Completion of Aft Optics System (AOS) performance testing signifies that all the telescope's mirror systems are ready for integration and testing, according to Lee Feinberg, NASA Optical Telescope Element manager for the James Webb Space Telescope at the Goddard Space Flight Center in Greenbelt, Md.
Northrop Grumman selected Ball as the principal subcontractor for the optical technology and lightweight mirror system. In all, Ball has designed and delivered the Webb's 18 beryllium primary mirror segments, secondary and tertiary mirrors, a fine steering mirror, and several engineering development units.
"Each optical element that Ball Aerospace builds for the Webb is extremely sophisticated," says David L. Taylor, Ball Aerospace's president and chief executive officer. "The successful completion of another milestone brings us one day closer to the launch of NASA's next major space observatory."
The AOS is a precision beryllium rectangular optical bench that houses the tertiary and fine steering mirror at the center of Webb's primary mirror. The AOS is surrounded by a shroud that eliminates stray light, and two large radiator panels that keep the assembly cold. This subsystem collects and focuses the light from the secondary mirror and feeds it into the science instruments.
Since May 2012, the AOS has undergone thermal, vibration, and cryogenic testing to demonstrate that it can withstand the rigorous vibration environment of the rocket launch and remain precisely aligned to function at the extremely cold temperatures in space.
The AOS is the last optical subsystem in the Webb's Optical Telescope Element to undergo and complete integration and test activities at Ball Aerospace. It will continue to be used at Ball Aerospace for integrated testing with the flight actuator drive unit and AOS source plate assembly.
In Sept. 2012, Ball began shipping the finished Webb primary mirrors to Goddard Space Flight Center, Greenbelt, Md. The remaining mirrors will arrive at Goddard this year, awaiting telescope integration in 2015.
On track for an October 2018 liftoff, the James Webb Space Telescope is the world's next-generation space observatory and successor to the Hubble Space Telescope. The most powerful space telescope ever built, Webb is a joint project of NASA, the European Space Agency, and the Canadian Space Agency.