NASA Conference Publication 3244 10^/x Second NASA Workshop on Wiring for Space Applications Proceedings of a workshop cosponsored by NASA Headquarters, Office of Safety and Mission Quality, and NASA Lewis Research Center, and held in Cleveland, Ohio, October 6-7, 1993 NASA NASA Conference Publication 3244 Second NASA Workshop on Wiring for Space Applications Proceedings of a workshop cosponsored by NASA Headquarters, Office of Safety and Mission Quality, and NASA Lewis Research Center, and held in Cleveland, Ohio, October 6-7, 1993 IV/1SA National Aeronautics and Space Administration Office of Management Scientific and Technical Information Program 1994 Page intentionally left blank PREFACE This document contains the proceedings of the Second NASA Workshop on Wiring for Space Applications held at NASA Lewis Research Center, Cleveland, Ohio, October 6-7, 1993. The workshop was sponsored by NASA Headquarters/Code QW Office of Safety and Mission Quality, Technical Standards Division and hosted by the NASA Lewis Research Center, Power Technology Division, Electrical Components and Systems Branch. The workshop addressed key technology issues in the field of electrical power wiring for space applications. Topics discussed included wiring insulation constructions, manufacturing technologies, and protection systems. In addition to reviewing the ongoing NASA and other related programs on space wiring, the workshop provided a forum in which the government and industry representatives could discuss the results of their research programs on the development of arc track-resistant wiring systems. The workshop organizers express their appreciation to the session chairmen, speakers, and participants, whose efforts contributed to the technical success of this event. Thanks are also due to Ms. Billie Hurt, Ms. Ruth Clark, Ms. Barbara Coles, and Ms. Brunilda Quinones for their relentless efforts in providing a well prepared and very efficient and organized workshop. Page intentionally left blank TABLE OF CONTENTS SUMMARY................................................................. vii AGENDA.................................................................. ix SESSION I—ORGANIZATIONS AND PROGRAMS .................................... 1 NASA Code Q Overview Daniel R. Mulville, NASA Headquarters ........................................ 3 Wiring for Space Applications Norman Schulze, NASA Headquarters ........................................ 7 ESTEC Wiring Test Programme Materials Related Properties M.D. Judd, ESTEC/ESA ................................................................... Robust 300 °C Wire Insulation System John G. Nairus, U.S. Air Force ............................................. 19 SESSION II—WIRING APPLICATIONS AND STANDARDS ............................. 25 NASA Wiring Program—Survey of NASA Experiences in Wiring System Safety Mark W. Stavnes, Sverdrup Technology, Inc .................................... 27 Selection of the Space Freedom (SSF) Flat Collector Circuit (FCC) Insulation Material Dawn Emerson, NASA Lewis Research Center ................................. 41 NASA Parts Program Office Responsibilities Patrick L. Kilroy, NASA Goddard Space Flight Center ............................ 51 NASA Parts Project Office—Basic Goals Jeanette Plante, Paramax Systems Corporation, A Unisys Company .................. 55 NAVAIR Aircraft Wiring Standardization and Qualification Program Thomas Meiner, Naval Air Warfare Center ..................................... 59 Organized Wiring Systems Thomas Meiner, Naval Air Warfare Center ..................................... 63 NEMA Wire and Cable Standards Development Programs Robert W. Baird, National Electrical Manufacturers Association ...................... 79 MSFC Inspections of Installed Polyimide Wire Joe C. Landers, NASA George C. Marshall Space Flight Center ..................... 95 SESSION III—WIRING TEST RESULTS .......................................... 103 Wiring for Space Applications Program Ahmad Hammoud, Sverdrup Technology, Inc . ................................. 105 v Flammability, Odor, Offgassing, Thermal Vacuum Stability, and Compatibility With Aerospace Fluids of Wire Insulations David Hirsch, Lockheed, and Harry Johnson, NASA White Sands Test Facility ......... 109 Electrical and Mechanical Testing of Wire Insulation for Space Applications Linda A. Burkhardt, McDonnell Douglas Aerospace ............................. 121 Evaluation of Pyrolysis and Arc Tracking on Candidate Wire Insulation Designs for Space Applications Thomas J. Stueber, Sverdrup Technology, Inc.. and Kenneth Hrovat. Cleveland State University........................................................... 131 Wire Insulation Degradation and Flammability in Low Gravity Robert Friedman, NASA Lewis Research Center ............................... 147 Breakdown Testing of Wiring Insulation J.R. Laghari, State University of New York at Buffalo ............................ 165 A New Test Method for the Assessment of the Arc Tracking Properties of Wire Insulation in Air, Oxygen Enriched Atmospheres and Vacuum Dieter Konig, Technical University of Darmstadt ................................ 173 High Temperature Polymer Dielectric Film Insulation Robert J. Jones, TRW .................................................. 189 High Temperature Arc-Track Resistant Aerospace Insulation William Dorogy, Foster-Miller, Inc ........................................... 