Triggered lightning risk assessment for reusable launch vehicles at the Southwest Regional and Oklahoma Spaceports

The objective of this study, sponsored by the Office of Commercial Space Transportation at the Federal Aviation Administration, was to assess risks from triggered lightning during suborbital launches and reentries of reusable launch vehicles (RLVs) from the proposed Southwest Regional Spaceport in New Mexico and Oklahoma Spaceport, Burns Flat, Oklahoma. Risk of triggered lightning was studied for five conceptual RLVs originating and/or landing at these proposed spaceports. Three areas were addressed: (1) observed frequencies of cloud-to-ground lightning at the proposed spaceports, including estimates of violation frequencies of the existing lightning launch commit criteria (LLCC), (2) estimates of the ambient fields required for triggering by each of the concept vehicles, including consideration of potential methods for estimating the probability of encountering these field magnitudes from the measured radar returns of thunderstorm anvil clouds, and (3) review of the current LLCC to determine if the criteria are relevant to each suborbital RLV concept, including an evaluation of local geographical effects pertaining to each spaceport to determine whether additional LLCC are necessary to conduct safe launch operations there. The findings for Area (1) are reported in a paper by G. Peng at this conference. The findings for the other areas are presented herein.