WHY TORTOISES ARE TOOK TO MOON?

WHY TORTOISES TOOK TO THE MOON?

Three months before a single human was launched toward the Moon, two tortoises had already come back. Sure, they didn’t get to make one giant leap for tortoise-kind on the surface. They just swung around the Moon. But along with some much smaller critters, they were the first citizens of Earth to get that far away from home! This was the USSR’s Zond 5 mission, and it was carried into space by a funky-looking rocket. It’s called the Proton, and it was so successful that its descendents were used for over half a century! If you take a look at a Proton rocket, you might think that it looks a little funny near the bottom. Especially in comparison to other rockets of the era. The first stage of the rocket, meaning the part that holds the first set of engines, has one big central tube surrounded by a bunch of smaller ones. And you might think that those outer tubes would be smaller boosters… separate rockets all coming together to add more oomph. But no. Those tubes are holding the Proton’s fuel. Meanwhile, the center tube holds the second ingredient in making the rocket go up… or in worse cases blow up… the oxidizer that makes the fuel combust. This arrangement was necessary because Proton had to be shipped by train, lying on its side. So the central tube could only be so big. And interestingly, what was in those fuel tanks actually made the rocket pretty controversial, especially during its development. All iterations of the Proton rocket, including the ones that sent missions around the Moon, relied on a fuel called Unsymmetrical dimethylhydrazine, or UDMH. And it’s incredibly toxic. It’s so toxic that one of the USSR’s chief rocket scientists didn’t want to use it. But it did have some perks. For example, UDMH, as well as the oxidizer in the Proton’s central tank, are hypergolic propellants,. That means that when you put them together, they’ll spontaneously ignite.

Since you don’t need something like a spark plug to set the reaction off, your rocket is at least a tiny bit simpler in design. Having one less part that could break is something worth aiming for. But perhaps the main benefit to UDMH was that it could be stored at room temperature, instead of needing to be kept super cold like most of the other rocket fuels on the market. And a rocket that doesn’t need its own fancy refrigeration system to keep its fuel from autoigniting is a huge plus. That special hypergolic propellant combo was used for the three main stages in every Proton rocket,] whether it’s the classic Proton-K, or the more modern Proton-M. But some missions, like the ones that sent critters around the Moon and back, needed a fourth stage added at the tippy top. The Proton-K’s bonus bit of rocket, called Blok D, used a different fuel and oxidizer combo. So if you look up the Zond 5 mission, you’ll see the rocket that got the job done called a Proton-KD. And sure, you’re probably looking it up

to learn more about those tortoises, but Zond 5 racked up a lot of first place ribbons besides ferrying the first Earthers around the Moon. Earthers? Earthians? Terrans? We probably need to settle on an official name, soon. Whatever we call our tortoise and non-tortoise travelers, Zond 5 didn’t technically get them into orbit of the Moon. But on In September 1968, it became the first mission to go around the Moon, period. And it was also the first mission to make it back to Earth after visiting another celestial body. Which I’m sure those tortoises appreciated. Now, you may be wondering, “Why tortoises?”

To which I would say,

“Well, why not tortoises?”.

But really, they were chosen for a pretty practical reason. They were easy to strap down. The critters were basically kept in very small cages that didn’t allow them to move. So no floating around, experiencing the joys of microgravity. Which is a huge bummer. It was also a huge bummer for the control group of tortoises kept in the same caged conditions back on Earth to figure out the biological consequences of spaceflight. Because the flight was short enough, none of the tortoises involved in this experiment had any food or water during the journey, or weeks on either side of the journey. But the ones that got to go to space at least had company. Zond 5 was a veritable ark, containing fruit fly eggs, meal worms, seeds, and bacteria. The researchers even reportedly sent human cells along for the ride, to see what space would do to them. But if we’re being honest, we all know the tortoises were the stars of the show. And happily, they returned to Earth in fairly good health.

They did lose about 10% of their body weight, which was about twice the amount lost by the tortoises in the control group. In other words, it wasn’t just because they weren’t allowed to eat or drink anything up there. But then again, this is only two tortoises, so it’s not exactly a definitive insight into what space travel does to a body. There were some other side effects,

but the research team attributed most of them to starvation, rather than space flight. And that’s a good thing, because it suggested humans would be a-ok to make a similar journey, so long as they were properly fed and watered. Of course, Apollo 8 would soon prove this on the US side of things, going around the Moon and telling the world Merry Christmas just a few months after Zond 5 had splashed down in the Indian Ocean. And a few years later, animals and astronauts would share a ride to the Moon. In 1972, five mice named Fe, Fi, Fo, Fum, and Phooey

orbited the Moon during the Apollo 17 mission. Unfortunately, our tortoise record-holders don’t seem to have had names. So if you want, you can leave a comment below sharing what names you think they should be given, over five decades later. Maybe there are a couple of lesser-known Renaissance artists that need a shoutout. Unfortunately, these tortoise cosmonauts had a bit of a downer ending, getting dissected to figure out how safe space travel would be for human cosmonauts. But there is a happier note we can finish on. A few more Protons ferried missions around the Moon and back, carrying even more animals. And while this class of rockets never got to take a human to the Moon, the Proton-K did launch the first two Russian modules of the International Space Station. Which humans have occupied continuously since 2000. For over half a century, the Proton-K and its successor, the Proton-M, were proper workhorses of the Soviet, and later Russian, fleet of space launch systems. But as of 2023, they are reportedly being phased out. Partly due to competition from private companies like SpaceX. Partly due to the fact that they’re still using that extra toxic hypergolic fuel. But even though it’s probably on its last legs, the Proton rocket will always be remembered for ensuring that tortoises definitely beat both hares and humans in the race to the Moon. And what better way is there to remember a historic space mission than turning it into a pin?