He earned a bachelor of science in physics from the Massachusetts Institute of Technology and a Ph.D. in astronomy from Harvard University.

At OSTP he was instrumental in guiding the creation and development of the science and technology aspects of the newly created Department of Homeland Security especially as they relate to weapons of mass destruction countermeasures.

He also served as the assistant deputy for technology at the Defense Airborne Reconnaissance Office, where he supervised sensor development for the RQ-1 Predator and RQ-4 Global Hawk Unmanned Aerial Vehicles (UAVs) and the development of common standards that allow for cross-service and cross-agency transfer of imagery and intelligence products.

He was the 13th Director of the National Institute of Standards and Technology (NIST), sworn into the office on July 26, 2005.

He became the president and CEO of SRI International in September 2014, succeeding Curtis Carlson.