Guides
How spy satellites and orbits really work, and the stories people tell about what else might be up there. Written in plain English, with sources, by the maker of Celestrike.
Satellites and orbits
How spy satellites work
What limits what a spy satellite can see: mirror size, altitude, sunlight, cloud and how often it passes over. Real figures, no maths needed.
Orbital mechanics without the maths
How orbits really work, in plain English: why higher is slower, why ground tracks drift, what inclination does and why changing orbit costs so much.
Low Earth orbit
Low Earth orbit explained: how high it is, how fast satellites go round, why imaging, the ISS and Starlink live there, and the price of drag and debris.
Sun-synchronous orbit
How a sun-synchronous orbit uses the Earth's bulge to pass over every place at the same local time, and why imaging and radar satellites use it.
Geostationary orbit
Geostationary orbit explained: why 35,786 km makes a satellite hang over one spot, what it is used for, and why it is no place for sharp pictures.
The unexplained
The Black Knight satellite
The Black Knight satellite legend traced claim by claim: Tesla's signals, long-delayed radio echoes, a 1960 dark satellite and a 1998 photo.
Black triangle UFOs
The black triangle UFO, from Rendlesham Forest to the Belgian wave and the Phoenix Lights: what witnesses reported and the documented explanations.
Comparisons
Games like Kerbal Space Program on iPhone and Android
Kerbal Space Program is not on phones. Three mobile games that scratch the same itch, what each one is about, and which to pick.
Celestrike vs Kerbal Space Program
Both games take real orbits seriously, but one is a rocket-building sandbox and the other a satellite strategy game. How they compare, point by point.
Celestrike vs XCOM 2
XCOM 2 is turn-based squad tactics against an alien occupation; Celestrike is satellite espionage where the unexplained creeps in. How they compare.