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NASA's Journey To Mars May Use Nuclear Rockets ( 224

MarkWhittington writes: NASA Administrator Charles Bolden has been making the rounds of congressional committees, defending the indefensible, that being the latest Obama space agency budget proposal. Thursday it was the turn of the House Science Committee to complain to Bolden that the budget underfunded the Journey to Mars and to vow that more money would be forthcoming. One of the other complaints Congress has been making is that NASA lacks a plan to get people to Mars, scheduled to happen sometime in the 2030s. Bolden was coy, suggesting that the time was not right to start firming up architectures and missions. However, he did drop an intriguing hint that a nuclear thermal rocket engine being developed at NASA's Marshall Spaceflight Center may take people to Mars quicker than chemical rockets.
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NASA's Journey To Mars May Use Nuclear Rockets

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  • by CajunArson ( 465943 ) on Friday March 18, 2016 @10:03AM (#51722719) Journal

    Quick, hide the sensitive people like children and, people who are less rational and more spastic than children like MDSolar! Somebody used the word NUKULAR and there might even be a RAYDEEASHUN!!

    We should ban all things nukular from space because polluting natural, artisanal, organic, and non-GMO space with radeyashun would be a crime!

    • Re:OMG! NUKULAR! (Score:5, Insightful)

      by AmiMoJo ( 196126 ) <mojo@world3.nBLUEet minus berry> on Friday March 18, 2016 @11:34AM (#51723655) Homepage Journal

      This is why you can't have new nuclear plants. Instead of addressing the very real issues, you simply mock the people raising them.

      In this case, there are also real concerns that are worth discussing too. The Russians have had a couple of incidents with their nuclear powered spacecraft. I'm sure NASA would take every precaution and it's probably fine, but then again you would hope they had done that with the shuttles too so it's something that needs consideration.

      • Re:OMG! NUKULAR! (Score:4, Insightful)

        by Coren22 ( 1625475 ) on Friday March 18, 2016 @04:02PM (#51726621) Journal

        Because the "real issues" being brought up are not. There are not these serious issues, and nuclear is very safe. When there are very minor releases of radiation, mdsolar, you and others like you flip your shit like everyone is going to die. This is not a serious issue, and a properly upgraded/replaced plant will not have any of the issues that cause meltdowns. But let's demonize nuclear energy for causing less radiation release than coal in normal operation, or even heavy metal mining for wind and solar.

  • by nimbius ( 983462 ) on Friday March 18, 2016 @10:17AM (#51722855) Homepage
    ESA: We made it to mars america! our rover is collecting samples and data.
    ISRO: America! we need some help analyzing these samples! can you send a rover to kindly do the needful?
    Russian space agency: Da. We are needing help with this outpost America. New supplies and ships needed for our colony.
    NASA: look guys uh....we're in our fifth government shutdown, the supreme courts been vacant for 3 years, I think...i think most of our drinking water is lead these days and we just pledged another 800 billion to the terror war and the great wall of mexico. But if you can somehow work Mars exploration into religious freedom i think we can keep the radio comms up another month.
  • by Anonymous Coward on Friday March 18, 2016 @10:17AM (#51722859)

    NASA had a nuclear thermal rocket program called NERVA back in the 60s (itself in part inherited from the US Air Force):

    The program successfully developed a nuclear thermal rocket engine (successful test-firings and everything), and there were plans to build a Saturn V with a nuclear upper stage, but the program was killed by Congress because of the old "give a mouse a cookie" problem. NTRs are basically only useful for sending enormous things to Mars (or other planets), like human colony modules, since the engine and tankage is so heavy that the efficiency only becomes a benefit when the payload is even bigger. The fear was that if Congress let NASA continue NERVA development, it would lead to greater pressure for human Mars missions, which would be expensive (though I'm sure a campaign of human exploration of Mars pales in comparison to the cost of the campaigns in Vietnam and elsewhere -- and it will certainly pay off more technology dividends and look better in the history books).

