why a flyby of mars may not live up to its intention

March 2, 2013

inspiration mars

There’s been plenty of news coverage regarding the Inspiration Mars mission being funded by space tourist and tycoon Dennis Tito, who says he’s willing to pay whatever it takes to make the manned flyby of Mars possible by 2018, when the planets best align for a 501 day round-trip. He needs the SpaceX Falcon Heavy rocket, a manned version of the Dragon tested and ready, and some way to address the intense cosmic ray bombardment in interplanetary space. So as far as ambitious missions go, this doesn’t sound technologically unfeasible Difficult? Certainly so, but not impractical. Expensive? Absolutely, but not so much that it would be impossible to raise the money, especially with crowdsourcing and the participation of other space-minded, wealthy, big picture human exploration enthusiasts. And there’s very unlikely to be a shortage of the married couples with engineering experience Tito suggest should make the flyby. However, there are big problems with what Inspiration Mars wants to do and how, despite the technical feasibility.

Basically, it’s a mission to show the world that the United States still has the lead in space travel and can send humans to Mars and back, just a flight or two away from actually landing them on the surface, as with the Apollo 8 flyby. This means that not only is 2018 important from a purely mechanical perspective, but as Tito says, the next opportunity in 2031 could see attempts from other space powers and would make it harder for the United States to be the first to fly by Mars, much less land on the Red Planet. Remember what happened to Apollo after it achieved its PR goals? Inspiration Mars might not have the same problem if it’s funded by wealthy supporters of long term human space exploration, but these supporters don’t have endless pools of money to pour into mission after mission and after a bad enough market crash, might not be able to justify the expense of supporting the foundation. Even worse, when the country is preoccupied with its unemployment rate, debt, and runaway political brinkmanship, who’s got time for Mars?

Just like the chorus of well meaning but horribly short-sighted voices protested Curiosity, and a pundit or two were unable to resist assailing Musk for not spending his fortune the same way as Bill Gates chose to, there’s bound to be a narrative of a rich old guy wasting money that might have fed some of the poor and needy in this country on some Martian pipe dream. That’s not a great PR project for STEM in the making, especially when we consider that the supposed decay of American science and technology isn’t what it’s made out to be and in fact, we don’t have the jobs for all the engineers and scientists we churn out. Inspiration Mars is one way to create jobs for some scientists and engineers for seven years, but certainly not a long term solution to a big problem that by now is downright institutional. Likewise, the five year design to launch time table seems aggressive to a fault because it doesn’t seem willing to take the time to mature any more efficient ways of getting humans to other worlds in order to make the schedule.

Using a version of a naval nuclear reactor fitted for spacecraft to power a new VASIMR plasma engine could get the crew to Mars faster, provide more energy, allow for more space, and more efficient and ambitious missions. Right now, Tito is planning to launch two people in a tiny pod to travel millions of miles for a year and a third, far away from any visual sign of home and no way back should something really bad happen far enough along in the mission just to show that this could be done. This seems downright inhumane and every simulation of spending a lot of time in crowded isolation on Earth came with familiar gravity, air, and knowledge that should things not work out, the participants can just leave. Even year-long stays on a space station came with the familiar blue marble constantly below and a short trip home possible in an emergency. But over one year in the space of an RV floating in the darkness with one other person, no niceties and creature comforts as part of a PR push for a well equipped, major mission? Seems rather harsh, and like the Mars 500 experiment shows, mentally exhausting for the astronauts.

Look, I’m one of the last people to say no to a Mars mission. My view on space exploration has consistently been that we’re under-funding it and not doing enough of it. But I also know that we have to do things the right way, plan for long term outposts and missions on another world, and we need to return to the Moon to help us do it. Then, we can build an inflatable space base that uses nuclear reactors adopted from submarines to power plasma engines and send larger and more diverse crews for long term missions to Mars, protected by an artificial magnetosphere and with ample supplies and materials for sustaining the station for years. Having a massive effort to start a Mars outpost and create comfortable, safe, efficient mission options would be a better PR effort than a flyby with what we have laying around just to say we can do it. After all, we won’t be exploring the rest of the solar system using chemical rockets if we want to get humans anywhere within a manageable time schedule. Why start an effort to land on Mars using an updated Apollo concept rather than develop a strategy for long term discovery and outpost building?

