Fred Whipple. Credit: Harvard-Smithsonian Center for Astrophysics

As the rocket blasts from the launch pad carrying NASA's Comet Nucleus Tour (CONTOUR) mission to outer space, it will carry with it the thoughts and hopes of many earthbound scientists. But none of these scientists is more eminent than Dr. Fred L. Whipple, who serves as a member of the CONTOUR Science Team and its inspirational leader. At the age of 95, Whipple is the oldest-ever member of a space mission science team. The CONTOUR mission will add yet another accomplishment to Whipple's long and distinguished career.

Fred Whipple, often referred to affectionately as "Dr. Comet," originated the "dirty snowball" model of comet structure in 1950. He theorized that, rather than loose conglomerates of dust and rock, comets were solid chunks of ice with dust and rocky particles mixed in. This model was confirmed 36 years later when the European Space Agency's Giotto mission passed by Halley's Comet.

In addition to his work on comets and the solar system, Whipple served as director of the Smithsonian Astrophysical Observatory from 1955 to 1973. In 1982, the former Mt. Hopkins Observatory in Arizona was renamed the Fred L. Whipple Observatory in his honor. But Whipple's greatest honor was receiving the President's Award for Distinguished Public Service from President Kennedy on June 12, 1963. This award is the highest U.S. civilian honor for government service, and was bestowed on Whipple for his leadership in creating a worldwide network to track orbiting satellites.

CONTOUR is a NASA Discovery mission to conduct close-up studies of the nucleus of at least two comets. Comets formed from the same nebula of material that formed the planets, so their study can tell us about the birth of our solar system. The CONTOUR mission will enable scientists to compare and contrast these frozen bodies in order to learn about their diversity. CONTOUR scientists will also study how comets evolve as they approach the sun. Current plans call for CONTOUR to visit Comets 2P/Encke and 73P/Schwassmann-Wachmann.

Headquartered in Cambridge, Massachusetts, the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists organized into seven research divisions study the origin, evolution, and ultimate fate of the universe.