1. The platform as a stepping stone

Olaf Stapledon’s Star Maker imagines civilizations building ever-larger structures in space, each one a platform for the next. The keeper platform mission is modest by comparison, but the logic is the same. Before we can build a desktop on a captured rock, we should learn to build a desktop on something smaller and closer: a reusable servicer in LEO.

Entry 173 recommended the platform as the next step after the hybrid demo and a contact demo. This entry sketches what that platform mission would actually be.

2. What the platform does

The keeper platform is a small spacecraft, larger than the demo servicer but still modest, that performs three functions:

  • Host payloads. Provide power, data, and attitude control for customer experiments or small instruments.
  • Demonstrate attachment. Carry and deploy standard attachment interfaces that future desktop modules can use.
  • Test long-duration operations. Stay in orbit for months or years, proving the bus can support continuous service.

It is not a space station. It is a bus with a job.

3. Spacecraft sketch

  • Mass: 200–400 kg.
  • Power: 1–2 kW from solar panels.
  • Payload capacity: 50–100 kg across several attachment points.
  • Propulsion: small chemical or electric thrusters for stationkeeping and phasing.
  • Communications: high-bandwidth link to ground, plus inter-satellite links if needed.
  • Lifetime: 2–3 years before deorbit or replacement.

This is roughly the size of a large microsatellite or a small satellite servicing vehicle. It is big enough to be useful, small enough to launch as a secondary payload.

4. Payload ideas

  • A small compute node that processes data on orbit.
  • A storage experiment that tests radiation-tolerant memory.
  • A camera or sensor that images Earth, space debris, or other satellites.
  • A 3D printer that manufactures small parts in vacuum.
  • A deployable solar panel or radiator that tests attachment interfaces.

Each payload should be something that teaches the keeper how to support the desktop objective. Random experiments are not enough.

5. Business model

The platform can generate early revenue by hosting payloads for universities, government labs, and commercial companies that want flight heritage without building their own satellite. Pricing can follow the model from entry 157: a hosted payload slot costs a fraction of a dedicated mission.

The deeper value is operational experience. Running a platform teaches the project how to manage power budgets, thermal loads, data queues, and customer expectations. These lessons are essential for the desktop.

6. Relation to the desktop

The platform is the desktop in miniature. If the keeper can run a platform that hosts, powers, and communicates with multiple payloads, it has proven most of the non-capture parts of the desktop objective. The remaining step is to move that capability onto a larger, more permanent substrate: a captured rock or a dedicated cislunar structure.

What this changes

  • The keeper platform is defined as a 200–400 kg LEO servicer that hosts payloads and tests attachment interfaces.
  • It serves as both a revenue source and a learning platform.
  • It is the bridge between the demo missions and the full desktop objective.
  • The next leisure entry can estimate the cost and schedule of this platform mission.