NASA scouts for Mars ideas

Several proposals expected to be made to study Red Planet

Jim Erickson, Rocky Mountain News

Published July 31, 2006 at midnight

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A bullet-shaped probe that streaks through the Martian atmosphere at 15,000 mph, gulping red dust and returning it to the Utah desert in a capsule.

A pair of plummeting copper spheres that blast 100-foot-wide craters on the surface of Mars, searching for underground ice and possible microbial hideaways.

These are two of the 20 or more innovative mission ideas expected to be submitted to NASA by Tuesday in the next round of the space agency's Mars Scout competition.

Mars Scout missions are relatively inexpensive, with tightly focused science goals. Scientists can suggest far-out schemes, as long as the mission can be done for $475 million and would help answer basic questions about the climate and geology of Mars, or help determine whether life ever existed there.

A winner will be announced in January 2008, and the spacecraft must launch by Jan. 31, 2012, said Michael Meyer, lead scientist for NASA's Mars exploration program.

"We fully recognize that we're not all-knowing and all-clever, and that there are a lot of wonderful ideas out there," Meyer said.

"Scout missions provide an opportunity for the community to come up with their harebrained ideas, some of which are pretty good," he said. "It gives us an opportunity to find and do science that we didn't necessarily anticipate, that we might have missed."

The first Mars Scout competition led to the August 2003 selection of Lockheed Martin's Phoenix probe, built at the company's Waterton Canyon facility in Jefferson County. Phoenix is scheduled to launch in August 2007 and will land on Mars' northern polar region.

Lockheed Martin Space Systems and Boulder's Ball Aerospace & Technologies are the industrial partners in several of the latest Mars Scout proposals. In December, up to three of the proposals will be selected for detailed study and $2 million grants.

Here's a look at five proposed Mars Scout missions - known by the acronyms THOR, SCIM, MOO, ARES and MAVEN. Lockheed Martin would build four of them, and Ball would construct the fifth.

"Between Lockheed Martin and Ball, I would think that a majority of the proposals will have Colorado connections," said Rich Dissly, deputy director for space advanced projects at Ball.

Making craters

THOR: Tracing Habitability, Organics and Resources

Arizona State University geologist Phil Christensen wants to blow two craters in the surface of Mars to search for water and places where microscopic life might be hidden.

THOR would be similar to, but much simpler than, NASA's audacious Deep Impact mission, which sent a copper-reinforced "impactor" slamming into a comet in July 2005 while a second probe photographed the collision.

Ball Aerospace built Deep Impact. THOR would be constructed by Lockheed Martin; Christensen is the lead scientist.

About a week before reaching Mars, the THOR mother ship would release two copper balls - one 2,640 pounds and the other 990 pounds. They would fall to the surface, accelerating to about 12,000 mph before impacting.

"It's literally just a couple of ballistic cannonballs screaming through the atmosphere, hitting, and making big craters - the bigger the better," Christensen said.

The larger ball is expected to blast a hole 15 feet deep and about 100 feet across at the target zone in Mars' middle latitudes. The goal is to get deep enough to dredge up icy dirt that could be an abode for Martian microorganisms.

"We're searching for mid-latitude regions where ice exists five or 10 feet below the surface," Christensen said. "But we want places where the temperatures occasionally get warm enough to melt that ice."

All known forms of life require liquid water.

"Having ice there is not necessarily enough," he said. "If you're trying to find environments where life could exist, you want liquid water."

The THOR mother ship would enter Mars' orbit and repeatedly pass over the craters - possibly for up to a month - photographing them and looking for the chemical signature of water with an infrared spectrometer.

"On Mars, if you throw a bunch of ice on the ground, that ice will sit there and evaporate like crazy," Christensen said. "We can look at the cloud of water vapor coming off that ice."

THOR would attempt to find icy places where future robotic rovers and landers could conduct detailed site tests.

Returning samples

SCIM: Sample Collection for Investigation of Mars

SCIM would be the first spacecraft to return samples from another planet.

The 9-foot-tall, bullet-shaped probe would streak through the thin Martian atmosphere at 15,000 mph, dipping as close as 25 miles to the surface. The "swoop and scoop" mission would capture about 1,000 dust grains and a quart of Mars air, returning them to Earth in a capsule that would parachute onto the Utah salt flats.

SCIM would be built by Lockheed Martin. Portions of the design borrow heavily from the company's successful Stardust mission.

In January 2004, Stardust flew through the dust cloud surrounding Comet Wild 2 and captured thousands of microscopic dust specks inside small blocks of an ultralight, spongy glass foam called aerogel.

Two years later, the Stardust return capsule landed safely in Utah. SCIM would use aerogel to catch Mars dust, and a return capsule nearly identical to Stardust's.

"Stardust really validated our approach," said Laurie Leshin, lead scientist on the SCIM proposal.

