Since 2004, Theisinger and Cook have alternated managing NASA's Mars Science Laboratory project, which landed the highly successful car-sized Curiosity rover on Mars last summer. Both previously managed NASA's Mars Exploration Rover project with its twin rovers, Spirit and Opportunity.
The TIME 100, as the magazine's Managing Editor Richard Stengel has explained, is "a list of the most influential people in the world. They're scientists, they're thinkers, they're philosophers, they're leaders, they're icons, they're artists, they're visionaries. People who are using their ideas, their visions, their actions to transform the world and have an effect on a multitude of people."
"We are honored to have three distinguished individuals from JPL on the TIME list of most influential people," said JPL Director Charles Elachi. "Their contributions in the fields of asteroid research and Mars exploration is representative of all the exciting and important work being done at NASA and JPL on behalf of the American people."
Theisinger is a native of Fresno, Calif., and lives now in La Crescenta, Calif. He graduated from the California Institute of Technology in Pasadena, with a degree in physics. His career at JPL began in 1967 with the Mariner 5 mission to Venus and now includes contributions to missions including the Voyager mission to the outer planets (launched in 1977 and still going) and the Galileo mission to Jupiter (launched in 1989 and concluded in 2003). His Mars experience dates back to the 1971 Mariner 9 orbiter mission to Mars.
NASA's Mars Science Laboratory project is using Curiosity to investigate the environmental history within Gale Crater, a location where the project has found that conditions were long ago favorable for microbial life. Curiosity, carrying 10 science instruments, landed in August 2012 to begin its two-year prime mission. JPL, a division of Caltech, manages the project for NASA's Science Mission Directorate in Washington.