning to go to Mars — and soon. Ref: Even if NASA knows that’s a dumb.idea, they pretty much have to comply. It’s their job.
      BTW, you omitted the recent discovery that Martian soils and dust probably contain substantial amounts of toxic perchlorates that have to somehow be prevented from getting into the astronaut’s environment.
      It’s pretty clear that getting a few astronauts to Mars and back is an undertaking on the scale of Apollo, the Space Shuttle, or the ISS. That is to say — $150,000,000,000. Likely more. Compare that to $2.5B for a Mars Rover. Not hard to see which provides more information for each dollar invested.

    • Mars is a one way trip. You can check out anytime you like but you can never leave.

    • The goal will be to colonize Mars. A backup plan for humanity in case an ELE reoccurs on Earth. This will be our first move off planet, with hope to someday be out of the solar system.

      • An isolated colony in a deep mine or under the sea would have the same back-up effect, for a fraction the cost. The “it’s a back-up plan” is predicated on the Mars mission being able to survive without further earth support, which is far from likely.

    • I agree about the waste part. Insurmountable? No. But at a large cost. I think the real question is what does sending people there give you that robots (way to go Curiosity!!) don’t. Not much I’d wager.

      • With Ristvan’s world view humanity would still be cowering in some African cave.
        Unless they are going to introduce Flying Robots there is a great deal that Men/Women can do that current robots can’t.
        But I would go for Moon Colonisation before Mars because of it’s lower Gravity Well, it is far easier to launch “stuff” from the Moon than Earth.
        Better to spend the Money on exploration than trying to control the climate.

  5. The choice is between nuclear and solar. link, link
    The nuclear option supplies both heat and electricity and doesn’t need battery backup for nighttime operation.

  6. With the advance in robotics and AI, man actually does not need human space travel, maybe to play a guitar.

    • Pretty much. The only real problem I’m aware of is the communications delay problem. In the worst case, round trip delay Earth-Mars is more than 20 minutes. That means robots can’t get instructions and react quickly.
      If that turns out to be a big deal, I could envision a future where robots on Mars are controlled by a group of humans in an underground base on one of the Martian moons.

  7. Contaminating a virgin planet with uranium, plutonium, and all their daughter isotopes? Oooh yeah. This will go over well with the greenies.

    • Just the most bizarre ‘philosophy’ imaginable. It’s as though they think people are making bad atoms or something which didn’t previously exist. A moments thought would tell them that virtually everything heavier than iron was blown out of a supernova at some point so what does it even mean to say we are contaminating planets or space?

  8. It might be worth pointing out to any Green protests about putting man made nuclear reactors on Mars that about a third of Mars is covered by debris from a natural fission reactor on the planet that went critical and produced a huge nuclear explosion dwarfing anything tourists or settlers from Earth could produce there. And of course Mother Nature got there first on Earth as well, as French geologists discovered in Gabon. Always worth pleasantly disappointing environmentalists who think evil people invented nuclear fission.

      • I think he’s referring to the catastrophist theory of the Phaeton explosion. It’s been a while since I read it, but the gist is that a planet located between Mars and Jupiter had way more radioactives at its core than Earth. These went critical, generating enough heat to tear the planet apart, shower Mars with debris, and leave the asteroid belt behind.
        Doing the math for even a Mars-sized planet requires an obscene amount of energy, though. But maybe he’s talking about something else.

      • My apologies to TA and Peter for not getting back sooner. No it wasn’t the Phaeton theory, I’m going to have to go and dig around in my books to find this reference. I remember at the time being surprised by the account, but it wasn’t, or at least didn’t read, as some fruitcake idea.
        I’ll get back to you if I can find it.

      • OK sorry guys, I think I have to call my comment on Mars as BS. I can’t find the original material and all that checking the internet comes up with is some loopy idea of an alien nuking of a civilisation on Mars. Good science fiction but that’s all. Still, in principle if natural fission reactions took place on Earth once there could be examples elsewhere – but that is speculation not fact.

      • There was a natural fission reactor on the Earth. Somewhere in S. Africa if my feeble memory is correct.
        However it never got anywhere close to going critical. The idea that a natural reactor could get concentrated enough to go critical is absurd.

