Rover unfolds on Mars like poetry in motion
Experts see hurdles on way to fully manned
-- possibly fully funded -- mission to Red Planet
By Diedtra Henderson
DENVER POST
Scientists view President Bush's plans to send humans to the moon and to Mars as the tonic to cure much of what ails NASA.
Even more exciting, Bush will back the promise of human space exploration with dollars to make it happen.
Bush pledges to pump up NASA's annual budget of about $15 billion by $800 million this year and will tack on 5 percent increases each year for the next five years, in a budget heading to Congress.
Meanwhile, NASA's Spirit rover has fully unfolded itself and stretched up to its full 4-foot, 11-inch height, making it ready to drive off the lander that delivered it to Mars, the space agency said Saturday.
The rover could reach the Martian surface as early as Wednesday morning.
"It now stands at full height and all six wheels are in their final position," mission manager Jennifer Trosper said during a news conference at NASA's Jet Propulsion Laboratory in Pasadena. **There's a lot of buzz and a lot of smiling faces here, even though we've heard nothing officially,** said Mike Coats, a former shuttle astronaut and vice president of advanced space transportation at Lockheed Martin Space Systems near Denver, speaking of Bush's expected announcement later this week.>
But the scientists, mathematicians and engineers on whose shoulders the Mars and moon missions would rest know many hurdles have to be overcome to turn Bush's dream into reality.
The Challenger and Columbia disasters are seared into the nation's soul. Even if the lunar and Mars spacecraft successfully slip into space, health risks for crews include cancer in the near term, cataracts and neurological disorders in the long term, as well as damaged DNA that could pass genetic defects to future generations of the astronauts' families.
Even simply floating weightless saps bone strength and makes fractures more likely, complicating tasks astronauts will be expected to complete to return to Earth.
Coats tells local schoolchildren that someone their age could be the first to explore Mars. But he weighs those inspirational words with sobering what ifs.
"Man, we don't want to get them back as jellyfish," Coats said.
The highest health risks accompany sending humans to Mars.
The fourth planet from the sun lies at least six months' travel distance from Earth.
The current NASA strategy is to launch every two years when the two planets' orbits draw them closer together, reducing flight time. That makes a manned Mars mission a three-year proposition for astronauts.
For much of that time, they would have to be shielded from potentially deadly doses of radiation. The Van Allen belts that surround Earth trap charged particles delivered by solar wind and cosmic rays, protecting humans from their harmful effects. Outside of Earth's protective cocoon, astronauts and their craft would be buffeted by heavy ions able to penetrate spacecraft or human skin. While the charged particles create the eerie Northern Lights on Earth, astronauts on Mars would be ducking for cover. Pulses of energy unleashed by solar flares pack enough punch to cause radiation sickness or death for unprotected astronauts.
What risk is acceptable?
"That's a fundamental issue," said Jeffrey Sutton, director of the National Space Biomedical Research Institute in Houston. "We cannot be entirely risk-averse. Exploration in harsh environments involves risk."
But cancer risks for astronauts headed to Mars may be too high for politicians, American voters and astronauts themselves to stomach.
The Associated Press contributed to this report.
The researchers have turned to history -- studying the health of Japanese atomic bomb survivors -- and have devised research projects to gauge hazards for astronauts zapped by radiation doses unlike those humans receive on Earth.
"We do not know if the cancer risk is too high or morally or legally acceptable because the error bars ... are too wide at this time," said Francis Cucinotta, radiation safety officer at NASA's Johnson Space Center.
After a 1,000-day Mars mission, a 40-year-old male astronaut would experience a 3.4 percent increase in his risk of developing life-ending cancer, researchers estimated in a 2001 study. But researchers said they were only 95 percent sure increases to that astronaut's risk would fall below 18.5 percent.
Change the gender and the odds get worse. The chances a female astronaut of the same age would suffer from a deadly form of cancer after a Mars mission rise by 5.7 percent. But the worst-case scenario could increase her risk by 30.8 percent.
