Astronaut explained why he wore gorilla suit on ISS as hilarious footage of prank resurfaces

Picture the scene, you're on board the International Space Station (ISS) when suddenly a gorilla comes speeding towards you unburdened by gravity.

That's what happened to British astronaut Tim Peake about a decade ago, after his American colleague, Scott Kelly, was sent a gorilla costume by his twin brother Mark.

The Kelly twins are both astronauts, although Scott has been in space longer, thanks to an experiment where one of the twins would leave Earth for an extended period of time, while the other would remain on Earth.

That experiment gave NASA a lot of interesting information to work with, but the brothers decided to conduct an experiment of their own by sending a gorilla costume up to the ISS.

Scott once spoke to People and explained exactly how the hilarious prank came to be, saying it was his brother's idea to cheer him up after a long time in space.

"I was on the phone with my brother one day and he said, 'Hey, I'm sending you a gorilla suit,'" Scott recounted. "And I said, 'Why?' And he goes, 'Because there's never been a gorilla in space before.'"

However, that suit was on board one of Elon Musk's unmanned SpaceX rockets, which blew up, but the astronaut twins weren't deterred from their plan to send a gorilla suit where no gorilla suit had gone before.

Scott said: "The next time I was on the phone with my brother, he goes, 'I'm sending you another gorilla suit'."

Once it arrived, he waited until he had a moment to himself on board the ISS and got changed into his costume, then proceeded to chase Peake along the corridors of one of humanity's greatest scientific achievements.

Footage of the prank routinely does the rounds on the internet, much to the joy of viewers who love seeing an astronaut get into a gorilla costume and scoot about the International Space Station after other astronauts.

What happens when you cry in space? #SpaceGorilla explains. What else do you want to know about? Join me on @Reddit now! #AskMeAnything pic.twitter.com/ZQrmjg89zU

— Scott Kelly (@StationCDRKelly) October 16, 2017

Our species has now reached the point where we can engage in gorilla suit-based tomfoolery in space, which must surely be a major milestone in the scientific progress of humanity.

We managed to put a man on the Moon, but perhaps the greater achievement is being able to send an astronaut a gorilla costume for them to have fun with on board the ISS.

Kelly said that Peake knew about the gorilla suit, so they staged their funny chase for the camera, but some of their other colleagues didn't spot what was going on.

On one occasion, he donned the suit and hid in another astronaut's sleeping quarters, and afterwards, was a little worried that I could have given him a heart attack'.

He also 'floated down' to visit the Russian astronauts in their part of the ISS, adding: "When they saw it, they were just laughing like you wouldn't believe."

He also did an educational video for children while wearing the suit, because who wouldn't want to learn something from a talking gorilla in space?