Organs in Orbit: Biomedical 3D Printing in Space

by Juman Al Naser

October 2025

NASA astronaut and flight engineer Jasmin Moghbeli working in the BioFabrication Facility (BFF), a 3D bioprinter on the International Space Station (ISS). Source: Astrobiology

Turning Science Fiction into Living Tissue

In November 2022, astronauts aboard the International Space Station (ISS) took a bold step toward turning science fiction into reality by successfully printing human tissue in orbit. This technique, known as bioprinting, faces major limitations on Earth because delicate tissues tend to collapse under the pull of gravity. In microgravity, however, tissues can develop more easily and hold their shape. This breakthrough opens the door to printing complex structures like cartilage, liver tissue, and even heart tissue. One of the most exciting projects currently underway focuses on printing the meniscus — a small but essential piece of cartilage that helps the knee move smoothly, absorb impact, and support joint function [1].

Meniscus Injuries: A Growing Challenge on Earth

In the United States, around 60 out of every 100,000 people undergo meniscus repair each year — a number that continues to rise. Meniscus surgery is now one of the most common orthopaedic procedures, yet many patients face early joint degeneration and long-term mobility issues after treatment [2]. Research aboard the ISS offers new hope. Advances in 3D bioprinting could lead to more effective therapies that lower healthcare costs, improve recovery outcomes, and potentially shorten surgical procedures. These innovations are up-and-coming for injured service members, who often suffer from meniscus damage due to the physical demands of their work.

Bioprinting in Orbit: Inside the BioFabrication Facility (BFF)

Developed and operated by Redwire Space, the BFF is the first 3D bioprinter built specifically for use in orbit. It uses bioinks — mixtures of living human and animal cells — to create complex tissue structures. Since its initial launch to the ISS in 2019, the BFF has been upgraded with advanced temperature controls to keep bioinks stable, along with enhanced camera systems that give ground teams better visibility and precision during the printing process [3].

One of its most ambitious projects is BFF-Meniscus-2, which aims to bio-print and culture a complete human knee meniscus in space. This marks the first attempt to produce a full meniscus in orbit. Once returned to Earth, the printed tissue will help researchers better understand how space-based bioprinting can support medical treatments, especially for injured service members who often suffer from joint damage [3].

Why Microgravity Matters

On Earth, printing soft tissues often requires scaffolding to keep structures from collapsing. While effective, this method limits how complex and lifelike the printed tissues can be. In the microgravity environment of the ISS, scaffolds aren’t needed. Tissues can form naturally and maintain their three-dimensional shape, enabling the creation of larger, more intricate models and, potentially, even complete organs that could one day be used in transplants [5].

Once printed, meniscus constructs are moved to the Advanced Space Experiment Processor (ADSEP), also operated by Redwire. There, they’re cultured for 14 days to strengthen and mature before being preserved and sent back to Earth for analysis. Bioprinting in space offers unique advantages: it enables the creation of realistic tissue models for drug testing, reduces the need for animal experiments, and opens the door to vascularized tissues that more closely resemble natural human organs [6].

Tackling the Organ Shortage and Transforming Drug Discovery

While astronauts already use 3D printing to produce tools and spare parts in orbit, bioprinting in space could help solve one of healthcare’s most pressing challenges: the shortage of transplantable organs. If systems like the BFF and the ADSEP can eventually mass-produce organs, they could make transplants more accessible and save countless lives.

Recent projects underscore this potential. Redwire has successfully bio-printed human heart tissue aboard the ISS, and ongoing research through partnerships with Axiom Space and the Wake Forest Institute for Regenerative Medicine is exploring liver and kidney constructs [7]. These efforts focus on developing vascularized tissues that could one day reduce the global demand for donor organs.

Bioprinting also has powerful implications for drug discovery. By producing organoids — miniature, functional versions of human organs — scientists can test new therapies in models that more closely mimic real human biology. This not only speeds up the development process but also reduces the need for animal testing [7]. As a result, research becomes both more accurate and more ethically sustainable, potentially accelerating the approval of life-saving treatments.

Navigating Obstacles

As promising as in-space bioprinting is, it still faces significant hurdles. One of the biggest challenges is ensuring that printed tissues remain safe and stable during their journey back to Earth — a process that demands ongoing research and innovation. There are also questions about scalability and cost. For bioprinting to truly transform healthcare, it must become accessible to patients and medical systems around the world.

Technical obstacles in orbit add another layer of complexity. Missions depend on multiple supply flights to deliver bioinks, living cells, and culture media. Delays and setbacks, such as the refrigeration failure during the NG-18 mission, have highlighted how difficult it is to maintain cell viability in space. In some cases, issues with media circulation have limited tissue growth [6]. Yet despite these challenges, researchers successfully printed and returned the largest tissue-engineered construct ever created in orbit, proving the resilience and long-term potential of the field.

Collaborations Driving Innovation

The success of in-space bioprinting relies on strong collaboration between public and private organisations. The meniscus project is a prime example of this approach. Redwire Space Technologies joined forces with the Uniformed Services University’s 4D Bio3 Center, The Geneva Foundation, NASA, and the ISS National Laboratory to make it happen. Astronauts aboard the ISS carried out precise bioprinting procedures, guided in real time by Red Wire’s Payload Operations Control Center on Earth [6].

This model of shared expertise and resources is essential for moving the field forward. By combining infrastructure, technical know-how, and research capabilities, these partnerships are accelerating the journey toward printing complex, functional tissues and eventually, entire organs in space.

Shaping Tomorrow

Additive manufacturing in space is on track to revolutionise regenerative medicine. As technology advances and partnerships strengthen, in-space bioprinting could offer real solutions to the global organ shortage, transform how surgeries are performed, and reshape the way new drugs are developed. What once seemed like science fiction is quickly becoming reality — a breakthrough that could redefine healthcare both on Earth and beyond.

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References

1. ISS National Lab. (2022). 3D Printer Capable of Printing Human Tissue Set to Launch to the ISS. [online] Available at: https://issnationallab.org/press-releases/ng18-3d-tissue-bff-redwire/.

2. UCSF Health. Meniscus Tear. [online] Available at: https://www.ucsfhealth.org/conditions/meniscus-tear.

3. ISS National Lab. (2023). Redwire Space Successfully 3D Prints a Human Meniscus. [online] Available at: https://issnationallab.org/iss360/redwire-space-3d-prints-meniscus/.

4. 3Dnatives. (2023). Redwire Has 3D Bioprinted the First Human Knee Meniscus in Space. [online] Available at: https://www.3dnatives.com/en/redwire-3d-bioprinted-human-knee-meniscus-space-130920236/.

5. Love, J. (2023). 3D Bioprinting - NASA. [online] Available at: https://www.nasa.gov/missions/station/iss-research/3d-bioprinting.

6. Devine, E. (2023). Redwire BioFabrication Facility Successfully Prints First Human Knee Meniscus on ISS, Paving the Way for Advanced In-Space Bioprinting Capabilities to Benefit Human Health. [online] Available at: https://ir.redwirespace.com/news-events/press-releases/detail/98/redwire-biofabrication-facility-successfully-prints-first.

7. Foust, J. (2023). Redwire demonstrates bioprinting human tissue in space. [online] Available at: https://spacenews.com/redwire-demonstrates-bioprinting-human-tissue-in-space/.