While the spotlight is on Ukraine, news regarding an extraordinary space technology, dreamed up here in Montreal, has gone virtually unnoticed.
Sending astronauts to Mars, as NASA and China plan to do in the 2030s, presents significant logistical and technological challenges. Missions can only be launched to Mars every 26 months, when our two planets are closest to each other. With current technology, NASA estimates it will take regarding 500 days for astronauts to reach the Red Planet. The transit time involves serious dangers for the crew exposed to cosmic rays, once out of the Earth’s magnetosphere.
A team of researchers from McGill University has designed a laser thermal propulsion system that would reduce transit times to Mars to just 45 days! Until this study, it was thought that a rocket might only transit to Mars at such speed with nuclear-powered engines.
The study was carried out by McGill graduate Emmanuel Duplay with Associate Professor Andrew Higgins and other researchers from the university’s Department of Mechanical Engineering. They propose a directed-energy propulsion system that uses terrestrial lasers to transmit energy to the spacecraft’s photovoltaic sensor to generate the electricity that propels it. The more powerful the laser, the greater the speed of the spacecraft. This technology might send satellites weighing 90 kg from Earth to Mars in just three days!
The “laser thermal propulsion system” proposed by Emmanuel Duplay and his team is relatively simple: several 100 megawatt lasers, each 10 m in diameter, are fused into a beam directed towards the spacecraft already in orbit which picks it up thanks to to an inflatable reflector.
Duplay explained to Universe Today that the laser flux coming from the Earth directly heats the thruster of the spacecraft, much like a giant steam boiler. The laser energy is focused and directed to the spacecraft’s fuel compartment, where the hydrogen creates a propelling force allowing the spacecraft to reach an incredible speed of 60,000 km/h. This allows it to accelerate rapidly, while relatively close to Earth. When the spacecraft has absorbed enough energy, the reflector detaches and returns to Earth orbit for reuse.
There is still a lot of research to be done to make this technology operational. Very large lasers and hydrogen propulsion chambers must first be developed.
In recent years, directed energy propulsion has been the subject of significant research. A concept for a laser-electric spacecraft is being studied by NASA in a joint study with the University of California at Santa Barbara and MIT.
Could Quebec, should it play a major role in the development of this technology? We are a major research center in the fields of electricity, lasers and hydrogen: the Hydro-Québec Research Institute (IREQ), the Optics, Photonics and Laser Research Center (COPL ) and the Hydrogen Research Institute (IRH).
We also have cheap electrical energy to generate the electricity needed to propel such a system if terrestrial lasers might ever be installed in Quebec. Emmanuel Duplay, who is currently studying aerospace engineering at the Delft University of Technology in Holland, should be invited to continue his research here on laser space propulsion systems.
