J Mission

Glossary

The space economy runs on jargon. Here’s the plain-English version of every term we use — from orbits and acronyms to the way the indexes are built. Anywhere these words appear on the site, a dotted underline means you can hover or tap for the definition.

Spaceflight basics

Cislunar: The region of space between Earth and the Moon, including lunar orbit — the arena J Mission tracks.
Cost per kilogram to orbit · $/kg · cost to orbit: The price to launch one kilogram to orbit — the headline measure of how affordable space access is.
Launch cadence: How frequently rockets launch — the pace of spaceflight.
NET (No Earlier Than): A launch's earliest possible date and time — it can, and often does, slip later.
Payload: The cargo a rocket carries to orbit — a satellite, spacecraft, or supplies.
Reusability · reusable · reuse: Recovering and reflying rocket hardware instead of throwing it away — the key to cheaper access to space.
Upmass · mass to orbit · upmass to orbit: The total mass of payloads launched to orbit — a measure of how much we're actually lifting into space.

Orbits

GEO (Geostationary Orbit) · Geostationary Orbit · Geostationary: About 35,786 km up, where a satellite circles in step with Earth's spin and appears fixed over one spot.
GTO (Geostationary Transfer Orbit) · Geostationary Transfer Orbit: An elliptical 'on-ramp' orbit used to boost a satellite up toward geostationary orbit.
LEO (Low Earth Orbit) · Low Earth Orbit: The region a few hundred kilometres up, where the ISS and most satellites fly.
MEO (Medium Earth Orbit) · Medium Earth Orbit: Between LEO and geostationary orbit; home to navigation constellations like GPS.
SSO (Sun-Synchronous Orbit) · Sun-Synchronous Orbit · Sun-synchronous: A near-polar orbit that passes over each spot on Earth at the same local time — ideal for imaging.

Commercial & civil space

Anchor tenant: A large, reliable customer — often a government — whose guaranteed business makes a venture financially viable.
Commercial space station: A privately owned and operated orbital station — the planned successor to the government-run ISS.
Free-flyer · free flyer: A space-station module that orbits on its own rather than being attached to a larger station.
ISRU (In-Situ Resource Utilization) · In-situ resource utilization · In-Situ Resource Utilization: Making fuel, water, or oxygen from materials found in space (like lunar ice) instead of shipping them from Earth.
PNT (Positioning, Navigation & Timing) · Positioning, Navigation, and Timing: Location and timing signals — essentially GPS — here being built for the Moon.
Propellant depot · propellant depot: An orbiting 'gas station' that stores fuel so spacecraft can top up before heading farther out.
Propellant transfer: Moving rocket fuel between vehicles or depots in orbit — needed to refuel for deep-space trips.
Pure-play (space company) · pure play: A company whose business is mostly space, not a big conglomerate with a small space side.
Self-sustaining (economy): An economy that pays for itself with private revenue, without relying on government funding to survive.

Programs, vehicles & missions

Artemis: NASA's program to return humans to the Moon and build a sustained lunar presence.
CLPS (Commercial Lunar Payload Services) · Commercial Lunar Payload Services: NASA's program that pays private companies to deliver cargo to the Moon.
Falcon 9 · Falcon 9: SpaceX's partially reusable workhorse rocket — the most-flown orbital launcher in the world.
ISS (International Space Station) · International Space Station: The continuously crewed laboratory in low Earth orbit, occupied since 2000.
LANS (Lunar Augmented Navigation System) · Lunar Augmented Navigation System: A planned satellite network providing GPS-like positioning at the Moon.
LCRNS (Lunar Communications Relay & Navigation Systems) · Lunar Communications Relay and Navigation Systems: NASA's planned set of relay satellites carrying comms and navigation to the Moon.
Starship: SpaceX's fully reusable super-heavy rocket, designed to slash the cost of reaching orbit and beyond.

Indexes & finance

Breadth: The share of companies that are up since tracking began — how broad the move is.
Chain-linked · chain-link · chain linked · chain-linking: Splicing an index across membership changes (like a new IPO) so additions don't cause an artificial jump.
Composite index · composite: A single score blended from several different measures.
Dispersion: The spread between the best and worst performers in the basket.
Equal-weight · equal-weighted · equally weighted: Giving every company the same weight, so one giant doesn't dominate the average.
Index: A single number that tracks a basket of things over time, set to a starting value for easy comparison.
Log scale · log scale · logarithmic: A chart axis where each step multiplies (100 → 200 → 400), so big percentage moves look comparable across the range.
QQQ (Nasdaq-100): A fund tracking the Nasdaq-100, a tech-heavy US stock benchmark.
Rebased to 100 · rebased: Setting the starting point to 100 so the value reads directly as percent change — 120 means up 20%.
S-1 filing · S-1: The financial document a company files with US regulators before going public — a cited primary source.
SPY (S&P 500): A fund tracking the S&P 500, the broad benchmark of large US companies.
YoY (year-over-year) · year-over-year · year over year: Compared with the same point one year earlier.

Data & methods

AT Protocol · AT Proto · ATProto: The open social-web standard behind Bluesky — J Mission publishes there, never on X.
GCAT: The General Catalog of Artificial Space Objects — an authoritative launch and payload catalog kept by astronomer Jonathan McDowell.
GDELT: A global project that monitors world news; used here to gauge how much coverage spaceflight is getting.
Launch Library 2: A free, community-run database of worldwide rocket launches, run by The Space Devs.
Min-max normalization · min-max normalized · min-max normalization · distance-to-range: Rescaling each measure to a 0–100 range over its own history so no single volatile number dominates a composite.
OECD / EC-JRC handbook · OECD/JRC · OECD / JRC · EC-JRC · OECD: The standard recipe for building a composite indicator: a stated framework, explicit normalization, and transparent weights.
Space-Track · Space-Track: The US Space Force's official catalog of objects in orbit.