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The dragons of Mars: all smoke and not much radiation

RAD instrument

Astronauts planted the last boot prints on the Moon over forty years ago. Since 1972, all would-be explorers at NASA and the space agencies of other nations have remained trapped on the surface of Earth or confined to Low Earth Orbit (LEO). No one has even attempted to venture beyond to the more interesting and lucrative destinations in the solar system like the asteroid belt or Mars.

After such a great start in the 1960’s, what happened? Why have the various space agencies dropped anchor so close to home? Why hasn’t the public demanded a lot more exploring from its explorers? Has mankind’s insatiable curiosity and drive to settle new worlds completely vanished?

No, the nature of mankind hasn’t changed much over the years. America has traveled the same road as other nations, and NASA’s biggest problems have nothing to do with science or technology. Simply put, NASA is a branch of the US federal government, and it has finally started acting like one.

NASA has matured into a risk-averse bureaucracy barely capable of mounting a mission anywhere farther than the International Space Station in LEO. Bureaucrats throughout the government satisfy themselves with exploration by television, from the comfort of home. Exploration by television seems cheaper and politically safer because heads rolled after two shuttle disasters. No one wants the next head to be their own.

But why stay in LEO? What’s so dangerous about the void beyond LEO that bureaucrats will do almost anything to prevent people from going there – even private citizens?

The simplest answer… beyond LEO, there be dragons.

Food for dragons: fear of the unknown

Deeper space beyond LEO contains new risks, new “dragons.” Presently, governments lack any compelling reasons to confront these dragons. The relentless advance of science and technology has slain some dragons, as cold hard facts replace sorcery and speculation. Other dragons refuse to die and, if anything, have grown uglier and more deadly as we feed them over time.

Fear of the unknown led 15th century seafarers to mark their maps with dragons in places that seemed dangerous. In 1497-99, Vasco da Gama sailed around the Cape of Good Hope with four ships and a crew of ~170. Only 55 returned, a 67% mortality rate. Chalk one up for Scurvy, the great Sea Dragon.

Flash forward over 500 years and little has changed. Fear of the unknown affects everything we do in space. We mark our solar system maps with scary dragon names like “Cosmic Rays,” “Zero Gravity,” or “Too Slow (needs advanced propulsion).”

While scientists and engineers know these dragons quite well, the media and general public don’t – which naturally leads to fear. We science fiction writers routinely use fear of the unknown as a plot device to create tension in our stories and movies. We invent imaginary dangers just over the next hill, new dragons that delight in punishing intrepid explorers for the insolence of their society. Why should the real world be any different?

Better food for dragons: fear of the known

Known fears can hurt us even more than unknown ones, especially when people quote statistics to manipulate or reinforce these fears. Statistical dragons often force society down the primrose path toward grotesque risk aversion. Witness the recent ban on balls during recess at a New York middle school, a perfect example of a small lizard (a low but real probability of playground injuries) growing into a big, ugly, fire-breathing dragon (teaching our children how to live in fear and avoid all risk). Governments like to feed dragons.

Governments still shape the space arena too, so we have come full-circle back to the dragons of space – and in particular, Mars. In our mission planning process, we try to minimize significant statistical dangers. Real hazards like zero-G and solar or cosmic radiation do exist – but are they small, harmless lizards or nasty dragons?

All hail Radiation, king of the dragons

The ugliest, meanest fire-breathing dragon is the risk of cancer caused by exposure to radiation in space. Whenever a Radiation Dragon shows its jagged teeth in the media, a conditioned public cringes in fear. This powerful, invisible dragon has murdered or mutilated countless people on Earth, and we know its cousins inhabit space beyond Low Earth Orbit.

On Earth, the Radiation Dragon can’t be halted, reasoned with, or avoided. In space, the Radiation Dragon can be avoided quite easily - literally by doing nothing. Space dragons won’t bother us if we all stay home and hide under our beds.

So that’s exactly what many smart people want NASA to do. Witness a Florida Today article by Todd Halvorson and a somewhat more balanced article by UK writer Rik Myslewski in The Register. Both encourage NASA to stay home and hide under the bed from all the scary dragons.

The tone of these articles is not unusual or extreme, given the risk-averse world we live in. It’s natural for the media to question the ethics of exposing astronauts to space radiation when they’ve been told how easily that dragon can be avoided. As usual, the arguments sound persuasive because some sketchy statistics do back them up. Both articles are well-written, typical examples of how we feed our dragons their favorite food: fear.

