Edward Weiler on the Origins of Hubble Servicing

David Soderblom, soderblom@stsci.edu

Edward Weiler, NASA Associate Administrator for the Science Mission Directorate, visited the Institute last summer, on the last day of the Calibration Workshop. Ed spent nearly 20 years (1979–1998) at NASA headquarters as Program Scientist for Space Telescope (starting before the “Hubble” was added). In that role, he was instrumental in ensuring the long-term operations of Hubble, the variety of science done with the telescope, and the importance of outreach efforts.

Perhaps more than any other single factor, the success of Hubble is due to regular visits by astronauts. They have repeatedly repaired and upgraded its support systems, and installed five generations of ever-more-powerful scientific instruments. While the planning for servicing may seem like an inevitability now, it was far from obvious in the early 1980s, as Ed told the audience that gathered to hear him—and to get their copies of his recent book, Hubble: A Journey Through Space and Time, signed. Thirty years ago the space shuttle had just started to fly, but the costs and difficulties of shuttle missions to Hubble were becoming apparent. At first, early servicing plans called for a return to Earth for a complete rebuilding, but it was soon clear that this was not realistic. Nor was the plan for a notional Orbiting Maneuvering Vehicle to ferry Hubble to a servicing bay in the space station.

Ed Weiler played a key role in defining Hubble’s successful serving program, and in seeing that the planning of the second generation of scientific instruments—Wide Field Planetary Camera 2 (WFPC2), Space Telescope Imaging Spectrograph, and Near Infrared Camera and Multi-Object Spectrograph—started well before the telescope was even launched. Indeed, the fact that WFPC2 was under construction afforded an opportunity to incorporate corrective optics inside the instrument, in time for the first servicing mission in 1993. This was a crucial step in solving the problems created by spherical aberration in Hubble’s primary mirror.

During his visit to the Institute, Ed had a chance to meet with old friends and to tell us about how early Hubble experiences have influenced astronomy well beyond Hubble itself. A notable example was the transfer to the National Science Foundation (NSF) of surplus CCDs from the first-generation Wide Field and Planetary Camera. NSF distributed the CCDs to ground-based observatories, resulting in a mini-revolution in contemporary astronomy even before Hubble’s launch.