A science blog with Eric Berger

The real reason why we won’t go to Mars in my lifetime?


It may be radiation.

There are numerous sources of space radiation that threaten astronauts above Earth’s atmosphere, but probably the most concerning comes from galactic cosmic rays, which are the nuclei of atoms, some as large as iron, accelerated to near the speed of light. Traditional shielding can’t stop these rays and they can cause serious damage to human tissues.

Astronauts aboard the international space station wear sensors on their flight suits which record radiation, but these external sensors can’t gather information where it’s needed most — inside bodies, at the site of vital organs.

So NASA and the European Space Agency launched a “phantom torso” named Matroshka in 2004 to record space radiation both inside and outside of the International Space Station. The device has 416 sensors inside its “body” to record radiation levels.


Sergei Krikalev (left) and John Phillips with Matroshka on the ISS.

The good news is that the radiation recorded by Matroshka matched the models of such exposure by NASA’s engineers. The bad news is that the Matroshka experiments confirm that we still don’t have any way to protect astronauts for longer than about six months in space.

From NASA:





There’s also the potential for cellular damage from solar flares, and Matroshka will soon be exposed to an artificial solar flare here on Earth. Lucky guy?

In any case this is the kind of basic information needed if we’re going to go beyond low-Earth orbit. Going further, to the Moon and possibly Mars, takes astronauts outside of the protective Van Allen radiation belt, where they will be subject to still greater levels of space radiation.

Tackling this problem will require considerable innovation.

Categories: Space
Eric Berger

29 Responses

  1. Walt Stone says:

    Yeah, thanks for bringing this topic up. It’s a crying shame that there’s no room on the next rover type mission to put that torso on a special package and have that package split off and get sent back into an Earth Orbit to then be picked up and brought down to the ground safely for analysis.

    And of course, with the solar flux currently at near historic lows, that would mean more cosmic radiation for any astronauts outside the protection that earth’s magnetic field provides.

  2. craig says:

    Another nail in the coffin of the thought that we humans can just trash Earth and move on to greener pastures somewhere else in the universe to trash once again. This is our home and will be for a very long time. We had better work a lot harder than we have been up to now if there is to be any hope of a decent future for us.

  3. TomTom1978 says:

    It seems like it may be better to try and develop a magnetic field around the space craft or moon base to deflect radiation. Probably would need some sort of nuclear powered device to generate enough power. I doubt your could achieve it with solar alone. Your thought on this Eric?

  4. Old Gringo Stan says:

    A Mars mission is of no value except for creating jobs at NASA.

    This is the blue planet and nuclear threats abound to destroy it. Obama had better wipe that smug look off his face and deal with Korea and Iran…….waiting to be attacked is death to many innocents……don’t threaten me, I will attack you first…….

  5. Sounds like some good science fair projects in there.

  6. ttyler5 says:

    Forget it, Craig.

    Many of the assumptions in the post above are way off base, notice the first mistake:

    “Putting enough radiation shielding around a spacecraft would make it far too heavy to launch ….”

    But of course we will build these vehicles in stages in orbit, not launch them from the ground.

    The cosmic radiation problem has already been dealt with for decades, it is a problem with a wide range of likely technological solutions

    — and it is certainly not going to keep the Human Race locked up in the **Green Prison State** some of the professional doomsayers employed in the environmentalist 501c’s seem to envision for the rest of us!

    The American people aren’t afflicted with the enviro-socialist global warming delusion.

    Nor have we contracted the Malthusian “Club of Rome” anti-economic growth ideology.

    The only “nail in the coffin” here

    — is in the idea that the rest of us have any intention of living in a dysfunctional dysutopian totalitarian “Green” state run by busy-body apparatchiks!

    [ For the youngsters: ]

  7. Ed C. says:

    ‘New research has recently begun to examine the use of superconducting magnet technology to protect astronauts from radiation during long-duration spaceflights, such as the interplanetary flights to Mars that are proposed in NASA’s current Vision for Space Exploration.

    The examinations of maintaining the magnetic field strength to repel radiation around a spacecraft are being studied in an experiment that is scheduled to be launched to the International Space Station for a three-year stay. The Alpha Magnetic Spectrometer (AMS)will employ a superconducting magnet to measure each particle’s momentum and the sign of its charge. Recent advances in superconducting technology and materials permit superconductive properties to exist at temperatures higher than 120 kelvin (−153° C), well above absolute zero.’

    Compressed from the article by Nancy Atkinson

    Monday, January 24, 2005


    My thoughts,

    Eric I think you are not taking the studies of magnetic field repulsion of radiation into account. I think your opinion is very pessimistic. I would think a superconducting magnetic field generator would allow a safe trip to and from mars. It could be powered by the same specialized solar panels that are used to power the Mars rovers which are much more efficient because they absorb 3 wavelengths of light instead of one like a standard solar panel. Expensive yes, but possible.

  8. Dr. Dave says:

    I read about this one or two years ago. I think it might have been an article in Scientific American.

