GREENBELT, Md., Dec. 17 (UPI) -- NASA says it will use lighting technology to help astronauts on the International Space Station sleep better during their "nights" in orbit.
High-tech light-emitting diodes are intended to help sustain a normal day-night cycle in the station's inhabitants, about half of whom routinely find themselves needing medication at some point to get to sleep, SPACE.com reported.
Astronauts have complained of insomnia and difficulty of getting even just six hours of sleep with their demanding schedules and unearthly environment.
"The station is noisy, carbon dioxide is high, you don't have a shower, there's a lot of angst because you've got to perform," NASA flight surgeon Smith Johnston said.
In an $11.2 million project, NASA will switch out the space station's fluorescent bulbs for an array of LEDs alternating between blue, white and red light, based on the time of day.
Blue light stimulates the human brain and suppresses melatonin, a sleep-inducing hormone, while spurring the formation of melanopsin, a "protein pigment" that keeps people awake.
The color red reverses the process, increasing melatonin while melanopsin is suppressed.
"You can dial in a natural day-night cycle on the space station," using the colored light technology, Johnston said.
NASA says it plans to have the light switchover complete by 2016.