  • by sinij ( 911942 ) on Friday March 18, 2016 @10:18AM (#51722867)
    We shouldn't pollute space with hard radiation!

    I can see environmentalists objecting with something like that.
  • What's the rush ? (Score:4, Insightful)

    by slashping ( 2674483 ) on Friday March 18, 2016 @10:28AM (#51722965)
    Mars is barren, extremely inhospitable, wasteland. Why are they in such a hurry to send meatbags there ?
    • by sinij ( 911942 )

      Why are they in such a hurry ?

      We don't fully understand extinction risks or fragility of our technological civilization. Getting to Marks is the first step in establishing permanent colony there. This way humanity could survive mass extinction on Earth.

      • by slashping ( 2674483 ) on Friday March 18, 2016 @10:47AM (#51723181)
        If you assume our civilization is too fragile to survive, planting a colony on Mars won't improve the odds, as that colony will be even more fragile and dependent on technology, for even the most basic human needs such as air, water, radiation shielding, and food. Other planet-wide extinction risks are sufficiently small that we don't have to rush right now. We could easily wait another century without significant change in odds.
        • by sinij ( 911942 )
          I assume you never backup your data, because if you system is too fragile to survive, what are the odds that your backup will survive?

          Actually, the odds of backup surviving are excellent. We are not talking about intrinsic fragility or propose that humanity has a tendency to self-destruct. If that the case, it is probably irrecoverable. We are talking unexpected one-off events. That why we backup our data. This why we need a functional Mars colony.
          • Re: (Score:2, Insightful)

            by slashping ( 2674483 )

            because if you system is too fragile to survive, what are the odds that your backup will survive?

            That's a stupid comparison. A regular backup disk provides excellent odds, for very small cost. A functional, self sufficient Mars colony, would be expensive beyond comprehension, and extremely fragile, even without unexpected events. If you want a backup for unexpected events, I suggest we build several shelters underground, or inside mountains where people can hide until the worst is over. That's a lot cheaper than building something on Mars.

            • by sinij ( 911942 )

              That's a stupid comparison.

              I agree, we shouldn't compare game-ending potential extinction of our species with slight harm of potentially losing some of your car videos.

              • No, we shouldn't. I'll be really sad when my car videos are gone, but I won't care being dead. But jokes aside, it's about the odds. There's a good chance my harddisk will fail in the next decade, and a very cheap and easy way to prevent much grief by installing a $100 backup system. There's only a very tiny chance our species will go extinct, and an extremely high cost of installing a backup with any kind of reliability. Keep in mind that a restore operation from a small colony on Mars, without any help f
                • by sinij ( 911942 )
                  It is about odds, and with humanity we need to reach 100% uptime in perpetuity without fully understanding the risks and while dealing with irrational actors. I don't subscribe to your arguments that Mars colony should not be compared to an offsite high-value data backup because of the costs. How expensive do you think financial exchange backups are? Astronomically so, and it is just money. I don't agree with you that we could understand the risks of extinction or civilization collapse, and because of that
                  • with humanity we need to reach 100% uptime

                    No, we don't, and we won't. We're all going to die, and our unique DNA patterns will fade away.

                    but if Western technological civilization collapses (as Mayan, Roman, Hindu, Byzantine, Persian civilizations did) for whatever reason, like being overrun by a Caliphate, humanity may not retain this technical ability.

                    The Martian civilization would collapse even quicker, and being in such a inhospitable environment, would be immediately sentenced to death. At least, if our Western civilization collapses here on Earth, there will be survivors to start another one.

        • In twenty years when the general purpose, self replicating, nanobots have destroyed the Earth, you'll be sorry. They will have been developed to "eat" oil spills, nuclear waste, tainted Chipotle burritos, and the like. Then the "oops" moment occurs (all plant and animal life are consumed by the nanites). It would be nice to have a self supporting colony established on another orb somewhere.

