A History of the Lightning Launch Commit Criteria and the Lightning Advisory Panel for America's Space Program (original) (raw)

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 21 st 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. 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 21 st 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. 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.