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  • Howard Lewis

    A small correction. Apollo 8 was not a flyby mission, but an lunar orbital mission. The US skipped that stepping stone. Otherwise I found this to be a thoughtful piece on Tito’s plan. I am not sure if two volunteers for the mission in such conditions is ‘inhuman’ although it would be exceedingly challenging, fraught with risk, and could end badly with a mental if not mechanical malfunction.

    My own musing on paying for this type of mission would be what if instead of wealthy individuals, wealthy corporations (likely tech) would pay for the mission as an advertisement for US tech superiority. I know getting Apple, MS, and Google to agree on anything would be stunning, but a guy can dream.

  • Bill Dietrich

    An “artificial magnetosphere” around a ship would take a LOT of energy, have an unknown effect on the passengers, and wouldn’t stop uncharged particles.

  • Bill Dietrich

    We’ve checked out nearby destinations (moon, Mars) a bit, and unfortunately found nothing very good there. A real self-sustaining colony needs atmosphere, gravity, radiation shielding, resources. Haven’t found them.

    We should kill NASA’s manned space program until we find something worth sending humans to. Something with a big benefit, worth the big cost. We haven’t found any such thing yet. Keep the unmanned program going. http://www.billdietrich.me/Reason/ReasonMannedSpaceProgram.html

  • TheBrett

    I’ll take any long distance manned mission at this time, especially this one. I’ve noticed there’s no real chorus of voices protesting it, since it’s Tito’s money and unlikely that he’ll hit the date on time without a secured funding stream.

    The downside of the rush is that it will be harder to set things up for an orbital mission to do what it could really do well in terms of science: remotely operating surface robotic probes with very low latency issues. Robots on the surface could be far more capable if they didn’t have a 20-minute lag time between them and mission control back on Earth.

    Using a version of a naval nuclear reactor fitted for spacecraft to power a new VASIMR plasma engine could get the crew to Mars faster, provide more energy, allow for more space, and more efficient and ambitious missions.

    VASIMR doesn’t really get you there faster than the type of mission that Robert Zubrin has proposed, which could get you there in six months with a conventional rocket. For orbital missions, on-site orbital fuel depots would be even more effective. Zubrin himself talked about it in a speech you can find on youtube.

    Not that I don’t think there’s no potential for electric drives, but VASIMR doesn’t seem like it would offer much benefits compared to conventional rocketry. You’d also want to power ones inward of the asteroid belt with solar panels instead of a nuclear reactor, since there’s less plumbing, politics, and massive radiator arrays involved.

    Seems rather harsh, and like the Mars 500 experiment shows, mentally exhausting for the astronauts.

    The rub there is that the people in that experiment weren’t going anywhere, and could leave at any time. The people in the capsule won’t be able to leave, and they’ll have the consolation that they’re going to Mars.

  • TheBrett

    It would also be much more complex than simply creating a “storm shelter” with a couple inches to a foot of water/fuel/whatever to protect against solar flares. Extra complexity is not good on an interplanetary spacecraft.

  • TheBrett

    Why colonies? It’s enough just to send manned and unmanned missions for science and (maybe a long ways down the line) profit.

  • newpapyrus

    I wish Mr. Tito’s enterprise good luck! But it would really be a stunt like climbing the highest mountain rather that a pioneering mission.

    NASA’s focus should be on establishing permanent outpost, first on the surface of the Moon and then on Mars.

    This would allow teleoperated robots to continuously explore practically every region on both worlds. Such machines could collect rocks and regolith samples that can later be returned to the permanently manned outposts for further scientific investigation or exported back to scientist on Earth during human returns to our home planet.

    Permanent outpost on the Moon and Mars could, of course, also lead to the commercialization and colonization of both worlds by– private industry.

