A former government scientist arrested earlier this week tried to provide Israel with classified information on satellites and early warning defense systems, says a grand jury indictment.

The grand jury indictment follows Monday's arrest of Stewart D. Nozette, who spent 16 years doing sensitive defense work for the Energy Department, the U.S. Naval Research Laboratory and the Defense Advanced Research Projects Agency.

The information Nozette allegedly tried to provide Israel in an FBI sting operation dealt with "satellites, early warning systems, means of defense or retaliation against large-scale attack, communications intelligence information and major elements of defense strategy," said the indictment, which did not elaborate.

Earlier this week, a former colleague said that Nozette was primarily a defense technologist who had worked on the Reagan-era Star Wars missile shield effort formally named the Strategic Defense Initiative.

The former colleague, Stanford University professor Scott Hubbard, said Nozette worked on the Star Wars project at the Energy Department's Lawrence Livermore National Laboratory. According to the indictment, Nozette worked there from 1990 to 1999.

One aspect of Nozette's work on the Strategic Defense Initiative involved a project called Timber Wind, an effort to develop a rocket engine powered by a nuclear reactor, said Steven Aftergood, director of the Project on Government Secrecy at the Federation of American Scientists.

"On a number of occasions I asked Dr. Nozette about the program, but he was always quite scrupulous about rebuffing my inquiries," Aftergood wrote on his group's Web site. "Timber Wind was canceled shortly after it became public, and other nuclear rocket initiatives likewise faded away in the 1990s, as the effort to develop nuclear rocketry for military or civilian applications surged and then collapsed."

At the Energy Department, Nozette had a "Q" clearance, which is equivalent to the Pentagon's Top Secret clearance.

Nozette, who received a Ph.D. in planetary sciences from the Massachusetts Institute of Technology in 1983, faces a court appearance next Thursday before a federal magistrate. He is jailed without bond.

Neither a criminal complaint filed earlier this week against Nozette nor the indictment allege that the government of Israel or anyone acting on its behalf violated U.S. law. The grand jury indictment alleging two counts of attempted espionage was handed up Wednesday.