International Space Station

Space is the most extreme lighting environment for humans. The International Space Station (ISS) orbits at 28,000 km/h, which means astronauts see 16 sunrises and 16 sunsets every day. With no natural light to anchor their body clocks, astronauts must rely entirely on artificial lighting. The challenge goes beyond superb hardware. The light must also support emotional wellbeing, regulate the biological clock and deliver excellent visual comfort.

In partnership with SAGA Space Architects, Yuji Lighting delivers a comprehensive, all-weather lighting environment through bespoke light recipes across four product series:

• SunWave™ series of natural circadian tunable white to mimic the natural lighting spectrum, achieving CRI up to 99.
• Well24™ series of intensive circadian tunable white to enhance the melanopic lighting effect to a stronger circadian stimulus.
• FlameWarm™ and RhythMax™ series — extreme non-white circadian light that maximizes the circadian stimulus, with an m-DER range of 0.042–2.000 while maintaining sufficient luminous efficacy.
• Single color LEDs to combine an RGB system for multiple color palettes for emotional regulation.

The result: an all-weather lighting environment that replaces the missing sun — keeping circadian rhythms, mood and focus stable across 16 sunrises a day.