Science in Space: February 2025

February was first proclaimed as American Heart Month in 1964. Since then, its 28 (or 29) days have served as an opportunity to encourage people to focus on their cardiovascular health.

The International Space Station serves as a platform for a variety of ongoing research on human health, including how different body systems adapt to weightlessness. This research includes assessing cardiovascular health in astronauts during and after spaceflight and other studies using models of the cardiovascular system, such as tissue cultures. The goal of this work is to help promote heart health for humans in space and everyone on Earth. For this Heart Month, here is a look at some of this spaceflight research

Building a better heart model

Microgravity exposure is known to cause changes in cardiovascular function. Engineered Heart Tissues assessed these changes using 3D cultured cardiac tissues that model the behavior of actual heart tissues better than traditional cell cultures. When exposed to weightlessness, these “heart-on-a-chip” cells behaved in a manner similar to aging on Earth. This finding suggests that these engineered tissues can be used to investigate the effects of space radiation and long-duration spaceflight on cardiac function. Engineered tissues also could support development of measures to help protect crew members during a mission to Mars. Advanced 3D culture methodology may inform development of strategies to prevent and treat cardiac diseases on Earth as well.

Private astronaut heart health

For decades, human research in space has focused on professional and government-agency astronauts, but commercial spaceflight opportunities now allow more people to participate in microgravity research. Cardioprotection Ax-1 analyzed cardiovascular and general health in private astronauts on the 17-day Axiom-1 mission.

The study found that 14 health biomarkers related to cardiac, liver, and kidney health remained within normal ranges during the mission, suggesting that spaceflight did not significantly affect the health of the astronaut subjects. This study paves the way for monitoring and studying the effects of spaceflight on private astronauts and developing health management plans for commercial space providers.

Better measurements for better health

Vascular Echo, an investigation from CSA (Canadian Space Agency), examined blood vessels and the heart using a variety of tools, including ultrasound. A published study suggests that 3D imaging technology might better measure cardiac and vascular anatomy than the 2D system routinely used on the space station. The research team also developed a probe for the ultrasound device that better directs the beam, making it possible for someone who is not an expert in sonography to take precise measurements. This technology could help astronauts monitor heart health and treat cardiovascular issues on a long-duration mission to the Moon or Mars. The technology also could help patients on Earth who live in remote locations, where an ultrasound operator may not always be available.

Long-term heart health in space

As part of exploring ways to keep astronauts healthy on missions to the Moon and Mars, NASA is conducting a suite of space station studies called CIPHER that looks at the effects of spaceflight lasting up to a year. One CIPHER study, Vascular Calcium, examines whether calcium lost from bone during spaceflight might deposit in the arteries, increasing vessel stiffness and contributing to increased risk of future cardiovascular disease. Astronaut volunteers provide blood and urine samples and undergo ultrasound and high-resolution scans of their bones and arteries for this investigation. Another CIPHER study, Coronary Responses, uses advanced imaging tests to measure heart and artery response to spaceflight.

These studies will help scientists determine whether spaceflight accelerates narrowing and stiffening of the arteries, known as atherosclerosis, or increases the risk of atrial fibrillation, a rapid and irregular heartbeat seen in middle-aged adults. This work also could help identify potential biomarkers and early warning indicators of cardiovascular disease.

Melissa Gaskill

International Space Station Research Communications Team

Johnson Space Center

Science in Space January 2025

At the start of a new year, many people think about making positive changes in their lives, such as improving physical fitness or learning a particular skill. Astronauts on the International Space Station work all year to maintain a high level of performance while adapting to changes in their physical fitness, cognitive ability, sensory perception, and other functions during spaceflight.

Research on the space station looks at how these qualities change in space, the ways those changes affect daily performance, and countermeasures to keep astronauts at their peak.

A current CSA (Canadian Space Agency) investigation, Space Health, assesses the effects of spaceflight on cardiovascular deconditioning. The investigation uses Bio-Monitor, wearable sensors that collect data such as pulse rate, blood pressure, breathing rate, skin temperature, and physical activity levels. Results could support development of an autonomous system to monitor cardiovascular health on future space missions. Similar technology could be used to monitor heart health in people on Earth.

Maintaining muscle fitness

During spaceflight, astronauts lose muscle mass and stiffness, an indication of strength. Astronauts exercise daily to counteract these effects, but monitoring the effectiveness of exercise had been limited to before and after flight due to the lack of technologies appropriate for use in space. The ESA (European Space Agency) Myotones investigation demonstrated that a small, non-invasive device accurately measured muscle stiffness and showed that current countermeasures seem to be effective for most muscle groups. Accurate inflight assessment could help scientists target certain muscles to optimize the effectiveness of exercise programs on future missions. The measuring device also could benefit patients in places on Earth without other means for monitoring.

Keeping a sharp mind

Research suggests that the effects of spaceflight on cognitive performance likely are due to the influence of stressors such as radiation and sleep disruption. Longer missions that increase the exposure to these hazards may change how they affect individuals.

Manual Control used a battery of tests to examine how spaceflight affects cognitive, sensory, and motor function right after landing. The day they return from spaceflight, astronauts demonstrate significant impairments in fine motor control and ability to multitask in simulated flying and driving challenges. Researchers attribute this to subtle physiological changes during spaceflight. Performance recovered once individuals were exposed to a task, suggesting that having crew members conduct simulated tasks right before actual ones could be beneficial. This work helps scientists ensure that crew members can safely land and conduct early operations on the Moon and Mars.

