Webb Telescope Reaches Halfway Point on Mirror Construction

Inside NASA’s Goddard Space Flight Center’s clean room, a robotic arm lifted and placed nine hexagonal-shapes, each measuring just over 4.2 ft across and weighing approximately 88 lbs, on a telescope structure.

On Monday, NASA reached a halfway point in the James Webb Space Telescope’s primary mirror construction by installing the ninth flight mirror of the planned 18 mirror array. Once completed, the segments will work as a single 21.3-ft mirror. Completion of the primary mirror is expected in early 2016.

“The years of planning and practicing is really paying dividends and the progress is really rewarding for everyone to see,” said Lee Feinberg, NASA’s Optical Telescope Element Manager.

With a planned launch from French Guiana in October 2018, the James Webb Space Telescope will be a premier observatory for the ensuing decade, serving thousands of astronomers worldwide.

“Webb is designed to look deeper into space to see the earliest stars and galaxies that formed in the universe and to look deep into nearby dust clouds to study the formation of stars and planets,” according to NASA. “In order to do this, Webb will have a much larger primary mirror than Hubble (2.7 times larger in diameter, or about 6 times larger in area), giving it more light-gathering power. It also will have infrared instruments with longer wavelength coverage and greatly improved sensitivity than Hubble.”  

NASA partnered with the European Space Agency and the Canadian Space Agency on the Webb telescope.  

Webb will operate markedly further than Hubble, which is in low-Earth orbit at roughly 375 mi. Webb will operate approximately 1 million mi from Earth, making it beyond reach for currently planned manned space missions.

Webb’s “lifetime is limited by the amount of fuel used for maintaining the orbit, and by the lifetime of the electronics and hardware in the harsh environment of space,” according to NASA. “Webb will carry fuel for a 10-year lifetime; the project will do mission assurance testing to guarantee five years of scientific operations starting at the end of the commissioning period six months after launch.”

The observatory is named after NASA’s second administrator James E. Webb, who led the Apollo missions, and oversaw over 75 launches during his career.