193 3M High Temperature Dielectric Film Edward Hampi, Jr., 3M Electrical Products Division ............................. 203 LIST OF ATTENDEES ....................................................... 211 vi SECOND NASA WORKSHOP ON WIRING FOR SPACE APPLICATIONS SUMMARY The Second NASA Workshop on Wiring For Space Applications was held at NASA Lewis Research Center, Cleveland, Ohio, October 6-7, 1993. The workshop was sponsored by NASA Headquarters, Code QW, Office of Safety and Mission Quality, Technical Standards Division and hosted by LeRC's Power Technology Division, Electrical Components and Systems Branch. Like its predecessor, the First NASA Workshop on Wiring For Space Applications, which was also hosted by NASA Lewis on July 23-24, 1991, this workshop addressed key technology and development issues pertaining to electrical power wiring for space-based applications. The workshop was organized into three sessions. Session I provided overviews of the NASA Office of Safety and Mission Quality, and the various ongoing programs on space wiring. These included the European Space Agency Wiring Program to understand the arc tracking phenomenon and develop detection techniques, the US Air Force Program to develop a 300°C wire insulation system for the aircraft environment, and the NASA Space Wiring Program to provide a technology base for the development of lightweight, arc track-resistant and reliable wiring systems for aerospace applications. Session II discussed the role of the various organizations and programs involved in the qualification, certification, and standardization of electrical wiring. These included the NASA Goddard Space Flight Center Parts Project Office (NPPO), Naval Air Warfare Center (NAWC), and the National Electrical Manufacturers Association (NEMA). A survey of space wiring failures, the effects of improper wiring system design and installation, and the wiring requirements for the Space Station Freedom were also presented in this session. Session III focused on the results of wiring tests performed by numerous organizations to address NASA's unique testing requirements. Experimental investigations on the effect of space environmental stresses on the performance of electrical wiring were presented and discussed. These stresses included atomic oxygen exposure, vacuum, ultraviolet radiation, high temperature, and low gravity. A proposed new test method for the assessment of arc tracking was also discussed and compared to the conventional testing techniques. Presentations were also given by industry representatives in this session on the state of the art development in the area of high temperature, high performance, arc track-resistant wiring insulation and dielectrics for aerospace applications. The workshop was attended by approximately 60 individuals from the United States, comprising government, industry, and academia and 3 visitors from Germany. A list of the attendees is included on page ix and the final workshop agenda is listed on page xii. vii The general consensus of the workshop was that space wiring failures are of a major concern and are detrimental to mission safety and success. Among the issues that were identified and recommended for further investigation include the development of new arc track-resistant wiring insulation constructions, better system designs, adequate circuit protection, and proper handling procedures. These factors, when implemented, will certainly improve the reliability and lifetime of space power systems. It is anticipated that a better understanding of arc tracking in wiring insulations will be achieved through the NASA Wiring For Space Applications Program, in conjunction with the efforts of other agencies and organizations. The resulting database of information will help in the development of lightweight, safe, and reliable power systems with new wiring constructions which are resistant to arc tracking and suitable for use in aerospace applications. The organizers once again express their appreciation to the volunteers and participants in making this workshop a very interesting and successful event. The support of NASA Headquarters Code QW for this program is gratefully acknowledged. viii SECOND NASA WORKSHOP ON WIRING FOR SPACE APPLICATIONS AGENDA October 6 - 7, 1993 NASA Lewis Research Center NASA Administration Building (Bldg. No. 3) Auditorium Wednesday, October 6 Session I: Oraanizations and Proarams Time Topic Speaker Organization 8:30 - 8:45 Opening Remarks R. Bercaw NASA/LeRC 8:45 - 9:15 NASA Code Q Overview D. Mulville NASA/HQ/QE 9:15 - 9:45 Wiring for Space Applications N. Schulze NASA/HQ/QE 9:45 - 10:15 Break 10:15 - 10:45 ESA Program Overview H. Reher MBB Deutsche Aerospace 10:45 - 11:15 Robust 300 C Wire Insulation System J. Nairus Wright Laboratory 11:15 - 11:30 Discussion 11:30 - 12:30 Lunch Session II: Wiring Applications and Standards Time Topic Speaker Organization 12:30 - 1:00 NASA Wiring Program - Survey of NASA M. Stavnes NASA/LeRC Experiences in Wiring System Safety 1:00 - 1:30 SSF Wiring Requirements D. Emerson NASA/LeRC 1:30 - 2:00 NASA Parts Program Office P. Kilroy NASA/GSFC Responsibilities 2:00 - 2:30 NASA Parts Project Office - Basic Goals J. Plante NPPO/Paramax 2:30 - 3:00 Break 3:00 - 3:30 NAVAIR Aircraft Wiring Standardization T. Meiner NAWC and Qualification Program 3:30 - 3:45 Organized Wiring Systems T. Meiner NAWC ix