NASA says Earth to Mars journey may be as long as 500 days, but some scientists say the time it takes to reach the planet can be slashed
NASA says that the period it takes humans to travel between Earth and Mars is some 500 days. However, some scientists suggest that it can be slashed hugely. In fact, they have devised a laser-thermal propulsion system that can make it happen. Shockingly, they say the Earth to Mars trip could take just 45 days. According to the predictions by NASA, the time taken to reach Mars is around 500 days currently, but these scientists based in Canada say it could be reduced manifold.
Engineers from McGill University, based in Montreal, Canada, say they have developed a new ‘laser-thermal’ propulsion system, using lasers to heat the hydrogen fuel. Termed as ‘directed-energy propulsion’, it uses enormous laser shots fired from Earth to power the photovoltaic panels present on the spacecraft, reported the Daily Mail.
Emmanuel Duplay, a McGill graduate and MSc Aerospace Engineering student at TU Delft, published a paper suggesting this could be used in a trip to Mars. Speaking to Universe Today, he said, “The ultimate application of directed-energy propulsion would be to propel a lightsail to the stars for true interstellar travel, a possibility that motivated our team that did this study.” Notably, NASA has plans to send humans to Mars in the 2030s.
However, the spacecraft required for such travel do not exist as of yet. They would require a 32ft diameter, 100-megawatt array of lasers, to be built. These will be Earth-based. For this application, lasers will be used to deliver power to photovoltaic arrays on a spacecraft, which is converted to electricity to power an engine. This idea is similar to a nuclear-electric propulsion (NEP) system, where a laser array takes the place of a nuclear reactor. According to Duplay, his concept is related but different.
“Our approach … permits the spacecraft to accelerate rapidly while it is still near earth, so the laser does not need to focus as far into space,” he said.
“Our spacecraft is like a dragster that accelerates very quickly while still near Earth. We believe we can even use the same laser-powered rocket engine to bring the booster back into Earth orbit, after it has thrown the main vehicle to Mars,” he added.
The research paper says, “The application of directed energy to spacecraft mission design is explored using rapid transit to Mars as the design objective. An Earth-based laser array of unprecedented size (10 m diameter) and power (100 MW) is assumed to be enabled by ongoing developments in photonic laser technology. A phased-array laser of this size and incorporating atmospheric compensation would be able to deliver laser power to spacecraft in cislunar space, where the incident laser is focused into a hydrogen heating chamber via an inflatable reflector. The hydrogen propellant is then exhausted through a nozzle to realize specific impulses of 3000 s. The architecture is shown to be immediately reusable via a burn-back maneuver to return the propulsion unit while still within range of the Earth-based laser.”
The findings from this research have been published on Arxiv.org