How animal astronauts paved the way for human space flight
The other day my kids came home from school all excited to tell me they had been watching Tim Peake, the astronaut set to make Britain’s first spacewalk. I was surprised how much excitement this had caused in my kids, but then one of my earliest memories is sitting with my father watching Neil Armstrong step on the moon; I can still recall it vividly.
The history of aeronautical and space exploration is one full not only of human heroes such as Yuri Gagarin but also of animal explorers, albeit passive ones. It was the Montgolfier brothers in 1783, worried about the effects of high altitude on human health, who hung a basket containing a live sheep, cockerel and duck below one of their earliest balloons.
This also turns out to be an early example of a controlled experiment: the sheep was there to represent human physiological responses, the duck as a control because they are accustomed to high altitudes and the cockerel as a second control since it is a bird not accustomed to high altitudes. All three survived their brief flight, in front of King Louis XVI and Marie Antoinette, and subsequently man took to the air.
Like the Montgolfier brothers, early space scientists were concerned about whether humans would be able to survive travel in space. So in 1947, a few fruit flies were the first animals in space, launched on top of an American V2 rocket and safely returned to earth, unlike many of the animals that followed them in the next decades.
During the late 1940s and 1950s a series of American rhesus monkeys all called Albert made trips with varying degrees of success into space. They showed humans could survive the rigour of space travel, or at least straight-up, straight-down missions.
The Russians’ chosen species to be their animal astronaut was the “stray dog”. Dogs were chosen for their physiological similarities to humans and strays were preferred as they already had experience of toughing it out on the freezing streets of Russia.
Laika, a mongrel from Moscow, became the first animal to go into orbit in 1957. She was sent into space with no way of returning her to Earth. It had been anticipated that Laika would have survived a week or so with the food and oxygen supplied to her, but Sputnik 2 overheated and she died after only a few hours.
Yet it was the missions with Laika and many other dogs that finally led to the cosmonaut Yuri Gagarin becoming the first human being in space in 1961. Despite the success of the first human, many more animals would be flown into space, especially dogs (more than 50 missions) and primates (more than 30 missions).
One of the most famous primate missions was undertaken by a young male chimpanzee called Ham in 1961. Ham had received mission training using positive reinforcement (banana pellets) and punishment (mild electric shock to his feet) to get him to pull levers during his mission – showing that astronauts did not have to be mere passengers.
The use of animal astronauts therefore laid the foundations for human space flight. As scientists wished to answer questions such as how microgravity will affect the flight of a butterfly, the formation of a spider’s web or a gecko’s reproduction, a veritable zoo of animals have gone beyond the Earth’s atmosphere.
Some of the experiments Peake is conducting during his time in space concern astrobiology, which sounds very cool to a mere Earth-bound biologist. He’s using the European Space Agency’s module called EXPOSE, which houses a variety of organisms such as bacteria and fungi which are exposed to the harsh conditions of space to see if they can survive.
The challenges of life in space are considerable – from huge temperature fluctuations, radiation and life in a vacuum – so the organisms chosen are known on Earth as extremophiles, species normally found in extreme conditions such as close to underwater volcanic vents (that is, high temperatures and extreme chemical conditions).
So far microorganisms known as “water bears” or tardigrades and some bacteria have been shown to survive the extreme conditions of space. Data from experiments on the International Space Station will enlighten us about the possibility of life on other planets and provide information useful for human lead trips to Mars and beyond.
My kids are rightly excited by the work of human astronauts but we should not forget the contribution that animals have made. And in 2008 Russia built a monument to Laika hailing her contribution to human space exploration.