Even before its successful landing earlier this week, NASA's Mars Science Laboratory was already sending back important scientific data-about the radiation exposure that astronauts might face during a mission to the Red Planet.

An image sent by NASA's Curiosity rover shortly after landing

The nuclear-powered roving robotic laboratory Curiosity touched down early on August 6, and is beaming back images while undergoing system checks. The Curiosity landing has generated worldwide interest, including interest in its plutonium power source.

Early on Monday morning (1:31AM Eastern Daylight Time), after having traveled 352 million miles, NASA's robotic rover Curiosity is scheduled to touch down inside the Gale Crater on the surface of Mars. Soon after, it will begin looking for clues about possible early forms of Martian life.

Part I:  Space nuclear reactor safety

Eric Loewen, president of the American Nuclear Society, kept up his rapid pace last week as he visited the ANS local section in Aiken, S.C., on February 15, and the one in Charlotte, N.C., on February 16. Loewen, as the featured speaker at the meetings of the two sections, presented his personal talk titled "Plutonium: Promise or Peril".

The reasons for using plutonium in space missions are often unclear to those outside the mission planning community. Observers may see or hear only that the space mission is nuclear related, and that the power source uses plutonium.

The Curiosity rover (Click to enlarge/Photo: NASA)