Contrast these articles to one that actually contains some scientific facts.

What happens when we stop feeding the Radiation Dragon its balanced diet of fear? Can it survive for long on its own? Let’s draw five concrete conclusions about at the topic of radiation in space without irrational fears getting in the way – and see if this dragon can survive. For now we will assume only data from the articles above, along with a helpful article about radiation from the Mayo Clinic.

Examiner’s Note: The Halvorson and Myslewski articles both reference the RAD instrument on the Curiosity rover as their main source of “new” data. The RAD science team has requested a delay in posting any results and conclusions within this article until they publish five pending science papers. That’s unfortunate, because the best way to reveal the true Radiation Dragon is by taking its photograph, i.e. studying the real data. But for now we’ll interpret its real size by looking at its shadow. Expect future updates adding more detail and supporting quotes, once the RAD publication embargo period has passed.

Examiner’s Note #2: Please don’t underestimate the importance of the pending RAD data. While dragons feed on fear, dragon-slayers feed on data. For purposes of this article and our high level concerns about space radiation, it doesn’t matter what special interests preach. Mission planners will take the real RAD results and design a successful Mars mission around them. That’s your take-home point, nice and simple.

1. Context is everything

Whenever we discuss Mars missions in the media, we absolutely must (!!) present clear, up-front details about the mission goals, plan, and assumptions. Many different Mars mission plans are feasible, and each results in a different radiation profile for an astronaut crew.

Several engineers or scientists consulted for this article reacted quite negatively to the Halvorson article because it discusses radiation risks and limits for internal NASA employees while implying vague, non-NASA mission plans. This classic bait-and-switch tactic encourages readers to reach some wrong conclusions about the size and reach of the Radiation Dragon.

For example, the 500-day mission duration quoted in the article obviously refers to Inspiration Mars, a mission organized by private American businessman Dennis Tito. This is not a NASA mission, though Tito does intend to work with some NASA engineers to overcome difficult technical issues. NASA has never formally planned a Mars fly-by mission with a 500-day trajectory, so references to it within the articles are completely irrelevant.

Likewise, the brief discussion and flippant dismissal of one-way missions to Mars obviously refers to the mission of Mars-One, an international non-profit organization. This group also would like to work with NASA on some technology issues, but they will not be including NASA employees in their pool of crew candidates (unless a NASA employee applies as a private citizen, just like everyone else). NASA has never formally planned a one-way mission to Mars, so references to it within the articles are also completely irrelevant.

A NASA study back around the year 1990 did suggest a ~500-day “opposition” style NASA Mars mission. That deeply flawed plan thankfully disintegrated over 22 years ago and has rarely reared its ugly head since then. But since NASA did plan an opposition-style mission to Mars way back then, any references to it in the articles (if that’s what was really intended) are relevant but ridiculously obsolete.

Remember that 22-year time interval. We will see that number again.

Modern conjunction-style Mars mission plans require less than 400 days of round-trip travel time in space, spread out over three calendar years. The current NASA plan for Mars assumes a conjunction-style mission if conventional propulsion is used. Therefore, references to 400 days in space on a three year mission would be relevant in the Halvorson article but are conspicuously absent, while references to a 180-day one-way trip to Mars in the Myslewski article lack the detail to either support or refute the conclusions of the article.

Furthermore, the RAD instrument traveled to Mars in an unshielded spacecraft using a longer trajectory, one that is not optimal for human missions. These details matter. We must carefully account for mission differences before drawing conclusions from RAD results and assessing the implications for future, optimized, shielded human missions. When this is done for most real mission plans, the previously published RAD results place the radiation exposure for a Mars-bound crew comfortably beneath the NASA lifetime limits for astronauts. No change of guidelines is required, at least for now.

Advanced propulsion (solar electric or nuclear thermal) might cut transit times to Mars down to somewhere between 30 and 90 days, depending upon numerous details. References to advanced propulsion in these articles are therefore also relevant… but as we shall see below, several critical details were left out of each article.

2. NASA vs The World

NASA employees are US federal government workers. They must adhere to all EPA and OSHA workplace regulations that constrain other federal workers. But what about everyone else?

As mentioned above, the two missions most likely to approach or land on Mars over the next ten years (Inspiration Mars and Mars-One) are both private missions. One is an international private mission.

