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 will observe the most distant objects in the universe, provide images of the very first galaxies ever formed and see unexplored planets around distant stars. The Webb Telescope is a joint project of NASA, the European Space Agency and the Canadian Space Agency.
Scientists working on NASA’s James Webb Space Telescope met another milestone recently when they completed performance testing on the observatory’s aft-optics subsystem at Ball Aerospace and Technologies Corp’s facilities in Boulder, Colo. Ball is the principal subcontractor to Northrop Grumman for the optical technology and lightweight mirror system.
“Completing Aft Optics System performance testing is significant because it means all of the telescope’s mirror systems are ready for integration and testing,” said Lee Feinberg, NASA Optical Telescope Element Manager for the James Webb Space Telescope at the Goddard Space Flight Center in Greenbelt, Md.
Since last May, the AOS has undergone a series of thermal, vibration and cryogenic testing to demonstrate that it can withstand the rigorous vibration environment of the rocket launch and remain precisely aligned in order to function at the extremely cold temperatures in space.
The AOS will remain at Ball Aerospace to be used in integrated testing with the flight actuator drive unit and AOS source plate assembly. The AOS is the final optical subsystem in the Webb’s Optical Telescope Element to complete integration and test activities at Ball Aerospace.
“Each optical element that Ball Aerospace builds for the Webb is extremely sophisticated,” said 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 the fine steering mirror installed 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.
Scientists at NASA are taking extra precautions in testing the optics of the James Webb Space Telescope, because, as we all remember, the Hubble Space Telescope had an error in the shape of its main mirror when it was launched in 1990, necessitating several Space Shuttle missions in order to correct it. In the end, this was accomplished successfully, allowing Hubble to bring us the breathtaking pictures from space we are all familiar with. Scientists and program managers at NASA are, however, understandably eager to avoid a repeat.
In September 2012, Ball began the process of shipping the finished Webb primary mirrors to NASA Goddard. The remaining mirrors will arrive at Goddard in 2013, awaiting telescope integration in 2015. The James Webb Space Telescope, named for a former NASA administrator, is on track for an October 2018 liftoff.. Its’ mirror is larger than that of Hubble, so it should be able to peer even further out into the universe and back in time, and should give us clues about the origin and very early history of the universe. There is even a chance that it might be able to directly image planets that are orbiting other stars, but that isn’t its main purpose, since it will observe primarily in the infra-red, not visible light spectrum.