mars_samplereturn_000929 WASHINGTON -- It's like bringing home the bacon, Martian style. For decades, high on NASA's wish list has been rocketing back to Earth clumps of Mars soil and rock via robot spacecraft.
One big problem: any NASA U-Haul plan for Mars sample return is expensive.
More than a decade ago, space agency engineers blueprinted such a Red Planet project. That scheme went nowhere fast after its price tag of some $5 billion produced sticker shock.
More recently, experts at Jet Propulsion Laboratory (JPL) in Pasadena, California, scripted a $1.5 billion
international undertaking for 2003 and 2005. It involved France and Italy, special rovers, landers and a Mars orbiter that lobs back to Earth two beer-can-sized containers of Martian turf. 
The Mars 2001 Lander was cancelled in the wake of the loss of the Polar Lander.
In that concept, the first batch of Mars would have nosedived into Utah in April 2008.
But the recent
back-to-back Mars failures forced NASA to overhaul its exploration plans for the Red Planet. Likely to be pushed downrange in time is a costly, but scientifically important, Mars sample return effort.Dot the planet
A new Mars master plan is slated for completion in mid-to-late October, a timetable that is always subject to change, said
Scott Hubbard, Mars Program Director at NASA Headquarters.NASA insiders suggest that an array of small-to-large missions is on tap.
Dotting Mars with packages of experiments, using balloons and mini-aircraft, as well as circling the planet with a mix of sensors can help piece together the true story of Mars' past and present.
When unveiled, the plan will look outward to 2020, "but with much more specificity this decade," Hubbard told SPACE.com. For months, Hubbard has been listening to Mars scientists, aerospace contractors, experts at the agency's far-flung field centers across the country and others.
Houston, we have a Mars plan
How best to "bring back the goods" -- samples from high-priority spots on Mars -- is also being re-evaluated.
For instance, Mars planners at NASA's Johnson Space Center (JSC) in Houston, Texas have come up with their own approach to bringing back Martian samples. New ways to collect them, and rocketing the specimens to Earth, are advocated.
~
One unique aspect of the still hush-hush JSC Mars sample-return scenario is use of
a space shuttle.The spacecraft that returns Martian soil and rock to Earth can be sealed in a sarcophagus in the shuttle bay under human supervision, as opposed to being sealed on the Martian surface under an automatic sequence, monitored only by telemetry.
Additionally, a desert landing of the shuttle -- at Edwards Air Force Base in California or at White Sands, New Mexico -- puts the Mars cargo down in isolated surroundings for quick transport to special handling facilities.
Also, since the shuttle is the safest delivery vehicle around, its use may help short-circuit public worries about "Martian bugs" escaping from any newly returned samples.
Needless to say, the still-expensive Houston plan has rung the "not invented here" alarms at JPL, said a government source. Other sample-return ideas are also being reviewed.
When will the dollars and technology match up with the "Mars smarts?" To pick the best spots for sampling and to make a mission possible and scientifically rewarding? This all remains unanswered.
Handful of soil
Any more delay in bringing back to Earth pieces of Mars is not welcome news to Chris McKay, a Mars expert at the
NASA Ames Research Center, near San Francisco, California."I am a bit disappointed that the revised Mars program seems to push sample return further into the future. I think that from an astrobiology point of view, a sample return, even a handful of soil, is going to give us the best science return," McKay said.
Once Martian soil and rock is safely stashed within laboratories on Earth, what can be done with those samples "is orders of magnitude better than what can be sent to Mars," McKay said.
"So while a sample return may cost more per mission, I believe it will cost less in terms of science achieved. This is certainly true for the search for evidence of a warmer, wetter Mars and the possibility of life during this early wetter period," McKay said.
If there's will...there's a way
Sample return is a costly undertaking, said Ron Greeley, a planetary geologist at Arizona State University in Tempe. He also chairs the Mars Exploration Program Analysis Group, a NASA advisory group.
Greeley said that just scooping up any old handful of Mars is not the most preferred course of action. Anywhere between a pound (500 grams) to just over 2 pounds (1 kilogram) of select Mars soil and rock chips is the ideal amount of sample needed for analysis, testing and storing, he said.
"Because of the investment, we want the samples to be the right kind of samples from the right place," Greeley said. "The overall science strategy is to make sure we collect enough information from orbit and from precursor landed missions that a program of returning samples is going to be justified, in terms of the huge expense in bringing the samples back. Nobody wants to see a stunt," he said.
William Boynton, professor of planetary science at the University of Arizona in Tucson said that the case for Mars sample return has been made many, many times. "In terms of science-per-dollar, it's clearly the way to go," Boynton said.
An impatient Boynton said that there's probably no reason why a 2007 sample mission can't be mounted.
"I think NASA just has to get the will to make it happen. Some people are holding out for not doing a sample return until it can be perfect, meaning going to the ideal site -- and that site likely having the signs of life. I think that's an unreasonable thing to wait for. In my view, that's kind of like always waiting for tomorrow," he said.
On-assignment astronauts
Holding off Mars sample missions for now is not a worry for David Paige, professor of planetary science at the University of California in Los Angeles.
"It's more a question of bang for the buck, and also the risk. We've got to think hard before we jump into it," Paige said. "Mars is a very 'target-rich' environment. We are very far from the point where sample return is absolutely required to make any further progress about how that planet works," he said.
Paige questioned whether the technology for returning Martian samples is mature enough. Moreover, the expense of the effort might curtail other Mars robotic-exploration projects, he said.
Could the best Mars sample-return strategy mean giving astronauts the duty of poking about the planet and bringing back a handpicked bounty?
"That could also be it. And those will be interesting samples," Paige said.
advertisement
