As of 11 a.m CST today (16 UTC on December 14, 2011), NASA’s Curiosity rover will have traveled 31.9 million miles of its 352-million-mile trip to Mars. That’s almost 1.8 million miles per day. After 18 days of traveling following its November 26 launch, Curiosity has begun analyzing radiation in space in order to assess how it would effect astronauts en route to the red planet.

The rover and its 10 science instruments are expected reach Mars on Aug. 6, 2012.

Curiosity’s Radiation Assessment Detector (RAD) is designed to monitor high-energy atomic and subatomic particles that are emitted by the sun and other objects in outer space. These particles zipping through space present a danger to humans attempting long-term space travel. Once on Mars, the RAD instrument – which is buried deep within the rover – will analyze the Martian surface. But for now, it’s essentially acting as a stand-in for a human astronaut, taking measurements of the space environment, according to a NASA press release.

In the release, Don Hassler, RAD’s principal investigator from the Southwest Research Institute in Boulder, Colorado, said:

RAD is serving as a proxy for an astronaut inside a spacecraft on the way to Mars. 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.

So far, Curiosity has been an exceptionally successful mission. NASA had planned six course adjustments for the craft, but due to the precision of the launch, the first adjustment was deemed unnecessary and postponed. The course will not need to be adjusted until mid-January.

In a press release, Louis D’Amario of NASA’s Jet Propulsion Laboratory in Pasadena, California, placed the Mars launch “among the most accurate interplanetary injections ever.”

Curiosity’s launch planned for the rover to miss Mars by 35,000 miles. The upper stage of its launch rocket, called Centaur, is not as thoroughly cleaned as the rover itself; the planned trajectory ensures that Centaur will not touch Mars, protecting the planet from any Earth microbes so as not to interfere with tests.

Bottom line: NASA’s new Mars rover – Curiosity – launched 18 days ago and is now 31.9 million miles along on its 352-million-mile trip to Mars. It has traveled almost 1.8 million miles per day. After 18 days of traveling following its November 26 launch, Curiosity has begun analyzing radiation in space in order to assess how it would effect astronauts en route to the red planet.

After successful launch, new 8-month mission to Mars underway