Now that I have your attention…
When you think of animals that have been sent to space, what comes to mind? Humans of course, but maybe you also remember the first “higher primate” in space, Ham the Chimpanzee (or Enos, the first primate to orbit the Earth). Or perhaps the dog Laika — the first animal to orbit the Earth — comes to mind. And of course, we’ve sent mice and insects and other organisms into space in the name of research as well.
What probably doesn’t immediately come to mind, however, are tortoises. But tortoises were exactly what the Soviets decided should be among the first animals to circle the Moon.
The Soviet’s Zond (translated: probe) program consisted of two distinct objectives. The first missions, Zond 1, 2, and 3, utilized the 3MV planetary probe and were designed to explore Mars and Venus. Zond 1 and 2 failed en route to their respective objective targets, while Zond 3 captured photos from the far side of the Moon on its way out on a Mars trajectory, though the timing wasn’t such that it would encounter the red planet.
Zond 5 Tortoises. Credit: RKK Energia.
Fueled by the “Moon race” between the United States and the Soviets, the following Zond missions employed the Soyuz 7K-L1 spacecraft and were all focused on the Moon. Zond 4 reached a distance of approximately 300,000km (186,411 miles) from the Earth before returning. Its trajectory took it on a course 180-degrees away from the Moon, and there are conflicting stories as to whether or not the Soviets intentionally sent the spacecraft on that course, or if there was a malfunction. It re-entered Earth’s atmosphere out of the Soviet’s control and was remotely detonated at an altitude of 10-15km (6-9 miles), and a couple of hundred kilometers off of the coast of Africa.
Finally, Zond 5 launched on September 14, 1968. Aimed for the Moon, it contained a biological payload including wine flies, meal worms, plants, bacteria, and… two Russian tortoises. Zond 5 took a circumlunar trajectory, which means it looped around the Moon, but didn’t go into multiple orbits around it. Think of a big, lop-sided, figure-eight, with the Earth within a large loop and the Moon within a smaller one. This is very similar to the emergency trajectory that Apollo 13 took, following the disastrous malfunctions that plagued that craft on its way to the Moon.
The circumlunar trajectory of Apollo 13 - Credit: AndrewBuck
The tortoises spent a week in space before splashing down in the Indian Ocean. The tortoises reportedly lost 10% of their body weight during their trip, but remained active and showed no loss of appetite. These tortoises became among the first Earthly lifeforms to complete a lunar flyby and return safely to Earth, proving it possible, and paving the way for future vertebrates such as Neil Armstrong and Buzz Aldrin.
Scientists examining the Zond 5 tortoises. - Credit: Energia.ru
Zond 5 wasn’t the end of the line for our half-shelled cosmonaut friends; Zond 7 and Zond 8 each carried multiple tortoises. Tortoises then came out of a 5-year retirement to be sent up again, aboard Soyuz 20 in 1975. This time, they were in for the long-haul, spending a total of 90.5 days in space and consequently breaking the record for the longest amount of time an animal had spent in space. Finally, in February of 2010, the Iranian Space Agency sent up their first biological payload into a sub-orbital flight; aboard were two turtles.,
So now you know the story of tortoises in space. From being among the first animals to take a trip around the Moon, to breaking records for time in space, tortoises are very much a part of “animaled” spaceflight. Like all of the others that have made Earth’s space programs successful, I tip my hat to the shelled reptiles for their contributions.