    Marcel F. Williams

  • gfish3000

    I’ll take any long distance manned mission at this time, especially this one.

    Isn’t that a little like saying “I’ll take anything edible, I’m starving?” We’re not talking about a cross-country road trip or even another lunar orbit or flyby. We’re talking about going to another planet and we owe it not only to ourselves to get it right, but to the astronauts undertaking this mission. Maybe it’s the professional techie in me, but I’d rather do it right than just do something, especially if it’s going to cost hundreds of millions of dollars to pull off and may end up setting the overall goal back.

    VASIMR doesn’t really get you there faster than the type of mission that Robert Zubrin has proposed, which could get you there in six months with a conventional rocket.

    Zubrin is very enthusiastic and he has the technical chops to plan Mars missions, but I think he’s way too gung-ho in many of his projections and too optimistic about both the speed and the cost of his proposals. He basically expects the government to pony up about $200 billion to colonize Mars which is simply not realistic for the foreseeable future. He wants to get there last week and his pronouncements drip with silent rage that we’re only sending robots and no one is willing to write the huge checks he wants for colonization projects.

    And yes, VASIMR would get you there a lot faster because it’s specific impulse far exceeds that of a chemical rocket if you give it an adequate power source. I don’t buy the claim of a 39 day trip to Mars because it seems overly rosy, but I can see even a 60 to 70 day trip being both feasible and infinitely better than six months going one way. Zubrin’s criticism of VASIMR seems largely based on his belief that we don’t need to get to Mars in faster than six months, therefore spending millions on a new propulsion technique is a waste of time and money because we need to get to Mars right now dammit, right now!

    You’d also want to power ones inward of the asteroid belt with solar panels instead of a nuclear reactor, since there’s less plumbing, politics, and massive radiator arrays involved.

    This is why I pointed to nuclear submarine reactors. They’re well tested, have been in use for decades, have an excellent track record, and there are many qualified engineers to build, maintain, and troubleshoot them. Considering we use them out at sea where the impact of a disaster would be many, many times worse than it would be in the air or in space without a second thought, they would be terrific candidates for powering the megawatt versions of VASIMR or other ion drives. Which we’ve had since the 1960s and in which we’ve been several under-investing since early 1970s…

  • Guest

    Maybe it’s the professional techie in me, but I’d rather do it right than just do something, especially if it’s going to cost hundreds of millions of dollars to pull off and may end up setting the overall goal back.

    How could it set the goal back? It’s not like there’s any indication that anyone else is about to plan a better Mars mission any time this century. Besides, the principles of this are quite sound, even if the scale is a little on the low side for my tastes.

    And yes, VASIMR would get you there a lot faster because it’s specific impulse far exceeds that of a chemical rocket if you give it an adequate power source. I don’t buy the claim of a 39 day trip to Mars because it seems overly rosy, but I can see even a 60 to 70 day trip being both feasible and infinitely better than six months going one way.

    That’s the thing, though – Zubrin pointed out that it doesn’t get there faster than six months, not even with a space nuclear reactor with non-existent levels of output per kilogram. He talks about it in his speech on it (for the record, the people involved in the project never claimed the 39-day trip – that was all Charles Bolden at NASA). It just adds a far greater degree of complexity and testing required for no real gains in terms of propulsion for a trip to Mars.

    This is why I pointed to nuclear submarine reactors. They’re well tested, have been in use for decades, have an excellent track record, and there are many qualified engineers to build, maintain, and troubleshoot them.

    What makes you think they translate well into space? Aside from the micro-gravity, there’s also the issue with cooling them in space, something the submarine reactors don’t have to worry about because they can dump their heat into seawater.

    If you’re operating inside of the asteroid belt, it makes more sense just to power your electric drive with solar panels instead of a reactor. Sunlight is constant in space, and you’ll have to build large radiators for the nuclear electric ship anyways.