          To have a self sustaining colony on Mars will take at least a century. And that assumes massive help from science,

      • There are no feasible scenarios where Earth would become less suitable for life than Mars. That includes scenarios like asteroid impact or nuclear war. Despite all the mass extinction events in Earth's history, some life has always survived. The same cannot be said for Mars.
    • Mars is barren, extremely inhospitable, wasteland. Why are they in such a hurry to send meatbags there ?

      Antarctica, the Mariana's Trench, the top of Mount Everest, the surface of the Moon and low earth orbit are all barren and extremely inhospitable wastelands and we've visited all of those. There are plenty of good reasons to want to put people on the surface of Mars too. We can learn a lot from inhospitable places and even more from figuring out how to get there and stay alive. Furthermore what is uninhabitable today may become a viable destination with an adequate application of technology. Nobody is

      • We can learn a lot from inhospitable places and even more from figuring out how to get there and stay alive.

        That's circular reasoning. We don't have a need to learn to stay alive if we're not going. What are those other "plenty of good reasons" ?

        Nobody is asking you to go

        That doesn't mean I like to see already small public funds wasted on missions with low return on investment.

    • Why are they in such a hurry to send meatbags there ?

      NASA has announced that the first passengers to Mars will not be volunteers, but they will be drafted for the mission. You have no choice . . . you're on a one-way trip to Mars.

      NASA's current picks are Hillary Clinton and Donald Trump.

      That's why they are in such a hurry. Gotta get that rocket launched before November.

    • Why the rush? Because Mars needs Women []!
    • by k6mfw ( 1182893 )
      They're falling back on outdated ideas like "manifest destiny" and painting Mars like a second Earth, struck some cord among a very vocal hard core group that has shouted down any rational space strategy ever since. This is why we will land a man on Mars 20 years from now, and we've been saying that for the past 50 years. I see no land rush to the Gobi Desert even though that place is thousand times easier to settle. We romanticized of settling Mars because it is so far away. Meanwhile we should ask if we c
  • >> may take people to Mars quicker

    Slowing down to catch the planet, getting back off the planet, and returning back to earth would all seem to be bigger problems.
  • by jfdavis668 ( 1414919 ) on Friday March 18, 2016 @10:40AM (#51723113)
    We need to launch a few nuclear tugs. They can be used to move spacecraft up to higher orbit, so we don't need to use large expendable boosters. Just get the craft into orbit, meet up with a tug, and push it to a higher orbit or even escape velocity. Then the tug can return to low orbit to be refueled and ready for the next mission. The tug still needs propellant, it just uses the nuclear power to heat it for propulsion.
    • by Rei ( 128717 )

      Or, for current tech (we don't have any nuclear reactors designed for use in space at the moment), solar-electric tugs. But indeed, tugs are an idea that's long overdue. High ISP propulsion systems have tiny thrust to dry mass ratios, so launching all of that dry mass every time is a major waste when you could just be launching the propellant.

      In the context of Mars, one looks at cyclers - craft designed to continually transfer between Earth and another body while hauling payloads, only needing periodic pr

    • There is literally no part of this idea that makes sense. Either way you still need to get your propellant to orbit in some manner, and having your "tug" move up and down in the gravity well just wastes twice as much fuel (2x delta-v). Adding nuclear power to this solves no problems and introduces others. Plus it's not like you can just park it somewhere convenient and take it up and down like an elevator.

      I don't think you thought this through. If you want a space elevator, you kinda have to build a space e

      • by Rei ( 128717 )

        Here's the part you're missing.


        Scenario 1: No tug.

