A chapter-by-chapter introduction to how spacecraft communicate, ordered from first radio contact to interplanetary networks.
Most writing on space data systems assumes you already speak the language. Blue Books are precise but unforgiving; textbooks slice the radio link and the application layer into separate disciplines. The Primer is a different shape — a single arc, told as a journey, that earns each acronym before introducing it.
You begin with two machines that cannot see each other, and end with a network of autonomous systems coordinating across light-minutes. Every chapter starts from a picture — an antenna, a packet, a station, a fleet — and works outward to the standards that make the picture true. By the end of a chapter, the standard is not a specification; it is the only thing the picture could have become.
Read it in order, or follow your curiosity through the sidebar — each chapter re-explains anything it needs from earlier. When a specification lands on your desk and you want intuition for what it is doing, the field reference links every entry back to the chapter that explains why it had to exist.