Researchers at McGill University, led by undergraduate Gabriel R. Dube and Associate Professor Andrew Higgins, have suggested a novel propulsion technique that could significantly expedite spacecraft travel throughout the solar system and potentially beyond. The team’s recent investigation of the Laser-Thermal Propulsion (LTP) system displays the technology’s potential for high-thrust, high-specific impulse missions, moving closer to reality the dream of swift journeys to destinations like Mars.
Breaking New Ground with Laser-Thermal Propulsion
The LTP concept, born from inspiration by interstellar projects like Breakthrough Starshot, utilizes directed energy to heat hydrogen propellant. This process allows for the powerful combination of high thrust and high specific impulse, desirable traits for reducing travel time to other planets. This propulsion method has been under study since at least 2022 when Higgins and his team first published their findings in Acta Astronautica and posited the technology’s use for rapid transits to Mars in as little as 45 days.
Experimenting with Directed Energy and Propellants
The current phase of experimentation uses a scaled-down laser setup to explore the technology’s feasibility. While the team does not have access to the full 100 MW laser originally conceptualized, their 3-kW laser setup in the lab is a significant step toward understanding how energy transfers to the propellant. Initial tests with argon gas, a stand-in for hydrogen, showed promising results, with a large percentage of laser energy converting to plasma.
Higgins and his colleagues constructed a testing facility to examine the behavior of argon gas under laser-induced plasma conditions. Their findings, based on pressure and spectral data, confirmed a high rate of energy transfer from the laser to the plasma. The experiments have brought into focus the need for a dedicated apparatus to conduct further research and refine the system’s performance.
The team intends to advance their studies by measuring the thrust capabilities of the LTP system, aiming to ascertain the potential acceleration and specific impulse it could deliver for future missions. Should their work prove successful, LTP may drastically cut down travel times to Mars and expedite exploratory missions across the solar system.
The promise of LTP, alongside other innovative concepts like hibernation systems for astronauts, could revolutionize space travel. With continued development, these technologies could lessen the need for extensive supplies on long-duration missions and mitigate health risks to astronauts from prolonged exposure to microgravity and radiation.
