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Scientists have proposed a dazzling new mission to travel to the stars that is inspired by the elegant flights of seabirds, such as albatrosses, reports a new study. The interstellar concept mission would harness shifting winds generated by the Sun in order to accelerate a spacecraft to as much as 2 percent the speed of light within two years, allowing it to soar into the vast expanse beyond our solar system.
Humans have dreamed about leaving the solar system for thousands of years, but the mind-boggling distances between stars present major challenges to this goal. NASA’s Voyager spacecraft, which were launched in 1977, are the first probes to enter interstellar space, but it will still take them tens of thousands of years to reach another star system.
Now, scientists led by Mathias Larrouturou, a spaceflight researcher at McGill University, have envisioned a much faster spacecraft that would mimic the “dynamic soaring” maneuvers of seabirds by gaining momentum from the solar wind, which is a stream of charged particles emitted by the Sun that creates a bubble around the solar system called the heliosphere.
The team found that their “new concept for spacecraft propulsion that invokes dynamic soaring” appears “feasible for a vehicle to achieve velocities approaching 2 percent of [the speed of light] after a year and a half” or “0.5 percent of [the speed of light] after 1 month,” depending on its trajectory through the solar system, according to a recent study published in Frontiers of Space Technologies.
“Inspired by the dynamic soaring maneuvers performed by seabirds and gliders in which differences in wind speed are exploited to gain velocity, in the proposed technique a lift-generating spacecraft circles between regions of the heliosphere that have different wind speeds, gaining energy in the process without the use of propellant and only modest onboard power requirements,” Larrouturou and his colleagues said in the study.
“The technique may comprise the first stage for a multistage mission to achieve true interstellar flight to other solar systems,” the researchers added.
Many interstellar concept missions have been proposed over the years, from tiny chips that use high-powered lasers to propel them to the stars, to hulking generation ships that carry humans across the galaxy. Larrouturou and his colleagues imagine a different kind of architecture centered around a “magnetohydrodynamic wing,” which is an invisible structure made of magnetic fields that is somewhat analogous to the physical wing of a bird or plane, according to the study.
This spectral wing could theoretically be produced by two plasma magnets placed along an antenna measuring several feet in length. In the right parts of the solar system, the field created by the magnets could interact with solar wind flows in different directions in much the same way that birds exploit wind turbulence to create lift.
“The result is a type of lift-generating wing, but without a physical structure,” the team explained in the study. “In dynamic soaring as practiced terrestrially, a lift-generating vehicle executes a maneuver that exploits the difference in wind speeds between two different regions of air, for example, the wind blowing over a hilltop and the quiescent air on the leeward side of the hill.”
If a probe of this kind was placed at the heliopause, the tumultuous boundary to the heliosphere, it could leverage these mixed wind flows to accelerate to speeds of around 3,720 miles per second in a matter of years. In other parts of the solar system, the spacecraft could reach a quarter of that speed in only a month, according to the team’s calculations.
A mission that hit the gas in this way could reach Jupiter in months, not years, and could potentially reach other stars in a matter of centuries. While this is still well beyond a human lifetime, it is a substantial improvement over the multi-millennia trips of slower spacecraft, like the Voyagers.
To that end, Larrouturou and his colleagues conclude their study with a technology roadmap for plasma magnet technology in practice. The team highlights two other concept missions, the Jupiter Observing Velocity Experiment (JOVE) and the Wind Rider Pathfinder Mission, as potential trailblazers of this novel approach to spaceflight.
“These groundbreaking missions would provide validation that meaningful propulsive power could be extracted from the solar wind, providing a foundation for the more advanced concept of extracting electrical power from the wind for lift-generation,” the researchers said.
“The ability to generate large values of lift-to-drag ratio via interaction with the flow of interplanetary and interstellar medium over a spacecraft is found to be feasible, at least from the perspective of the physical principles involved,” they concluded.