    The amount of shielding required was astronomical. (Bad pun, intentional.) I believe water was one of the best shields. But, with the urine recovery purification system, not as much water would be required for a journey to Mars.

    ttyler5 is correct in that we could “build” the spacecraft in orbit. But, that assumes we would have some method of using robotic arms that would have could be moved away from the ISS as I believe there would be too much danger assembling the craft attached to the ISS.

    Assuming the shielding could be added in orbit, then the next hurdle would be to generate enough thrust to increase the velocity from about 17,500 mph to at least 25,000 mph which is the escape velocity from Earth. However, it may require an even greater delta V to go to Mars. All it will take is money, and lots of it.

  9. ttyler5 says:


    ” … develop a magnetic field around the space craft or moon base to deflect radiation.”

    For example, a VASIMR rocket engine would already be using magnetic fields to both accelerate and contain the plasma, maybe the system could be expanded to create fields to protect the crew and cargo.

    But look, Tom, I’d say it is far more likely that in the early manned missions to Mars we will construct a multi-shelled craft in orbit, with one or more shells of the vehicle constructed as radiation barriers.

    Think of — I hate to say “Russian”, but! — Russian nesting dolls! :^D :^D :^D

    On the Martian surface, we can also bury the base facility.

  10. ttyler5 says:

    Here’s the story of the original Mars mission plan from the USSR, the UR700M, from 1969:

    These excerpts cover how and why we got into low earth orbit for such a long time:

    ” By 1972 the Nixon administration had canceled NASA’s plans for manned Mars missions. Perhaps not coincidentally, a Soviet expert commission the same year concluded that the Mars project – and the UR-700M booster – were beyond the technical and economical capabilities of the Soviet Union and should be shelved indefinitely.” ….

    ” The UR-700M/LK-700 advanced project was reviewed by the expert commission in 1972. Their conclusions were:

    ” * The problem of crew survival of the 650 day long trip to Mars had not been solved. 12 to 15 years of research aboard space stations in low earth orbit on the adaptation of the human organism to the weightlessness and radiation environment of space would be needed.

    ” * The nuclear engines of 3.6 tf and 40 tf in the Mars-injection stage of the first variant were only in the draft project stage at that time. 15 to 20 years of development would be needed before they would be ready for use in manned spacecraft.

    ” * The radiation safety problem of nuclear propulsion had only been solved theoretically. Negotiations would be needed with the United States before international permission could be obtained to place large nuclear reactors in orbit.

    ” * Without the use of nuclear energy, the spacecraft mass of 2500 to 3000 metric tons was too large to be practical.

    ” * 30 to 40 billion rubles would be needed at 1973 prices to accomplish this project. No such sum was considered to be available.

    ” Therefore the commission concluded the Mars project – and the UR-700M booster – should be shelved indefinitely.”

  11. hunter says:

    A relatively inexpensive test, that should have been done decades ago, would have been to place sensors like this on a Mars-bound mission and see what happens.

    We can and will make the leap into the ocean of stars. The sooner we focus on doing it, instead of finding excuses to put it off, the better off we will be.

  12. craig says:


    Posted by: hunter at May 31, 2009 09:29 AM

    Charity begins, or at least should begin, at home. And another one, better here than there.

    There is only one realistic doomsday scenario for Earth in anywhere near the short, in cosmic time, term and that is an asteroid of adquate size to make what we are doing now to add to climate change seem like the perverbial walk in the park hitting this planet.

    I think the better bet to “save the human race” would be to work together with other nations to be able to identify and destroy or divert any such asteroid. Having such a capability up and running and at the ready would be far more productive than trips to Mars, a place where life as we know it cannot exist outside of highly protective artificial environments.

    Blue sky scientific study is fine but only within conducted within some realistic financial contraints and budget realities.

  13. KAB says:

    “Charity begins, or at least should begin, at home.” Posted by: craig

    You realize that’s a conservative philosophy. Since when have you ever preached that? We thought your mantra was always big business is bad. Is this the craig we know and love?


  14. Witty Nickname says:

    Solution: tin foil.

    Come on NASA, this is not rocket surgery!

  15. SAN says:

    Mass shielding would seem to have a maintenance and reliability advantage over an EM type shield, and consumes no power. If it turns out that mass shielding is the way to go, might be cheaper if we get it out there rather than fly it up. We could crush up some of our moon rocks and check their ability to shield against GCR’s and solar flares.

    Amazing that a local field around a ship could be as effective at diverting radiation as earth’s field, which spans tens of thousands of miles. The maximum field intensity to work over such a short range would need to be extreme. Would probably get serious interstellar iron dust bunnies piling up around the poles.

    Also curious what the effect of solar flares on a ship’s EM shield would be. When high-altitude H-bombs go off or big solar flares erupt, all those charged particles interacting with earth’s magnetic field lines create an EM pulse which can do bad things to electonics and power transmission systems. Wonder why a ship’s own field wouldn’t create a similar effect.

    On the plus side, Spirit and Opportunity laugh at radiation.

  16. Rorschach says:

    In a couple hundred years when the earth’s magnetic field collapes, the Van Allen belts will cease to be effective shields and the whole Earth will be inundated with cosmic rays just as the moon and mars are now. So we’ll have to deal with the problem sooner or later, better sooner than later.

