Mars Mission Poses Problems but Has Possibly Big Rewards
President Bush’s goal of sending a manned expedition to Mars within 30 years poses unprecedented scientific and technological challenges but it also may lead to new insights into human and planetary evolution--and perhaps even to material returns.
Chief among the obstacles is the debilitating, and possibly fatal, effects of prolonged exposure to zero gravity.
But a Mars mission also would require more durable and lighter-weight building materials, better ways to protect spacecraft from debris and astronauts from radiation and--above all--more powerful rockets, perhaps nuclear-fueled, capable of launching massive vehicles and their components to the distant planet.
“Clearly, it’s a much larger challenge than going to the moon,” said John E. Pike, associate director for space policy at the Federation of American Scientists.
On the bright side, however, the asteroid belt between Mars and Jupiter is studded with minerals such as cobalt, nickel and platinum that, if mined, could be worth hundreds of billions of dollars. “Those materials are available to the first nation that gets there,” said one scientist.
Close-up studies of Mars’ surface and atmosphere also may provide new understanding of the basic forces that govern the solar system’s evolution and possible signs of whether life ever existed there.
In addition, astronomy conducted from Mars would be able to explore the cosmos with hundreds of thousands of times greater clarity than previously possible--the new orbiting Hubble Space Telescope notwithstanding.
First, however, there are some political realities to be dealt with on Earth.
It remains to be seen if the Democratic Congress--at a time of whopping deficits and rising interest rates--will go along with the mission’s estimated price tag of $500 billion. President Bush did not mention the projected cost in either of his two major speeches on Mars, the most recent on Friday in Texas.
The technological challenges may be more formidable.
One current NASA scenario calls for Mars-going spacecraft to be assembled at the orbiting $30-billion space station, which the space agency hopes to complete around the turn of the century. Such spaceships might then shuttle between Earth and Mars.
Reducing travel time looms as the central challenge to a human mission to Mars because of the deleterious effects of zero gravity on astronauts. NASA scientists believe nuclear-powered rockets might reduce the one-way trip from a year to several months.
But whether such an advanced technology is feasible is “too speculative” for now, according to scientists at the George C. Marshall Institute, a science think tank in Washington. “No element of research in preparation for the missions is more important,” they said in a recent report.
The withering effect of prolonged weightlessness on bones and muscles were strikingly demonstrated when two Soviet cosmonauts returned to Earth after more than a year in orbit: They had enormous difficulty walking--despite having exercised strenuously each day they lived in space.
Experiments in the U.S. Skylab suggest that loss of bone mass could amount to 30% during a two-year round trip to Mars, leaving the legs and spine dangerously fragile. Other tests have shown that serious immune deficiency could develop, while calcium loss could cause kidney stones.
According to Marshall’s scientists, NASA acknowledges the importance of the zero-gravity problem but the agency has yet to recognize the need to conduct research and development into artificial gravity as a possible solution.
In addition, they said, the hazards of prolonged zero-gravity would be exacerbated by the spacecraft’s rapid deceleration upon arrival at Mars. The sudden braking could put severe stress on the crew’s weakened cardiac systems and skeletal structures.
The Marshall scientists called for creation of a presidential commission, made up of experts from academia, industry and government, to oversee the mission.
