G. Scott Hubbard, who has led a NASA research center since 2002 and investigated the space shuttle Columbia tragedy, is stepping down to accept a position with an organization that studies the possibility of life beyond Earth, he said Monday.

Hubbard, 57, will occupy the Carl Sagan Chair for the Study of Life in the Universe at the SETI Institute, effective Feb. 15.

"My new position at the SETI Institute allows me to return to the research arena and pursue a lifelong interest in the search for life in the universe and its origins on Earth," he aid.

SETI, which stands for the "search for extraterrestrial intelligence," houses research into the origin of life and how it might be found on other planets and moons. The institute, in Mountain View, Calif., is a nonprofit organization and home to dozens of researchers.

Hubbard joined the nearby NASA Ames Research Center in 1987 and as director worked to increase collaboration with neighboring universities and companies.

In 2003, he was named to the board that helped determine the cause of the Columbia's disintegration that January.

Earlier, he was the first Mars program director at NASA headquarters, where he worked to correct problems that doomed two spacecraft in 1999.

Hubbard's new position is named for Carl Sagan, a planetary researcher who popularized science and the search for life through his work on NASA missions, books and the PBS television series "Cosmos." Sagan died in 1996.