NASA sent two wooden capsules to the Moon in 1962, but they missed and may still be orbiting the Sun today

Getting a rocket to the Moon was only half the problem. Engineers also had to work out what would happen once a spacecraft got there.

In the early 1960s, NASA’s Ranger programme was designed to send probes towards the Moon, capturing images as they approached the lunar surface and collecting scientific data before impact. Some of the spacecraft carried separate capsules which included a seismometer, an instrument designed to detect ground vibrations. To protect it, engineers placed the capsule inside a sphere made of balsa wood.

According to NASA’s description of the Ranger Block II design, the wooden sphere formed part of a system intended to help the seismometer capsule survive a low-speed impact on the Moon. The sphere size was roughly 65 centimetres across. It was a practical solution to a difficult program that how an instrument reaches the lunar surface intact enough to do its job.


The plan was to make the capsule separate from spacecraft near the Moon, slow it down and hence hit the surface. The seismometer could then have helped scientists investigate the Moon’s interior. But the first missions using this design did not go as planned.

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Two probes missed their destination

Ranger 3 lifted off on January 26, 1962. A string of malfunctions sent it off course, and it flew past the Moon without landing. NASA’s mission record says it ended up in orbit around the Sun.

Ranger 5 followed on October 18, the same year. Its power system failed after launch, so the spacecraft could not make the course correction it needed. According to NASA’s Ranger 5 history, it passed the Moon at about 450 miles (724 kilometres) and then also settled into solar orbit.

Neither mission succeeded in its primary goal of placing a seismometer on the Moon. Instead, both capsules missed their target and may have spent decades orbiting the Sun, far beyond what their designers intended. Built to cushion scientific instruments on impact with the lunar surface, the wooden capsules were never meant to survive a journey through interplanetary space.

The science was not a complete loss

Ranger 3 returned useful information before the mission failed. NASA records that it provided with the first measurements of interplanetary gamma-ray flux, a data that contributed to early efforts to study high energy radiation in space.

Before Ranger 5 batteries were depleted and its system stopped working, it sent back about four hours of data from its gamma-ray experiment. The results did not compensate for the missed lunar landing, but they show why a failed spacecraft is not always a total scientific loss.

NASA continued developing The Ranger series, and later missions finally returned with close up images of the Moon. Ranger 7, launched in 1964, succeeded where the earlier attempts had failed, transmitting thousands of photographs before impacting the lunar surface.

The wider programme’s progress depended on learning from missions that fell short. The wooden capsule was one element of that work: a way to get a fragile instrument through the last, hardest part of a lunar journey.

A small piece of engineering with a long afterlife

In a 2017 report, Scientific American noted that the wooden-cased capsules aboard Ranger 3 and Ranger 5 are believed to still be orbiting the Sun.

However, there has been no recent sighting or confirmation of their condition. NASA’s mission records document the spacecraft’s trajectories, while the belief that the wooden capsules continue to travel through space stems from historical accounts of their design and the missions’ eventual paths.

The wooden spheres were never intended to be a defining feature of NASA’s lunar programme. They were a practical engineering solution to a specific challenge. Yet their story highlights how space exploration has been shaped not just by landmark landings, but also by the unconventional materials and experimental designs engineers used along the way.