Organic Tissue

Growing protein crystals or organic tissues in microgravity results in larger and more uniform structures, potentially enabling to grow organs.

Updated: 2023-03-12

Created: 2018-11-01


Active research for decades and multiple companies, but technology not yet ready to grow organs.


  • Growing human organs.
  • Growing human skin.
  • Protein crystal growth (skin, hair, nails).
  • Larger more ordered crystals.2
  • Producing stem cell for personalized medicine.
  • Making protein-based artificial retinas.

Why & Solution

Bio-medical scientists grow artificial proteins in laboratories on Earth to understand how they work and to learn how to adjust treatments and medications accordingly. The problem is that proteins grow into flat, dimensionless blobs making them hard to analyze with existing equipment. When proteins are grown in the microgravitational environment of space, wonderfully large and articulate structures emerge. These space-borne protein crystal can be easily tested and this makes it easier for researchers to find cures for diseases. Because proteins grow so well in space, organs and artificial skin can also. Any protein damaged beyond repair by accidents or diseases can be grown more efficiently in the low gravity.4

In the long term, other products may potentially be profitably manufactured in LEO for sale on Earth—for example, growing human organs in space for transplant operations. However, we found that the current state of technological readiness of this potential process did not fall into the timeframe discussed in report "Market Analysis of a Privately Owned and Operated Space Station". Research on 3D tissue engineering on the Space Shuttle and the ISS has shown improvements in the size and quality of tissues grown in space compared to those grown on Earth. Growing tissues on Earth results in clumped, almost two-dimensional materials, while growing tissues in space results in more uniformity in three dimensions, similar to how beads produced in space are almost perfect spheres. For most organs, threedimensional tissue engineering still tends to be at an early stage of development; the technology readiness level (TRL) of this research is low. On a scale of 1 to 10, with 10 being ready for commercial launch, in 2014, Carroll et al. (2014) rated tissue engineering to grow organs as TRL-3. According to some, growing portions of organs and muscles in microgravity on parabolic and suborbital flights has shown promise and may become commercially viable by 2024 (expert interview).1

Cells can grow into larger networks without gravity pulling them down into their container as would happen on Earth. "The idea of how microgravity can help cells grow has been around for a long time; in fact, one of the dominant tools that medical pharmaceutical research uses today, the rotating wall vessel, was actually developed as part of an '80s space shuttle effort at NASA," MacDonald said. "The cells aren't smart, but they're adaptable," Harper said. "And if they touch a side or a surface, it gives them a message that's biologically misleading." "Organs, of course, are incredibly high-value, both in their ability to save life, but also their cost in terms of the medical economy," MacDonald said. "You've started to see companies start to experiment — so far, not on the space station, but on parabolic flights."3

Space Tango and partners were selected by NASA in 2020 for 3 proposals focused on regenerative medicine:

  • Space Tango and its partner Cedars-Sinai of Los Angeles are developing pilot-scale systems for the production in space of large batches of stem cells to be used in personalized medical treatment for a variety of diseases. The development of induced pluripotent stem cells (iPSC) for commercial personalized medicine applications is done in space because the work to date on the space station demonstrates stem cells retain their “stemness” for longer durations in microgravity, allowing a delay of differentiation that has the potential to enable larger batches of cells to be produced. The pilot-scale systems, built for the space station to serve as basis for future commercial manufacturing systems, will incorporate regulatory strategies to support FDA clinical trial production of personalized medicine stem cell therapies on the space station. This includes Current Good Manufacturing Practices (CGMP) conditions, required for production of stem cell therapies for human use in patients. 
  • Space Tango and its partner LambdaVision of Farmington, Connecticut, are developing a system to manufacture protein-based retinal implants, or artificial retinas, in microgravity. The market for this work is millions of patients suffering retinal degenerative diseases, including retinitis pigmentosa (RP) and age-related macular degeneration (AMD), a leading cause of blindness for adults over 55 years old. This effort builds on a validation flight completed in late 2018 that demonstrated the proof of concept for generating multilayered protein-based thin films in space using a miniaturized layer-by-layer manufacturing device. This project will further mature the manufacturing system, producing protein-based artificial retinas in space that would be returned to Earth for surgical implant to restore sight for patients suffering from degenerative retinal diseases. This work will establish the necessary regulatory requirements for producing biomedical products in space, including Current Good Manufacturing Practices (CGMP). The microgravity environment of space hinders convection and sedimentation in the manufacturing process, enabling more uniform layers, improved stability and higher quality than can be produced on Earth. 
  • Space Tango and its partners at UC San Diego/Sanford Consortium in La Jolla, California, are working to establish a new on-orbit biomedical sector for stem cell advancement, with a fully operational self-sustaining orbital laboratory anticipated by 2025. The team is working to refine current hardware capabilities and process flow, extending the capabilities of ground-based laboratories with regular access to the space station via secured flight opportunities. Stem cells differentiate into tissue specific progenitors that can be used in microgravity to better understand aging and immune dysfunction, providing an opportunity to accelerate advances in regenerative medicine and the development of potential new therapeutic approaches. The target market for this orbital laboratory is a new approach to stem cell translational medicine.


