By Patricia Daukantas
Two of the most amazing instruments of 20th-century optics are going on display at the Smithsonian Institution in Washington, D.C. (U.S.A.).
WF/PC-2 and COSTAR, the instruments that gave the Hubble Space Telescope its clear vision after its spherical aberration was discovered in 1990, will be on view at the National Air and Space Museum from now on, except for a brief tour of other venues later this year and early next year.
Both of these instruments were installed on the orbiting telescope during the first NASA servicing mission in 1993. When astronauts revisited Hubble for the fifth and final time earlier this year, they replaced WF/PC-2 and COSTAR with newer cameras and brought the old instruments back to Earth.
WF/PC-2 – the Wide-Field/Planetary Camera 2 – took the most memorable space photographs of the last 15 years: colliding galaxies, puffy planetary nebulae, newborn stars emerging from gas clouds, and the famous Hubble Deep Field. Ed Weiler, associate administrator for NASA’s Science Mission Directorate, has called it “the camera that saved Hubble.”
COSTAR – the Corrective Optics Space Telescope Axial Replacement – served as the “eyeglasses” for the rest of Hubble’s instrumentation. It is no longer needed because every other camera and spectrograph that has been installed on Hubble servicing missions contains its own corrective optics.
We take Hubble and its awesome image and data libraries for granted now, but the discovery of its primary mirror’s spherical aberration in the summer of 1990 really threw astronomers and the space program for a loop. How was this flaw supposed to be fixed AFTER the telescope was already orbiting the Earth? Figuring out how to do just that was an enormous feat of optical science and engineering, and several OSA members played key roles in that accomplishment. At the 2008 Frontiers in Optics meeting in Rochester, N.Y. (U.S.A.), a session of the special “NASA at 50” symposium focused on the team effort to repair Hubble.