A scientist who allegedly tried to sell classified secrets to Israel had worked on the U.S. government's Star Wars missile shield program, and the Justice Department declared Tuesday that he had tried to share some of the nation's most guarded secrets. Arrested in an FBI sting operation, Stewart David Nozette was jailed without bond and accused in a criminal complaint of two counts of attempting to communicate, deliver and transmit classified information. In an interview, Scott Hubbard, a former colleague, said that Nozette was primarily a defense technologist who had worked on the Reagan-era Star Wars effort formally named the Strategic Defense Initiative. ''This was leading edge, Department of Defense national security work,'' said Hubbard, a professor of aerospace at Stanford University who worked for 20 years at NASA. Nozette held a special security clearance equivalent to the Defense Department's top secret and ''critical nuclear weapon design information'' clearances. Authorities became worried about possible espionage activity by Nozette after an investigation by NASA's inspector general in 2006 began looking at whether Nozette submitted false claims for expenses that were not actually incurred. In probing Nozette's finances in that case, investigators found indications he might be working for a foreign government, and they launched a national security investigation that eventually led to the undercover FBI sting.