While other spacecraft, such as Lucy, have used solar energy to operate instruments, Psyche will be among the first of NASA’s deep space missions to use solar energy for both onboard and propulsion operations.
Paulo Lozano, director of MIT’s space propulsion lab, says Psyche could lay the groundwork for more solar-powered space exploration. Eventually, technology could help us study multiple celestial bodies for extended periods of time and potentially make missions with humans outside Earth’s orbits more affordable and feasible.
“It actually opens up the opportunity to explore and commercialize space in a way we have not seen before,” Lozano says.
Because a spacecraft that uses solar-electric propulsion requires less propellant than a chemical propulsion, it has more room on board for cargo, scientific instruments and one-day astronauts. One company, Accion Systems, is developing more efficient ion thrusters for Cubesats as well as larger satellites and other spacecraft.
Solar propulsion technology is already common in satellites orbiting the Earth, but until now it has not been a powerful enough alternative to chemically powered engines to be used so often in spacecraft en route to deep space. Advances in solar energy propulsion will change that.
The technology behind Psyche had its first major test in Dawn, an exploration spacecraft that used solar energy and ion thrusters. Dawn eventually fell silent as it orbited the dwarf planet Ceres (where it will remain in orbit for decades) in 2018, three years after the mission was to end. These thrusters can operate for years without running out of fuel, but they provide relatively low propulsion compared to conventional propulsion.
Psyche’s thrusters will be able to generate three times as much pressure as its predecessors, and about a year after launch, it will be assisted by Mars’ gravity to change its trajectory before finally reaching its 2026 target.