Abstract: For many years, the NASA Orbital Debris Program Office has been collecting measurements of the orbital debris environment from the Haystack Ultra-wideband Satellite Imaging Radar (HUSIR) and its auxiliary (HAX). These measurements sample the small debris population in low earth orbit (LEO). This paper will provide an overview of recent observations and highlight trends in selected debris populations. Using the NASA size estimation model, objects with a characteristic size of 1 cm and larger o…