The Machines, by the Numbers

Everything in this book eventually comes down to a small set of numbers that either close or they don't. This section is where I lay them out plainly, stripped of narrative, so you can check the argument against the arithmetic. There are three products here, and they are two different machines. The breeder, Hyperion, is a deuterium–tritium spherical tokamak whose job is not to sell electricity but to make fuel — tritium, helium-3, and 14 MeV neutrons. The burner is a deuterium–helium-3 tandem-mirror generator whose job is to burn that fuel for firm, low-neutron power; it ships in two housings, Aegis for fixed defense installations and MetroVolt for data centers, and the physics under both is the same. Every figure below is public — published open-access and independently reproducible from the design basis. I have deliberately kept money out of these tables. Where economics matter, they show up as an honest gate at the end, not as a number I am asking you to trust.

Hyperion — the Breeder

Hyperion is the near-term product and the cash engine of the whole plan, and it is important to be blunt about what it is: a foundry, not a power plant. On a full engineering balance it is net-negative on electricity — roughly −79 MWe — because the point is the fuel and the neutrons coming out, not the watts. The gain is real and it is modest. A scientific Q of about 3.4 means the plasma returns a few times the power put into it — enough to run a breeding foundry, nowhere near enough to run a grid. That distinction is the honest center of gravity for this machine.

A word on why these particular numbers hang together. The negative triangularity (δ = −0.30) is not a cosmetic choice; it is a way of holding the plasma edge in a regime that stays quieter under load, which matters enormously in a compact, high-field machine. The 8 T on-axis field is delivered by REBCO high-temperature superconducting magnets that see almost 17 T at the conductor itself — the gap between those two numbers is a magnet-engineering story, and it is the hardest thing on the machine. And the TBR of 1.8 is the whole business case in one figure: the blanket makes 1.8 tritons for every one the plasma consumes, so the foundry breeds a genuine surplus. That surplus, about 4 kg of tritium a year, is the product.

Aegis — the Burner for Fixed Defense Sites

Aegis is the burner in its first housing: firm, dispatchable power for fixed installations that cannot tolerate an intermittent supply. It runs the deuterium–helium-3 reaction, which is prized because it is aneutronic in the main channel — the neutron fraction is only about 5.44%, roughly an order of magnitude below a D–T machine. Fewer neutrons means less activation, less shielding, and a longer-lived structure, and it opens the door to direct energy conversion: capturing the charged fusion products as electricity without a steam cycle in the middle. To hold a D–³He plasma you need extreme fields, and Aegis delivers them — nearly 26.5 T at the high-field end plugs.

The geometry is worth pausing on, because a tandem mirror is a very different animal from a tokamak. It is a long, straight machine — about 440 m end to end — that traps the plasma between two high-field magnetic plugs rather than bending it into a ring. The plugs at 26.49 T do the confining; the central cell at 17 T does the burning. That length is not a flaw to be engineered away; it is what a mirror trades for a simpler, open geometry and a clean shot at direct conversion. The 2032 date is a ~100 MW test unit that exists to prove the physics, and 2036 is when the commercial ~1 GW machines begin. Aegis and MetroVolt are the same reactor in different clothes; the numbers in this table describe both.

MetroVolt — the Burner for Data Centers

MetroVolt is that same burner pointed at a different customer: firm, clean, around-the-clock power for AI data centers, whose appetite for uninterrupted electricity is the defining infrastructure problem of this decade. The core physics is identical to Aegis — same D–³He reaction, same low neutron fraction, same field ladder, same direct conversion. What is different is the deployment story, and specifically how far it can scale, because MetroVolt is where the long-run fleet lives.

The single most important line in that table is the one about fuel. Early burners run on helium-3 made by the breeder, and that supply is limited — enough to prove the machines, not enough to build a fleet. The fleet-scale story, ~90 units and roughly 90 GW by 2050, is gated on helium-3 arriving from the Moon around 2040. Until that supply exists, MetroVolt is a small number of demonstrated machines, not a grid-scale answer. I would rather tell you that plainly than paper over it.

