Metals from the Reentry of Spacecraft in Stratospheric Particles (Invited Presentation)

The number of satellites in orbit is expected to increase by over a factor of 10 by 2030. Most of these satellites will be disposed of within 5 years of launch by destructive reentry in the atmosphere. When satellites and spent rocket boosters reenter the atmosphere, metals are vaporized and recondense onto small particles in the mesosphere.

NOAA's Stratospheric Aerosol Budget and Radiation Experiment (SABRE) mission in February and March 2023 sampled the stratospheric polar vortex, which contains air descending from the mesosphere. The Particle Analysis by Laser Mass Spectrometry (PALMS) instrument measured the chemical composition of individual stratospheric particles. Besides sulfuric acid and metals from ablated meteoroids, a significant number of particles contained metals that can be traced back to the reentry of satellites and rocket boosters. We will discuss the number and composition of these particles in the stratosphere as well as what they might imply for stratospheric chemistry.