Exploring Mars: Astronaut Versus Astrobot

However, critics say that this next generation of launch vehicles still fails to address the fundamental hazards of human spaceflight. “It’s old technology cobbled together and resold,” says Alex Roland, a professor of history at Duke University who testified before Congress about the Columbia accident in 2003.

The new Ares rocket, like its predecessors, will essentially rely upon a controlled explosion to blast astronauts into space. “As long as that is the case, you don’t want to be carrying people aboard,” says Roland.

Once aloft, human voyagers to Mars will grapple with the psychological issues posed by a trip lasting two to three years, with most of it spent traveling in an interplanetary void. These explorers will be separated from their families and confined in a relatively cramped environment with the same crewmembers for months. A communications delay with Earth of anywhere from eight to 44 minutes will encumber conversations with support personnel and loved ones alike.

Cosmic rays will also pose a grave threat to Mars-bound astronauts. Like X-rays on Earth, though more powerful, cosmic rays harm human tissue and can lead to cancers and degenerative disorders like cataracts.

Earth’s atmosphere and magnetic field deflect most cosmic rays, guarding people on our planet’s surface and also on the low-orbiting International Space Station. Mars-goers, however, will lack these defenses. NASA engineers hope that advanced spacecraft shielding, currently in development, will ward off this cosmic radiation, says Frank Sulzman, the space agency’s radiation project executive at Brookhaven National Laboratory in Upton, NY.

Other physical health issues, such as bone and muscle loss from extended periods in the weightlessness of microgravity, will plague explorers during their journey as well.

And once the astronauts arrive, the plain fact that Mars does not support human life will further expose them to many perils. Mars has a thin, unbreathable atmosphere, and its surface has an average temperature of about -80 degrees Fahrenheit (-60 degrees Celsius). Dust storms, the fiercest in the solar system and which are thought to gust up to nearly 100 miles per hour (161 kilometers per hour), can rage over the entire planet for months.

Keeping these travelers alive, healthy and working in such extremes will prove complicated and costly. “We live within a very narrow range of tolerances,” says Sipes. “Mars presents a lot of challenges to those limits.”

The scientific inefficiency of human exploration becomes clear, according to critics, when considering this myriad of medical and technological obstacles. “All we’ve learned from putting humans in space is how to put humans in space, and that’s kind of a circular argument,” says Bob Park, a professor of physics at the University of Maryland, College Park, and a longtime critic of human spaceflight.

As soon as humans are introduced into an exploratory mission, the basic goal of the journey becomes survival, rather than scientific discovery, says Duke’s Roland. So can robots do the job that much better?

Rise of the Machines

Though half of the 40 or so mission craft sent to Mars have failed in some way, from lost contact to accidental destruction, robots remain conveniently inexpensive. While the Phoenix craft cost a cool $420 million, this price tag is a pittance next to the $40-80 billion that a manned mission is conservatively expected to cost. Given NASA’s history of budget overruns (the International Space Station being a prime example), the final tally for transporting humans to the Red Planet could reach half a trillion dollars—the figure originally estimated by the space agency for such a mission back in 1989.

Roland calls this approach a poor allocation of financial resources and argues that it’s time for NASA to finally break with its costly history of misguided human escapades. “Two-thirds of the trillion dollars spent over the space years has been spent on manned spaceflights,” he says. “Robots can do so much . . . a Mars rover mission that could have returned to Earth with samples should have happened 25 years ago. All this time, people could have been touching Martian soil at the Air and Space Museum.”