The Apollo program used several television cameras in its space missions in the late 1960s and 1970s; some of these Apollo TV cameras were also used on the later Skylab and Apollo–Soyuz Test Project missions. These cameras varied in design, with image quality improving significantly with each successive model. Two companies made these various camera systems: RCA and Westinghouse. Originally, these slow-scan television (SSTV) cameras, running at 10 frames per second (fps), produced only black-and-white pictures and first flew on the Apollo 7 mission in October 1968. A color camera – using a field-sequential color system – flew on the Apollo 10 mission in May 1969, and every mission after that. The color camera ran at the North American standard 30 fps. The cameras all used image pickup tube