Aircraft modification for an aerosol microphysics experiment

The aerosol microphysics experiment requires an aircraft that can carry roughly 10 tonnes of SO₂ and associated hardware to ~14 km and release it in a controlled way. Only a few aircraft with that capability currently exist: most widebody jets have service ceilings up to 13 km, and the business jets that could reach 14 km do so only with payloads near the experiment's minimum. Because the tropopause (the boundary between the lower atmosphere and the stratosphere) is lower at the poles, ~14 km is stratospheric at high latitudes, which is where a retrofitted aircraft makes the experiment possible. Once an appropriate platform is purchased, it then must be fitted with all of the necessary tanks, distribution systems, and sensors to safely carry and disperse SO₂. 

Acquiring and modifying a suitable aircraft is among the most expensive and longest-lead items on the experiment's critical path, and it must be complete — including flight testing of the release system — before the aerosol microphysics experiment can be conducted. Which aircraft to modify will follow from the aircraft retrofit analysis.

This activity covers acquiring an aircraft and modifying it to safely store, carry, and release SO₂ at stratospheric altitudes for the aerosol microphysics experiment. Platform selection will follow the findings of the aircraft retrofit analysis. Modifications include integrating SO₂ storage tanks, release nozzles, and associated plumbing — using the tank and nozzle system designed and lab-validated under the Develop SO₂ hardware activity — followed by fully integrated testingto validate release mechanics under realistic flight conditions.