Since 2008, SpaceX has received cumulative US federal obligations of 16.68 billion dollars across more than 270 prime awards. Contract ceilings reach 29.68 billion if every option is exercised. The lunar lander for the Artemis programme accounts for 4.04 billion. Crewed flights to the space station add up to 5.92 billion. During its first decade the company operated on roughly one billion dollars in total, and about half of that came from progress payments on government contracts.

I do not cite these figures as an accusation. They belong to the rare cases where public procurement produced a genuine new capability instead of merely paying for an existing one. My point lies elsewhere. The people who raise these sums will never set foot on another body in the solar system. They are financing a departure they will not join.

The silent assumption behind every long investment

Societies have paid forward across generations many times. In 1713 in Freiberg, Hans Carl von Carlowitz wrote down how a forest must be cut so that it still carries the grandchild. A pension fund pays out to people who are paying in today. A deep repository is built for descendants who have no names yet. All of this counts as a model of foresight.

Every one of those cases rests on an assumption so obvious that nobody writes it down. The recipient stays a member of the same community. The grandchild stands in the same forest. The future pensioner pays into the same fund that supports today's elderly. The people protected by the repository remain reachable by the same routes we use. Giving and receiving happen inside one system, merely at different times.

That assumption now disappears for the first time.

Separation is not a risk, it is the objective

Every serious settlement plan names self-sufficiency as its purpose. A settlement counts as successful once it can hold without resupply from Earth. Put plainly: the project succeeds only when the recipient has left the community that paid for it.

In any other generational investment that outcome would be an accident. Here it is the design goal. For the first time we are building a descendant whose departure we do not merely accept but deliberately pursue. This is not a charge against the enterprise. It describes how it is built, and the consequences have never been worked through.

The body sets the direction

The separation does not stay political. It becomes physical.

Anyone living in weightlessness for an extended period loses one to two percent of bone mass per month. Despite intensive exercise, astronauts never return fully to their baseline. Japan's space agency operated a centrifuge on the space station in which mice lived under lunar gravity. That gravity prevented muscle atrophy. It did not prevent the shift in muscle fibre type. Partial gravity works, then, but it does not replace Earth.

Everything we know comes from adult bodies that finished growing on Earth. For a human being conceived, raised and matured in one third of Earth's gravity there is not a single data point. Nobody has ever built a centrifuge covering the range between weightlessness and full gravity across a developmental span. Nobody is planning one.

I will not turn this into a claim I cannot support. Whether a person born there could ever stand on Earth is unknown. The decisive sentence is a different one, and it is beyond dispute: we will find out only after the first child exists. The question of the return journey will not be answered in advance, it will be observed afterwards.

Where the theory of justice runs out

For decades, scholars have argued over why we owe anything at all to future people who cannot give anything back. The strongest answers follow two lines.

The first rests on the continuous overlap of generations. The old depend on the young, so later people are not defencelessly exposed to us, and from that mutual dependence a real duty arises. The second rests on the economic system. Only because we count on future people does our entire stock of capital remain sensibly invested. Erase the future and you devalue the present.

Both arguments assume the recipient stays inside the system. A population on another body does not overlap with us. It does not sustain our funds. It does not keep our capital meaningful. It cannot give anything back even when it wants to, because mass is too expensive across that distance and because the path back into a heavier body may not be open at all.

So the entire scaffolding of intergenerational justice fails at precisely this point. Nobody has noticed, because this case has never been built before.

An investment becomes an inheritance

When the usual terms fail, the act needs a different name. An investment expects a return inside the same system. That does not apply here. Development aid expects accountability. That does not apply either, because no audit reaches across this distance.

What is actually happening is an inheritance. A community passes part of its wealth to descendants who then go their own way. An inheritance knows no consideration in return. It knows conditions, but only in one single moment, namely before the handover. After that the testator is out of reach.

That moment is running now. As long as a settlement needs resupply, it is reachable. This is the final phase in which anything at all can be agreed. The day it becomes self-sufficient is also the day every condition ends that we failed to build in beforehand.

What can actually flow back across the distance

The answer sits closer than it first appears. Sending material back is the most expensive movement this enterprise contains. There is, however, one cargo whose transport costs almost nothing.

A settlement beyond Earth is forced to solve problems that nobody on Earth has to solve under comparable pressure. It must cycle air for years with nothing arriving to replace it. It must recover water until losses approach zero. It must grow food on minimal area. It must develop medicine for bodies operating under low gravity. It must make building materials from whatever lies outside the door.

Every one of those solutions is immediately useful on Earth, and useful exactly where the need is greatest. Dry regions, damaged soils, places without dependable supply. The people who pay for the departure and stay behind are precisely the group for whom this knowledge makes the largest difference.

That is the return which survives the distance. It consists of knowledge, because knowledge travels as a signal rather than as freight. It has to be open and permanent, meaning no licence barrier and no expiry. And it has to enter the contracts now, while the money still flows and the recipient still answers.

The window is still open

We are standing before a handover that offers no second chance. Every generation before us could rely on its descendants remaining in the same space where claims can be raised. We are giving up that certainty, and we are giving it up voluntarily, because it is exactly what we want.

I consider the open return of all knowledge earned out there to be the only consideration that outlasts such a separation, because it needs no enforcement and presumes no reach. Anyone who knows a second one that works without compulsion should name it.

Homepage: https://planet-futures.org