University of Wisconsin-Madison Physical Sciences Lab

Learn More: WUPPE

[ASTRO package in use above] [WUPPE locator graphic]

WUPPE is the Wisconsin Ultraviolet Photo-Polarimeter Experiment, designed to acquire simultaneous spectral and polarization data in the 1400 to 3300 Angstrom spectral range, requiring operation in space. The primary mirror is 50 cm (20 inches) in diameter, allowing observation down to 16th magnitude. PSL designed and built some primary structural components for the WUPPE telescope, including the main telescope tube that spaces the optics in the Cassegrain configuration.

PSL was originally contacted to weld some tube components that were already designed and built. The parts were already to finished shape, with no allowance for the distortions that normally occur in welding. PSL was then asked to provide a plan for making replacement parts and to make the parts, on a fast schedule.

PSL mechanical engineer Ken Kriesel began with surveying possible industrial partners for their processing capabilities, then developed a new tube design, process plan and schedule. Tools for the process were designed and built while material for the tube was being obtained.

The telescope tube began as certified material obtained from NASA’s Marshall Space Flight Center. Each 2" (5cm) thick flat plate weighed about 600 pounds (2700N) and measured about 31 by 80 inches (79 × 203 cm) when received. At the end of many processing steps, the space-ready tubes weighed about 57 pounds (254N) each with large areas as thin as 0.2" (5mm), measuring 28.46 inches (72.29cm) long by 23.95 inch (60.83cm) outside diameter and were leak proof (airtight). The thin wall (thickness less than 1/100 of diameter) required special care in machining. Processing steps included attaching support ears, heating in a furnace to soften the plate, rolling up the plate into a tube, weld joint preparation, 4 passes of welding the seam combined with 100% radiographic inspection after each welding pass, machining the tube ends and weld area, heat treatment, stretching to make the metal strong again, further heat treatment, and machining to final shape and size. All the production design and scheduling, all the welding and most of the machining was performed by PSL.

Because of NASA standards for payloads on manned space flight missions such as shuttle launches, all the materials used required certification and record keeping for composition and processing, including the plate, welding wire, and weld shielding gases, heat treatment furnace temperature recordings, weld radiographs, and polished samples made from test weld coupons.

The main tube cost much less than 1% of the total for the telescope but was an absolutely vital component in need of an immediate solution. Working with industry, including Ladish in Cudahy WI, Thermtech in Waukesha WI, and Wisconsin Industrial Testing in Brookfield WI, as well as Badger Welding Supply in Madison WI, allowed PSL to provide timely delivery of a quality product made by processes that no one organization was fully equipped to deliver alone.

The initial tube components were designed and built from June 1982 to May 1983. The successful replacement components were designed and produced from May 10 to September 15 1983, and shipped September 26 1983 to the UW Madison Space Astronomy Lab. PSL subsequently built additional components for WUPPE. Space Astronomy Lab integrated the PSL-provided parts in preparation for shipment to Kennedy Space Flight Center and inclusion into the Astro-1 payload, scheduled for launch on the flight following the January 1986 Challenger launch.

After the Challenger accident, scientific flights were lower priority than military and other classified flights, so Astro-1 (NASA Mission STS-35) and WUPPE waited until December 1990. WUPPE flew again in March 1995 on Astro-2 (NASA Mission STS-67). It has since been retired to the UW Space Place, 2300 South Park Street, Madison WI, where it is on display with the long rectangular sunshade removed.

Link to all NASA Space Shuttle Missions