The technique could at least help find ice

Jun 25, 2009 10:38 GMT  ·  By
Deployed on future rovers on the surface of Mars, the new MTDEM system could help mission controllers detect water buried deep under the Red Planet's surface
   Deployed on future rovers on the surface of Mars, the new MTDEM system could help mission controllers detect water buried deep under the Red Planet's surface

Experts at the Southwest Research Institute (SwRI) and the Ball Aerospace and Technologies Corp. managed to create a tool that could prove to be invaluable for future Mars exploration missions. The device, which is pretty basic in concept and looks, has the ability to detect ground water buried deep under the surface of the Red Planet. With the discovery of water on the planet, the goal of manned space exploration there could be brought one step closer.

The Mars Time Domain Electromagnetic Sounder (MTDEM) tool works based on the principle of detecting the electrical conductivity of the subsurface. The way it achieves that is by generating electrical currents in the ground using induction, and then detecting the secondary magnetic fields that are formed. This means that the instrument can then accurately reconstruct the conductivity patterns of the areas above which it is traveling, giving mission controllers an exact view of the planet's “basement.”

“Groundwater that has been out of atmospheric circulation for eons will be very salty. It is a near-ideal exploration target for inductive systems,” SwRI Space Science and Engineering Division MTDEM Principal Investigator Dr. Robert Grimm explains, quoted by PhysOrg. He adds that the MARSIS and SHARAD penetration radars, which are already placed in the Martian orbit, are not efficient in detecting water buried under solid rock, and also that the inductive principle they use is different than the one proposed for the MTDEM tool.

“The radars have been very useful in imaging through ice and through very dry, low-density rock, but they have not lived up to expectations to look through solid rock and find water,” he says. The keys to the new system are flat-lying loops of wire, which are shot by a delivery system, and fall on the ground. They are used to generate and receive the electrical signals, but the team ran into a few problems while trying to get their design right.

“The main challenge was getting the spooling right. The spools had to be compact yet allow rapid payout of a thin wire at more than 30 meters per second (70 miles per hour),” Ball Aerospace and Technologies Corp. Mechanical Engineer Robert Warden shares. The contractor is in charge of building the MTDEM deployment system altogether.

“Electromagnetic induction methods are widely used in groundwater exploration. We have been mapping groundwater in Hawaii for many years,” Zapata Incorporated expert James Pfieffer says of the system's efficiency. The geophysical company provided field support and testing for the new device.