Microsecond Laser Ablation Propulsion Potential of Common Orbital Debris Materials

Abstract

The rising quantity of debris in Earth orbit could trigger Kessler Syndrome, an uncontrolled growth in the number of debris objects. Laser ablation could be one part of a holistic solution for the orbital debris problem for removing <1 cm diameter debris. In ablative laser orbital debris removal, a remote laser vaporizes or delivers impulse to remove targeted objects from orbit. This experimental study seeks to collect data to assess whether laser ablation can impart sufficient impulse to effectively remove orbital debris. Materials representing a significant fraction of the overall debris mass were chosen as targets including aluminium, copper, nickel, phenolic, steel, and titanium. A ~100 microsecond duration pulsed Nd:YAG laser beam was focused to ablate these targets in a vacuum chamber at ~10^-2 Pa. The threshold fluence for ablation was measured for each material. Imparted impulse was measured for each shot to calculate momentum coupling coefficient. Optical profilometry was used to calculate removed mass and thereby construct specific impulse and mass per energy. The data are used to assess achievable delta-v for a corresponding range of debris particle masses and to document propulsion parameters for a set of debris analogous materials to support future work in laser orbital debris removal. The range of delta-v implied by the results supports the idea that removal of some size classes of Earth orbital debris particles using laser orbital debris removal could be viable. Technical challenges remain in delivering high fluence to orbit to remove debris.