  9. Let us hope that the person who couldn’t transpose imperial to metric has been sacked else the fission power units will crash down from the last few feet (metres) and contaminate the surface of Mars for centuries.

  10. I recently traveled back in time to 1970.
    I stood by a busy road with a sign that read …
    i was carried away to a psychiatric hospital. (they still existed then)
    Fortunately the time machine was on auto and I was able to return.
    (making accurate predictions of the future is not safe)

  11. Sadly, we are almost as far in time from the moon landing, as the moon landing was from Kitty Hawk.
    As a fan of science fiction literature ( and science non-fiction literature 🙂 ), I am deeply saddened by our lack of outposts on the moon.
    Sincerely wish humans swam together better than we do.

      • That sign needs revising from
        Other countries have far more ambition.
        The management involved in the Apollo series said that the Space Race was the best & the worst thing to happen to space exploration.
        Once the USA won the Moon Race they basicall gave up on space exploration.
        But places like India & China will take on that mantle instead.

    • Remember back in the day when everyone was talking about the colonisation of inner space and watching Jack Custard movies? Oh yes, why bother with all of that nawsty vacuum and hard radiation in cryogenic temperatures at low gee when two thirds of the Earth isn’t even explored yet. We were all going to be living on the bottom of the sea Captain Nemo style and farming kelp for food while mining manganese nodules.
      And why not? Compared with Mars or the Moon it would be a cakewalk. Relatively warm with plenty of oxygen around and no radiation hazards down there. All you have to deal with is a bit of pressure and manage corrosion issues sensibly.
      Somehow it didn’t happen though.

    • David Ball wrote: ” I am deeply saddened by our lack of outposts on the moon.”
      I think the reason for the lack of lunar colonies is that there is no commercial reason to do so. If no financial profits are to be made, then only governments will put up the money to establish colonies, and governments will only do so if there are political profits to be made.
      Back in 1492 when Columbus first sailed across the Atlantic, had he discovered the Americas to consist of lifeless desert with no useful minerals, he would have sailed straight back and history would have forgotten him. Instead, there was gold and silver to be found, land to be claimed, colonies to established, all in a rich, fertile land. Now if someone could find a way of making money from lunar colonies (lots of money), there would be colonies established there within five years.

      • There are no self-sufficient colonies in Antarctica either, for pretty much the same reasons as there are none on the moon — it is not a nice place to live, you can’t grow stuff, it’s expensive to get to and it is more or less valueless.
        For all the “imagine if Colombus” fantasies, we don’t colonize useless places.

  12. Terraforming Mars is a joke as many have stated the reasons why. Go to the moon and if we can stay there successful, then maybe go to Mars or start mining asteroids.

  13. They should use a liquid metal reactor, liquid sodium. Best bet, low pressure, low maintenance.

  14. I think Mars exploration is a little premature at this time. We need to go one baby step at a time with space development. But I’m glad to see NASA developing small nuclear powerplants because they can be used in near-Earth space and on the Moon. Commercial space will be interested in this power supply.
    NASA should focus on developing human-friendly habitats (artificial gravity and radiation protection) in near-Earth space and focus on a colony on the Moon. That’s a full plate right there, and anything they develop in the process can be used at Mars, too.
    Let Musk take a shot at Mars if he feels like gambling the money. NASA needs to be much more measured.

    • So, TA, in the unlikely, and maybe unforeseen event (like a tsunami flooding the backup generators) happens to de-orbit a near Earth nuclear reactor, Does it have a heat shield and parachute system to insure a soft landing? Or does it just burn up in the atmosphere and spread all it’s radioactive material across the planet?

      • You obviously know little about Natural Radiation if you are so worried about a micro reactor’s worth of radioactivity.

      • Mike even if it doesn’t burn up, the small lump of radioactive material will be easy to find and recover.
        PS, as A C points out. The small amount of radiation, if it is spread over several hundred square miles will be undetectable against background radiation anyway.

      • Yeah MarkW, I hope your kids don’t find it in the backyard and “play” with it.

  15. Hopefully they will develop a reactor design that could quickly be switched to commercial mass production for use on earth when the Mars travel budget gets cut. Others may already be working on such projects, but a bit of extra competition would be no bad thing and might speed things up. We have already lost several decades in development efforts due to political-enviromentalism interference.

