While Neil Armstrong and Buzz Aldrin were concluding humanity's first Moonwalk, the Soviets made an oopsie: their Luna 15 probe crashed into the Moon. The crash site was about 530 miles from the Sea of Tranquility.
On July 21, 1969, people around the world were glued to TV images of the Apollo 11 astronauts on the Moon. But space specialists were also tracking the Soviet Luna 15 probe, which had launched three days before the Apollo mission. Luna 15 was just one in a long line of Soviet probes that had made it to the Moon—Luna 2 was the first human-made object to crash into the Moon way back in August 1959 (other Luna missions included the first lunar flybys, first photographs of the far side of the Moon, and so on).
Robots and Radios
Luna 15's primary mission, although the Soviets didn't admit it at the time, was to land, collect samples of the lunar surface, and then return the sample via a small capsule. If that had worked, the sample would have been the first robotic return of lunar material, scoring a PR victory for the Soviet space program. Of course, that didn't work out.
Frank Borman on the Apollo 8 mission. Image courtesy of NASA.
The timing of the Luna 15 mission was a little freaky for NASA, as it would orbit the Moon at the same time as Apollo 11, and both would be transmitting radio signals to Earth. NASA enlisted Apollo 8 commander Frank Borman to get some intelligence on Luna 15's flight plan; Borman was friendly with the Soviets, and had just returned from a trip to the USSR (indeed, he was the first astronaut to do so). NASA's concern was that Luna 15 might introduce radio interference if its orbit was too close to that of Apollo 11. Borman's info from the Soviets confirmed that it wouldn't be a problem, and a worldwide sigh of relief followed.
Luna 16 image courtesy of NASA.
The Luna 16 mission (pictured above) later succeeded where Luna 15 had failed. Luna 16 was the first robotic probe to land on the Moon and return a sample to Earth; the sample came back on September 24, 1970. It brought home 101 grams of lunar regolith. (The Apollo 11 astronauts brought back well over 20 kilograms of material, though it was a dramatically larger and more expensive mission. It's notable that in 1970, the Soviets had robots capable of doing this work—that's a huge achievement.)
Drama of the Highest Order
There is an audio recording of scientists monitoring the Luna 15 mission (spanning July 19-21, 1969). The audio was released in 2009 to coincide with the 40th anniversary of the Moon landing. The audio is from British scientists at the Jodrell Bank Observatory, and features astronomer Sir Bernard Lovell and others who were listening in to both American and Soviet radio transmissions via the Lovell radio telescope.
The recordings span various sessions, with the first drama being a Luna 15 course change on Sunday, July 20. That course change brought it closer to the landing site of Apollo, which was a bit of a shocker given the Soviet flight plan previously provided. The next dramatic moment came on July 21 when the probe began to descend; it suddenly became clear to Lovell's team that Luna 15 was designed to land, not just take orbital photos as the Soviets had indicated. This surprised everyone in the listening room, and you can hear them discuss a rumor from a source in Moscow suggesting that the probe was designed to return a sample. The team proceeds to listen as the probe lands, exclaiming "It's landing!" and "Phew!" The very last line is classic: "I say, this has really been drama of the highest order!"