        Launch #1:
        Earth: Launch spacecraft + heavy but efficient propulsion system + propellant tank + propellant for said system to LEO
        LEO: Spacecraft + heavy but efficient propulsion system + propellant tank + propellant to MTO & capture to LMO
        LMO: Spacecraft + heavy but efficient propulsion system + propellant tank + remainder of propellant to ETO & capture to LEO
        LEO: Spacecraft ditches everything else (letting it burn up), reenters and lands


        • See the difference? In the latter case, you don't have to keep launching the heavy but efficient propulsion system. It's as if all subsequent launches get a heavy but efficient propulsion system for free.

          They don't get a heavy but efficient propulsion system for free. They get it for the initial launch cost, propellant, and more propellant to get it back to where it might be useful again. If your tug is heavy that would mean that it would need to be even more efficient to be economical. Without some plausible numbers to throw into a delta-v calculator I am afraid that I will remain skeptical.

          • by Rei ( 128717 )

            They don't get a heavy but efficient propulsion system for free. They get it for the initial launch cost

            You only pay that *once* - only on the intial launch. Every time after that, yes, it is free.


            1) You're seriously going to pretend that I didn't just write that?
            2) The propellant mass is far less than the craft mass

            , and more propellant to get it back to where it might be useful again

            1) It both starts and ends where it's useful (LEO).
            2) The propellant cost for a system like VASIMR maneuvering b

      • It depends on the ISP of the Tug right? If the tug ISP is 10x that of the alternative for the fuel mass you climbed out of the gravity well with then it would be a win to use the tug right before you start up you light the candle on your *really* dirty *really* high ISP engine.

      • 1: You only push the engines into orbit once. That's where the cost is the highest. 2: You only need to bring up fuel, not oxidizer. Chemical rockets need both. Hydrogen fuel is very light, compared to the oxygen you don't need. Yes, the fuel could be something else. 3: Large expendable boosters are not reused. I know Spacex is trying to change that. 4: Far easier to create a reusable launcher to low Earth orbit than one which can throw ships to higher orbits.
  • by tarpitcod ( 822436 ) on Friday March 18, 2016 @10:41AM (#51723129)

    A 0.01g constant acceleration ship gives you the Solar System.

    A ship capable of a constant 0.01g acceleration would be a game-changer. Break the steps down as X-prizes. Build a 0.001g ship. Scale it up to a 0.005g ship. Next step is get it to 0.01g and you can reach Mars in three months and anywhere out to Pluto in just less than a year. First place to go? Prospecting the asteroid belt would be my vote. Find useful stuff, use it to build more useful stuff.

    • What we need is better propulsion, period. High acceleration for short bursts is just as good.
      • Better propulsion I'm all for, but it's hard to beat a constant drive for long distances with a burst of acceleration. Every day the constant-g ship with a measly 1/100g is adding the equivalent of 8.6g for about 100 seconds. Or 1g for 864 seconds. The delta-v just keeps adding up.

        • Better propulsion I'm all for, but it's hard to beat a constant drive for long distances with a burst of acceleration. Every day the constant-g ship with a measly 1/100g is adding the equivalent of 8.6g for about 100 seconds. Or 1g for 864 seconds. The delta-v just keeps adding up.

          No, it won't, because your constant-g ship will run out of fuel after a short time. Unless, of course, you come up with much better propulsion, which was my point.

          • The better propulsion is implicit if you want a constant g ship (for any meaningful distance), so I think we are agreeing. I didn't make it explicit because it is implicit once you run the calculations that a chemical or nuclear-thermal rocket won't cut it due to fuel mass. To be more explicit, I'd love a propulsion system that can do better than 1/100g for months, but I doubt we will get there soon. A propulsion system that could do 1/100g is much more achievable with existing technology and a worthy go

    • This is one of the dumber things posted to slashdot. It's like suggesting that an over-unity device would solve our electric needs. If you have some magic box that never needs fuel, sure, you can go anywhere. In the real world your ability to go somewhere is limited by the rocket equation. Talking about spaceship engines in terms of acceleration is as meaningless as talking about CPUs in terms of gigabytes. You don't get to hand-wave away conservation of momentum.