Program Timeline at a Glance

The three tables above describe the machines. This one describes the sequence — the order the dates arrive in, and why each step is allowed to happen only after the one before it has earned it. Read it top to bottom as a single chain: the foundry gets built and makes fuel; the fuel and the revenue pay for a test burner; the test burner proves the mirror; the commercial fleet begins; and the fleet only reaches scale once the fuel constraint lifts. The dates are targets on the honest, deliberately conservative horizon, not promises of a hard early date.

A few things to notice in that column of dates. The first is the gap between 2026 and 2030: the design is solved now, but the first hardware milestone is years away, and nothing in between is a net-gain claim. The second is that the breeder line and the burner line run in parallel, not in series — the foundry is already maturing while the first test burner is being built, because the foundry is what funds the burner. The third is that the single most consequential date is ~2040, lunar helium-3, because everything to the right of it — the whole leap from a few demonstrated machines to a ninety-unit fleet — is gated on that fuel arriving. Slide that date and the far end of the timeline slides with it. Where two dates are shown for the same event (target versus planning basis), the earlier is what we aim at and the later is what we plan around; the honesty of the schedule lives in that pair.

How to Read These

A few conventions, so the tables don't mislead. Q_sci is scientific gain — fusion power out divided by heating power into the plasma — and it is not the same as putting net electricity on a grid; a machine can have a healthy Q and still be a net consumer of power once you account for everything it takes to run. Hyperion is exactly that case, on purpose, which is why its electrical balance is listed as negative and its role as a foundry rather than a power plant. f_n, the neutron fraction, is the share of fusion energy carried by neutrons; lower is better for a power machine because neutrons are the source of activation and structural damage. TBR, the tritium breeding ratio, above 1.0 means the machine breeds more fuel than it burns.

The fusion-reaction rows are the textbook reactions each machine runs, with the energy split between the products shown in MeV — millions of electron-volts, the natural unit for a single nuclear event. Read those numbers as where the energy goes: in the breeder's D–T reaction, most of it (14.1 MeV) rides out on the neutron, which is exactly why the breeder is a foundry and a materials machine; in the burner's D–³He reaction, most of it (14.7 MeV) rides out on a charged proton, which is exactly why the burner can collect it with direct energy conversion instead of boiling water. The whole strategic difference between the two machines is visible in which product carries the energy.

The field numbers come in pairs — an on-axis or central-cell value and a much higher peak value at the conductor — because the magnet always sees a harder field than the plasma does, and the peak number is the one that sets the engineering limit. That is why the tables quote the breeder by its 8 T on-axis value and list the burner's pair explicitly — 17 T in the central cell and 26.49 T at the plug; the smaller number is what the plasma feels, the larger is what the magnet must survive.

The operating-mode rows say driven for every machine: each is externally heated rather than left to sustain itself, which is a deliberate design choice for controllability, not a shortfall. And the build-time rows describe a learning curve, not a fixed duration — first-of-a-kind units take longest, and each later unit is meant to be built faster as the program repeats itself. The dates in the datasheets and in the timeline are targets on a conservative horizon; where a target and a planning basis differ, both are shown rather than the flattering one alone.

Every figure here is a design-basis value from the open-access publications, or a date from the published program plan; none of it is a financial projection, and there are no costs, prices, or margins anywhere in this section by design. The fleet figures describe the shape of the program — a few breeders, many burners, gated on lunar helium-3 — not a return on anything.

The Honest Gates

Numbers in a table can make anything look finished. These three products are not finished, and the discipline of this book is to say exactly where the edges are.

Materials first. The near-term business is fuel and materials, not electricity. Hyperion is net-negative on power and I say so in its own datasheet. It earns its place by breeding tritium and helium-3, and that is a real market — just not the grid.

The burner's economics need cheap lunar helium-3. The physics of Aegis and MetroVolt is solved and published, but the fleet-scale case rests on a fuel that does not yet ship from where it needs to. Terrestrial helium-3 cannot carry a power fleet; lunar helium-3, arriving around 2040, is what makes the burner economic. Take that supply away and the fleet numbers in the MetroVolt table do not stand.

No hardware net-gain before ~2030. The gain is solved, published, and reproducible from the design basis — but no hardware has been built yet. Construction begins in Q2 2027; first tritium is targeted for ~2030. Any claim of a hardware net-gain milestone before then would be dishonest, and this book does not make it. "Gain solved" is a statement about the design. "Gain built" is a date that has not yet arrived.