EVERETT, Wash. – Fluke Corporation, the world’s leading supplier of handheld test and measurement equipment, announced that a modified Fluke 54 Series II digital thermometer was used by the crew of the U.S. space shuttle Discovery in a demonstration of space-based repair of Thermal Protection System (TPS) tiles during the shuttle’s “Return to Flight” voyage. Testing emergency inspection and repair techniques was one of the primary goals of Discovery’s August 2005 mission.
Adapted for work in space by Swales Aerospace, Beltsville, MD, the Fluke 54 thermometer and a Fluke 80PK-27 surface probe accompanied mission crew members Steve Robinson and Soichi Noguchi in their space walk on day five of the mission. It was used to check surface temperatures during testing of a “space spackle” type of sealant material called NOAX (short for Non-Oxide Adhesive eXperimental) that may be used to patch small cracks in the thermal tiles if they are damaged during launch or in flight.
According to George Tansill, mechanisms engineer for Swales Aerospace, the Fluke 54 Series II was “critical” to NASA personnel’s understanding of the NOAX application temperature, providing accurate readings that were invaluable in helping analysts compare the sealant’s properties under “real-space” conditions with thermal analysis predictions made prior to the mission. In fact, the Fluke 54 Series II performed so well, said Tansill, NASA decided to leave the unit with the crew of the international space station rather than bringing it back to Earth as planned.
“Since it’s vital that any equipment sent into space be rugged and reliable under the extreme conditions of space, NASA required Fluke’s involvement in our modifications,” said Tansill. “We needed to know as much as possible about how the digital thermometer was made and what materials were in it. Fluke personnel were extremely responsive. They gave us the information we needed and were critical in helping us get the instrument ready for space under tight deadline conditions.”
Tansill said the Fluke 54 required surprisingly few changes to ready it for space duty. It was enclosed in a protective aluminum chassis with a plastic window over the thermometer screen and wrapped in a multi-layer blanket of reflective Mylar. With this protective covering, the Fluke 54 stays within its operating range outside the shuttle for up to 8 hours. In the event of a cosmic particle strike that could affect the unit’s software, Swales engineers installed an external switch to disconnect the Fluke 54 battery and automatically reset the software. The space thermometer was also modified for single-button operation for the one temperature test required. The Fluke 80PK-27 Industrial Surface probe was shortened and attached rigidly to the aluminum chassis.
Fluke Corporation is the leader in compact, professional electronic test tools. Fluke products are used by technicians and engineers in service, installation, maintenance, manufacturing test and quality functions in a variety of industries throughout the world.