    He basically expects the government to pony up about $200 billion to colonize Mars which is simply not realistic for the foreseeable future. He wants to get there last week and his pronouncements drip with silent rage that we’re only sending robots and no one is willing to write the huge checks he wants for colonization projects.

    He’s too attached to the idea that Mars is the “new frontier”, and a place we must settle if we want to avoid dropping into some kind of eco-stagnation (Zubrin is also a big-time libertarian, and writes a column for the National Review).

    I think it’s understandable, though. If you grew up seeing all these amazing accomplishments of NASA, and heard people talking about how it was on to Mars, then O’Neill space colonies, etc, you’d be pretty disappointed in current progress, too. Plus, there was a brief period where a variant on his proposal (Mars Semi-Direct) looked like it might get some support, but then the focus on the ISS killed it again.

    Personally, I’m in no hurry, and I think space colonization is an outdated trope from Space Opera. We’ll get there when we get there, and I don’t mind using robots to do it either.

  • TheBrett

    Sorry, that’s my post. For some reason, it was creating a picture of the Zubrin speech at the bottom. I couldn’t delete it, so I tried deleting my post – and that just left it as a “guest” post.

  • Paul451

    You don’t need them to agree. Apple current has $130 billion in cash reserves.Google has $50 billion.

    Both could fund Tito’s mission several times over from the rounding off error in these two numbers. At least Google is funding its Lunar X-Prize, and does a large amount of internal curiosity-driven research. Apple is doing SFA with its hoard.

  • Paul451

    A storm shelter is only useful during a storm. The idea of a magnetic deflector is that it lowers the cumulative exposure, you’d still need a shelter for actual solar storms.

    The thing is, on the moon you can see light patches surrounded by dark rings in the dark regolith that correspond to extremely weak local magnetic fields. Much too weak, theoretically, to deflect radiation. (The light patches are where there’s believed to be less radiation exposure of the regolith. The dark rings are where the regolith got a “double dose” from the deflected radiation.) If we can figure out what’s going on, we should be able to replicate the effect, without generating a full, power-hungry, “artificial magnetosphere”.

  • Paul451

    NASA’s focus should be on establishing permanent outpost, first on the surface of the Moon and then on Mars. This would allow….

    Talking about what it would “allow” is pointless. In reality, every proposal for such a mission (whether lunar base, space station, going all the way back to Apollo) has soon seen these uses stripped away in order to fund the inevitably overbudget/behind-schedule primary stated Purpose of being “a lunar base” or “a space station” or “putting a man on the moon”. Hell, Constellation couldn’t even keep the base, before cancellation it was a single lander. It’s hard to see that culture changing.

    Things need to be the other way around, where you do a lunar base because it’s the best way to achieve the actual goal of, say, robotic exploration. [**] And to get into that position, NASA needs to seed development of much more basic technology, such as orbital depots, more commercial crew programs, hab modules, etc.

    The key point I get from Tito’s Mars plan is that he intends to just put together existing (under development) tech/services in novel way. He might be pushing the limits of human endurance, but he’s not developing any new technology. The SpaceX-heavy baseline proposal (already scrapped apparently) is a Dragon capsule fitted with a Paragon ECLSS and a small Bigelow inflatable, all launched on a single Falcon Heavy on a free-return trajectory. No nukes, no ion drives, no tethered habitats, no lander. “What we have, and no more.”

    And that’s where NASA should be aiming to be. Where it is actually cheaper to order up a manned mission than to build a specialised multi-billion dollar probe. Where a sample return is cheaper than a $2.5b mobile robot laboratory.

    [** It seems unlikely that a base is actually the best solution. Assuming the radio-lag really was an issue, then either an orbital facility or multiple mobile habs with 2/3 man teams of robot wranglers, seem like much better solutions than a single fixed base. But since we haven't landed a single lander/rover on the moon since Apollo, lunar exploration hardly seems a NASA priority, however "obvious" it is to the rest of us.]

  • newpapyrus

    The Moon and Mars have practically every element necessary for sustaining human life, including gravity and practically unlimited resources for radiation shielding. The Moon’s greatest advantage is its low gravity well which should eventually allow a lunar colony to dominate satellite manufacturing and launching within cis-lunar space.

