Optimizing SGP4 Satellite Orbit Propagation with Zig Programming Language

astroz is now the fastest general purpose SGP4 implementation I'm aware of, hitting 11-13M propagations per second in native Zig and ~7M/s through Python with just pip install astroz

The key insight is that SGP4 is a deterministic algorithm: given the same inputs, it always produces the same outputs. This makes it a perfect candidate for compile-time evaluation

Zig's comptime feature allows us to precompute these expensive operations at compile time, essentially baking the results directly into the binary

By using SIMD (Single Instruction, Multiple Data), we can process multiple satellite positions simultaneously

The memory layout matters more than you might think. Traditional implementations often store satellite data in arrays of structs, but for vectorized operations, structs of arrays is often better