Fermi Explorer: British physicist proposes sending a probe to Alpha Centauri for $15 million

British physicist Philip Johnston has unveiled the Fermi Explorer project — a concept for an interstellar mission that would send a compact probe to the Alpha Centauri system. The project's total budget is $15 million, with launch planned for 2029. The mission's main goal is not simply to reach the neighboring star system, but to visually test one of the key hypotheses of the Fermi paradox and thereby bring the search for extraterrestrial life closer, by proving that an interstellar flight is technically achievable without the colossal resources of an entire civilization.

Simplicity instead of billion-dollar budgets

Unlike ambitious concepts such as laser sails or billion-dollar budget requests to NASA, the Fermi Explorer team set out to build the simplest and cheapest spacecraft possible based on existing technologies. The compact probe will carry a payload weighing just 1 kg, a xenon tank, and solar panels powering a solar-electric engine. This approach allows the entire project to fit within a $15 million budget and become feasible in the near term, rather than in some distant future.

Trajectory, the Oberth effect, and the role of AI

The key engineering challenge was the weakening of sunlight: beyond Jupiter's orbit, the solar-electric engine loses efficiency due to insufficient radiation. This problem was solved with the help of the AI company Physical Superintelligence, whose algorithm produced an 81-page report on a new flight trajectory. According to the calculations, after being placed into low Earth orbit, the spacecraft will perform a series of solar close approaches, reducing the distance to 0.42 astronomical units. Using the high solar flux and the Oberth effect at perihelion, the probe will accelerate to 25 km/s and leave the Solar System roughly 12 years after launch. Direct communication with the spacecraft will be maintained only during the first 18 months; beyond that, ground-based telescopes will be able to track its path using retroreflectors up to about Jupiter's orbit, after which the craft will enter ballistic mode.

Contradictory data

Available sources disagree on the estimated flight time to the target. The original project description and a number of publications (including rbc.ua) cite an approximate timeframe of 77,000 years to reach the Alpha Centauri system. Meanwhile, other outlets (for example, shazoo.ru) round this figure to 80,000 years. The discrepancy is likely due to rounding and to accounting for different acceleration scenarios; however, the exact figure is not standardized in open materials, and both versions are cited equally.

Philosophical context: the Fermi paradox and the "Great Filter"

The creators emphasize that even with a long flight, the very act of launching the spacecraft is of principled significance. "If humanity is capable of building such a craft, this refutes the notion that living species are unwilling or unable to send ships to neighboring stars," the scientists note. Thus, the mission is intended to provide an argument that the absence of traces of extraterrestrial civilizations (the Fermi paradox) is not explained by the technical impossibility of interstellar flights. The authors also hope that this step will make society reflect on its responsibility for preserving its own civilization in the face of the "Great Filter" threats — from nuclear risks to the uncontrolled development of artificial intelligence.