Development of lightweight mirror technology for the Next Generation Space Telescope

In 2009, NASA plans to launch the Next Generation Space Telescope (NGST) to the L2 point, 1.5 million kilometers from Earth. With a 6-meter diameter mirror, NGST is a successor to the Hubble Space Telescope with 5 times the collecting aperture. As part of NASA's Origins Program, the ten-year observing mission will search for the "first light" of the universe. NGST will provide astronomers with unparalleled light collection, mid-infrared sensitivity, spatial resolution and field of view. Mirror technology is critical to the system's success. The hard part is solving the problem of how to launch a 6m, 600 kg, mirror into space on a 4-meter diameter rocket. Additionally, high performance is expected at operating temperatures of 50K. This paper reviews the mirror requirements and development efforts.