Astronomers eagerly anticipate the final Hubble Space Telescope (HST) servicing mission, set to blast off May 12 from NASA's Kennedy Space Center in Florida. And they are already hard at work designing the observatory that will take over after Hubble sees its final light.
Hubble is, in the lingo of telescope engineering, a UVOIR instrument: Its 2.4-meter light-collecting mirror samples wavelengths of light in the ultraviolet (UV), optical (O), and near-infrared (IR).
The James Webb Space Telescope, slated for launch in 2013, will have a much larger light-collecting mirror — 6.5 meters — than Hubble. But it will operate in the infrared.
No one knows how long HST will continue to function after the final servicing mission. It’s been in space since 1990 — 19 years and counting.
HST’s presumptive successor is ATLAST: the Advanced Technology Large-Aperture Space Telescope. I came across a detailed report on the telescope, authored by a large group of scientists and engineers from companies and scientific institutions — including Marc Postman of the Space Telescope Science Institute.
The Postman report is part of Astro2010, the ongoing “decadal survey” in astronomy and astrophysics. Every 10 years, the National Research Council of The National Academy of Sciences undertakes the surveys to recommend scientific priorities for the coming decade. ATLAST is just one idea vying for support.
ATLAST’s primary mirror would be 8 to 16 meters wide. The 8-meter concept (pictured above) assumes a solid mirror, like that of HST. The 16-meter version would have to be an unfolding assembly of segmented mirrors, like the one on the James Webb Space Telescope. Postman’s group projects the telescope could be ready for launch by 2025. Technology development, design, and planning would cost hundreds of millions of dollars.
For one thing, ATLAST would have the ability to actually detect oxygen, ozone, water, and other possible life signs (“biosignatures”) in the atmospheres of extrasolar planets. It could probe deeper than ever into the processes that create stars. And, we can assume, it will send home spectacular images of the cosmos in even greater detail than HST has captured.
Image credit: Frassanito & Associates, Inc. and the
Future In-Space Operations Working Group