# Light in spacecraft

Space and habitable environments

Based on the technical review of 31 August 2026; sources checked on 15 September 2026

Academy edition

Taking terrestrial life into space means understanding the conditions it needs. On a spacecraft, lighting must fit sleep, work, visibility, instruments and biological cycles. They become parts of one engineering task.

> Avoid carrying accumulated engineering mistakes into space.

SpaceX · interior concept. The image shows a layout; flight lighting specifications cannot be determined from it.

[Original SpaceX image](https://sxcontent9668.azureedge.us/cms-assets/assets/10_28_25_cabin_06_30a49f27a3.jpg)

## What should be reproduced?

Nature provides a starting point: day and night, direction, spectrum, shadows and gradual transitions. Design turns that example into testable requirements. Continuous bright light, spill into sleeping areas and controls that people cannot override deserve early attention. Benefits of a particular solution must be tested under stated conditions.



## The ISS: a daily rhythm within an orbital rhythm

The ISS experiences roughly 16 sunrises per Earth day while its crew follows a GMT schedule. NASA’s Lighting Effects studied the switch to LEDs with adjustable intensity and colour. The ESA/SAGA Circadian Light cabin experiment followed a sleep schedule. Operational equipment and an experimental installation have different purposes and status.

[S09 · NASA · ISS Lighting Effects · 2017](https://www.nasa.gov/blogs/stationreport/2017/11/13/iss-daily-summary-report-11-13-2017/)

[S10 · ESA · Circadian Light · 2023](https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/A_good_night_s_sleep_in_orbit)

## What NASA measures

JSC Lighting Lab works with lamps, cameras, glare and shadows, modelling orbital and surface environments. Its tools include Radiance and Zemax. For the Academy, this illustrates how scene calculations can be combined with measurements and human evaluation.

[S07 · NASA JSC · Lighting Lab](https://www.nasa.gov/reference/jsc-lighting/)

## Light at the eye

NASA-STD-3001, Volume 2, Revision F, dated 14 July 2026, includes circadian lighting specifications. Two parameters from Table 8.7-2 appear below. Application requires the full standard and measurement conditions.

[S08 · NASA-STD-3001 · Volume 2 · Revision F](https://standards.nasa.gov/standard/NASA/NASA-STD-3001_VOL_2)

### Two NASA circadian lighting parameters

| Mode | Melanopic EDI, lx | Melanopic DER |
| --- | --- | --- |
| General lighting during waking hours | ≥ 250 | ≥ 0.7 |
| Pre-sleep | 8 ± 2 | ≤ 0.3 |

At the cornea in the vertical plane; both conditions must hold together. These are specifications for NASA human-rated systems. Personal home recommendations require a separate assessment.

## What the SpaceX concept shows

The supplied illustration shows extended lighting strips, pale surfaces and light around the compartment perimeter. These features allow discussion of placement and possible reflections. Assessment requires spectra, photometry, operating modes, eye positions, screen behaviour and emergency power. The review and image do not supply those data. A proposed lighting architecture can serve as a design assignment.



## Three tasks in one spacecraft

People need visibility, comfort and lighting coordinated with their schedule. Cameras and navigation need discernible detail, controlled reflections and compatibility with imaging settings. Plants need their own lighting conditions. A shared model should account for each subsystem’s power and heat, light spill and failure behaviour. This is the Academy’s proposed engineering framework.



## Plants and living light

NASA uses Veggie and Advanced Plant Habitat for plant research in controlled environments. UMAMI studies a squid and its luminous bacterial partners. Bioluminescence is part of the living system under investigation. These projects provide insufficient evidence to justify illuminating a crew compartment with living organisms.

[S11 · NASA · UMAMI](https://science.nasa.gov/biological-physical/investigations/umami/)

[S13 · NASA · Plant Biology Hardware](https://science.nasa.gov/biological-physical/focus-areas/plant-biology/hardware/)

## What to test on Earth first

Start with one autonomous compartment: define geometry, sources, schedules, human positions and system states. Compare modes, check light spill into sleeping areas, camera operation and manual override. Consider lighting alongside noise, air and temperature. Ground testing can reveal a mistake before it becomes part of a spacecraft.



## Astronaut Moments · Anil Menon

NASA describes his experience as SpaceX’s first flight surgeon. He launched to the ISS aboard Soyuz MS-29 on 14 July 2026. This offers biographical context for medicine in human spaceflight.

[Watch on YouTube](https://youtu.be/1RcHY6zwnaI)

[NASA biography](https://www.nasa.gov/people/nasa-astronaut-anil-menon/)

[S07 · NASA JSC · Lighting Lab](https://www.nasa.gov/reference/jsc-lighting/)

[S08 · NASA-STD-3001 · Volume 2 · Revision F](https://standards.nasa.gov/standard/NASA/NASA-STD-3001_VOL_2)

[S09 · NASA · ISS Lighting Effects · 2017](https://www.nasa.gov/blogs/stationreport/2017/11/13/iss-daily-summary-report-11-13-2017/)

[S10 · ESA · Circadian Light · 2023](https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/A_good_night_s_sleep_in_orbit)

[S11 · NASA · UMAMI](https://science.nasa.gov/biological-physical/investigations/umami/)

[S12 · NASA · Anil Menon](https://www.nasa.gov/people/nasa-astronaut-anil-menon/)

[S13 · NASA · Plant Biology Hardware](https://science.nasa.gov/biological-physical/focus-areas/plant-biology/hardware/)

Light Academy · 1.5.0 · 2026-09-17