Zond 5: In 1968 Two Soviet Steppe Tortoises Beat Humans To Orbiting Around The Moon

The 20th Century had its fair share of ups and significant downs, but an absolute highlight has to be how humanity went from being a largely ground-based species to one that can fly and leave the planet to visit others.

The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.

A huge driver of this progress was not just the pursuit of knowledge, or doing things "not because they are easy, but because they are hard", but to crush the competition in the space race. The US and the Soviet Union raced to send humans into space, around the planet, and to the Moon, slipping ahead of each other at various stages.

In March 1966, the Soviet Union became the first to send a spacecraft around the Moon, with the launch of Luna 10. The satellite, and the Luna 12 which followed, contained spectrometers to study the lunar surface and gamma radiation, and was not crewed. As well as achieving the first orbit of the Moon, it nabbed up another title.

"On 3 April 1966, Luna 10 was put into a selenocentric orbit -- becoming the moon's first man-made satellite," NASA explains. "It had an apogee of 1015 km, a perigee of 350 km, an inclination to the equatorial plane of 72 degrees. The orbital time was 2 hours 58 minutes. The Luna 12 orbit was: apogee 1740 km, perigee 100 km, inclination 20 degrees, orbital time 3 hours 25 minutes."

After the mission was over and the satellite powered down, it orbited for an unknown amount of time before crashing down to the lunar surface. 

Both the Soviet Union and the USA wanted to go further than this, and return a spacecraft to Earth after sending it around the Moon, as well as landing on it. The Soviet Union had two separate programs attempting to achieve this aim, with the Saturn-V class N1 Moon rocket attempting to place a human on our natural satellite, and the Zond program for attempting to circumnavigate the Moon. By the mid-60s, it wasn't looking too promising on this second front.

"The Zond was essentially a Soyuz spacecraft with the Orbital Module removed to save weight, replaced with a high-gain antenna and navigation instruments to enable lunar missions," NASA explains. "Although it used the greater lift capability of the Proton rocket with a new upper stage to send the spacecraft and two cosmonauts on a free-return circumlunar trajectory, that capability was not enough to actually place the Zond into lunar orbit."

In March 1968, the Soviet Union had a partial success with Zond 4. With this launch, they were able to take the spacecraft out to lunar distances (though not around the Moon) even if navigation system errors meant that a soft-landing back on Earth wasn't possible.

Later that year, in September, the Soviet Union tried again with Zond 5. This time, the spacecraft included a payload of animals, including two Russian steppe tortoises, and a selection of plants, wine flies, and worms.

"Zond 5 launched successfully on September 15, 1968, from the Baykonur Cosmodrome in Kazakhstan, and after a short time in a low Earth parking orbit, the Proton’s upper stage ignited for a second time to send the spacecraft toward the Moon," NASA explains. "After a 3-day journey, Zond 5 passed 1,950 kilometers above the Moon’s farside and began its trip back toward Earth."

These animals, which would surely have been a little confused at why the ground no longer stuck to its feet, survived the trip. Unlike the previous missions, Zond 5 was able to make it back to the Earth. Though the guidance systems failed, meaning that the mission did not make a soft landing in Soviet territory, the spacecraft capsule touched down safely in the Indian Ocean and recovered by Soviet sailors.

After being returned to Moscow, scientists found that the tortoises were in good health, though they had lost a little weight whilst in space. They were also completely unaware that they had become the first animals in history to circumnavigate the Moon, and then return to the Earth. Though they were unaware of the significance of this, the USA was not, and it pushed them ever further in the space race.

"The flight of Zond-5 caused concern in the U.S. that the Soviets would place cosmonauts aboard the next Zond and complete the first crewed circumlunar mission," NASA explains, adding that satellite images of another rocket in the Soviet Union added to fears they would be beaten to the lunar surface. "The apparently successful Zond 5 mission coupled with the photos of the Soviet lunar booster on the launch pad may have contributed to the decision to send Apollo 8 on its circumlunar mission in December 1968, bringing the Moon landing one step closer."