    Marcel F. Williams

  • Paul451

    especially if it’s going to cost hundreds of millions of dollars to pull off and may end up setting the overall goal back.

    a) Not your dollars. How are you hurt by them being misspent?

    b) No else has a proposal for 2018. The next “magic window” is 2032, so we’ll have 14 years of not going to Mars the get the “been there, done that” out of our system.

    And I’m hoping that by proving the concept of private adventurers creating space missions from off-the-shelf parts, it will encourage others to try for other “firsts”, like say a private manned lunar landing, or a Venus flyby. And enough of those sorts of missions will field test systems so that when 2032 rolls around, we are likely to see a long list of nations funding the same “off the shelf” Mars lander missions, trying to get there first before a random billionaire makes them all look stupid again.

    Currently, NASA’s greatest ambition is for a 2032 orbit-only manned Mars mission (not much more than Tito’s proposal), with a manned lander mission waiting until the 2050 magic window.

  • gfish3000

    Ok, now I follow. I thought the posts looked a little weird, like they should’ve been part of one reply. At any rate…

    Not your dollars. How are you hurt by them being misspent?

    Of course they’re not my dollars and it’s Tito’s responsibility for dealing with his financial planning for Inspiration Mars, not mine. But if his mission fails to do what he wants it to do or ultimately fizzles and we’re left with a Martian flyby, he would become a cautionary tale to others who might have been inspired by add their money into the venture.

    Look, we know that wealthy and dedicated people can do big things. We see them do it every day and there’s little question that between Tito, Musk, Bigelow, and Branson there’s a whole private space industry in the making. But that’s even more of a reason for them to be making smart, long term investments. So what we we wait another 14 years? Maybe we won’t need to with new propulsion systems? And we’ll have all this time to build a massive Earth, orbital, and lunar infrastructure funded by tourism and science.

    That’s the thing, though – Zubrin pointed out that it doesn’t get there faster than six months, not even with a space nuclear reactor…

    Like I said, Zubrin wants us to be on Mars years ago and his entire line of debate about VASMIR rests on saying that because the scale model is not performing like the planned interplanetary thruster configuration, it’s never going to work so instead we should just follow the same plan he’s been pitching since the early 1990s. This is not a rational argument, it’s stubbornness and calling well understood technology going through its formal trials a hoax is childish.

    While Ad Astra does extrapolate a rosy full scale scenario, he uses their lowest bound data as his guide while seething about how everyone who doesn’t see the needs to do Mars direct right this very second just doesn’t know what he or she is talking about. Like I said, his plan strains credulity on many levels and you don’t want a zealot putting together your mission plan. Have you ever read some of his books? There’s so much hate for NASA dripping from every page for not executing on his plans, it’s as if he keeps a nice cold glass of Hatoraide next to his computer.

    What makes you think [submarine nuclear reactors] translate well into space?

    They’re designed to be light, go for long periods between maintenance, absorb a lot of radiation damage. and they can be cooled by liquid metal, as is now done for a number of nuclear submarines which are designed to use sodium. I’m sure there are nuclear engineers who have many ideas about how to cool nuclear reactors in space as well but I can’t give you an authoritative opinion on that. Though I could tell you how I see a C&C and communication setup being put together and programmed for all this.

    If you’re operating inside of the asteroid belt, it makes more sense just to power your electric drive with solar panels instead of a reactor.

    You’re going to be limited by the efficiency of your photovoltaic materials and your energy density will be far, far lower. There’s a reason why we didn’t stick solar panels on Curiosity but gave it an RTG instead. Now it has an expected lifespan of three years rather than three months and can do things Spirit and Opportunity couldn’t even think about doing. Yes, we can launch a ship with enormous solar panels to Mars. But why when we can give them a lot more power?

    If you grew up seeing all these amazing accomplishments of NASA, and heard people talking about how it was on to Mars, then O’Neill space colonies, etc, you’d be pretty disappointed in current progress, too.

