Primer

Volume X · 01 · Why LEO

01 · The bet

Why LEO

GEO is one sat for a continent and 240 ms of light. LEO is the opposite: a short hop, a quieter radio, and many birds so someone is always above you.

In English

GEO hangs in one spot and is far. LEO is nearby: quieter radios, tiny ping, and a sat that vanishes over the horizon. If you want always-on from LEO, you need a flock.

Try this
Toggle LEO / MEO / GEO. Read RTT, path loss, and how many birds.
Keep this
LEO: short light, many sats. GEO: one sat, long light.

Lab · close, fast, many

GEO is one satellite for a continent, 240 ms of light, a loud radio. LEO is the opposite: dimmer path loss, a few milliseconds, and you need a flock because each bird races over the horizon.

One-hop RTT
45.2 ms
Path loss (12 GHz)
191 dB
Birds for always-on
~40 per plane

ISS, Starlink, Earth observation

Free-space path loss grows 20 log(r). GEO is ~40 dB worse than 550 km LEO at the same frequency, which is why user terminals can be a pizza box instead of a driveway.

The “birds for always-on” count is a one-plane sketch. Real shells mix inclinations so mid-latitudes are not starved. That is Volume X’s flock lab.