https://ntrs.nasa.gov/search.jsp?R=20110000675 2019-08-30T13:44:50+00:00Z NASA/SP—2010–216283 A History of the Lightning Launch Commit Criteria and the Lightning Advisory Panel for America’s Space Program Francis J. Merceret, Editor NASA, John F. Kennedy Space Center John C. Willett, Editor Air Force Research Laboratory (Retired) Hugh J. Christian University of Alabama in Huntsville James E. Dye National Center for Atmospheric Research, Boulder, Colorado E. Phillip Krider University of Arizona, Department of Atmospheric Sciences John T. Madura NASA, John F. Kennedy Space Center T. Paul O’Brien Aerospace Corporation, El Segundo, California W. David Rust National Severe Storms Laboratory Richard L. Walterscheid Aerospace Corporation, Space Sciences Department, El Segundo, California National Aeronautics and Space Administration John F. Kennedy Space Center Kennedy Space Center, FL 32899 August 2010 Executive Summary Since natural and artificially-initiated (or ‘triggered’) lightning are demonstrated hazards to the launch of space vehicles, the American space program has responded by establishing a set of Lightning Launch Commit Criteria (LLCC) and Definitions to mitigate the risk. The LLCC apply to all Federal Government ranges and have been adopted by the Federal Aviation Administration for application at state-operated and private spaceports. The LLCC and their associated definitions have been developed, reviewed, and approved over the years of the American space program starting from relatively simple rules in the mid-twentieth century (that were not adequate) to a complex suite for launch operations in the early 21st century. During this evolutionary process, a “Lightning Advisory Panel (LAP)” of top American scientists in the field of atmospheric electricity was established to guide it. This history document provides a context for and explanation of the evolution of the LLCC and the LAP. A companion document on the rationale is currently being prepared by the LAP to provide the physical, mathematical, and operational justification for the current LLCC. Lightning that takes place naturally in thunderstorms was recognized as a threat to spaceflight early in the space age, and the early launch rules prohibited flight through thunderstorms. What had not been recognized until Apollo XII was launched in 1969, was that an ascending rocket could “trigger” lightning if it flew into highly electrified clouds, even in the absence of natural lightning. Apollo XII was struck twice by triggered lightning, and as a result, additional rules were added to forbid flying within 5 NM of thunderstorms or through certain non-thunderstorm clouds that experience showed had the potential of being electrified. During the time between Apollo XII and the beginning of the Space Shuttle Program, several important research programs were carried out to learn more about lightning and cloud electricity in Florida, and additional instrumentation was installed at the KSC and Eastern Range (ER). The LLCC were modified for the Skylab program in 1973 and again for the Apollo-Soyuz Test Project in 1975. Expendable launch vehicles (ELV) had their own separate but similar rules. In 1979 the nascent Shuttle program adopted a set of LLCC that included constraints and waivers that were based on surface electric field mill measurements. The ELV rules did not adopt the field mill criteria. In 1987, triggered lightning caused the loss of Atlas/Centaur 67 (AC 67) and its Fleetsatcom payload. A major cause of this accident was the failure of the ELV rules to include a field mill criterion. The Shuttle rules would have prohibited the launch of AC 67. In the aftermath of several investigations and a Congressional Hearing, a lightning “Peer Review Committee”, a predecessor of the LAP, was established to guide NASA and the Air Force in the drafting of LLCC and the conduct of associated research. Several major research projects were undertaken, including the first “Airborne Field Mill Program” (ABFM I, 1990-1992) in which direct measurements of electric fields in Florida clouds were made from a specially instrumented aircraft. ABFM I resulted in several improvements to the LLCC, and the lessons learned ultimately led to an even more successful ABFM II campaign a decade later. As new knowledge and additional operational experience has been gained, the LLCC have been updated to preserve or increase their safety and increase launch availability. All launches of ELV and manned vehicles now use the same rules, which simplifies their understanding and application and minimizes the cost of the weather infrastructure to support them. In the future, the processes and procedures that have evolved can be used to facilitate further improvements in both launch availability and safety as new research findings become available. i Preface Natural and triggered lightning is a demonstrated hazard to the launch of space vehicles, and the American space program has responded by establishing the “Lightning Launch Commit Criteria (LLCC)” to mitigate the risk. These LLCC are a complex set of rules with associated Definitions which