    Well, I grew up hearing about them and I’m disappointed about the lack of progress too. But you don’t see me preaching the need to colonize Mars right now as if it was a religion and thrashing everyone’s ideas for how to do things differently and potentially better as nothing but noise, hoaxes, and delays, and demanding a near blank check from the government.

    Plus, there was a brief period where a variant on his proposal (Mars Semi-Direct) looked like it might get some support, but then the focus on the ISS killed it again.

    Actually what killed Mars Semi-Direct was the price tag. I’m sorry Zubrin’s pet project was killed but that happens to everybody. He hasn’t gotten over it, I get it, but again, that doesn’t give him the right to crown himself the Mars messiah and preach from on high what will and will not work when it comes to getting to Mars. He’s not the only smart person who wants to go there and his Mars Direct plan is not the holy grail of space exploration. Now can we please, please drop his rants?

    I think space colonization is an outdated trope from Space Opera.

    Hey, space operas are a very near and dear thing to me dammit! There are distinct advantages of having space colonies if you have the technology, but I do agree that we’re not there yet and would like to focus on something that will actually get us there, not another PR stunt designed to say “we can do it!” rather than “we want to become a true space-faring species and advance ourselves as a civilization.”

  • TheBrett

    Of course they’re not my dollars and it’s Tito’s responsibility for dealing with his financial planning for Inspiration Mars, not mine. But if his mission fails to do what he wants it to do or ultimately fizzles and we’re left with a Martian flyby, he would become a cautionary tale to others who might have been inspired by add their money into the venture.

    That’s actually Paul’s segment you’re citing, but I’ll respond anyways. :D

    Where do you think the smart, long-term investments begin? They begin with testing ways to do stuff like this: sending people on interplanetary missions. If Tito somehow pulls this off, even with as much off-the-shelf hardware as he can afford, we’ll have pushed the boundaries on technology.

    Like I said, Zubrin wants us to be on Mars years ago and his entire line of debate about VASMIR rests on saying that because the scale model is not performing like the planned interplanetary thruster configuration,

    What else are we supposed to base it on? That’s all there is aside from engines on paper. And that’s Zubrin’s point – we’re neglecting ways we actually could do this with tried-and-true technology* in favor of engines on paper where the math doesn’t even work out that well.

    That’s not Ad Astra’s fault, since they never claimed it could get there in 39 days – that was Bolden at NASA.

    * Mostly tried-and-true, since Mars Direct needs a nuclear reactor that doesn’t exist.

    I’m sure there are nuclear engineers who have many ideas about how to cool nuclear reactors in space as well but I can’t give you an authoritative opinion on that.

    You either have to dump it into a heat sink (like Apollo did) or radiate it away in space (like the ISS). Dumping it into the fuel isn’t really an option over several months, and radiating a megawatt-level reactor’s waste heat away will require large radiator panels with the circulation system to cycle that heat.

    You’re going to be limited by the efficiency of your photovoltaic materials and your energy density will be far, far lower. There’s a reason why we didn’t stick solar panels on Curiosity but gave it an RTG instead.

    Obviously, but Mars isn’t that bad in terms of solar radiation. Even at aphelion, you’ll still get 36% of the intensity of the Sun’s light on them, and that’s constant as long as your ship stays out of the shadow of the planet. You’ll have to build large solar panel arrays in orbit, but your nuke ship is going to need large radiator panels anyways – both would require orbital assembly.

    Curiosity is on the surface of Mars, so the panels really aren’t as useful because of the day-night cycle. That’s not a problem for your spaceship, which will presumably stay up in orbit or in transit.

    And need I mention the politics issue? It will be far, far easier to get public support and consent to build a solar-powered ship in orbit, as opposed to sending up a nuclear reactor.

    Well, I grew up hearing about them and I’m disappointed about the lack of progress too.

    Seeing, not hearing. Zubrin’s old enough to have seen the Apollo missions on television when they happened.

