A new large area detector for in-situ observation of small anthropogenic debris in Low Earth Orbit - SAILOR

Data on the flux of orbital debris in the critical size range of 0.1 – 50 mm is urgently needed. To obtain it, a large

area detector (SAILOR) using thin deorbit sails (or drag sails) with acoustic sensors and a camera imaging system

is proposed. The acoustic sensors will give impact time and a rough estimation of impact location and hole size

on the sail. A pair of such sails, one behind the other, will provide impactor speed (to ± a few %) and trajectory (to

± a few degrees). The optical detector system will image the holes in the sails, providing hole shape and a separate

measure of hole size (good to ± a few %). A 3-year mission, SAILOR, would be launched in 2029 to a sun�synchronous, near-polar orbit at 850 km, consisting of one spacecraft with a 25 m2 exposed area. Given the expected flux, this should provide space debris measurements in the critical mm-sized regime.

Presented at the 9th European Conference on Space Debris, Bonn, Germany, 1–4 April 2025, published by the ESA Space Debris Office