The Risks of Airplane and Spacecraft Travel — By the Numbers

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In the “UK Government Review of Commercial Spaceplane Certification and Operations Technical Report,” there is a fascinating section outlining the risks of aviation and spaceflight. It is worth quoting at length because it shows the risks people take in different types of flights, and the nearly complete lack of safety data involving the emerging field of space tourism.

The key excerpts are below. I’ve added emphasis to spotlight the key statistics.

Over the past hundred years, commercial aviation has evolved to the extent that, for public transport, operations involving ICAO-certified aircraft achieve a catastrophic failure rate better than 1×10-7. This means that catastrophic failure takes place less than once in every 10 million hours of flight.

For general aviation, the standards are typically between 1 in 10,000 and 1 in 100,000 – less stringent than for public transport, but still deemed an acceptable level of safety, given the nature of the activity.

The commercial spaceplane industry is new and the safety performance of spaceplanes largely unknown. Furthermore, the total number of commercial spaceplane flights before 2018 is likely to be very small; it is likely that meaningful safety data about commercial spaceplanes will only be accumulated some years thereafter. Previous spaceplane operations have used experimental vehicles operated largely by government agencies and, although some safety data is available, it may not be applicable to commercial operations….

During its technical visit to the US, the UK Government team was informed by NASA that it considered a target level of safety of 1 in 1,000 to be achievable for orbital operations, and 1 in 10,000 for sub-orbital operations in the future. These figures are understood to be broadly in line with ESA targets as well as with the draft safety standards being developed by the IAASS. However, it is worth highlighting that historically, orbital operations have experienced approximately 1 catastrophic failure every 100 launches (ie 1×10-2).

Both the US Government and the FAA AST have made it clear that they accept that spaceflight is a high-risk activity; hence their regulatory approach is to focus on the protection of the uninvolved general public (also known as third parties). This differs from normal commercial aviation, where the focus is on protection of passengers and crew, and works on the basis that if the risks to passengers and crew are minimised, then the public is inherently protected, too.

The FAA AST has set a target level of safety of 30×10-6 for third party risks to collective members of the general public, and 1×10-6 for a risk to an individual. In plainer terms, this means that the acceptable risk of third party casualties is 0.00003 per mission, or 3 casualties in every 100,000 missions. Missions which cannot demonstrate that they should meet this target will not be granted a launch licence.

So, there you have it. A target level for how many people on the ground these news space vehicles can kill in order to be considered for a launch license. Of course, without any real flight experience, the FAA AST is simply guessing as it issues licenses to new providers. Time will tell.