      • Nobody is suggesting that our constant-g rocket will run forever. That is obviously impossible. But it may well run for long enough to be useful, and better than a chemical or nuclear-thermal rocket.

        Your argument about ignoring conservation of momentum is also wrong, as is your comment about the rocket equation. It's because of those two facts that we need really high ISP. That means nuclear. It probably means something like a fission-fragment rocket to get high enough ISP.

        So go ahead, take the cheap-s

        • Nobody is suggesting that our constant-g rocket will run forever.

          The point is you're missing terms from your equation, and it's not sensible to describe a rocket engine in terms of acceleration alone: you need the other factors in the rocket equation: total mass, mass-to-fuel ratio, time, and effective propellant velocity. You can't escape dealing with those terms unless you have a reactionless drive, and that requires dispensing with conservation of energy. A "1G drive" is a meaningless concept, and I stand by the validity of my analogies.

          • I'm thinking of things with very high ISP for all the reasons you are citing. The point I'm trying to make is that if we could build a 1/100g drive then we could do a hell of a lot, and low acceleration drives can accomplish lots.

            So I didn't think your analogy was fair at all. It seemed, to be honest, the same kind of analogy used to prove that putting humans on the moon is impossible. It's like people saying the rocket equation directly proved that we couldn't possibly build a single-stage rocket that w

            • There is no such thing as a "1/100g engine". There might be such thing as an engine which could maintain 1/100g over a specified period of time, with a given total mass and mass-to-fuel ratio. You need all the parts to even be making a sensible statement. It's fine to point out that small constant acceleration can lead to a large change in position/velocity over a long enough timeframe, but that actually has nothing to do with building rocket engines. Clearly we have rocket engines which can sustain acceler

    • Yeah, it'd be great if we could just wish new physics into being.

      Might as well wish for wormholes or teleportation.

      In reality, we need rockets. And chemical rockets actually work just fine. Nuclear-thermal would cost about as much as SLS, and wouldn't even be that useful, it'd just be a nice in-space stage. Reusable launch tech (which we're getting thanks to SpaceX, Blue Origin, Masten Space Systems, and others) gets you cheap launch which makes a nuclear-thermal stage an unnecessary frivolity. Nuclear-ther

  • by Robotbeat ( 461248 ) on Friday March 18, 2016 @11:14AM (#51723443) Journal

    There is a plan that would get us to Mars soon and in the budget we have. But Congress wouldn't like it because it wouldn't use their favorite pork rocket (SLS), and possibly not even Orion (which is a less-bad idea than SLS is, but still ultra inefficient).

    But the fact is that we didn't even have a "plan" to get to the Moon when JFK made his Rice University speech. Or we did, but it was wrong. The original plan was to use direct ascent of the Apollo command module off the surface of the Moon and go straight back to Earth. But such a plan would've required a launch vehicle much larger than the Saturn V. Instead, we used Lunar Orbit Rendezvous, which allowed us to use just Saturn V. And of course, we had to shut down Saturn V production during the Apollo program because even Saturn V was too expensive and unsustainable. SLS is even worse, as it uses old Shuttle parts (developed in the 1970s, for God(dard)'s sake!) which were originally intended to be reusable but now we're just throwing away (the worst of both worlds... the upfront cost of reusable parts and the expense of throwing the whole thing away each time), and so we can afford to fly just once every other year (and each Mars mission will require several launches).

    We can explore Mars entirely with EELV-class launch vehicles. Atlas V has a 7.2 meter fairing available, Delta IV Heavy can put about 28 tons in orbit (enough for the largest "single piece", provided we use docking... but no orbital assembly required), Falcon Heavy will launch within a year (it starts testing in Texas soon), can put over 50 tons to orbit (more with cross-feed), and Vulcan (the successor to Atlas V and Delta IV being designed now with Blue Origin's BE-4 engine) can handle a 8.4 meter fairing (same as SLS) and in Heavy configuration could also handle at least 50 tons to LEO.

