Chris Anderson

From 1988 through 1994, I was employed at the Space Telescope Science Institute, which operates the Hubble Space Telescope. Ever since, I've kept a close eye on the efforts to keep Hubble's steady stream of discoveries flowing.

Since its launch in 1990, Hubble has been visited four times by the Space Shuttle. On the first servicing mission - in December 1993 - spacewalking astronauts performed "eye surgery" on the orbiting telescope to correct its flawed vision. Subsequent missions have upgraded Hubble's scientific instruments and other hardware.

After the tragic loss of shuttle Columbia, NASA deemed a final visit to Hubble - too far from the International Space Station should a rescue be needed - too risky. New management opted for one last trip to service the aging telescope. It would have launched this week, with a first-ever "rescue shuttle" waiting on the launch pad.

Then, 12 days ago, Hubble's main ("Side A") data handling circuitry failed, leaving the satellite incapable of beaming data to Earth. The redundant system ("Side B") has never been used in Hubble's 18 years on orbit, so there's no guarantee it will work. Given this turn of events, NASA decided to postpone the final servicing mission until early 2009 to allow astronauts and engineers to develop a repair strategy for Side A.

In the next day or two NASA managers will meet to weigh the risk of turning on Side B. If they do, Hubble could resume its science duties before the end of the month, and with any luck will continue working until its successor, the James Webb Space Telescope, launches in 2013.

If you'd like to see Hubble with your own eyes, there are a series of passes coming up during the week Oct. 19-24.

Details are available at www.heavens-above.com; just put in your viewing location and click on "HST" under the "Satellites" category.

Next week: Star counting with the family.

Chris Anderson manages the College of Southern Idaho's Centennial Observatory in Twin Falls. He can be reached at 208-732-6663 or canderson@csi.edu.

Sky calendar through Thursday Planets One hour before sunrise: Saturn: E, low One hour after sunset: Venus: WSW, extremely low Jupiter: SSW, low Moon Full moon Tuesday, 2:02 p.m.