Now in color

Apollo 10 transmitted the first color television signal from the CSM, filming everything from the docking procedure to connect the LM and CSM to the surface of the Moon from lunar orbit. The mission also included the first camera “viewfinder” for the astronauts — a small black-and-white television monitor, comprised largely of off-the-shelf components, featuring a 2 by 2.75-inch (5 by 7 cm) screen.

The Apollo color camera was not state of the art in its design — in fact, it was based on a camera first developed in 1940 by CBS, called a color-wheel camera. As its name implies, a color-wheel camera includes a spinning filter wheel behind the lens, which captures separate images in red, green, and blue through filters. Back on earth, these separate images were combined into one full-color image.

This camera was chosen for its low weight and power consumption, but its signal didn’t mesh with the standard format of American color TV, NTSC color. So the television signals were sent from the tracking stations to NASA’s Mission Control Center in Houston in black and white, where the final color conversion was made for public broadcast in NTSC format.

TV from the Moon

Even though the CSM was equipped with a color camera at the time, Apollo 11’s transmissions from the Moon were in black-and-white. In an interview with TVTechnology.com, NASA employee Dick Nafzger said the black-and-white format was used during the first lunar landing to ensure good signal to noise — in other words, it increased the chances that the tracking stations could lock on to the signal and relay the best possible image. So Neil and Buzz were recorded in black and white on the surface, while color TV was transmitted from the CSM. It wasn’t until after the success of Apollo 11’s TV transmissions, Nafzger said, that NASA felt confident that color TV, which requires larger bandwidth, could be sent from the Moon.

Apollo 11’s initial lunar TV transmissions were recorded with the camera mounted on the LM’s descent stage. As he exited the LM’s hatch, Armstrong pulled a lanyard to expose the camera and Aldrin powered it on from the cockpit to capture the historic first steps. The signals were sent via the LM’s antenna to NASA tracking stations in Goldstone, California and Canberra, Australia, and also to the Parkes radio telescope in New South Wales, Australia. The latter, with its nearly 210-foot (64 m) diameter dish, provided the highest-quality signal of the three and was used as the main source of the first broadcast.

After those famous first steps, the camera was moved from the LM to a stand to record both astronauts at work. It remained attached to the LM via a power cable, but that power would abruptly cut off at the end of the EVA when the ascent stage launched. Later missions, however, would carry the additional equipment necessary to continue recording and transmitting after power from the LM to the camera had been severed.

Though that first TV broadcast from the Moon had its hitches, overall it was a resounding success. The carefully wrought technology designed for the harsh lunar landscape performed admirably, bringing the world together on this historic mission and creating a live window as men stepped out into the previously unknown.