NASA officials said Monday that Webb, the successor to the Hubble Space Telescope, has passed the last of its tests at the Greenbelt facility.
It will soon be shipped to the NASA Johnson Space Center in Houston for its next round of testing.
"The Webb telescope is about to embark on its next step in reaching the stars as it has successfully completed its integration and testing at Goddard," Bill Ochs, NASA's Webb telescope project manager, said in a statement. "It is also a sad time as we say goodbye to the Webb Telescope at Goddard, but are excited to begin cryogenic testing at Johnson."
The telescope has been in development, construction and assembly process for two decades, and its mirror and instruments have come together in a massive clean room at Goddard just over the past several years.
It is designed to see farther into space, and with greater sensitivity to light, than the Hubble. Its observations are expected to revolutionize understanding of the early universe, just as Hubble did starting in the 1990s, and to explore distant Earth-like planets in ways Hubble cannot.
The telescope's observatory, including its 21-foot mirror and set of four science instruments, spent months facing a battery of tests designed to show it can withstand the violent vibrations and loud sounds it will experience when it's launched next year.
Now, it will be tested in a large cryochamber at the Johnson center to prove it can operate in the chill of space.
NASA officials would not say when the move to Houston will occur, citing security concerns.
From there, the observatory is headed for Northrop Grumman Aerospace Systems in Redondo Beach, Calif., where it will be integrated with its six-layer sun shield that protects the instruments and mirror from interference.
It will travel by barge from California, through the Panama Canal, to French Guiana on the northern coast of South America, for its launch, slated for next October. The European Space Agency has a space port there.