HAMPTON, VIRGINIA -- Through thick or thin. That motto lies at the heart of the search for biology on enigmatic Europa, one of Jupiter’s many moons.

Europa already lies in the sights of engineers at the Jet Propulsion Laboratory (JPL) in Pasadena, California. They are working toward flying an orbiter in 2008 to circle the moon. This craft would carry radar gear to survey Europa’s fractured blanket of ice, gauging the thickness of the crust.

The team hopes to find an icy inroad into Europa’s subsurface. Locating the leanest spots of frozen terrain might permit future landers to core through that ice, then unleash an underwater robot outfitted to look for life.

Dig and dive

Here at the NASA Langley Research Center, Frederic Stillwagen leads a study on a lander dedicated to the exobiological exploration of Europa, dubbed E³ for short. Stillwagen is a Tracking and Telemetry Systems Engineer.

The bottom line of the E³ study, Stillwagen told SPACE.com, concerns how best to penetrate and dive below the craggy face of Europa. The study hopes to determine if Europa contains the basic elements found in frozen surface or sub-surface samples, in order to constitute evidence for biology outside of Earth.

"If we want to see this mission in our lifetime, we need to invest in the technologies to make this occur," Stillwagen said. His study team has centered on 2030 as a candidate date for the Europa mission.

The orbiter would have a survival period of two years, swinging around Jupiter in a "favorable" orbit -- one that minimizes the vehicle’s exposure to the planet’s intense radiation fields. The orbiter deploys a mapper/lander. which would take a one-to-two month period to determine the exact location for a safe touchdown.

Sweeping down to Europa’s surface, the lander hauls enough fuel to avoid setting down in cracks, craters, canyons, or other pitfalls. Once resting upon Europa, the lander’s real business begins.

To burrow down through Europa’s crust, the lander dispatches the cryobot/hydrobot. As this device travels into the moon’s depths, the surrounding ice will shield the equipment from the ultra-heavy blasts of radiation that soak the surface.

Stillwagen said the E³ study group set the boundary of ice through which the cryobot/hydrobot vehicle would burrow at 1.8 miles (3 kilometers). "It’ll take a year to get below the surface," he said, noting that the ice shell of Europa may extend even deeper.

"Europa’s surface is so cold. It would take a long time to go through, even if you were drilling," Stillwagen observed. The cryobot would melt its way through the super-cold surface using nuclear power, he said.

"All indications are that the ice is constantly moving and flowing due to gravitational tidal effects caused by Jupiter. That means the cryobot has to work independently and can’t be attached to the lander. Otherwise, the tether would be cut," he said.

Plowing its way downward, the cryobot releases "communications pucks" -- small relays deposited at various depths in the ice. As the ice probe moves ever deeper, the pucks work together to transmit science data collected by the robot, sending that information to the surface lander. "It’s going to be checking for life all the way, as it goes through the ice," Stillwagen said.

The cryobot would possess artificial intelligence to control heating individual quadrants of itself, allowing the device to steer around potential obstacles such as rocks, boulders, or whatever else may be buried within the icy mantle.

Breaking through the ice, ostensibly into Europa’s liquid subsurface, the cryobot releases a mini-submersible. This hydrobot, Stillwagen adds, then begins its primary role of underwater snooping.