  16. Forgetting the lack of a stable rotation on it’s axes, a molten core for a magnetic field, or the lack of mass needed to hold a dense enough atmosphere. That same lack of mass will also not provide the gravity needed to prevent critical bone loss. Same goes for a Moon base as well. The viable colony is one orbiting the Earth, with an artificially generated gravity via centrifugal force.

    • But even then you’ve got the cosmic ray problem as well as all sorts of other radiation. Not to mention construction of something like that in space. We can barely get large objects above 100 miles, let alone to geosynchronous orbit or one of the Lagrange points.
      What we need is some reason to tackle all those problems, such as some magic widget or elixir that can only be made in microgravity, or some special thing only found on the moon.
      So far we’ve had nothing. I wish it weren’t so, as I’ve been a huge space fan all my life.

      • “What we need is some reason to tackle all those problems,”
        The main reason to tackle those problems is to ensure the survival of the human race.
        Radiation protection in space can be provided by a one-meter thick covering of ice around a habitat.
        We don’t need large space structures in order to benefit from artificial gravity (centrifugal force) all we need is a couple of habitat modules separated by a mile-long cable, or just one habitat module with a dead weight on the other end.
        When the habitat modules are caused to revolve around the common center at one revolution per minute, the equivalent of one Earth gravity is generated in the habitat modules. This type of vehicle would also be the safe, comfortable way to travel back and forth to Mars, putting them in permanent Earth/Mars orbits like those proposed by Buzz Aldrin with his “cycling space stations”.
        Artificial gravity and radiation protection are essential for longterm human operations in space. They should be a priority of NASA.

  17. Yep agree the answer is habitats, not necessarily orbiting just the Earth. As for cosmic ray shielding, that will be organised by using moon rocks as shielding, launched from the Moon by electromagnetic catapult. See Gerrard K. O’Neill’s “The High Frontier”.

  18. @ Author Irene Klotz.
    “About 16 kCi of 238Pu were dispersed in the upper atmosphere of the southern hemisphere
    in April 1964 when a navigational satellite with its SNAP 9A generator…”
    p 90 in
    Radiochimica Acta J2, 89-103(1983) ©
    Akademische Verlagsgesellschaft, Wiesbaden 1983

  19. There is no water on the moon and no water at Mars. Without water, no colonies. End of story.

    • One large comet would provide all the water needed in the short term, however I am sure that water can be manufactured if required.
      We don’t do it Earth because we don’t need to.

      • Manufactured out of what? You need hydrogen to make water, and where are you going to get that from?
        One large comet would provide all the water needed in the short term
        How are you going to stop, manouevre and then lower a comet onto Mars? At 10 miles per second, they don’t just brake you know.
        People lose all sense of the possible when it comes to space.

    • There is water ice on the Moon in craters permanently sheltered from sunlight. There is also water ice on Mercury.
      The main reason NASA should establish a base on the Moon is to harvest the water ice that is there and use that ice to lower the costs of space exploration and development.

  20. does anyone have a number? the real number of how much tax payer money NASA pizzles through with 0 return?
    The real number is far greater than one we are given for space programs
    NASA has been scamming billions for junk science for decades

  21. What is a nuclear physicists favourite meal? Fission chips. ………
    I’ll get my coat…..

  22. “…small nuclear fission reactors, which work by splitting uranium atoms to generate heat, which is then converted into electric power.”
    Are they going to carry water with them to make steam with? Or are there other ways of making electricity with heat?

  23. Hmmmm…let’s see…maybe try searching for something called a thermo-electric generator?

  24. Money is on they will attempt to have a base on the moon first. Interestingly it has a two week day and night so nuke power is required.
    Why the powers that be disregard thorium for mere low power TMG’s running off a dangerously fast decaying isotope is withering.
    That unit on the back of Mars Curiosity rover could only muster 125 watts when first assembled.

  25. Bryan A
    July 10, 2017 at 10:18 am
    Mars also does have an abundance of water ice about just below the surface.
    Clearly visible in these images from the Phoenix Lander
    That is dry ice not frozen water.

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