A former government scientist charged with attempting to sell technology secrets to Israel has confessed to one count of espionage.
Stewart Nozette will serve a sentence of 13 years in prison after making a plea deal with prosecutors.
He has been in jail since his arrest in 2009 after a sting operation by an undercover FBI agent.
Nozette was accused of seeking millions of dollars to sell classified information.
He could have faced a death sentence if convicted on all four counts of attempted espionage with which he had been charged.
'Career choice'
Nozette worked in the government for several decades, including at Nasa, the National Space Council and the Department of Energy.
He told the undercover FBI agent that the secrets he was offering to Israel had cost the US government anywhere from $200m (£125m) to nearly $1bn to develop.
According court papers, Nozette told the agent he had "made a career choice", during their conversation at the upmarket Mayflower Hotel in downtown Washington in October 2009.
Out of his suburban Washington home, Nozette ran the Alliance for Competitive Technology, a non-profit organisation with agreements to develop technology for the US government.
Attorney General Eric Holder has ordered special communications restrictions placed on Nozette in jail.
His top-secret knowledge reportedly includes America's nuclear missile programme.
http://www.bbc.co.uk/news/world-us-canada-14825820
Note: 7 September 2011 Last updated at 15:42 GMT