A US court has denied bail to the NASA scientist who was arrested by the FBI on espionage charges and allegedly tried to sell classified defence documents to an Israeli agent for 2 million dollars.Stewart David Nozette, who was one of the principal investigators for the Chandrayan-I mission of ISRO and played a key role in finding water on the Moon, pleaded not guilty when he was produced before a court .But, the judge Deborah Robinson denied his bail application arguing that he is being considered as a flight risk and should remain in jail awaiting trial. Nozette, who was indicted early this week on charges of selling classified US information to an undercover Israeli agent, faces death penalty.He has been charged with two counts of attempted espionage for allegedly trying to sell secrets to an FBI agent posing as an Israeli intelligence officer.