Most real people in the world don’t lose sleep at night worrying about US government workplace regulations. Quoted opinions by EPA bureaucrats lack much relevancy to the 99.99% of the world that doesn’t work for the US government. Lumping every possible Mars explorer or settler together into a nice, tidy contextual framework… is grossly misleading.

This distinction becomes more important when we consider one of the rising players in space: China. A communist regime halfway around the world doesn’t care about US workplace regulations. It can set whatever policies it wants to. If China turns its gaze toward Mars, any concern about the radiation dosage causing a slight increase in lifetime cancer risk for their astronauts will probably be considered… for about two seconds. Then, <flush>…

3. Ethics and opportunity costs

The articles suggest an ethical dilemma because “NASA would have to knowingly expose astronauts to cancerous, or even lethal, levels of space radiation.” Yet what is the alternative?

Even leaving our astronauts grounded on Earth exposes them to cancerous, possibly lethal levels of radiation – or even worse carcinogens. Recall the Radiation Dragon on Earth – it murders millions of people each year. Refer to the Mayo Clinic article for a much better context on cancer risks.

Theoretically, fatal cancer can develop from a single damaged strand of DNA. Therefore, any level of radiation strong enough to damage DNA can potentially cause lethal cancer, on Earth or in space. The statistical risk for very small doses might be near zero, but it will never reach zero. Any ethical question therefore becomes a simple matter of thresholding, i.e. where do we draw a divider line on a graph? And what do we give up, when we draw that line?

Another irritant in the Halvorson and Myslewski articles is the assumption that by reevaluating radiation guidelines, NASA is somehow acting unethically. Isn’t the exact opposite even more true? We must always change our world view when presented with new data. Failure to do so would lead to disaster at NASA.

Complicating the ethical landscape further is the key economics concept of opportunity cost. For early Mars missions, we must always keep opportunity costs firmly in mind while considering the statistics of small numbers that these missions represent.

Let’s say NASA sends a crew of six people to Mars. Let’s also assume that everything we thought we knew about radiation in space turns out to be wrong. Instead of a 3% increase in the lifetime risk of developing cancer, the crew is actually exposed to a 30% risk, i.e. the science community somehow missed their estimate by a whole order of magnitude. What does this actually mean?

It means that instead of two crew members developing fatal cancer at some point late in life, perhaps four will. The mortality rate for cancer would approach the mortality rate for scurvy on Vasco da Gama's "successful" voyage. Yet, the absolute difference is only two lives.

So... in order to save the lives of two astronauts – assuming the whole six person crew doesn’t die first in a motorcade accident after their return to Earth or we don’t cure cancer completely 30 years from now – we are willing to change the mission plan… how exactly?

This is where opportunity costs must be factored into the ethical equations. Should we double the amount of radiation shielding – vastly increasing the mission cost and complexity to the point where we geometrically increase the overall risk in other parts of the mission or drop critically needed mass that could reduce mission risk by 50%… all to hypothetically save two lives thirty years from now? Should we first develop nuclear propulsion as the Halvorson and Myslewski articles suggest, at a cost of tens of billions of taxpayer dollars that could have been spent developing surface rovers, water purification advances, or crop growth breakthroughs that benefit all of mankind? All to save two lives… maybe?

In fact, opportunity costs destroy the whole concept of “saving two lives.” If two people die from cancer, they won't die from any number of other causes. How do you “save” a life, when fatality risks are endless and so far in the future? We are all going to die someday. Here, we are merely debating how we are going to die.

Contrast the arguments above to the normal playground of the EPA. Assuming a US population of close to 311 million people, a 30% increase in cancer risk equates to 93 million people. One can make a more solid argument in favor of expensive mitigation steps when the opportunity cost is a shorter productive lifetime for millions.

Another thing we know about the Radiation Dragon… it doesn’t discriminate. All potential NASA destinations and mission plans beyond low-Earth orbit contain substantial and somewhat comparable radiation risks, though details like timeframes, available shielding, and the ratio of solar to cosmic radiation may vary. Ruling out one destination (Mars) effectively rules them all out. We might as well stay home, turn out the lights, and crawl under the bed again.

The Radiation Dragon may be scary… but an excessive fear of any dragon is much worse. Enough said.

4. Twenty-two years ago…er, from now…

Let’s go back to that 22 year interval. Recall that 22 years ago, NASA Mars mission planners preferred “opposition” style missions that exposed the crew to ~500 days of hard radiation in space (including a Venus fry-by) while limiting their useful work time on Mars to a brief 30 day walkabout. This plan died long ago because it made absolutely no sense after something better came along.

