Hi again —

The last note was about why Orbital Roster exists. This one is about a mental model I keep coming back to, and that I just built into the site: New Space is four operating zones connected by one value chain. Once you see it, the whole sprawling industry snaps into focus.

The value chain: Upstream → ISAM → Downstream

Every space activity sits somewhere on a three-step chain.

• Upstream — design, manufacturing and launch. The rockets and the spacecraft buses. This is the part everyone pictures.
• ISAM — in-space servicing, assembly and manufacturing: refueling satellites, repairing them, building structures in orbit instead of folding them into a fairing. The U.S. now has a national strategy and implementation plan for it, and NASA ran flagship demonstrators like OSAM-1. It's the step that turns satellites from disposable into maintainable. (NASA ISAM · national strategy · OSAM-1)
• Downstream — the data platforms, apps and markets that sit on top: Earth-observation imagery, position-navigation-timing, communications. The part most people actually use, usually without knowing it. (PNT / GPS)

The interesting companies are increasingly the ones bending the chain — making the middle step (ISAM) real.

The four operating zones

The second axis is where in space you operate. The physics, the customers and the hard problems change completely as you move out.

1. The Earth-orbital economy. LEO/MEO/GEO: launch, satcom, PNT, Earth observation, and now tourism. It's also where the housekeeping problems live — orbital debris and space-traffic management — which is why there are now whole offices devoted to not crashing into each other. (NASA Orbital Debris Program Office · U.S. TraCSS · ESA Space Debris Office)

2. Cislunar transit & infrastructure. The volume between high Earth orbit and the Moon, including the Lagrange points and staging orbits like the Near-Rectilinear Halo Orbit that NASA's Gateway will use. This is the new "highway" — navigation, comms, space-domain awareness, and the tugs, depots and waystations that move things along it. (NASA on the Gateway NRHO)

3. Lunar orbit & surface. Landers, rovers, power and comm relays, habitats — and the one that changes the economics of everything: ISRU, using local resources like polar water ice for life support and propellant instead of hauling them from Earth. (NASA ISRU)

4. Deep space. Mars, asteroids, the Sun-Earth Lagrange points; planetary defense and far-space telescopes; the autonomy, radiation shielding and deep-space communications that make any of it possible — increasingly with ISAM to assemble observatories too big to launch in one piece.

Why it matters for the map

These two axes are the cleanest way I've found to ask "who actually does what" in space. So I added both to Orbital Roster: you can now filter the directory by operating zone and by value-chain stage, alongside sector and location.

Try it: filter the companies directory to Lunar orbit & surface and you get exactly the firms betting on the Moon — Interlune, Intuitive Machines, Astrolab, Honeybee — next to the launch providers that get them there. Filter to ISAM and you find the servicing-and-assembly companies quietly building the missing middle of the chain.

The whole live map is at orbitalroster.com.

Speaking of who does what — here's how the publicly-traded space companies moved this past week:

Space stocks — 7-day movers

Delayed market data via Yahoo Finance — for information only, not investment advice.

More soon — and thank you, genuinely, for reading.

— Elio @thespacemechanic

References & further reading

• NASA — In-Space Servicing, Assembly, and Manufacturing (ISAM): https://www.nasa.gov/nexis/isam/
• White House OSTP — National ISAM Strategy (via SpaceNews): https://spacenews.com/white-house-releases-in-space-servicing-strategy/
• NASA — OSAM-1 mission: https://www.nasa.gov/mission/on-orbit-servicing-assembly-and-manufacturing-1/
• NASA — The Gateway's Near-Rectilinear Halo Orbit: https://www.nasa.gov/centers-and-facilities/johnson/lunar-near-rectilinear-halo-orbit-gateway/
• NASA — In-Situ Resource Utilization (ISRU): https://www.nasa.gov/mission/in-situ-resource-utilization-isru/
• NASA — Orbital Debris Program Office: https://orbitaldebris.jsc.nasa.gov/
• U.S. Office of Space Commerce — Traffic Coordination System for Space (TraCSS): https://space.commerce.gov/traffic-coordination-system-for-space-tracss/
• ESA — Space Debris Office: https://www.esa.int/Space_Safety/Space_Debris/About_the_Space_Debris_Office
• U.S. Government — GPS / position, navigation & timing: https://www.gps.gov/