Beyond Stage 1 / The program
Beyond Stage 1
How the rail gets built, what each stage costs, and what the probe sends home.
01 / How it gets built
How it gets built.
Solar collectors and lasers near Mercury's orbit, about 0.3 AU, where sunlight is about 11 times stronger. One heavy-lift launch each for the station hardware. The collector membranes are the real launch bill: roughly 140–190 km² of ideal collectors at 23% efficiency — conditional on 27 relays at 98–99% each — at 0.3 AU, roughly 30–190 Starship-class launches, plus radiators not yet massed Projection. Reaching Mercury's orbit is the hard part: MESSENGER and BepiColombo needed 6–7 years of planetary flybys. Ours can sail inward on their own collector membranes, or use Venus flybys.
Their size is set by geometry, not power. To hold the beam on a 22 m sail across a 0.1 AU gap, each needs a membrane optic 1–2 km across, a few to ten tonnes each Projection. A Starship-class carrier launched outward drops 2–5 of them as it goes. Each settles into its own orbit using its membrane as a solar sail.
Rides to a high orbit or an escape trajectory, then sails off Earth's orbital speed on sunlight — a 484 m² sail cannot climb out of low orbit against drag. Still the cheapest launch in the program, and the one that leaves for another star.
Projection About 30 stations. Roughly 10 launches to place them, roughly 30–190 to lift the collectors, plus radiators not yet massed. Lower bounds: bare membrane mass, before structure and the propulsion to reach 0.3 AU. The rail's launch bill is membrane mass, not station count.
02 / Where it leads
Where it leads.
Everything in this section is a projection. It is what the physics and the current cost of hardware allow, not a commitment.
A solar-powered 100 kW-class station.
The first solar station: placed inward from Earth, with hours of beam on a sail, the first passive relay in space and the first beam-riding test. It proves the power-station design at ISS-class power; the rail is two million times more.
The rail.
About 30 stations from 0.3 to 3.5 AU: solar power stations near Mercury's orbit and relay stations trailing outward, dropped off several per carrier launch.
A probe to Alpha Centauri.
A 1 kg probe with a 22 m sail at 100 g of acceleration, pushed by the full rail. Projected figures based on 2P/c and the Stage 4 station count. 150 GW is the power intercepted at the sail; after relay losses the stations emit 197–259 GW (projection).
For scale: Voyager 1 has been flying for 49 years and is 171 AU from the Sun, moving at 16.9 km/s. It is the most distant human-made object ever built. Distance as of September 2026.
Coming off the rail at 30,000 km/s, the probe is travelling about 1,780 times faster than Voyager 1.
It passes Voyager 1's current distance roughly ten days after the push ends.
03 / The cost ladder
Order-of-magnitude projections.
Proof, hardware and launch by category; $22–36M with a 30% reserve on those bands; program-level staff, operations and integration are not yet estimated. $25M is the planning figure and the first tranche.
ProjectionOne solar-powered 100 kW-class station, ISS-class power. Target, not an estimate.
ProjectionMercury-orbit station and sun-dive probe
ProjectionFor the lasers alone, on 197–259 GW emitted: $20–26B at $0.10 per watt, $197–259B at $1 per watt. $1/W is what the Starshot system model assumes for a solar-system precursor; $0.01/W is its stated requirement for the interstellar design, not a price (Parkin 2018). Collectors, radiators, relay optics, transport and operations are not yet priced.
ProjectionStage 1 is roughly 0.01–0.1% of the program and retires the two cheapest risks no one has tested in space. It does not retire the relay, beam-riding, heat or power-station risks; those are listed above.
04 / What we get
What we get.
Alpha Centauri.
The nearest star system, about 4.3 light-years away. Three stars: two Sun-like stars, A and B, orbiting each other, and Proxima Centauri, a red dwarf at 4.24 light-years, the nearest star of all. Proxima has a confirmed roughly Earth-mass planet in its habitable zone, Proxima b, on an 11-day orbit, and a smaller confirmed planet, Proxima d.
In August 2024 JWST imaged a candidate Saturn-to-Jupiter-mass planet about 2 AU from Alpha Centauri A. It is still unconfirmed and awaiting follow-up. Aug 2024 observation; 2025 analysis. Source.
It is the closest place with a possibly habitable world to look at.
What a 1 kg flyby at 10% of light speed returns.
The probe cannot stop. It crosses the Sun–Earth distance in 83 minutes, so the science at the target lasts hours.
Tens to hundreds of km per pixel from a 10 cm camera, depending on approach distance. Any telescope gives a single pixel for the foreseeable future.
Water, oxygen, methane. The biosignature question.
Whether the planet has a magnetic field — one of the deciding inputs for habitability around a flaring red dwarf, though a single pass cannot tell an intrinsic field from an induced one.
Measured in place, at the star.
And for the entire cruise: the interstellar medium sampled at an astronomical unit every 83 minutes across four light-years. The two Voyagers have been measuring it since 2012 and 2018 and are now about 170 AU out; this is the same medium at a thousand times the reach.
Data comes home at bits to kilobits per second, using the sail itself as the antenna. The signal takes 4.2 years. First images arrive roughly 48 years after launch. No instrument, power, shielding or communications budget exists yet for a 1 kg spacecraft; these are what a flyby could return, not what one has been designed to.
The same rail, closer to home.
Run at lower speed, the same rail delivers probes across the solar system in days.
Coast time at 1% of light speed, from the Sun. Reaching the rail adds months.
Coast time at 1% of light speed, from the Sun. Reaching the rail adds months. New Horizons took 9½ years.
Fast flyby probes to the outer planets and the interstellar boundary are the near-term product. Alpha Centauri is the proof that the rail reaches beyond the solar system at all.
05 / Standing on prior work
The physics is forty years old. The build plan is not.
A solar laser near Mercury and a 1,000 km lens near Saturn. The physics has stood for forty years; the scale was judged absurd.
Cited for forty years as the reference design; never built at any scale.
Stations in a line, and a four-phase incremental pathway to get there. NASA NIAC Phase I and a $500k Phase II (2013–15); a 450 g platform pushed on an air track in 2015.
Funded to the bench, never to flight.
A proposed ground-to-orbit laser-sail demonstration ladder.
Designed, never flown.
One 100 GW ground array. It funded lab work — Caltech's sail measurements acknowledge it (Source) — but most of the pledged $100M was never delivered and nothing flew.
Paused since 2024; most of its pledged $100M was never delivered.
A NASA-side beamed-energy demonstration study in the same period.
Designed, never flown.
One modular phased array that grows by adding elements: "not all or nothing", starting with ground and CubeSat tests.
The incremental-build idea in print before ours.
A CubeSat pushing a credit-card sail on a chipsat.
Sought seed funding; never flew.
Solar-pumped stations firing in succession, 10 g probe to 7.7% of light speed.
A paper study; no flight follow-up.
What is different here: a few solar power stations feeding a chain of passive relays, rather than a laser at every station or one giant array; a first flight rung priced at a rideshare slot; and the sun-dive to the head of the rail. The incremental build is Lubin's, Bae's and the Caltech KISS study's idea; the chain of successive stations with handoff is van den Donker's. We are standing on them, not beside them.
06 / Partner with us
Partner with us.
We are raising $25M for Stage 1 from investors and philanthropic funders who want to see the first laser push of a sail in space, and the first handoff, measured and published. First flight data at about $2.5–5.5M.