National Aeronautics and Space Administration officials said Mather has been dividing his time working on the JWST and serving as lead scientist in NASA's Office of the Chief Scientist.
"My priority now for JWST is entirely driven by the needs of the project," said Mather. "As the telescope progresses, we have numerous challenges ahead of us on the technical side that have to be addressed. However, despite the workload, I still plan to continue to serve in the Office of the Chief Scientist a few days a week until further notice."
The Webb Telescope, the next step after the Hubble Space Telescope, is a large, infrared-optimized space telescope that's scheduled for launch in 2013, NASA said. The new telescope will have a mirror 21.3 feet in diameter and a sunshield the size of a tennis court. It will be in an orbit about 1 million miles from Earth.
Mather and George Smoot of the Lawrence Berkeley National Laboratory received the 2006 Nobel Prize for Physics for their collaborative work in understanding the big-bang theory.