Redwire (Techshot) page at Factories in Space

Redwire Space is accelerating humanity’s expansion into space by delivering reliable, economical, and sustainable infrastructure for future generations.


A 3D BioFabrication Facility (BFF) developed by nScrypt and Techshot and designed to 3D print thick tissue and organs using adult stem cells will launch to the International Space Station (ISS) aboard the next SpaceX cargo resupply mission.

During the companies years of research, it was found that 3D bioprinted soft, easily flowing biomaterials (i.e, human tissue) collapse under their own weight. However, these same materials are able to maintain their shapes when produced in the microgravity environment of space.

Thus, these structures, which will consist of blood vessels and muscle, will be 3D bioprinted in space and placed in a cell-culturing system that strengthens them over time. This will permit them to become viable, self-supporting tissues that will remain solid once back on Earth.

The initial phase for BFF, which could last an estimated two years, will involve creating test prints of cardiac-like tissue of increasing thickness. The following phase will involve an Earth-based evaluation of heart patches manufactured in space under a microscope and potentially in small animals such as rats. This is expected to last through 2024.

NASA, Redwire and the Uniformed Services University of the Health Sciences Center for Biotechnology (4DBio3) are sending a new 3D printer to the International Space Station, Redwire's BioFabrication Facility, to bioprint a human knee meniscus in orbit and study the result on Earth. Ideally, this will lead to treatments for the meniscal injuries that US soldiers all-too-frequently face.

The BFF-Meniscus-2 investigation, a collaboration between Redwire and the Uniformed Services University of the Health Sciences Center for Biotechnology (4DBio3), will build on a 2019 experiment where the BFF 3D printed a meniscus scaffold using bioink derived from human tissue proteins. BFF-Meniscus-2 will use an upgraded BFF that allows greater temperature control when printing with bioinks that are sensitive to temperatures.

Redwire hopes to 3D print whole organs in space, although it characterizes this as a "long-term" goal. The company is also using NASA's Advanced Plant Habitat for a project to identify genes for space-friendly plants. Another investigation will use a NASA furnace to create and demo passive cooling for electronics in low gravity.

Earthly Solution Risk

Exists due to active research e.g Vascular Tissue Challenge by New Organ and NASA to create thick, metabolically-functional human vascularized organ tissue in a controlled laboratory environment.


  1. Keith W. Crane et al. Market Analysis of a Privately Owned and Operated Space Station. IDA Science & Technology Policy Institute. Published in March 2017. Source

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  2. Ioana Cozmuta et al. Space Portal NASA Ames Research Center. Microgravity-Based Commercialization Opportunities for Material Sciences and Life Sciences: A Silicon Valley Perspective. Source

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  3. Making Stuff in Space: Off-Earth Manufacturing Is Just Getting Started. Sarah Lewin, Published 2018-05-11. Accessed 2019-01-31. Source

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  4. Andrew M. Thorpe, The Commercial Space Age: Conquering Space Through Commerce, 2003. Source

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