  • gfish3000

    what makes him angry about it is that he thinks it’s NASA’s excuse for doing nothing…

    Which is not fair to NASA. He seems to believe anything that does not get humans to Mars right away is a waste of time and money. It’s as if he didn’t work at the agency and isn’t aware of the political environment under which it lives. Plus, again, there’s his “you bastards, you killed my project” thing he’s been obsessed with for decades…

    and that Ad Astra is actively out there saying that any Mars mission is unsafe until we can work out their program.

    And that’s not fair to Ad Astra either because that’s not what the company is saying at all. The point that the faster we get humans to Mars the less exposure they’ll have to cosmic rays is factual and valid. The point that a six month slog through space is tedious and difficult for the human mind is valid as well. What scares me about Zubrin is that he’s so nonchalant about the health and mental well-being of astronauts because he thinks he’s willing to endure anything to get to Mars, thus future interplanetary explorers should be too.

    A spacecraft reactor might not mass quite that much, but it will still be very massive, far beyond anything we could do in one launch.

    Quite possibly, but I’m not imagining a single reactor as the solution, but rather a cluster of them to add some modularity to the design. This way if one of the components in one of the reactors renders it inoperable, the craft is not dead in space. Solar panels would also be a handy backup for all essential life support systems, if not their main power source. But I’m just not seeing a workable space station with a million square meters of solar panels. It’s just too hard to beat the energy density of a nuclear reactor and using solar to help fill in gaps and provide reliable backups in case something goes wrong.

    And you can still have depots, maintenance bays, and all sorts of other niceties long the way to Mars which would actually be great because it fits into my “invest in the infrastructure for space exploration, not the PR stunts” theme.

    Aside from being places where people who really want to live in a space habitat and can afford to do so choose to live more or less for the hell of it, I don’t see what the advantages are.

    If you have a large enough society and really know your nanotech, you’ll want to mine asteroids. Likewise, you’d be able to evacuate to other worlds if something goes horribly wrong with one. You can also do all sorts of possibly useful exploration because you’ll never know what you’ll find when you go exploring. That’s how we got to where we are today.

  • TheBrett

    The point that a six month slog through space is tedious and difficult for the human mind is valid as well. What scares me about Zubrin is that he’s so nonchalant about the health and mental well-being of astronauts because he thinks he’s willing to endure anything to get to Mars, thus future interplanetary explorers should be too.

    I do think he tends to smooth over some of the difficulties with Mars Direct, including the training, the possible health consequences of being in low gravity for more than two years (low on Mars, micro-gravity in space), and some of the technical issues.

    But it’s not “impatience” to question as to why we need a more exotic space drive to do something, when it may be possible to do it with tried-and-true hardware.

    Solar panels would also be a handy backup for all essential life support systems, if not their main power source. But I’m just not seeing a workable space station with a million square meters of solar panels.

    Both a big solar ship and a big nuclear ship will have to be assembled in space, along with all the infrastructure required for that. I just don’t think that it’s going to be better to go with a set of nuclear reactors that will require a quarter million square meters of radiator fins (plus all the plumbing involved, and the heat off the crew quarters and the rest of the spaceship), versus a million square feet in solar panels. I mean, a 25 meter heat exchanger is a big deal today, one of the biggest. Whereas a million square meters of solar panels doesn’t strike me as too problematic for a civilization that has the infrastructure to build a massive solar- and/or nuclear-electric ship anyways.

    Once you get beyond the inner solar system, you just don’t have a choice – it’s nuclear or chemical. But inside the asteroid belt, I believe solar is superior.

    And you can still have depots, maintenance bays, and all sorts of other niceties long the way to Mars which would actually be great because it fits into my “invest in the infrastructure for space exploration, not the PR stunts” theme.

    If you can get them to Mars, fuel depots might be more practical around Mars than around Earth. Mars already has two sizeable asteroids you can use that may have volatiles, while for Earth you’d either need to launch the fuel into space or drag an NEO into the orbit of Earth or the Moon.

