This article documents lessons learned from experiences in NASA's Apollo and Skylab Programs. These lessons are valuable for future missions, NASA exploration, and commercial flights. The article describes the author's experiences as an electrical engineer supporting design, testing, and mission operations during various Apollo, Skylab, and Apollo Soyuz Test Project missions. Incidents include the Apollo 13 oxygen tank explosion, the Apollo 14 docking close call, the Apollo 15 propulsion system electrical short, the Apollo 10 inadvertent lunar module abort, the Skylab 4 loss of control for entry, the Apollo Soyuz Test Project crew ingestion of toxic propellant, the Apollo 7 AC bus short, and the Apollo 16 Lunar Rover Vehicle anomalies. Lessons from two incidents on uncrewed flights, the Apollo 4 launch pad instrumentation electrical noise and the Mars Viking test stand electrical noise problem, are also included because of their direct relevance to human spaceflight.