Between 1966 and 1968, NASA launched seven unmanned spacecraft toward the moon. Two of them crashed, but five of them successfully landed on the lunar surface. Managed and operated by the Jet Propulsion Laboratory in Pasadena, they were designed to show that it was possible to soft-land something on the moon, paving the way for human beings to follow. Until Surveyors got there, no one knew for sure if it was even possible for people to stand on the moon: was the surface solid? Or was it buried in soft dust miles thick that would swallow up man and machine?
Unlike the manned Apollo spaceships, the Surveyors did not go into orbit around the moon before landing. Like current unmanned ships to Mars, they took a direct route. Hurtling toward the moon, they fired their retrorockets for landing barely three minutes before they would otherwise smash into the surface. The first attempt, Surveyor 1, on June 2, 1966—forty-five years ago now—became the first American space probe to land on another world. It landed in the Sea of Storms, the same place where the Russians had previously landed a probe.
The Russians had beaten us to the moon with an unmanned probe by three months. Their Luna 9 probe had become the first craft to ever land somewhere beyond Earth. The Luna 9 probe had touched down on February 3. But it survived only three days. During its brief life, it transmitted a total of 9 images, including 5 panoramas of the lunar surface.
In contrast, the Surveyor 1 continued transmitting information to Earth for seven months, from its landing on June 2 until it finally stopped working on January 7, 1967. It sent over 11,000 images of the lunar surface back to the scientists in Pasadena.
The next American probe, Surveyor 2 failed to decelerate and crashed into the moon on September 20, 1966. It was followed by Survey 3, which landed once again in the Sea of Storms region of the moon. It managed to send back only around 6300 pictures of the moon’s surface. The rocks near its landing site were very reflective and had confused the lunar descent radar, so the engines didn’t shut off like they were supposed to. As a result, Surveyor 3 bounced twice on the lunar surface. The first bounce sent it back up 35 feet, while the second bounce sent it 11 feet. The bouncing damaged the camera slightly. Then, after the extreme cold and darkness of the first lunar night shut the solar powered craft down, it never woke up again.
Surveyor 3 was the first spacecraft to be equipped with a mechanical scoop, which allowed it to dig into the lunar soil and to perform some simple analysis.
Surveyor 3 stands out from the other seven Surveyor missions because the second manned landing on the moon, Apollo 12, purposely landed within about six hundred feet of Surveyor 3 on November 19, 1969. Pete Conrad and Alan L. Bean were the astronauts aboard that Lunar Module (with Conrad becoming the third man to walk on the moon, followed by Bean as the fourth). Conrad and Bean remain the only people to have ever caught up to and touched one of our robotic spacecraft on another world. So close had they landed, the Surveyor probe was coated with dust blown up by their Lunar Module’s descent engine. Conrad and Bean carefully examined the probe and photographed it. They also removed several pieces from it, including its television camera, which they brought back with them to Earth. Surveyor 3’s camera is now on display in the National Air and Space Museum of the Smithsonian Institution in Washington DC.
In 2009 the Lunar Reconnaissance Orbiter (launched on June 18, 2009), an American satellite still in operation in orbit around the moon, extensively photographed the Surveyor 3 landing site. Besides imaging the Surveyor probe, it imaged the descent stage of the Apollo 12 lunar lander. Even the astronauts’ foot prints can be seen around the two vehicles. With no air, wind, rain or running water on the moon, those footprints should remain visible for thousands of years.
Following Surveyor 3, four more attempts to land Surveyor probes followed. The next attempt came on July 14, 1967, but it crashed. After that, however, there were nothing but successful landings. Surveyor 5 reached the Sea of Tranquility on September 11, 1967, Surveyor 6 reached Sinus Medii (Bay of the Center) on November 10, 1967 and the last Surveyor touched down near the crater Tycho on January 10, 1968. During Christmastime of that same year, Apollo 8 took three astronauts to the moon, where they circled ten times in orbit and returned safely. The next year, on July 20, human beings at last walked upon the soil where the five successful Surveyors had blazed a trail.