    If you have a large enough society and really know your nanotech, you’ll want to mine asteroids. Likewise, you’d be able to evacuate to other worlds if something goes horribly wrong with one.

    There’s no natural catastrophe that a primarily Earth-bound civilization couldn’t deal with, with some spacecraft capable of deflecting asteroids. You’d need something on the order of a minor planet in line to impact with the Earth to make planetary evacuation mandatory.

    Exploration doesn’t need colonists.

  • Paul451

    But if his mission [...] ultimately fizzles and we’re left with a Martian flyby

    Err, that is his mission. Yeah he had NASA-style PR puffery about promoting innovation, inspiring children etc, but everyone tunes out that kind of crap. All people hear is “Mars flyby in 5 years”. If he delivers “Mars flyby in 5 years”, that will be seen as a huge success. If he fails, hardly anyone will remember. (Same as hardly anyone remembers previous failed claims.)

    The only thing that could do damage is if it launches, and the couple dies part way. Or has terminal radiation sickness by the time they return.

    The latter could end manned space flight, much moreso than a mere accidental death. Not right away, but interest would just fizzle out. No new programs, nothing to ever replace an ended program. Poison in the well.

    [Interesting scenario, if we lose communication with them near Mars. No known reason, just all comms and all telemetry cut off, never heard from again. Imagine the conspiracy nuts.]

  • Paul451

    I haven’t been able to find out how much heat an S6G-level reactor generates to create its 165 MW,

    I think you’ll find that 165MW is the heat output (from the 200 ton core). The electrical output is closer to 23MW.

  • Paul451

    There’s no natural catastrophe that a primarily Earth-bound civilization couldn’t deal with,

    Pandemic, super-volcano, comet (may not be enough time between detection and getting a ship in an intersect orbit (especially if it hits on the way in)). And of course, old faithful, all out nuclear war. Probably others that I haven’t thought of.

    These may not specifically require you to “evacuate the planet” (and honestly, not an option for our level of civilisation), but it is a hell of a lot easier to cope with a disaster when there are economically self-sufficient groups outside the disaster zone who can send help/money. And that requires more than a few asteroid miners and explorers, that means entire “nations” in space.

  • TheBrett

    I think you’ll find that 165MW is the heat output (from the 200 ton core). The electrical output is closer to 23MW.

    I’m just going off the figures I’ve found for the S6G’s power output. It doesn’t surprise me that the electrical output is far lower, since that reactor is used both for electrical power and to drive the submarine.

    That simply makes using a nuclear VASIMR even less attractive inside of Mars’ orbit. You’ll need the radiator surfaces for nine of them, far more than you’d likely get with ISS-level efficiency solar panels on a much larger scale.

    Also waste heat isn’t a problem. Not only does Mars’ atmosphere allow heat to convect away with an apparently annoying efficiency, any waste heat that reaches the rest of the rover is actually welcome. Completely different rules to being in space.

    I agree that it’s not a problem planet-side, since you can use the atmosphere and ground to dump your waste heat. Space is a lot worse for it than in an atmosphere.

    No one ever set up a new purely socialist colony and just let the experiment run. (A few communes in California don’t count. They are too small to avoid simple Cat Society politics.)

    There were at least several utopian communities tried in the US in the 19th century, particularly religious ones – the Hutterites, Shakers, and Mormons in the temporary Law of Consecration period come to mind. Some did better than others, but they generally didn’t scale well.

    So colonies in space will produce ways of thinking that will feed back to Earth. New political systems, new economic models. And failures. For example, it would be nice to see true communism tried and failed. And true libertarianism. Get it out of the way once and for all.

    Ultimately, though, the colonists either need an overwhelming desire to get away from the Earth plus the resources/assets/knowledge to do it, or the colony needs a strong economic foundation. The New England colonies in North America had both.

    It’s a question mark in the long run, because what might seem impossibly expensive for a relatively small group of people to fund may not stay that way. The Puritans were able to hire ships to bring them over using a well-connected, reasonably prosperous group of people, but we’re not quite at that point yet with space travel.