U.S. District Judge Gerald Bruce Lee approved the sentence, which was brokered by Regan's lawyers and prosecutors. As part of the agreement, the government promised not to prosecute Regan's wife, Anette, and allowed her to keep Regan's military pension.
Regan also agreed to tell the government about any classified information he may have given to a foreign country.
Regan avoided the death penalty when the jury decided that in attempting to spy for Iraq he did not offer documents concerning nuclear weapons, military satellites or war plans.
Ethel and Julius Rosenberg were the last Americans put to death for spying. They were executed in 1953 for conspiring to steal U.S. atomic secrets for the Soviet Union.
A married father of four from Bowie, Md., Regan worked at the National Reconnaissance Office, which operates the government's spy satellites. He first worked there for the Air Force, then as a civilian employee for TRW, a defense contractor.
Prosecutors said Regan had credit card debts of $117,000 when he drafted a letter to Saddam offering to sell U.S. intelligence for $13 million. He made similar offers to Chinese and Libyan officials, though prosecutors acknowledged he never actually passed any secrets to any government.
Using his access to a classified Internet network, Regan looked up dozens of top-secret documents, including satellite photos of Iraqi missile sites. He was arrested Aug. 23, 2001, at Dulles International Airport outside Washington while boarding a flight for Zurich, Switzerland.
Regan was carrying information with the coded coordinates of Iraqi and Chinese missile sites, the missiles that were stored there, and the dates the information was obtained, prosecutors said. He also had the addresses of the Chinese and Iraqi embassies in Switzerland and Austria in his wallet and tucked into his right shoe.
Defense lawyers said Regan might have fantasized about spying, but had no real intention of selling secrets. And his lawyers argued that the information he had with him when arrested was easily available through public sources.