Luna 9 – The First Lunar Soft-Landing

The Soviets claimed many firsts in their space race with the United States. First person in space (and orbit), first woman in space, first satellite in orbit. Most would agree, however, that the United States accomplished the biggest first by being the first (and to this day, only) to land humans on the Moon. But the Soviet space program did claim a important lunar firsts of their own: the first lunar fly-by, the first pictures of the far side of the Moon, and the first soft-landing of a probe on the Moon’s surface.

Luna 9 model

Luna 9 model – Source: NASA.gov

On February 3, 1966, the Soviet spacecraft, Luna 9, completed its 3-day journey to the Moon and landed safely on the lunar surface. This ‘soft-landing’ (as in: not a crash-landing) marked the first time a human-made craft survived a landing on any body other than Earth. The successful landing was accomplished by a number of systems that all had to work flawlessly: inflation of an airbag system to cushion the impact, the retrorocket burn to slow the craft, and the deployment of a contact sensor to determine the precise altitude above the Moon. At an altitude of 5 meters, the contact sensor was triggered: engines were shut off and the landing capsule was ejected. Though the craft’s speed was reduced significantly, it still impacted the Moon at a velocity of 22 km/hr (13.7 miles per hour). The airbags allowed the capsule to safely bounce several times before it came to rest.

Following landing and an approximately four-minute pause, four petals that served as the craft’s shell unfolded and stabilized the probe the ground. Antennas were deployed and the craft’s television camera began recording the lunar landscape, capturing the first views ever seen from the surface of the Moon. In addition to the images and radiation readings, the landing also disproved models that suggested that the Moon was covered in a thick layer of dust that would cause any craft (and eventually, persons) who landed there to sink.

One of the first images taken from the Moon's surface

One of the first images taken from the Moon’s surface – Source: Smithsonian National Air and Space Museum

Luna 9’s batteries lasted for three days after landing, during which the craft was able to record a number of panoramic images and beam them back to Earth.

Joddrell Bank, the British observatory located at the University of Manchester, had been paying close attention to the race between the Soviets and the United States. Scientists there not only tracked Luna 9’s progress, but they also recognized the type of signal that the craft was beaming back. They deployed the correct receiving equipment and were able to acquire the lunar images and publish them before the Soviets even managed to see them. There’s still debate as to whether the Soviet scientists let this happen on purpose or not.

While the Soviets soft-landed their craft first, the United States wasn’t far behind. Three months after Luna 9, the US landed Surveyor 1 on the Moon’s surface. Various robots continued to explore the Moon, paving the way for the humans that followed them. After the United States stopped sending astronauts to the Moon in 1972, the next soft-landing wouldn’t occur until 2013, when the Chinese lander Chang’e-3 brought the rover Yutu to explore our celestial neighbor.