    We can also use either SpaceX's Dragon or Boeing's Starliner capsules, which are much more efficient, to get crew to space and back. The actual vehicle to bring astronauts to Mars vicinity wouldn't actually bring Orion along anyway, as the current plan is to rendezvous in a distant retrograde lunar orbit.

    Our human exploration funding is dominated by SLS and Orion, both elements of which are way too expensive and will be available in full form much later than EELV-class vehicles (available now, with twice the capacity available sooner than SLS's first test launch) and Dragon/Starliner (set for 2017 crewed debut). Instead of wasting our funding on two elements we don't need, we could spend the money on a small transfer vehicle (perhaps using solar-electric propulsion, but chemical rockets would work, too) and a Mars lander/ascent vehicle in addition to surface elements.

    Instead of duplicating effort, we should focus on what we actually need to do Mars. Lander and transit hab.

    Congress (or rather, those in Congress who make a stink about space exploration because it provides jobs in their districtrs) knows SLS/Orion aren't strictly required, knows they're very expensive (which is why they're supportive of them... more cost = more jobs in their district), what they want is to somehow cement SLS/Orion in place so their districts are guaranteed to receive funds for decades. That's really the whole issue, here. ...there's also a huge revolution going on in spaceflight. Truly affordable reusable vertical takeoff, vertical landing (VTVL) rocket technology is now scaling up to enormous size. You have SpaceX with reusable flyback boosters for Falcon 9 and Heavy, plus Blue Origin tooling up for their own VTVL orbital vehicle. ULA (who makes Atlas V and Delta IV) is developing orbital refueling technology with Vulcan, which is hugely enabling. And we're just getting started. SpaceX has plans for an enormous reusable launch vehicle also using methane/LOx technology and intends to send people in 2025 (perhaps using Falcon Heavy and a Raptor-based lander, perhaps using the enormous vehicle). This is far earlier than any NASA plan could possibly hope for given its budget and Co

    • Yes, the space program does seem to be driven by pork barrel politics. I always had the feeling that the Space Station was conjured up as a way to spend lots of money after the Apollo program was cancelled. What a waste of money that was - we should be on Mars by now.
      • Re: (Score:2, Interesting)

        by Rei ( 128717 )

        No, the space station was a relic of the Apollo era.

        Here was the thinking of the time, still high on the success of the Apollo program and dreaming of an even grander future (one in which their budgets didn't get deeply slashed).

        1) We'll launch Skylab. It's going to get tons of usage.
        2) At the same time, we'll develop a reusable launch system - a Space Shuttle. It's going to get tons and tons of usage and so it'll be very cheap per launch even if annual programme costs are high. And we'll save money beca

        • Yes. I remember being a kid in the late '60s, with Apollo well underway, thinking that by the '80s we would have visited most of the planets in the solar system, and that we would have real space stations in orbit - rotating ones. Yes, it sure did fall apart.
    • by Rei ( 128717 )

      Couldn't agree with you more. :)

      Part of NASA's problem is it just has too much infrastructure that it really needs to get rid of that would be way too painful for a government-run agency to just close. So it has to keep all of those people and facilities working on something. They make the goals to suit what they possess rather than the other way around. Sometimes that develops useful things. Sometimes it's just absurdly expensive busywork.

      Changing the culture is going to require a combination of a Whi

  • Or they might use an improbability machine. Maybe, or an inertialess drive, or maybe -

    sigh. another maybe article.

  • I am typically first in line to balk at mysterious propulsion systems that are claimed to work while violating our current understanding of physics. We have them by the truckload and they are bullshit.

    But wait...

    Back in 2001 a small satellite propulsion research company was investigating different techniques involving electric engines. That in itself is nothing spectacular. For whatever reason, they developed and tested a closed cavity microwave drive. I do not now the story of why they did such a thin

Thufir's a Harkonnen now.