The spacecraft that will carry NASA's James Webb Space Telescope to its orbit nearly a million miles from Earth has completed a Critical Design Review for the structure that supports Webb's data link to NASA's ground station.

Northrop Grumman is under contract to NASA's Goddard Space Flight Center in Greenbelt, Md., for the design and development of the telescope, sunshield and spacecraft.

Now ready for fabrication, the Webb spacecraft's communications support structure stows and holds the communications antenna when folded for launch. When the telescope unfurls in space, the antenna is released and points to NASA's Deep Space Network, transmitting data to the world's scientists.

Another spacecraft structure, the solar array, has completed its preliminary design audit and moves into the detailed design phase.

The spacecraft's solar array supplies all electrical power to the science instruments, communications equipment and computers for the entire telescope.

The solar array is the first component that deploys once the telescope separates from the launch vehicle and its performance is critical. Without power, there is no science mission.

"This progress represents a steady path forward on spacecraft subsystems," said Andy Cohen, Webb spacecraft manager, Northrop Grumman Aerospace Systems.

"We've accelerated the structural build of the spacecraft by four and a half months, and have completed qualification testing for the engineering model of the command and telemetry processor, our main onboard computer, responsible for all spacecraft operations and fine guidance of the telescope."

Successor to the Hubble Space Telescope, the James Webb Space Telescope is the world's next-generation space observatory. It will be the most powerful space telescope ever built.

Webb will observe the most distant objects in the universe, provide images of the very first galaxies ever formed and study planets around distant stars. The Webb Telescope is a joint project of NASA, the European Space Agency and the Canadian Space Agency.