Tag Archives: programmable LED lighting system

Space Station Twilight Zone

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NASA Identifier: iss002e5413 Night and day don’t exist on the International Space Station, where astronauts live in the equivalent of a twilight zone: Repeated exposure — or lack of exposure — to the wrong wavelengths of light at the wrong time disrupts their biological clocks and circadian rhythms. Still, the views are beautiful: This sunset view with the space station’s solar array in the frame was taken by the Expedition Two crew in 2010.

NASA Identifier: iss002e5413
Night and day don’t exist on the International Space Station, where astronauts live in the equivalent of a twilight zone: Repeated exposure — or lack of exposure — to the wrong wavelengths of light at the wrong time disrupts their biological clocks and circadian rhythms. Still, the views are beautiful: This sunset view with the space station’s solar array in the frame was taken by the Expedition Two crew in 2010.

The International Space Station orbits the Earth every 90 minutes, creating incredible photography opportunities for astronauts who see approximately 16 sunrises and sunsets in a 24-hour period. Night and day don’t exist on the space station, where astronauts live in the equivalent of a twilight zone: Repeated exposure — or lack of exposure — to the wrong wavelengths of light at the wrong time throws their biological clocks out of whack and disrupts their circadian rhythms. The astronauts are cut off from the natural light-dark cycle and therefore have to create their own.

Astronauts typically only get about six hours of sleep in a 24-hour period due to a number of factors, including circadian misalignment. They suffer from insomnia and fatigue: dangerous conditions in space where they are required to work slam shifts — the performance of critical, time-specific operations, such as docking. Sleep loss can severely impair the astronauts’ cognitive functions within a few days, increasing the risk of mission errors and putting their health and safety at risk.

So electric light is coming to the astronauts’ rescue to help with both circadian misalignment and providing an acute stimulant to reduce fatigue in the form of a programmable LED wavelength system being designed and tested by a specialized lighting team of neuroscientists and NASA engineers.

The LED lighting system being designed for the space station will far exceed the sophistication of the aging fluorescent lights now in place. The lighting system is scheduled to be installed in phases, starting in fall 2016 in the U.S. crew quarters and eventually expanding to the entire U.S. module of the space station.

Image courtesy of NASA This educational LED lighting model was prepared to illustrate the full-color spectrum of light that the new, programmable system will provide astronauts — a system that will allow for greater lighting control with the manipulation, or fine-tuning, of color wavelengths.

Image courtesy of NASA
This educational LED lighting model was prepared to illustrate the full-color spectrum of light that the new, programmable system will provide astronauts — a system that will allow for greater lighting control with the manipulation, or fine-tuning, of light’s wavelengths.

No, says neuroscientist Steven W. Lockley, the new LED lights (above) won’t really resemble disco lights. The new, programmable system will provide greater lighting control with the manipulation, or fine-tuning, of the wavelength and intensity of light to either stimulate, when alertness or circadian resetting is required, or not stimulate, for example prior to sleep, the circadian photoreception system. A system of multiple LEDs, he explains in talks, can produce thousands and thousands of combinations of light.

As a countermeasure for fatigue and circadian disruption, and to improve vision, health, safety, and performance, the astronauts will actually see variations of white light, designed to enhance or minimize stimulation as required.

The Rocket Science of Better Light

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Photo courtesy of NASA Electric light is coming to the astronauts’ aid in the form of a programmable LED wavelength system. U.S. Astronaut Mike Fincke holds an early prototype of an LED lighting unit that was installed on the space station during Expedition 18 about six years ago.

Electric light is coming to the astronauts’ aid in the form of a programmable LED wavelength system. U.S. Astronaut Mike Fincke holds an early prototype of an LED lighting unit that was installed on the space station.

To work in conjunction with the eye’s nonvisual system, the International Space Station’s high-precision LED lighting system will offer three main settings:

1) high alertness (blue-enriched light): suppresses melatonin, accelerates the shifting of the circadian clock, and boosts reaction times and performance.

2) general illumination: a bright and full spectrum of evenly distributed light — like that of daytime — improves visibility and maintains alertness and cognitive function.

3) pre-sleep, or bedtime (red-enriched white light): de-emphasizes blue light and promotes relaxation and sleep.

The lighting is being designed to help the astronauts relax, sleep, awaken feeling refreshed, and quickly shift their body clocks to better handle dangerous unpredictability in a line of work where one wrong move can mean mortal disaster.

The lights are designed to provide the right light at the right time, from blue-enriched alerting light in the morning, to lighting to maintain good vision during the working day, and then a blue-depleted and lower intensity light before bed to help relaxation and facilitate sleep.

Circadian neuroscientist Steven W. Lockley explains that along with the new lighting, we also need a new way to measure light as the current standards and meters are concerned only with light for vision. Light meters — along with current industry lighting standards — are attuned to the peak light sensitivity of the eye’s daytime color vision system.

The field is designing new ways to describe light so that the nonvisual benefits are also captured, Lockley says, allowing lighting designers and architects to start to incorporate the benefits of light into their designs. The spectral fingerprint of all lighting design should be based on optimizing both the visual and nonvisual benefits of light.

Safety-sensitive occupations, such as those found in the law enforcement and military fields, can benefit from this technology as well. Submarine crews, for example, just like astronauts, lack access to natural light-dark cycles.

A research article published in Acta Astronautica (George C. Brainard, et al., 2012, “Solid-state lighting for the International Space Station: Tests of visual performance and melatonin regulation”) describes the future of lighting.

As the article details, the development of specialized lighting for long-duration space exploration “will ultimately revolutionize how our public facilities, work places and homes are illuminated in the coming decades. … By refining multipurpose lights for astronaut safety, health and well-being in spaceflight, the door is opened for new lighting strategies that can be evolved for use on Earth.”

Everywhere electric light is used, Lockley says, we can do a better job of it. We’re only at the start of understanding what this photoreceptor system does. And as the general public becomes aware of the multipurpose lighting being developed for astronauts, he predicts an explosion in the availability of LED technology on Earth.

NASA Identifier: 259129main_ISS015E18958_full As researchers have written, the development of specialized lighting for long-duration space exploration is helping to open the door for new lighting strategies that can be evolved for use on Earth. The workings of the LED lighting system being developed for the International Space Station hold tremendous implications for myriad lighting applications on Earth.

NASA Identifier: 259129main_ISS015E18958_full
As researchers have written, the development of specialized lighting for long-duration space exploration is helping to open the door for new lighting strategies that can be evolved for use on Earth. The workings of the LED lighting system being designed and tested for the International Space Station hold tremendous implications for myriad lighting applications on Earth.