Sleep in Space

Space shuttle Endeavour launched on Wed., July 15, from NASA's Kennedy Space Center in Florida. Today the shuttle undocked from the International Space Station.

After 13 days in space, how has the shuttle’s crew been sleeping? Surprisingly well, MSNBC reports.

"We sleep very well in space,” Endeavour astronaut Julie Payette told reporters. “Can you imagine? We have a sleeping bag each, and when you get into it you float in the sleeping bag...So all you have to do is just attach it somewhere."

Astronauts haven’t always slept so soundly in space. A 2001 study of five astronauts found that their average sleep duration was only about 6.5 hours per day.

Subjective sleep quality also was poor. They had less of the deep stage of slow-wave sleep during the last third of their sleep period.

One challenge that can hinder sleep in space is the highly variable light-dark cycle. NASA reports that the sun rises every 90 minutes during a mission.

Long missions can be especially challenging. A 2001 case study found that space missions lasting more than three months may lead to more sleep problems.

What about waking up in space? That’s when the Mission Control Center in Houston, Texas, gets involved.

It sends wake-up music to the space shuttle crew. This morning the wake-up song was “Proud to Be an American” by Lee Greenwood.

STS-127 is the 127th space shuttle flight; it is the 29th shuttle mission to the International Space Station.

Endeavour is scheduled to land at Kennedy Space Center on Friday at 10:47 a.m. EDT.

Learn more about space sleep from NASA. Read more about sleeping provisions for astronauts.

Image courtesy of NASA