  17. Someone says:

    So what was the radiation dosage observed? Even the NASA article was real skinny on facts.

    From memory, the annual allowable Federal dosage is 500 mREM per year, while 5 REM/year has not been shown to have an observable effect. If the dosage is much above this, then there is a problem.

    The second question is how much the radiation changes as we get away from Earth’s orbit. I can see scenarios where the dosage may increase, and ones where it decreases. The only answer is, I think, to do more research.

  18. ttyler5 says:

    ” … Mars, a place where life as we know it cannot exist outside of highly protective artificial environments.”

    Actually, that should read:

    ” Mars, a local planet we must first reach on our way to learning how to reach habitable planets in other solar systems. ”

    Followed by: “Jovian system”.

  19. Nemo says:


    Then the solution is not to carry the silly urine recovery system.

    Look, folks, there is no need to make this problem more difficult than it is.

    Ten meters of water will provide the same shielding as Earth’s entire atmosphere, providing a radiation environment equivalent to the ambient at Earth’s surface. But there is no need for such a rigorous standard. Five meters of water would provide the shielding equivalent to that experienced by airline crews and nuclear plant workers.

    Five meters of water surrounding a Salyut-sized habitat would mass over 500 tons. That’s a lot of mass to launch. But even at current (Proton/Long March) launch prices, that’s about $1 billion to launch all that water.

    That’s a lot of money, to be sure, but in the context of a Mars program that will likely cost over $100 billion, it is not a big percentage of the total. And, more to the point, it is almost certainly less than the cost of the research required for the other solutions being proposed, such as electromagnetic shielding.

    With that much water, there is no need for recycling, so the mass and cost of the water recycling system could be eliminated. Just surround the habitat with a cluster of water tanks, arranged to provide adequate shielding even with one empty tank, and start the mission with that tank empty. As the first supply water tank is consumed, the empty tank is filled with waste water. When the first supply water tank is depleted, switch supply to tank 2 and start using tank 1 for waste water. In that manner, there will always be one empty tank. This scheme also enhances crew safety by eliminating failure of the water recycling system as a failure mode.

    By awarding competitive contracts to deliver the water, the government could also encourage the development of lower-cost launch, which would do more to reduce the overall cost of Mars exploration than just about anything else that has been proposed. It’s all about the flight rate.

  20. Ken says:

    I would have thought the main reason we won’t go to Mars anytime soon is because of costs. It’s just not worth it with any technology we have for the next 50 years.

  21. Jason says:

    This is the reason we explore – to conquer the unknown. We have a problem – and we create a solution. Who knows what might come from it? Not too long ago we thought we couldn’t carry enough water with us. Turns out – we’ll use our urine. Think of the 3rd world countries – without sewage systems – that could use this and revolutionize their way of life?

    Investment is at the very essence of the unknown. The greatest minds ensure it will be a wise – and sound investment for ROI purposes…

  22. Justin Kugler says:

    When I was an intern in Franklin Chang-Diaz’s lab, one of the things they were looking at was positioning the fuel tanks for the VASIMR around the crew modules for radiation shielding.

    There’s no hit to overall vehicle mass by creatively arranging the structure to protect the crew. While electromagnetic shielding may be an option in the future, I agree that unpowered options are likely to be the first line of defense.

  23. Funnwithmunn says:

    Looking forward to the day when the USA builds and launches the USS Einstein(from the ISS?) to explore the Universe (as seen from the Hubble)!

  24. exdoublexx says:

    So we can’t go to Mars. Can we go to Katy?

  25. ~ tax leech says:

    Thanks to NASA’s monopolistic parasitism, we’ll not be going to Mars nearly as soon as we otherwise could. Why won’t monopolistic, bureaucatic NASA put the private sector in charge of its own space initiatives, with NASA simply setting the goals and getting out of the way? Google does precisely that with its space endeavors:



    NASA could as well, through its (woefully underfunded) competitive prizes program:



    Currently that program still receives well under 1% of NASA’s bloated annual $20 billion budget, which is larger than those of the rest of the world’s civilian space agencies combined. Don’t we taxpayers deserve far better?

  26. TransAmer99 says:

    After the next hurricane wipes out Katy, TX, I’d think NASA would be much more interested in exploration activities there than on Mars.

  27. hunter says:

    As for shielding, I think we will end up using a combination of solutions:

    1- craft design itself. the manned areas can be designed with radiation blocking materials wherever practical.

    2- innocvative materials combinations, like polyester and water, and polyester and boron:

    3- special ‘storm shelters’ for crew to retreat to when things get too hot.

    We can – and will- go to Mars and far beyond, when we decide to do it. It is not technically unfeasible. The risks are no worse than those of Europeans exploring the western hemisphere.

    Each challenge is there to be overcome. Overcoming the challenges will not be cheap, but the benefits will be vast.

  28. BG says:

    Don’t like flyin’, I sure ain’t goin’ into Space to get perforated at the atomic level.

  29. Blazestop says:

    We can’t…we won’t….you better not…and thus we have the Flat Earth Society.