FAA's Approaches to Ground and NAS Separation Distances for Commercial Rocket Launches

Abstract

An experimental permit issued by the Federal Aviation Administration’s Office of Commercial Space Transportation (FAA/AST) authorizes reusable suborbital rockets (RLVs) to fly within a predefined operating area. Specifically, an operating area must contain a suborbital rocket’s vacuum instantaneous impact point. This paper will present an update of the work performed since the publishing of the AIAA conference paper titled “Separation Distances for Rocket Launch Operations” at the 2008 AIAA Atmospheric Flight Mechanics Conference. The focus of the above mentioned paper was on the necessary aircraft separation distances from rockets that launched into the national airspace system (NAS). This paper will include updates to the aircraft buffer zone size regarding probability of failure allocation, sensitivity to aircraft vulnerability, effects of wind conditions, and debris catalogue sensitivity, as well as adding information on ground buffer zones for reusable suborbital rockets. In the previously mentioned paper, it is recommended that the probability of failure for each point in time is equal to 1.0 for a reusable suborbital launch. More recent research examines the resulting aircraft buffer zone size if the probability of failure for the overall mission is equal to 1.0 and uniformly allocated to specific times of flight. The sensitivity of the aircraft buffer zone size to the commercial transport aircraft vulnerability model is also reported on in this paper. Day of launch wind conditions and debris catalogue development can significantly change the aircraft buffer zone size and it is important to characterize how these factors can affect the launch operations. The FAA/AST does not require an experimental permit applicant to perform a quantitative risk analysis to obtain a permit and instead has adopted the approach of determining a ground buffer zone around an operating area similar to the aircraft buffer zone. The ground buffer zone protects the public from reusable suborbital rocket explosions near the operating area boundary. Determining the size of the ground buffer zone is a multi step process. This paper will familiarize the reader with these processes and the methodologies that support them along with the results of the aircraft buffer zones in regard to the probability of failure allocation, aircraft vulnerability, wind effects, and debris catalogues.