On November 28, a syndicated op-ed by Charles Wohlforth and Amanda Hendrix appeared in the Los Angeles Times and carried over the following days by a number of other newspapers claiming that journeys to Mars are just a dream. According to these writers, the race to Mars “can’t be won with either’s [NASA’s or SpaceX’s] current technology, regardless of their spending or commitment. The barrier is human biology. Even a short sortie mission to Mars would be extremely hazardous to human health. A Mars colony is out of the question.”
These pessimistic pronouncements have no scientific basis. For example, while Wohlforth and Hendrix point to a UC Irvine study in which irradiated mice sustained brain damage, they failed to note that the mice in question received their dose at about 40,000 times the rate it would be experienced by astronauts on a journey to Mars. This discrepancy makes the study invalid. In toxicology dose rates are critical. A glass of wine a night will cause no ill effects; 40,000 glasses of wine drunk at once would unquestionably be fatal.
In fact, not only do the cosmic ray alarmists lack foundation for their claims, we have direct contrary evidence. As a result of extensive stays onboard the International Space Station or Mir, about a dozen astronauts and cosmonauts have already experienced cosmic day doses comparable to a Mars journey, and there have been no radiological casualties. This is not surprising, since, on the basis of extensive radiation health knowledge, the radiation doses and dose rates involved pose no threat whatsoever of short-term effects, and at most about a 1 percent increase in statistical risk of contracting cancer at sometime later in life.
The authors are on somewhat firmer ground when they talk about the dangers of extended exposure to zero gravity, as there have in fact been harmful effects, including thinning of bones and weakening of muscles, observed. However, it must be noted that literally scores of astronauts and cosmonauts taking six-month tours (an equal duration to that required for flight from Earth to Mars using current propulsion) have survived such exposures. Moreover, a countermeasure — artificial gravity produced by spinning the spacecraft — that would eliminate all such effects is readily available.
Ignoring these facts, Wohlforth and Hendrix say that “space propulsion would need a giant technical leap to make a Mars roundtrip in a safe period of 150 days.” They then pile on further impossibilities by saying that the goal should really be not Mars at all, but Saturn’s moon Titan, which is not only ultra cold and ultra dark, but ten times further away than the Red Planet.
Engineering is the art of making the impossible possible. Those who seek to make the possible seem impossible are members of a very different profession. Americans should not allow their horizons to be constrained by such defeatists.
Mars – the new world of our time – is within reach. It holds the key to the truth about the potential prevalence and diversity of life in the universe. It is the bracing challenge that will draw millions of our youth into science and engineering, with vast benefits to our society as a result. But more than that, it is the first step into an open frontier, offering an unlimited future for humanity.
The effort to get there won’t be free of either risk or cost. But from a technical point of view, we are much closer today to being able to send humans to the Red Planet than we were to being able to send men to the Moon in 1961, and we were there eight years later. For us to accept claims that we can no longer do such things is to accept the idea that we have become less than the kind of people we used to be.
And that is the one thing that this country cannot afford.