AVATAR: A Virtual Astronaut Tissue Analog Response
The AVATAR (A Virtual Astronaut Tissue Analog Response) investigation uses organ-on-a-chip devices, or organ chips, to study the effects of increased radiation and microgravity on human health.
The AVATAR (A Virtual Astronaut Tissue Analog Response) investigation used organ-on-a-chip devices, or organ chips, to study the effects of deep space radiation and microgravity on human health during Artemis II. The chips contain cells from the astronauts and flew side-by-side with crew on their approximately 10-day journey around the Moon. This research, combined with other studies on the health and performance of Artemis II astronauts, will give NASA insight into how to best protect astronauts as exploration expands to the surface of the Moon, Mars, and beyond.
Organ chips, also referred to as tissue chips or microphysiological systems, are roughly the size of a USB thumb drive and used to help understand — and then predict — how an individual might respond to a variety of stressors, such as radiation or medical treatments, including pharmaceuticals. Essentially, these small devices serve as “avatars” for human organs.
Organ chips contain living human cells that are grown to model the structures and functions of specific regions in human organs, such as the brain, lungs, heart, pancreas, and liver — they can beat like a heart, breathe like a lung, or metabolize like a liver. Tissue chips can be linked together to mimic how organs interact with each other, which is important for understanding how the whole human body responds to stressors or treatments.
The investigation is a collaboration between NASA, government agencies, and industry partners, leveraging commercial expertise to gain a deeper understanding of human biology and disease. This research could accelerate innovations in personalized healthcare, both for astronauts in space and patients on Earth.

The AVATAR (A Virtual Astronaut Tissue Analog Response) investigation on Artemis II uses organ-on-a-chip devices, or organ chips, to study the effects of increased radiation and microgravity on human health.
image credit: Emulate
For more information visit
https://science.nasa.gov/biological-physical/investigations/avatar/#Organ-Chips
Credits
credit: NASA Headquarters
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Technical support
- Amy Moran (Global Science and Technology, Inc.)
Release date
This page was originally published on Wednesday, April 8, 2026.
This page was last updated on Friday, April 10, 2026 at 7:16 PM EDT.