must be satisfied before the launch of a space vehicle is permitted. The Definitions are an integral part of the LLCC and the term LLCC as used in this History is explicitly intended to include those Definitions. They apply to all Federal Government ranges including not only the well-known Eastern Range at Cape Canaveral, Florida and the Western Range at Vandenberg AFB, California, but also to smaller ranges such as the NASA range at Wallops Island, Virginia and the Air Force range at Kwajalein Atoll in the Pacific Ocean and others. In addition, these same LLCC have been adopted by the Federal Aviation Administration for application at state-operated and private spaceports. The LLCC are developed and approved through a complex process, but the core science and recommendations for precise wording of the operative parts of the rules are provided by a “Lightning Advisory Panel (LAP)” consisting of American scientists working in atmospheric electricity and related disciplines including cloud physics and statistics. The LAP works closely with the operational personnel who must implement the LLCC in practice to assure that the rules are not only scientifically sound, but also realistic and practical. The LLCC have evolved over the history of the American space program from relatively simple mid-twentieth century rules that proved inadequate to the complex suite that governs launch operations in the early part of the 21st century. Following the destruction of an Atlas-Centaur launch vehicle by triggered lightning in 1987, the LAP was established to guide the process. Expert guidance is required because there is always a tension between the essential need to fly safely by avoiding lightning strikes and the need to fly economically by avoiding unnecessary launch delays and scrubs. The LLCC have become complex because increased knowledge has permitted exceptions under certain conditions from what are otherwise broad prohibitions to flight. These exceptions reduce the number of occasions under which a launch will be scrubbed for violation of the LLCC when, in fact, it would have been safe to fly. As the LLCC have become more complex, launch vehicle operators, range managers, and safety personnel have continuously requested briefings and discussions on the origin of the rules and the rationale behind them. This history document is designed to provide a historical context and explanation for the origin of the LLCC and the LAP. A companion rationale document is being prepared by the LAP to provide the scientific, mathematical, and operational basis for the current LLCC. Acknowledgements Reconstructing more than 50 years of the history of weather support required a substantial effort not only by the authors and editors of this document, but also by colleagues and associates. Much of the history has not been formally documented before, and much of what existed at one time has now apparently been lost. This task would not have been possible without the assistance of many people who took time away from their busy workloads and deadlines to help us track down important events that are shrouded in the mists of the past. We especially appreciate and recognize the contributions and assistance of the USAF 45th Weather Squadron at Cape Canaveral Air Force Station (CCAFS) and Patrick AFB in Florida and the NOAA Spaceflight Meteorology Group (SMG) at Johnson Spaceflight Center in Houston, Texas. We thank Bill Roeder and Billie Boyd of the 45th Weather Squadron and Michael Maier and David Chapman of the Eastern Range Technical Services Contractor (Computer Sciences Raytheon) for providing the history of lightning-related and other instrumentation at Kennedy Space Center (KSC) and CCAFS. We thank Tim Oram of SMG for his insights on weather support during the early years of manned spaceflight. Bill Bihner and Jack Ernst (retired) at NASA headquarters provided recollections of the formation of the Peer Review Committee and its evolution into the modern Lightning Advisory Panel. Launa Maier of the KSC Safety and Mission Assurance Directorate provided valuable recollections of the research programs and lightning infrastructure development during the years immediately following the AC 67 accident. In addition to providing a figure and some references for the document, Jennifer Wilson of the KSC Weather Office handled the logistics of several face-to-face meetings of the LAP at KSC. Without these meetings dedicated to this History’s organization and production, it could not have been completed. Jennifer Rosenberger of the KSC Launch Processing Directorate did extensive reformatting and copy editing to prepare the original manuscript for public release in this NASA Special Publication series. We appreciate her diligence and attention to detail that substantially reduced the number of errors and inconsistencies in the presentation of the material. Funding for the project was provided by the NASA Office of Safety and Mission Assurance (OSMA) Assurance Management Office (AMO). The authors and editors appreciate OSMA/AMO reviews of the final draft of this paper by Launa Maier and Tony Willingham.