NASA currently plans to send astronauts to Mars in the year 2035 (or later). Do the math… that’s 22 years from now. 22 years!

So… this major ethical challenge at NASA, the radiation risk to an astronaut on a Mars mission, won’t matter for another 22 years? Seriously?

Who knows what will change between now and then. New technologies, better plans, a different economic situation, different goals, perhaps NASA won’t even exist! Some Denver Space Industry Analyst 22 years from now will likely look back at today and wonder how we could assume such utter nonsense in our thoughts about Mars missions.

As your Examiner-of-today writes this article, the US government can’t even predict what will happen 22 weeks from now. NASA and another 14.5% of the government just reopened after being Shut Down for two weeks, and more serious budget battles loom endlessly on the horizon. The United States treasury is way beyond broke, and the current administration hasn’t even tried to pass a budget since 2008. Forecasts call for skyrocketing deficits, and the media skewers anyone proposing tough-love solutions. At this brief moment in time, trying to look 22 years into the future seems rather difficult.

5. Other dragons dwarf the Radiation Dragon.

We shouldn’t spend too much time on this obvious statement. During the next 22 years, NASA planners would probably be thrilled if they could somehow reduce the other risk factors on a Mars mission down to a level where the radiation risk actually matters.

Dwarfing risk factors include the effects of zero gravity on the human body, the likelihood of random equipment failures, psych issues, inadequacies of our current EDL (entry, descent, and landing) techniques for heavy payloads, and of course the mother of all risks, the Return Trip to Earth. Compared to any of these dragons, radiation risks on a well-designed mission barely deserve to be mentioned.

Yet… space radiation risks are mentioned frequently in the media while these other risks are not. One wonders, “Why??” Does our society have a sub-conscious need to feed the Radiation Dragon? Why do we design our space program around the small lizards rather than the fire-breathing dragons or, much better, the dragon-slayers?

In conclusion: The Curious Curse of the Oakland A’s

As your Examiner writes this article, the 2013 baseball playoffs rage onward. My St Louis Cardinals look good again, only one game away from the World Series, so it’s fitting that this article concludes with some profound wisdom from America’s Favorite Pastime. What does baseball have to do with radiation in space, you might ask? Well, it’s all about the Oakland A’s.

Those of you who recall the 2011 smash hit movie Moneyball will immediately know the name Billy Beane. As the general manager of the Oakland A’s baseball team, Beane has put together winning teams on shoestring budgets so often during the past decade that fans are surprised when the A’s don’t make the playoffs. They would be even more surprised if the A’s survived the first round in the playoffs, which has only happened once out of seven tries since the year 2000. Refer to this article in the NY Times for the gory details – and for the quotes below that make sense of this tangent.

Beane builds his teams around statistics. He knows every baseball season has 162 games. In a season of that length, he can use statistics to win enough games to reach the playoffs. But then things change, as these quotes from Beane in the NY Times article state so perfectly:

General Manager Billy Beane, the architect of a string of surprisingly successful A’s teams both then and now, said that his deeply statistical, low-cost system “doesn’t work in the playoffs,” adding, “My job is to get us to the playoffs.”

What happens in the postseason, he said, is “luck,” prefacing the word with an R-rated adjective.

Beane’s bane is the fact that a team only needs to win three games of five to survive the first round of baseball playoffs. Five games is much fewer than 162 games, just as six astronauts on a mission to Mars is much fewer than a million random people in the general population. Beane knows painfully well that once you’re in the playoffs, you can throw the statistics out the window. Getting to the next round, statistically speaking, is indeed “luck.”

The lesson for NASA is obvious. If bureaucrats enforce overly strict guidelines for radiation exposure on the first mission to Mars, preventing a mission from even happening, it’s the equivalent of trying to plan luck. Their goal should be to “make the playoffs,” i.e. fly a real mission while taking reasonable steps to reduce the risk of radiation so the crew has a fighting chance of survival in the first round. Once you’re in the playoffs, Billy Beane, it’s a whole new ball game.

Avoiding the Radiation Dragon will require some luck, no matter the planning or statistics. As for the fans of the Oakland A’s… cheer up. There’s always next year.

Disclaimers: The Denver Space Industry Examiner works at the Southwest Research Instrument, the company which developed the RAD instrument. He also is a technical adviser to Mars-One. Neither organization contributed official content or opinions to this article.

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