NASA scientists explain why astronauts strap down their arms to avoid 'zombie pose'

NASA scientists have explained the unusual measures astronauts must take to get a good night's sleep in space.

Maybe you need the soothing sounds of white noise to help you nod-off, or perhaps, no matter what, you tend to toss and turn for hours on end.

Either way, imagine trying to sleep while floating in zero-gravity.

It's a challenge hundreds of astronauts have faced - particularly those working stints on the International Space Station (ISS) for months at a time.

Yet, surprisingly, scientists claim getting some shut-eye 400 kilometers (250 miles) above Earth is more comfortable that you'd expect.

It's of paramount importance to astronauts, as the effects of sleep deprivation - especially while on high-stakes missions - could be devastating.

Rachel Jansen and Erin Flynn-Evans, NASA scientists studying spaceflight, told the Washington Post all about the fascinating subject.

Jansen explained how in microgravity, astronauts 'don’t have the sensation of lying in bed with a cover applying some sort of pressure'.

"They just float around," she said. "So astronauts choose what works best for them."

Detailing the specifics, Jansen continued: "They’ll strap themselves to one of the surfaces - and that can be anywhere because there’s no up or down.

"The resting posture in space is kind of like a zombie pose, where arms involuntarily rise to about shoulder height and just float there."

My arms are aching at the mere thought of that.

Could you sleep in the zombie pose? (HUM Images/Universal Images Group via Getty Images)

Jansen said some people 'strap their arms down' to avoid the zombie pose - which makes me think of those cute viral videos of babies being released from their swaddles in the mornings.

Anyway, just like us here on Earth, astronauts might also use 'an eye mask to help block light and distractions,' Jansen added.

Each crew member is advised to sleep for around eight and a half hours. They're given access to private sleeping quarters, which include improved light and temperature controls.

Yet, they face a unique challenge on the ISS: the station orbits Earth every 90 minutes, meaning they encounter 16 sunrises and sunsets a day.

“That plays havoc with circadian rhythms,” Jansen said.

To counter this, NASA upgraded the ISS’s lighting system to simulate a more Earth-like day-night cycle.

Sleeping in zero gravity has its benefits (Space Frontiers/Getty Images)

Flynn-Evans explained how a lot people find sleeping in space quite comforting.

"One of the most common things that the crew members report is that their pain goes away in space, because a lot of the aches and pains that prevent us from sleeping come from gravity," she said.

"In space, everything sort of eases up, and often that feels good. I can’t think of a time when someone told me they didn’t enjoy sleeping in space, actually."

Maybe a trip to space would sort a lot of us out...