Linville, Ray P
Editor’s Note: Logistics Spectrum begins a new, occasional feature to examine logistics trends and issues that will shape logistics management for the year 2000 (Y2K) and beyond. Although the articles in this issue by Dr. von Braun and Prof. Blanchard point out the enduring challenges of logistics, “Y2K Logistics” will attempt to explore ideas and events that will influence logistics activities in the new millennium. Contributions to this column are requested.
How would a Y2K logistician describe the item being repaired?
“Oh, my gosh. Beautiful!” said Astronaut Mark Lee about the 12-ton, 43foot-tall Hubble Space Telescope.
On-orbit repairs to the observatory began on Feb. 13 when two astronauts Steven Smith and Lee – floated into the cargo bay of space shuttle Discovery.
Working in alternating two-man teams, Discovery’s crew staged five backto-back spacewalks that lasted over 33 hours to install two new science instruments and other critical equipment to replace aging components in NASA’s second Hubble service call since 1993.
The service call replaced 4,500 pounds of hardware, made about 150 electrical connections or disconnections in the process, and installed 12 square feet of makeshift insulation.
The $2-billion telescope’s vision was improved by adding two $100 millionplus science instruments, a spectrograph with two-dimensional sensors and a near-infrared camera. Each one is the size of a telephone booth.
The service call’s cost? About $350 million.
Nearly 370 miles above Earth, the astronauts replaced 1970s-era science instruments with state-of-the-art devices.
During the first space walk, Lee and Smith installed two new science instruments that should allow Hubble to scan even deeper into the universe.
“It will really put Hubble into a position of having world-class scientific capability well into the 21st century,” said Ed Weiler, NASA’s chief Hubble scientist.
During the second spacewalk, Astronauts Gregory Harbaugh and Joseph Tanner installed a new data recorder and a guidance sensor to help Hubble track astronomical targets. They also discovered a surprising number of rips and tears, some up to 18 inches long, in the multilayer insulation that protects Hubble’s outer skin from ultraviolet light and degradation from atomic oxygen.
On the third spacewalk, which lasted six hours, Lee and Smith replaced an data interface unit that translates and relays commands from Hubble’s central computer to various systems. Lee had to disconnect and reconnect small electrical cables similar to those that plug into personal computers. The team also replaced an antiquated data recorder with a digital recorder that can store 12 billion bytes of computer data.
During the fourth spacewalk, Harbaugh and Tanner completed the telescope’s overhaul by installing a new solar array control system.
A fifth, unplanned spacewalk was made on Feb. 17 to repair the telescope’s insulation. Although some repairs were made, full repairs must wait for an already scheduled service call in 1999. During that mission, a new central computer, a set of new solar arrays and a state-of-the-art camera will be installed.
Emergency Repair Kit
Lee and Smith spent four hours repairing the insulation and used parachute cord, alligator clips and thermal blankets from an emergency repair kit to cover three equipment bays that house sensitive electronic items.
When Discovery’s seven-man crew captured the telescope, it had logged 996 million miles and made more than 110,100 observations of stars, galaxies, planets and other astronomical objects since its 1990 launch.
The 25,500-pound Hubble, with new instruments and makeshift bandages to protect its skin, was slowly released into open space on Feb. 19.
On Feb. 21, Discovery landed at Cape Canaveral. Mission complete.
(Two articles by Lyle Paulson, CPL, in the November-December 1996 issue of Logistics Spectrum provide more information on NASA servicing missions and preparations for the 1997 mission. Members interested in space logistics should affiliate with SOLE’s Space Application Division.)
Copyright Society of Logistics Engineers May/Jun 1997
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