NASA's Curiosity rover has started work even before it reaches Mars by monitoring space radiation during its 8-month trip from Earth to Mars to determine the environment that an astronaut would encounter on a future human mission to the Red Planet.

One of 10 instruments on board the next rover mission to Mars, the Radiation Assessment Detector (RAD) will monitor high-energy atomic and subatomic particles from the sun, distant supernovas and other sources, including radiation on the surface of Mars, which could be harmful to astronauts or any microbes.

Findings of the research will aid in planning for future human missions to the Red Planet, NASA said.

"RAD is serving as a proxy for an astronaut inside a spacecraft on the way to Mars," said Don Hassler, RAD's principal investigator from the Southwest Research Institute in Boulder, Colo."The instrument is deep inside the spacecraft, the way an astronaut would be. Understanding the effects of the spacecraft on the radiation field will be valuable in designing craft for astronauts to travel to Mars."

Curiosity launched on Nov. 26 from Cape Canaveral, Fla., aboard the Mars Science Laboratory (MSL).

"The first data packets from RAD look great," said Hassle. "We are seeing a strong flux in space, even inside the spacecraft, about four times higher doses of radiation than the baseline we measured on the launch pad from the RTG, or radioisotope thermoelectric generator, used to power the rover. It's very exciting to begin the science mission."

According to NASA, previous monitoring of energetic-particle radiation in space has used instruments at or near the surface of various spacecraft but the RAD instrument is on the rover inside the spacecraft and shielded by other components of MSL.

"While Curiosity will not look for signs of life on Mars, what it might find could be a game- changer about the origin and evolution of life on Earth and elsewhere in the universe," said Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters in Washington.

"One thing is certain: the rover's discoveries will provide critical data that will impact human and robotic planning and research for decades," he added.

NASA said that as of noon EST on Dec. 14, the spacecraft will have traveled 31.9 million miles (51.3 million kilometers) of its 352-million-mile (567-million-kilometer) flight to Mars. The first trajectory correction maneuver during the trip is being planned for mid-January.