This is not the first attempt to launch an interstellar spacecraft toward Alpha Centauri. In 2016, billionaire technology investor Yuri Milner announced Breakthrough Starshot, a mission designed to send humanity’s first spacecraft to another star system. The concept called for powerful lasers to propel tiny interstellar probes to speeds of up to one-fifth the speed of light, potentially allowing them to reach Alpha Centauri within 20 years. Although Milner pledged $100 million to support the proof of concept, the project has yet to launch a spacecraft after nearly a decade.
“We didn’t want to do another Breakthrough Starshot,” says Philip Johnston, co-founder and director of the Fermi Explorer mission. “We’re fully committed to actually launching something.” The new interstellar mission is being funded by individual private donors and is expected to cost approximately $15 million.
To remain within that budget, the Fermi Explorer team is not requiring the spacecraft to reach its destination within a human lifetime. “Let’s think of a way to get to another planet,” Johnston says.
The spacecraft is expected to carry at least 1 kilogram of cargo, including artistic and scientific payloads, personal messages, and copies of the Golden Record. The gold-plated disc contains sounds and images from Earth and was placed aboard NASA’s two Voyager spacecraft in 1977 as a message to any civilizations that might discover them.
Interstellar travel is extraordinarily challenging. Alpha Centauri is approximately 25 trillion miles from Earth. Voyager 1, one of the fastest spacecraft ever launched, has been traveling since 1977 but has covered less than 1% of that distance. At Voyager 1’s current speed, reaching Alpha Centauri would take more than 70,000 years.
Johnston and his colleagues spent a year searching for a practical way to send a small, solar-powered spacecraft to Alpha Centauri for roughly $15 million. Their biggest challenge was finding enough power for the mission without making the spacecraft too heavy, which would increase the energy required for propulsion.
After struggling to identify a viable trajectory, Johnston discussed the problem on a podcast hosted by physicist Alex Wisner-Gross, co-founder of PSI. Wisner-Gross suggested using an AI system developed by her laboratory called Get Physics Done. The open-source software takes a complex physics research question, divides it into smaller tasks, and determines which simulations to run with AI models such as Anthropic’s Claude and OpenAI’s GPT.
Within a week, the AI system identified what Johnston described as an unprecedented trajectory. According to the researchers, the approach combines established orbital maneuvers in a way the Fermi Explorer team had not previously considered. The research paper has not yet undergone peer review. The proposed trajectory would initially send the spacecraft inward, allowing it to pass closer to the Sun than Mercury. During each close solar approach, the spacecraft would fire its engines while receiving up to four times more sunlight on its solar panels. Delivering thrust at high speeds could provide more energy than using the same maneuvers farther from the Sun. Because the engines would operate only near the Sun, the spacecraft could use smaller solar panels and remain relatively lightweight.
Source: www.technologyreview.com