Standard Measures collects a set of physical and mental measurements related to human spaceflight risks, including a cognition test battery, from astronauts before, during, and after missions. Using these data, researchers found that astronauts on 6-month missions demonstrated generally stable cognitive performance with mild changes in certain areas, including processing speed, working memory, attention, and willingness to take risks. The finding provides baseline data that could help identify cognitive changes on future missions and support development of appropriate countermeasures. This research includes the largest sample of professional astronauts published to date.

Evaluating perception

Another function that can be affected by spaceflight is sensory perception, such as the ability to interpret motion, orientation, and distance. We use our visual perception of the height and width of objects around us, for example, to complete tasks such as reaching for an object and deciding whether we can fit through an opening. VECTION, a CSA investigation, found that microgravity had no immediate effect on the ability to perceive the height of an object, indicating that astronauts can safely perform tasks that rely on this judgment soon after they arrive in space. Researchers concluded there is no need for countermeasures but did suggest that space travelers be made aware of late-emerging and potentially long-lasting changes in the ability to perceive object height.

Melissa Gaskill

International Space Station Research Communications Team

Johnson Space Center

For more than 24 years, NASA has supported a continuous U.S. human presence aboard the International Space Station, advancing scientific knowledge and making research breakthroughs not possible on Earth for the benefit of humanity. The space station is a springboard to NASA’s next great leaps in exploration, including future missions to the Moon under Artemis, and ultimately, human exploration of Mars.

Read more about the groundbreaking work conducted in 2024 aboard the station:

Robot performs remote simulated surgery

On long-duration missions, crew members may need surgical procedures, whether simple stitches or an emergency appendectomy. A small robot successfully performed simulated surgical procedures on the space station in early February 2024 for the Robotic Surgery Tech Demo, using two “hands” to grasp and cut rubber bands simulating tissue. Researchers compare the procedures conducted aboard the station and on Earth to evaluate the effects of microgravity and communication delays between space and ground.

3D metal print in space

On May 30,2024, the ESA (European Space Agency) Metal 3D Printer investigation created a small stainless steel s-curve, the first metal 3D print in space. Crew members on future missions could print metal parts for equipment maintenance, eliminating the need to pack spare parts and tools at launch. This technology also has the potential to improve additive manufacturing on Earth.

Here’s looking at you, Earth

The space station orbits roughly 250 miles above and passes over 90 percent of Earth’s population, providing a unique perspective for photographing the planet. Astronauts have taken more than 5.3 million images of Earth to monitor the planet’s changing landscape. The Expedition 71 crew took over 630,000 images, well above the average of roughly 105,000 for a single mission. This year, images included the April solar eclipse and auroras produced as the Sun’s 11-year activity cycle peaks. Others supported response to over 14 disaster events including hurricanes. In addition, 80,000 images were geolocated using machine learning, improving public search capabilities.

Miles of flawless fibers

From mid-February to mid-March of 2024, the Flawless Space Fibers-1 system produced more than seven miles of optical fiber in space. One draw of more than a half mile of fiber surpassed the prior record of 82 feet for the longest fiber manufactured in space, demonstrating that commercial lengths of fiber can be produced in orbit. Fibers produced in microgravity can be superior to those produced in Earth’s gravity. These fibers are made from ZBLAN, a glass alloy with the potential to provide more than 10 times the transmission capacity of traditional silica-based fibers.

Tell-tale heart

In May 2024, BFF-Cardiac successfully bioprinted a three-dimensional human heart tissue sample using the Redwire BioFabrication Facility. Tissues bioprinted in the microgravity of the space station hold their shape without the use of artificial scaffolds. These bioprinted human heart tissues eventually could be used to create personalized patches for tissue damaged by events such as heart attacks. The tissue sample is undergoing further testing on Earth.

Station-tested radiation technology flown on Artemis I

The Orion spacecraft carried 5,600 passive and 34 active radiation detectors on its Artemis I uncrewed mission around the Moon in November 2022. Some of these devices previously were tested on the space station: HERA (Hybrid Electronic Radiation Assessor), which detects radiation events such as solar flares; the ESA (European Space Agency) Active Dosimeters, a wearable device collecting real-time data on individual radiation doses; and the AstroRad Vest, a garment to protect radiation-sensitive organs and tissues. In 2024, researchers released evaluation of data collected in 2022 by these tools that indicate the Orion spacecraft can protect astronauts on lunar missions from potentially hazardous radiation. The orbiting laboratory remains a valuable platform for testing technology for missions beyond Earth’s orbit.

Record participation in Fifth Robo-Pro Challenge

A record 661 teams and 2,788 applicants from thirteen countries, regions, and organizations participated in the fifth Kibo Robo-Pro Challenge, which wrapped its final round in September. This educational program from JAXA (Japan Aerospace Exploration Agency) has students solve various problems by programming free-flying Astrobee robots aboard the space station. Participants gain hands-on experience with space robot technology and software programming and interact with others from around the world.

Melissa Gaskill
International Space Station Research Communications Team|
Johnson Space Center