WASHINGTON -- The robotic reach to the Red Planet includes grabbing, bagging and then shipping Martian soil and rocks back to Earth.

But bringing home the goods, Mars style, is neither easy nor cheap to do. In terms of engineering difficulty, some officials call it "Apollo without astronauts."

For years, NASA has wrestled with numerous cash and carry concepts to return chunks of the extraterrestrial terra firma, enough material so electron-microscope peering scientists can get a hands-on feel for Mars. Scrutiny of those bits and pieces may well reveal a message of life. Whether its old news or a fresh communique from the Suns fourth planet is part of the allure.

Since earlier this year, the Jet Propulsion Laboratory (JPL) in Pasadena, California, and four major aerospace firms have been in collective deep thought when it comes to landing the big one -- getting some of Mars here on Earth. The prime companies involved are Ball Aerospace; Boeing, Lockheed Martin; and TRW.

"Were leaving no stone unturned," said Steve Matousek, deputy manager of JPLs Advanced Studies Office for plotting out solar system exploration. Reports from the industry partners are due in late October, with teams honing in on approaches to reduce risk, contain costs and select the best technologies to do the job, he said.

Any Mars sample return is a series of tough-to-do, ship-and-shoot steps. And all of it done robotically.

Get to Mars; plop down on the surface; grab samples; load them into a rocket; launch the precious cargo off the planet; get the freight from afar safely down on Earth. Add on the critical need that Martian rock and soil should be kept in tip-top shape. That is, dont foul the samples with bacteria brought from our world and, more importantly, take precautions that the specimens dont contain microbial misfits harmful to Earth biology, including us.

Assuring protection of the sample, as well as maximizing safety in bringing Mars grab bag into Earths biosphere "are paramount requirements," said Richard Mattingly, JPLs technical manager for the industry studies. "Its a very complicated mission. Thats why these industry looks are needed."

Matousek and Mattingly said piecing together a viable Mars return sample effort could involve testing technologies in Earth orbit or deep space before committing to a full-up mission.

"Are there flight demonstrations near Earth or deep space demonstrations that need to be done? The jury is still out on that," Matousek told SPACE.com.

Matousek said that industry and NASA experts are mulling over an array of options to transform Mars return sample from paper idea to reality.

Among them: Should standard chemical propulsion or ion engine oomph -- like that used on the Deep Space 1 mission -- be tasked to get to Mars and spiral down into low Mars orbit? Is it better to have a lander fly directly from Earth, rather than deploy it from Mars orbit? Once on Mars surface, is a rover needed, or can a lander drill down, contain, and then hurl samples off the planet from its touchdown spot? Once off Mars, should the sample be shot outward for robotic pick-up in low Mars orbit or to a more distant Mars-Sun-Earth gravitational balance point? For the return-leg, do you use a chemical rocket or ion engine to boost the sample directly back to Earth, or first put it into Earth orbit for capture by a space shuttle?

These and other trade-offs are being meticulously analyzed, Mattingly said.

A given is for the mission to be launched in 2011, but teams are also looking at a 2013 time frame too. Anywhere from a little over a pound to approximately double that (500 grams to one kilogram) is the wished-for weight of the returned samples.

Price tag for the mission? "The constraint given to the industry teams is in the $1 billion to $2 billion range. We felt, if it passed the $2 billion mark, it just didnt fit into the program," Matousek said.

"There isnt anything aside from budget that says we couldnt do it in 2011. So it depends on how the budget in the future goes," Mattingly added.

John Connolly, a key thinker in the NASA Johnson Space Centers (JSC) Exploration Office, welcomes the revived looks at how to snare and shoot back fresh ground from Mars.

"There are new technologies on the horizon, like solar electric propulsion, that might enable you do things in entirely new ways. Those technologies didnt exist when some of the early decisions were being made about Mars sample return," Connolly said.

Engineers at the Houston-based space center see a blend of solar electric propulsion and the unique attributes of the space shuttle to land Mars materials on Earth. For one, using a shuttle means a Mars return vehicle wouldnt require reentry shielding to thwart the high-temperature loads as the craft plunges through Earths atmosphere. That blistering heat could alter the sample and thus compromise the total amount of science information held within the Mars material.

Also, leaving reentry shielding here on Earth is a welcomed weight-savings bonus for spacecraft designers.

Connolly said the shuttle option being proposed features a rendezvous with a solar electric-propelled Mars return vehicle in Earth orbit. The shuttles robot arm then plucks from space either the entire return vehicle or extracts the smaller sample canister. The arm gingerly tucks the hardware into a specially built "vault" or "casket" mounted within the shuttles voluminous cargo bay.

With the Mars sample in tow, the shuttle glides back to Earth for a wheeled landing.

In the event that something dire happens during the shuttles landing phase, the vault is beefed up to take a crash impact, Connolly said. "This idea combines the inherent reliability of the shuttle and the vaults reliability, giving you a system that we thought would work pretty well," he said.

"I think the public would be very confident that the shuttle could do the job," Connolly said.