Those risk estimates are important when engineers design shielding for spacecraft, which increases mission cost and weight.
The toll of weightlessness on the human body is a bit easier to gauge, thanks to lengthy missions, including the 75.2 million miles Shannon Lucid traveled during her 188-day Mir Space Station mission.
By studying the health of astronauts and cosmonauts, patients on bed rest and animals, researchers know that depriving the body of gravity's effects can sap 1 percent to 1.5 percent of bone mineral density per month.
The progressive osteoporosis-like changes to bone lessen when astronauts return to Earth. Mars has just 40 percent of Earth's gravity.
"Is that enough to really slow down the rate of bone loss in humans? The answer to that is we don't know," Sutton said.
Researchers don't even know if astronaut bones return to normal on Earth.
Planners would have to account for the likelihood that bone fractures and motion sickness that accompany returning to a gravity-driven world would hinder the crew from completing mission-critical tasks.
And since space crews are older than in Gemini and Apollo days, planners will have to sort out how to conduct space medicine on the fly. International Space Station crews know if they can't quickly stem a mysterious air leak, they can hop into a Soyuz capsule and return. Mars astronauts would need six months to return.
"These are not barriers to us moving forward," Sutton said. "They are challenges that can be met and can be solved."
Scientists shrug when asked about the technical difficulty of returning to the moon for the first time since 1972. Been there, done that 30 years ago, they chorus about the three-day trip.
"Let me put it differently: The challenges are political and financial," said Bruce Jakosky, director of the Center for Astrobiology at the University of Colorado's Laboratory for Atmospheric and Space Physics.
"Is this something we want to take on, given the increased cost and the risks? Personally I'm not convinced, as a country, we're willing to put astronauts' lives at risk," Jakosky said.
Still, there are benefits that could accompany the return of humans to the Moon, including sparking more interest in space science as a career.
"That's something I've always hoped would happen," said Bill Farrand, a geologist at the Boulder-based Space Science Institute among the Mars Exploration Rover science team. "When I was just 7 and 8 is when the Apollo missions were going on. Those were a great inspiration to me."
Saturday's unfolding of the Spirit rover was one of the most complex deployments ever performed by a robotic spacecraft, mechanical systems engineer Chris Voorhees said. NASA had to fold up the 384-pound rover to make it fit inside the lander, which opened up like a four-petal flower.
When Spirit does leave the lander, it will take a different route than scientists had hoped. Air bags used to cushion the rover's landing are now blocking the ramp NASA had planned to use. Instead, Spirit will turn 120 degrees to its right and take a second, more risky ramp to the ground, mission manager Matt Wallace said.
Even though it remains on its lander, 16 inches above the martian surface, Spirit already has found traces of minerals that could have formed in what might have been an ancient lake at the landing site.
That geologic observation could support theories that liquid water persisted on the surface of the planet during Mars' ancient past and provided an environment conducive to life.
However, scientists stressed that finding the minerals, called carbonates, does not immediately prove the lake theory. The carbonate dust also could have formed by reactions with the tiny amounts of water vapor found in the martian atmosphere.
"We've got a bunch of ideas and we don't know which one is right yet," said Steven Squyres of Cornell University, the mission's main scientist. A previous NASA spacecraft detected carbonates from orbit.
Spirit also was measuring the temperature and makeup of the rocks and soil around it with its thermal emission spectrometer.
The instrument sees infrared radiation -- heat -- emitted by objects, including rocks and soil. Variations in the radiation indicate differences in mineralogical composition. That's crucial information for scientists eager to learn what sort of rocks lie strewn around Spirit and which of them are most worth analyzing.
Photographs taken by Spirit of its surroundings have also been trickling in, deputy project scientist Albert Haldemann said.
The $820 million Mars Exploration Rover project includes a second, identical rover, named Opportunity, which is scheduled to land on Jan. 24.
NASA sent the two robotic geologists to prospect for evidence that Mars may once have been a wet world conducive to life.
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