By Patricia Daukantas

First, it was an expensive dream. Next, it was the butt of worldwide jokes – nearsighted and rhyming with “trouble.” Today, though, the Hubble Space Telescope (HST) is an indispensable instrument in the toolboxes of astronomers, and they are celebrating the 20^th anniversary of its ride into Earth orbit.

NASA’s space shuttle Discovery carried Hubble into orbit on April 24, 1990. Already by then, the telescope idea had been on a long and complex path to realization.

Princeton University astrophysicist Lyman Spitzer Jr. (1914-1997) had been pointing out the advantages of an extraterrestrial observatory as far back as 1946 – more than a decade before the launch of the first space satellite. The astronomical community fought back against budget cuts for years until construction funding was approved in the late 1970s. After cost overruns, Hubble was nearly ready to go by January 1986, when the shuttle Challenger‘s accident grounded the remaining shuttles and forced a long postponement of Hubble’s launch.

Once Hubble got off the ground, of course, reports of the primary mirror’s spherical aberration made headlines all over the planet. (These reports surfaced in late May and early June – I’ll bet that nobody at NASA will be commemorating that 20^th anniversary.) Fortunately, some of the brightest minds in optical science – including more than a few OSA members – got to work on the Independent Optics Review Panel and set to work on designing a package of corrective optics for the orbiting telescope. Installing the corrective instrument, dubbed COSTAR, was the top priority of the first Hubble servicing mission in the fall of 1993.

OPN covered this story with several articles. We devoted much of the November 1993 issue to the Hubble rescue effort, with such articles as “Engineering the COSTAR” and “Optical Testing and Verification on HST.” In the August 1994 issue, representatives of a NASA subcontractor, Tinsley Laboratories, wrote about their production of the corrective optics that were then integrated into the instrument package built by Ball Aerospace.

Astronomers cheered when they saw the first crisp, clear Hubble images of a nearby galaxy following that first servicing mission. The Hubble discoveries made in the last 16 years are way too numerous to summarize in any blog post.

This weekend, you can celebrate Hubble’s 20^th anniversary by visiting NASA’s commemorative page or the Hubble public information site. You can join in the Hubble pop culture contest, “friend” Hubble on Facebook, send a congratulatory message on Twitter.com with the hashtag #hst20 or even help astronomers classify galaxies found on real Hubble images with the Galaxy Zoo: Hubble project.

Happy 20^th Birthday, Hubble, and we hope you’re still active to celebrate your 25^th!

2010-04 April, Astronomy, Astrophysics astronomy, hubble, optics, space telescopes, telescopes