On July 20, 1969, Apollo 11 beamed video from the moon back to Earth, live. Here's how they did it.
"One small step for a man," would not be the iconic line it is today if it hadn't been captured on video, for millions of Earthlings to watch as the first human set foot on the moon. As the NASA documentary below explains, shooting live video on moon was "crucial for credibility of the mission," but posed a serious logistical challenge. Westinghouse engineer Stan Lebar, who was the program manager of the Apollo TV Lunar Camera project, was tasked with developing energy-efficient cameras that would withstand temperatures of plus or minus 250 degrees. They ran on seven watts of power, the amount required to illuminate one Christmas tree light, Lebar says. The resulting TV broadcast was an amazing audiovisual achievement -- a giant leap in real time.
In the short video clip below, Lebar introduces the two cameras used on the Apollo 11 mission: the color TV camera that shot from the command module and the black and white camera that captured Neil Armstrong's "first monumental steps."
In 2009, NASA restored the video footage of the missions and recently made HD versions of the new clips available online. In the documentary above, Dick Nafzger, the restoration team leader, explains, "There's nothing being created. There's nothing being manufactured. We're restoring and extracting data that's in the video." A short montage, below, reveals the breathtaking, sharper footage of Apollo 11's historic journey.
Beaming the footage back to the millions of viewers back on Earth, live, was yet another challenge. The signal was transmitted from the moon to stations in Australia and California, converted to a standard broadcast format, and transmitted to Houston and then broadcast on TV. NASA diagrams show the setup:
Ironically, the groundbreaking broadcast only encouraged skeptics who postulate a "moon landing hoax." It doesn't help that the original recordings of the signal from space (before it was converted for broadcast, degrading the image quality and losing other data) have disappeared. NASA documents the unsuccessful search for the missing Apollo 11 tapes in detail in a report:
Perhaps there are no clear answers. All that can be said with any certainly is that NASA and the Goddard Space Flight Center followed all procedures in storing the Apollo telemetry tapes, the search team has concluded. After reviewing their content and determining that Apollo program managers no longer needed the data, Goddard personnel shipped the telemetry tapes to WNRC for storage. Over the ensuing years, Goddard recalled them and either reused the one-inch tapes to meet a network shortage in the early 1980s or disposed of them because of the high cost of storing them. At no time did anyone recognize the unique content on roughly 45 tapes containing the actual moonwalk video. At no time did anyone ever consider what could be possible nearly 40 years into the future with the advent of new technology.
The broadcast tapes provided enough material to work with, however, and the restoration team managed to upgrade 15 clips from the landing. More than 40 years later, it's still amazing to look back at the technology that made the broadcast possible: a live signal from the moon, 250,000 miles above Earth, flickering on TV screens in living rooms around the world.
All images and videos courtesy of NASA.
NASA documentaries via YouTube user overloadinformation.