Astronaut John Grunsfeld holds onto a handrail as he performs work on the Hubble Space Telescope.
On May 14, 2009, STS-125 astronauts successfully installed the new Wide Field Camera 3 (WFC3) in the Hubble Space Telescope. Among those anxiously monitoring the operation from the ground were two SESDA II scientists, who played a significant role in developing and calibrating the principal detector in WFC3. As part of a team working at the NASA/GSFC Detector Characterization Laboratory our experts conducted a long series of tests and analyses to gain a detailed understanding of the internal properties of the WFC3 detectors. By carefully studying how those detectors respond when imaging sources over a wide range of brightness, and against all sorts of backgrounds, they have enabled WFC3 to produce the best and most accurately calibrated images possible. Now that WFC3 has been installed in the Hubble, the SESDA II team will continue to refine their understanding of the instrument through additional tests of the flight-spare detectors through the checkout period and beyond.
