NASA still maintains some of the Voyager spacecraft code from the 70s era

NASA operates the Voyager spacecraft using assembly language code written for specialized 1970s-era processors, not the commonly cited Fortran, with total onboard memory comparable to a small modern image file. While the popular narrative depicts aging engineers in their 80s as the only ones who understand the code, the current flight team at JPL is smaller and mostly younger, though the real challenge lies in lost or fragmented documentation from decades of office moves and the difficulty of maintaining systems designed nearly 50 years ago. The underlying problem is more about incomplete records and institutional knowledge gaps than the programming language itself or the age of current engineers.