Designing a mission concept for atmospheric plume measurements during a rocket launch event

The frequency of space launches has increased dramatically as costs plummet and demand rises with the advent of use cases (such as mega constellations or larger-scale exploration). This increase in launch cadence is enabled by reusable launchers, whose technology is progressing in Europe. They provide enhanced material efficiency while adding complexity to flight paths, burn patterns and more. There is, however, a notable gap in observational evidence regarding emissions and their subsequent atmospheric effects, especially for liquid or hybrid solid/liquid propellants.

We present ongoing work within the ESA project FIREWALL (Facilitate Inquiry of Rocket Emission impact With Atmosphere Lower Layers) that aims to design a mission concept for measuring emission and plume properties during the takeoff and return of current or near-future launch vehicles. It leverages expertise in the fields of ground observations at the launch site, airborne in-situ measurements with different available platforms like aircraft, balloons or sounding rockets, satellite remote sensing of contrails or trace gases, as well as plume and global atmospheric modelling. Thereby the major atmospheric burn events of a modern launcher shall be captured in unprecedented extent and detail to better quantify their atmospheric effects.

This innovative atmospheric science mission brings together experts from the fields of atmospheric measurements with space launch system operators and airspace authorities. Additionally, input will be provided by experts in plume thermodynamics and chemistry modelling, trajectory and dispersion modelling as well as weather forecasting. The gathered mission concept devises a recipe to operate a comprehensive suite of measurement platforms and instruments at a scheduled rocket launch event, including a list of objectives and requirements as well as a comprehensive risk assessment.