Human Brain and Heart Tissue Models Head to Space Station to Probe Aging in Orbit

In a launch that marks a striking milestone for space biomedicine, researchers at the Icahn School of Medicine at Mount Sinai are sending bioengineered human brain and cardiovascular tissue models into orbit for the first time aboard the SpaceX CRS-35 resupply mission to the International Space Station. The two investigations, announced on October 13, 2026, will use miniature organ-like systems known as organoids and organ-chips to examine how microgravity and elevated radiation reshape human brain activity, cardiovascular function, and the biological processes of aging. The effort draws together scientists from the Departments of Stem Cell Biology and Regenerative Medicine, Neuroscience, and Surgery, as well as the Cardiovascular Research Institute, positioning Mount Sinai among the leading academic institutions now treating low Earth orbit as a laboratory for human physiology.

The scientific rationale is grounded in a well-documented but poorly understood phenomenon: spaceflight imposes a combination of microgravity and increased radiation exposure that produces biological changes resembling accelerated aging. Astronauts on long-duration missions experience shifts in bone density, muscle mass, immune function, and cardiovascular regulation, and emerging evidence suggests that the brain may be similarly vulnerable. What remains largely unknown is how human brain tissue itself responds at the cellular and molecular level, and why those responses might differ from one astronaut to another. By flying laboratory-grown human tissue to the space station across a series of missions, the Mount Sinai team aims to isolate these effects in a controlled human model, free of the confounding variables that make astronaut health data difficult to interpret.

The centerpiece of the brain-focused investigation is the miBrain, a bioengineered model of human brain tissue developed by project leader Joel W. Blanchard, PhD, Associate Professor of Stem Cell Biology and Regenerative Medicine, and Neuroscience, at the Icahn School of Medicine at Mount Sinai. The miBrain is derived from patient-induced pluripotent stem cells, meaning it can be generated from the genetic background of specific donors. Crucially, the model contains all of the brain’s major cell types, including neurons, the astrocytes that support them, and resident immune cells, along with functional vasculature. That completeness matters: many simpler brain models capture only neurons, while the interplay between neural activity, glial support, immune signaling, and blood vessels is central to how the brain responds to stress, injury, and disease.

In collaboration with NASA and the aerospace company Space Tango, Mount Sinai is conducting a series of spaceflights designed to validate the miBrain model and to assess brain cell signaling and function in the space environment. The work aboard the station will track how the tissue’s cellular networks behave under microgravity, whether stress responses accumulate over time, and how those patterns vary between tissue models derived from different donors. According to Blanchard, the research could establish miBrain as a practical tool for assessing neurological risk before and during spaceflight, with the team aiming to identify biomarkers of injury, determine how genetic risk factors alter susceptibility, and evaluate countermeasures that protect brain health. Such countermeasures could range from pharmaceutical interventions to mission-planning strategies, all tested first in human tissue rather than in astronauts themselves.

The aging dimension of the study extends its relevance far beyond the astronaut corps. Because spaceflight appears to accelerate some aging-like processes, the orbiting brain tissue offers a compressed window into changes that unfold over decades on Earth. The researchers will use the missions to study how the miBrain model changes with age and to determine how common genetic risk factors for neurodegeneration, such as the APOE4 variant, influence the aging process for people on Earth. APOE4 is one of the strongest known genetic risk factors for Alzheimer’s disease, and understanding how it modifies tissue responses to environmental stress could inform prevention and treatment strategies for the general population. In this sense, the space station functions as a time machine of sorts, allowing scientists to observe aging-related biology on a timescale that terrestrial laboratories cannot easily match.

The second Mount Sinai investigation turns to the cardiovascular system, where the consequences of spaceflight are equally consequential. Beating cardiovascular organoids grown from healthy human stem cells will launch inside a microfluidic device called the µCVchip, engineered to keep living tissue perfused, stimulated, and monitored for extended periods. The team, led by Kevin D. Costa, PhD, Associate Professor of Surgery, and David Sachs, PhD, Assistant Professor of Surgery, previously sent stem cell-derived cardiac muscle cells, or cardiomyocytes, into space in 2023 on NASA’s 29th SpaceX Commercial Resupply Services mission to assess cell viability. That earlier flight established that human cardiac cells could survive launch and orbital conditions; the current mission extends the question from survival to function.

The CRS-35 payload includes two µCVchips containing up to 16 beating cardiovascular organoids housed within Space Tango’s automated CubeLab system. Once aboard the station, the system will perform daily electrical pacing, pressure testing, microscopic imaging, and fluid sample collection, generating a continuous physiological record of how human heart and blood vessel tissues respond to extended microgravity exposure. Electrical pacing mimics the rhythmic stimulation the heart receives in the body, allowing researchers to measure contractile force and responsiveness under standardized conditions. Pressure testing probes the mechanical properties of the engineered vasculature, while serial fluid sampling preserves the molecular milieu, including signaling proteins and metabolites released by the tissue, for later analysis on the ground. Together these measurements build a longitudinal portrait of cardiac adaptation, or maladaptation, in orbit.

The cardiovascular stakes are significant because spaceflight induces changes in the cardiovascular system that resemble some effects of aging, including alterations in vascular stiffness and cardiac performance. Costa and Sachs note that the findings could help identify new ways to protect astronauts’ heart health during long missions, and could also inform new therapies for cardiovascular disease in aging populations on Earth. With space agencies planning multi-year journeys to the Moon and Mars, and with cardiovascular disease remaining the leading cause of death worldwide, a human tissue platform that links the two problems has obvious dual value. Countermeasures validated in orbit, whether drugs, exercise-mimicking compounds, or genetic insights, could translate directly into geriatric medicine.

Institutional leaders at Mount Sinai framed the launches as evidence of a rapidly expanding space science program. Sarah E. Millar, PhD, Dean for Academic and Scientific Affairs and Chair of the Department of Stem Cell Biology and Regenerative Medicine, said the team is proud that the missions will carry stem cell-derived organoids from the Blanchard, Sachs, and Costa laboratories to the International Space Station, adding that the projects highlight the institution’s growing work in space science and innovation and that the results will help refine how astronauts are prepared for spaceflight while potentially improving care for aging populations across the Mount Sinai Health System and surrounding communities. Michael L. Marin, MD, Chair of the Department of Surgery, said the laboratory is exploring organoid physiology in space and that the expected data will deepen understanding of how specific tissues respond to altered gravitational forces.

As the CRS-35 mission settles into orbit, the experiments it carries represent a broader shift in how biomedical research is conducted. Rather than sending humans into space and studying what happens to them, scientists can now send human tissue models that replicate individual biology, run automated experiments autonomously, and return molecular data that would be impossible to collect from crew members. If the miBrain and µCVchip investigations succeed, the result will be a validated, repeatable platform for testing neurological and cardiovascular risk in space, one that could safeguard future astronauts on missions to Mars while simultaneously accelerating the search for treatments against the aging-related diseases that affect millions on Earth. The next frontier of medicine, it turns out, may be studied several hundred kilometers above it.

Subject of Research: Effects of microgravity and space radiation on bioengineered human brain and cardiovascular tissue models aboard the International Space Station

Article Title: Mount Sinai scientists to send human tissue models into space to study brain, heart health, and aging in microgravity

Article References: Mount Sinai scientists to send human tissue models into space to study brain, heart health, and aging in microgravity. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: Mount Sinai, International Space Station, SpaceX CRS-35, organoids, miBrain, organ-chips, microgravity, space biology, cardiovascular health, neurodegeneration, APOE4, aging