Laser Ablation Propulsion in the Martian Environment

Abstract

Mars exploration is governed by a ruthless mass-ledger: every kilogram of ascent propellant ferried from Earth displaces payload or science return. Laser-ablation propulsion (LAP) addresses this constraint by transferring energy remotely. A laser mounted on a lander or orbiter delivers nanosecond pulses to a small pad on the vehicle; the pad ejects a high-velocity plasma plume, and the recoil produces thrust while the power plant stays off-board. This thesis quantifies LAP performance for the first time under Martian ambient (600 Pa, 210 K CO₂). A coupled thermal–mechanical model implemented in ANSYS Mechanical APDL tracks crater evolution, phase explosion, and impulse generation for polytetrafluoroethylene (PTFE), carbon-fiber composite, and basaltic/regolith ablators. Parametric sweeps over 1–10 J pulse energy and 50–200 µm spot diameter predict momentum-coupling coefficients up to (4.2 ± 0.3) × 10⁻⁵ N·s·J⁻¹ and specific impulse 900–3200 s. These figures exceed chemical engines in propellant efficiency and encroach on Hall-thruster territory while retaining orders-of-magnitude higher thrust-to-mass because the laser mass is external.

Mission-level scaling indicates a 500 kW orbital fibre-laser can loft a 50 kg sample-return canister to 1.2 km with <15% pad mass, cutting Earth-launch mass by ~30% relative to methane/LOX ascent. Pulses shorter than 20 ns favor plasma-dominated ablation and maximum specific impulse (I_sp); pulses around 50 ns maximize the momentum-coupling coefficient (C_m) for hopper-scale thrust. A hybrid composite–regolith pad is proposed to reconcile coupling efficiency with in-situ manufacturability.

In the future, laboratory validation can be done using a torsional thrust stand and gated schlieren plume imaging, after which computational fluid dynamics can be embedded to capture dusty-gas entrainment. By mapping the material–pulse design space and demonstrating a credible mass advantage, this work positions externally powered LAP as the missing middle ground between high-thrust chemical rockets and high-I_sp electric thrusters—enabling agile surface mobility and lightweight ascent for the next generation of Mars missions.