By March 2026, the best public figure for Canada’s total investment in the International Space Station is about C$3.7 billion. That number is not drawn from a single federal webpage that lays out the entire history in one neat line. It has to be assembled from the strongest official figures in the public record: about C$2.2 billion spent from the beginning of Canada’s ISS effort through 2017, up to C$379 million announced in Budget 2016 to extend participation to 2024, and C$1.1 billion announced in Budget 2023 to continue participation to 2030.