This paper describes elements of the US government's response to the Space Shuttle Columbia accident and other actions recently taken, relevant to public safety during launch and entry of spacecraft. The Columbia accident generated numerous debris impacts capable of causing public harm, including major property damage as well as serious injury to members of the public on the ground, in aircraft, and on waterborne vessels. The Columbia Accident Investigation Board (CAIB) commissioned an analysis by ACTA Inc. that found the lack of reported casualties on the ground was a reasonably expected result based on the recovered debris data, census data, and mathematical methods consistent with current standards for launch debris risk analyses. [1, 2] A more detailed aircraft risk analysis, funded by the Federal Aviation Administration (FAA), used the actual records of aircraft activity at the time of the accident, and found that the probability of an impact by Columbia debris to commercial aircraft in the vicinity was at least one in a thousand, and the chance of an impact to general aviation was at least one in a hundred. [3] After FAA executives were briefed about the potential for aircraft impacts during the Columbia accident, and the challenges presented by integration of innovative vehicles such as SpaceShipOne into the National Airspace System (NAS), the FAA began to investigate a decision support tool to better manage the interface of space and air traffic in the future. In addition, the FAA asked the Common Standards Working Group (CSWG) to investigate risk and air traffic management issues that arise in the event of space vehicle accidents and to develop safety standards to govern the interface between space and air traffic. Most recently, the FAA funded a study of aircraft risk around operating areas for future flights of suborbital rockets that may be authorized by an Experimental Permit (EP). Congress mandated that the FAA develop the EP regime as a streamlined regulatory mechanism relative to a launch license to facilitate research and development tests of reusable suborbital rockets. In response to this Congressional mandate, the FAA has taken a clean sheet look at public risks from launch, including risks to people on the ground, in aircraft, or waterborne vessels of any kind. As a result, several qualitative guiding principles for public safety were formulated that can be used to establish specific quantitative requirements to demonstrate adequate public protection. This paper discusses such efforts made by the US government in response to the Columbia accident, and proposes possible performance standards and safety requirements for public safety based on recent work sponsored by the FAA. For example, this paper presents an analysis of data on aircraft accidents, including serious injuries and fatalities on-board and on the ground, and proposes quantitative safety requirements that would demonstrate compliance with the following performance standard: for any individual not involved in the mission, but participating in a voluntary activity that increases their background risk (such as traveling in an aircraft or waterborne vessel), the chances of casualty resulting from the mission should be no greater than the background risk associated with the voluntary activity.
