The Fermi Explorer mission is seeking partners and funding for a tiny spacecraft that its founders hope to launch towards Alpha Centauri in 2029 — although the journey would take about 80,000 years.
The project has been established by Starcloud founders Philip Johnston, Adi Oltean and Ezra Feilden, alongside programme manager Garret Jameson. The non-profit is inviting contributions from spacecraft manufacturers, scientists and artists to help assemble a vehicle capable of travelling beyond the Solar System.
If launched, it would be the first human-made object deliberately sent towards another star. It would also become the sixth spacecraft to leave the Solar System, following probes including Voyager 1 and Voyager 2, Pioneer 10 and Pioneer 11, and New Horizons.
Fermi Explorer estimates that the mission would cost about 15 million dollars (£11.6 million). Its proposed payload would measure 10cm square and weigh about 1kg, with the organisation considering scientific instruments and artistic material in a role similar to the sensors and Golden Record carried by NASA’s Voyager probes.
Fermi Explorer plans a long route to Alpha Centauri
The spacecraft would initially travel as a rideshare on a conventional rocket. It would then use low-power electric propulsion and a sequence of carefully planned orbits to build enough momentum to leave the Solar System on a trajectory towards Alpha Centauri.
The probe is expected to operate for roughly 12 years before entering a final coast phase. It would then continue through interstellar space without an active mission team expecting to receive data from it at the other end.
Alpha Centauri is about 41 trillion kilometres from Earth. Voyager 1, launched in 1977 and the most distant human-made object, is currently about 26 billion kilometres away — a comparison that illustrates the scale of the proposed journey.
Johnston said the decision to accept an 80,000-year travel time was deliberate, rather than attempting to develop propulsion technology that could reach another star within a human lifetime.
“I also got excited and then disappointed!” Johnston said, referring to the collapse of enthusiasm around previous interstellar proposals. “That’s the reason we are doing the mission. We are hell-bent on actually launching something in three years.”
He added: “The big difference with most other [interstellar] missions and the Fermi Explorer is that the others all try to do it in a human lifetime, which means billion-dollar propulsion R&D programmes. We have very deliberately picked 80,000 years as the minimum viable mission.”
The project takes its name from the Fermi paradox, which examines why humanity has not found evidence of other intelligent life despite the vast number of stars in the universe. Its organisers say the mission is intended to mark a historic first and test the practical limits of human exploration.
Johnston said the spacecraft would not be designed to power itself back up after its journey. “If a dinosaur bone can last 200 million years then a metal box can easily survive the radiation environment we expect for 50,000 years,” he said. “We hope that a future human civilisation will intercept it.”
The proposal follows the collapse in 2025 of Breakthrough Starshot, a multi-billion-dollar initiative backed by Yuri Milner and Mark Zuckerberg that aimed to propel small spacecraft to Alpha Centauri using powerful lasers. Fermi Explorer is instead proposing a slower mission based on established space technology.
