In August 2012, the Voyager 1 spacecraft made history by becoming the first manmade object to transverse the heliopause, meaning it had left the boundaries of our solar system. Since then, only one other spacecraft has done this, Voyager 2, and this is because it just takes too long to do so. Jason Benkoski wants to change this fact.
Jason Benkoski works in the Johns Hopkins University Applied Physics Laboratory, where he is working on what he believes is the quickest way to escape the confines of our Sun. Using a “solar simulator,” Benkoski has recently demonstrated on a smaller scale that his idea is plausible, a solar thermal engine.
The idea behind a solar thermal engine is much different from a traditional chemical-based engine. It would be integrated directly into a spacecraft’s heat shielding, and below that would lie a complex set of tubing. A spacecraft equipped with this type of engine needs to make a close pass by the Sun and push hydrogen into the tubing, causing the hydrogen to expand and be forced out of a nozzle.
A spacecraft using a solar thermal engine making a close pass by the Sun would hypothetically allow it to travel around 200,000 miles per hour. To put that into perspective, Voyager 1 could only travel along at 30,000 miles per hour, and it took the spacecraft 35 years to finally pass the heliopause that way. A solar thermal engine would allow us to make that same trip significantly faster.
The team at the Applied Physics Laboratory believes that their engine would be capable of carrying a spacecraft three times farther than the heliopause. Not only that, but they also believe that they could reach that point in half the time it took Voyager 1 just to reach the heliopause, meaning their spacecraft would be capable of traveling much faster and farther.
In 2019, NASA reached out to the Applied Physics Laboratory for assistance in studying new ways to embark on an interstellar mission. The results of these studies are due to be submitted to the National Academies of Sciences, Engineering, and Medicine’s Heliophysics decadal survey at the end of 2021.
The idea behind the solar thermal engine has been proven to work on a very small scale. But despite this, much work still needs to be done before we are sending a spacecraft out into the dark unknown using the Sun’s energy.