Humans on Mars: Risk vs. Reward

humans on mars

Some of the boffins who hate human space exploration are at it again, claiming that humans on Mars exploration is “too risky.”  Their new hobby horse – spaceflight is a cancer risk.  That’s right, spaceflight can give you cancer, so we shouldn’t send brave men and women to Mars (for their own good, of course!).

For those who aren’t space buffs, let me just say that NASA is one of the most conservative science institutions in the world.  That ‘conservatism’ isn’t political, but it does come in two flavors; how much evidence do you need to declare a discovery, and how much risk is acceptable in a scientific endeavor.  Let’s look at them one at a time.

Scientific conservatism is generally a good thing.  Mathematicians prove things, scientists do not.  Scientists gather evidence, track data, and state what they ‘know’ within a given level of confidence that is backed up by heavy-duty statistical analysis.  A good scientist realizes that the sort of proof that we all learned in high-school geometry class (an absolute proof – good for all time and in all situations) really isn’t possible in science.  A scientist’s job is to continue to gather data and as the number of points on the graph goes up, our confidence that we have the right explanation for things also goes up – but it never reaches that magical level of “absolute proof.”  We all blithely refer to “Newton’s Law of Universal Gravitation” as if it were absolutely proved – but Einstein’s relativity theory corrected and adjusted Newton’s theory because Einstein realized that Newton’s theory didn’t apply in all situations ‘universally.’

The flip-side of scientific conservatism can be seen where scientists simply refuse to accept new evidence that lies outside the parameters of current theory simply because they don’t believe it intellectually, or cannot accept it emotionally – it all amounts to much of the same thing.  We have seen this in Galileo’s fight with the renaissance Church over the structure of the solar system, and current battles fought over teaching evolution in schools, primarily on religious grounds.  We see it in other places too, such as the fight through most of the 20th century over the existence of black holes and the evidence of bacterial life on Mars detected by the Viking landers.  Thomas Kuhn (The Structure of Scientific Revolutions) tells us that scientific revolutions don’t succeed on the basis on overwhelming evidence; rather, they succeed when the old opponents retire and die off leaving the field clear for the new young bucks to make their mark and take over the classrooms and journals.

The second sort of conservatism has little or nothing to do with scientific activity; it is a risk-aversion conservatism that seeks to eliminate all risks to human and material resources.  Many a tort lawyer will tell you that a company’s practices or products represent an “unacceptable risk to the public”.  They will also tell you, often in the same breath, that this means that a) someone is to blame, and b) someone must pay through the nose.  This practice of risk-mining and exploitation through the court system combined with professionally excoriating and financially defenestrating the blameworthy for profit has made many industries (and their management) extremely risk averse.  Industries quite rightly seek to limit the risks to the public which consumes their products and services; it is their public and professional duty to do so – and they know they will be held professionally and financially accountable if they do not.  This is all well and good, so far as it goes.

NASA is a bit different, it isn’t in the business of making products or providing services to the general public – they are explorers.  Of course, our current administration doesn’t seem to think that we (the United States) should be in the business of human space exploration anymore.  But like a kidney stone, ‘this too, shall pass.’  The fact is that America IS in the business of human space exploration, the public overwhelmingly supports it, and there has NEVER been a shortage of brave American men and women willing and able to put the flag on their shoulder and a helmet on their head and climb aboard space vehicles to be hurled into the unknown on a column of fire and engineering expertise.

Is it risky?  You bet!  The first Apollo astronauts understood that the odds of their coming through their pioneering mission to the Moon and back held perhaps a 50/50 chance of success and survival; and they all fought hard for the honor of being chosen for those seats.  They understood that the risks; personal, scientific, and financial, were all worth it because the rewards were so great.  The public understood it, too – and supported both the enterprise and the astronauts unreservedly.   The Space Shuttle fleet flew some 150 missions and two of 5 orbiters and their crews were lost (a 40% failure rate over a lifetime of service).  None of those astronauts begrudged the risk.  Their legacy, from the Hubble Space Telescope to the International Space Station, is monumental – and it was worth the risk.

How about going to Mars?  How much is it worth to explore, and one day, colonize our sister planet?  How much is it worth to open up a new world with as much land area as the Earth has?  How much would it be worth to prove (or disprove) that Mars has indigenous life?  How much would it be worth to insure that a Humanity living on two worlds could never be wiped out by a single global catastrophe?  According to the risk-analysis wonks, an increase of 3% in your lifetime risk of getting cancer from radiation exposure in space is “too much.”  Three percent?  Really?!?

So what else gives you a 2-3% lifetime risk of getting cancer?  Living on Earth, that’s what!  According to various cancer research organizations, there are many cancers that already carry a 2-3% risk over your lifetime.  Here are a few of them:

Cancer type

Male lifetime risk

Female lifetime risk




< 1%







< 1%

























According to the current model of risk/reward strategies (3% increase in your lifetime risk for ALL cancer makes it ‘too risky’ to go to Mars) there are a lot of things NASA wouldn’t approve of.  Certainly prostate glands for men and breasts for women would be off the certified equipment list, and certainly having a colon doesn’t seem to be good for anybody.  A uterus might just make the list, but it probably wouldn’t be recommended and funding for one wouldn’t clear Congress.  Certainly the combined risk of bladder, kidney and stomach cancer would make drinking even water off the recommended activity list, and sunshine would be banned all together due to melanoma risk.  All in all, it certainly looks like NASA wouldn’t approve of humans exploring Earth, either.

Of course, there are strategies to reduce risk, and we certainly shouldn’t over look them.  According to the American Cancer Society and Cancer Research UK, your overall risk of getting some form of cancer is approximately 33% in your lifetime – but risk can be cut 40% (4 in 10 cases of cancer in a given population can be avoided) by regular exercise, cutting down on booze, quitting smoking, and using sun screen regularly.  Then there are those of us who are happy to be equipped with such things as breasts, prostate glands, skin, colons, uteruses and kidneys; we’ve rather gotten used to having them and consider the rewards of having them to be definitely ‘worth the risk.’

You know what?  There’s a whole planet up there waiting for us!  And anyone who wants to withdraw their passport application because the trip is ‘too risky’ is welcome to drop out.  To hell with them, the rest of us want to go to Mars!