NASA’s Webb Space Telescope receives first mirror installation
26 November 2015
NASA has successfully installed the first of 18 flight mirrors on the James Webb Space Telescope, beginning a critical piece of the observatory’s construction.
In the clean room at NASA’s Goddard Space Flight Center in Greenbelt, Maryland this week, the engineering team used a robot arm to lift and lower the hexagonal-shaped segment that measures just over 1.3m across and weighs approximately 40kg. After being pieced together, the 18 primary mirror segments will work together as one large 6.5m mirror. The full installation is expected to be complete early next year.
“The James Webb Space Telescope will be the premier astronomical observatory of the next decade,” says John Grunsfeld, astronaut and associate administrator of the Science Mission Directorate at NASA Headquarters in Washington. “This first-mirror installation milestone symbolises all the new and specialised technology that was developed to enable the observatory to study the first stars and galaxies, examine the formation stellar systems and planetary formation, provide answers to the evolution of our own solar system, and make the next big steps in the search for life beyond Earth on exoplanets.”
Several innovative technologies have been developed for the Webb Telescope, which is targeted for launch in 2018, and is the successor to NASA's Hubble Space Telescope. Webb will study every phase in the history of our universe, including the cosmos’ first luminous glows, the formation of solar systems capable of supporting life on planets like Earth, and the evolution of our own solar system.
The 18 separate segments unfold and adjust to shape after launch. The mirrors are made of ultra-lightweight beryllium chosen for its thermal and mechanical properties at cryogenic temperatures. Each segment also has a thin gold coating chosen for its ability to reflect infrared light. The telescope’s biggest feature is a tennis court sized five-layer sunshield that attenuates heat from the sun more than a million times.
The mirrors must remain precisely aligned in space in order for Webb to successfully carry out science investigations. While operating at extraordinarily low temperatures, the backplane must not move more than 38nm.
The mirrors were built by Ball Aerospace & Technologies Corp., Boulder, Colorado. Ball is the principal subcontractor to Northrop Grumman for the optical technology and lightweight mirror system. The installation of the mirrors on the telescope structure is performed by Harris Corporation of Rochester, New York. Harris Corporation leads integration and testing for the telescope.
The James Webb Space Telescope is an international project led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.
You can follow the mirror installation on a live webcam here.