"It also shows that there's extraordinary scientific interest here on Earth in working with these kinds of samples," said Leshin, director of sciences and exploration at NASA's Goddard Space Flight Center.

"There are literally hundreds of scientists from probably a dozen countries, at this point, already working on Stardust samples."

Mars is a frigid desert today, but it may once have been wet. NASA's Opportunity rover found evidence that water once flowed through rocks near its landing site.

But it's unclear how widespread the Martian waters were. SCIM would help answer that question, Leshin said.

Fine dust grains are sensitive indicators of past exposure to water, she said. Analyzing the grains can reveal the types of environments they came from - rivers, lakes or oceans, for example - and whether the conditions there might have favored the emergence of life.

"The nice thing about the SCIM sample is it's sort of a global grab bag," Leshin said.

"The dust gets all mixed up around the planet by global dust storms. So it's like a little mini-rock collection from Mars," she said. "You get little tiny bits of samples from all over the planet."

Seeking methane

MOO: Mars Organics Observer

In 2004, researchers with Europe's Mars Express mission created a stir by reporting the detection of small amounts of methane in the Martian atmosphere.

On Earth, methane is emitted by volcanoes and microorganisms, among other things. A confirmed detection of methane on Mars could point to active volcanism or life, though other explanations are possible.

The Mars Express announcement was greeted with skepticism by some planetary scientists. Last year, NASA scientist Michael Mumma was among a group of researchers who used telescopes in Hawaii and Chile to gain ground-based data that he says strengthen the case for Martian methane.

Now Mumma, a senior scientist at the Goddard Space Flight Center, wants to send a spacecraft to search for sources of Martian methane and other "biomarker" gases that could indicate current life.

The MOO spacecraft would observe the entire sunlit disk of Mars continuously, from a perch about 600,000 miles from the planet.

"What we have proposed to do is to map the entire planet and to pinpoint the active regions," he said.

Mumma is the lead scientist on the MOO proposal; Ball Aerospace is the industrial partner.

"Many people would like it to be life," he said of the methane reports. "Some would not. I really don't care one way or another. I just want to know the answer."

MOO would carry an infrared spectrometer and a multi-spectral camera. It could spot individual methane sources, but it wouldn't be able to say for sure whether microbes or volcanoes produced the gas.

"You won't ever really identify whether it's biology until you're actually there, making some kind of in situ measurements that can distinguish the kinds of biological forms that we can't test remotely," Mumma said.

Robotic airplane

ARES: Aerial Regional-scale Environmental Survey of Mars

ARES would be a rocket-powered, robotic airplane with a 21-foot wingspan. About the size of a Cessna 172, ARES would be the first plane to fly on another planet.

Lockheed Martin would build the plane's rocket propulsion system, the protective aeroshell that delivers the compactly folded craft into the Mars atmosphere, and the telecommunications system that transmits the plane's pictures and data.

The plane itself was designed by NASA's Langley Research Center and would be built by Aurora Flight Sciences of Virginia.

After emerging from its aeroshell cocoon, ARES would unfold its wings and embark on a two-hour flight spanning hundreds of miles, said lead scientist Joel Levine of Langley. The plane would fly a mile above Mars' heavily cratered southern highlands, relaying real-time video while sniffing for methane and other gases that could indicate current biological activity.

"Mars Express believes they have detected methane on Mars, but their spacecraft is 250 miles above the surface," Levine said. "ARES flies a mile above the surface for hundreds of miles and will be able to pinpoint methane - if it's there."

Studying atmosphere

MAVEN: Mars Atmosphere and Volatile Evolution

In addition to being wetter than it is today, ancient Mars likely had a much thicker atmosphere.

But around 3.5 billion years ago, the planet started to lose that dense air. Gradually, it was transformed into a frigid desert with a tenuous carbon dioxide atmosphere.

"The evidence is increasingly pointing to loss of the atmosphere to space as a major mechanism - if not the dominant mechanism - for that change," said University of Colorado planetary scientist Bruce Jakosky.

MAVEN would orbit Mars and study the planet's upper atmosphere: measuring its composition; the current rate of atoms escaping into space; and the influence of the solar wind, a stream of charged particles leaking from our home star's outer layers.

"We're going to solve the mystery of Mars' lost atmosphere," said Jakosky, lead scientist on the MAVEN proposal. "We'll explain where it went and how it went there."

The probe would fly in an elongated loop: 100 miles from the surface at its closest approach and 3,100 miles from the planet at the most distant part of its orbit.

MAVEN would rely heavily on technology used on Mars Odyssey and Mars Reconnaissance Orbiter, two of the three Lockheed Martin-built NASA probes currently circling Mars.

"There are a small number of spacecraft providers that can do a credible Mars proposal, and Lockheed Martin is at the top of that list," Jakosky said.

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