In-space manufacturing

In plain language

In-space manufacturing covers making, repairing and recycling objects in orbit, so that crews and spacecraft do not have to carry every spare part or material from Earth. The idea is that a broken part could be printed or repaired on site. Some materials may also be easier to make without gravity. Polymer parts have been printed in space, but making metal parts in orbit is still at an early stage.

The most visible results so far involve glass and crystals. In 2024, NASA reported that its Flawless Space Fibers-1 investigation on the International Space Station drew optical fibre, with more than seven miles (11.9 km) produced in total. NASA says that crystals grow more slowly in microgravity, so fibre drawn in orbit can be cooled before crystals form. A separate company, Varda Space Industries, says its 2024 W-1 capsule mission grew drug crystals inside the capsule, but its website does not publish yield or purity figures.

A 2026 peer-reviewed study grew a small indium arsenide-antimonide crystal aboard the China Space Station and compared it with a ground-grown sample. The orbital crystal had fewer defects and a more uniform composition, but it is a small research result, not a production line. A second 2026 peer-reviewed study reports that ritonavir Form III made in orbit survived the return to Earth with stable physical and chemical properties. That shows the crystal survived the flight. It does not show a medical benefit.

Technical explanation

NASA states that crystal growth is slower in microgravity, so drawn fibre can be cooled before crystals form. The NASA page describes the Flawless Space Fibers-1 investigation as having achieved three of four ZBLAN goals set by NASA's InSpace Production Applications (InSPA) programme. The fourth goal, fibre of quality ten times greater than ground-made fibre, needs analysis after the samples return to Earth. NASA reports more than seven miles (11.9 km) of fibre drawn in total, with more than 3,700 feet (1,141 metres) drawn in a single day. The page dates the drawing to mid-February to mid-March, and its article is dated 25 March 2024. The page also reports at least seven draws longer than 700 metres.

On the manufacturing side, Hoffmann and Elwany (2023) review additive manufacturing for space and note that polymer printing was demonstrated in space in 2014, while methods for metals and other materials are still needed. Prater and colleagues (2018) describe NASA's in-space manufacturing project and its plan for a multimaterial fabrication laboratory on the station, to be deployed in the early 2020s.

Material made in orbit usually has to return to Earth to be tested or used, so reentry is part of the production chain. Varda reports, on its own website, that its W-1 capsule reentered on 21 February 2024 after growing crystals of the antiretroviral drug ritonavir (Form III) inside the capsule. The page gives no yield, purity or measurement method, so these results should be treated as company-reported until independent data are published.

A 2026 npj Microgravity study (Huang and colleagues, 2026) grew an InAs0.933Sb0.067 single crystal about 11 mm in diameter aboard the China Space Station over 60 hours. The crystal had a growth length of about 2.5 mm. Compared with a 1-g sample, the orbital crystal had about one order of magnitude fewer dislocations (about 1 × 10^5 against 1 × 10^6 per cm²) and a higher electron mobility (about 12,590 against 6,070 cm²/V·s) at similar carrier concentration (about 5.6 × 10^17 per cm³). The authors attribute the high carrier concentration to arsenic and antimony vacancies and state that future work should focus on terrestrial growth of high-quality crystals.

A 2026 npj Microgravity study (Bauser and colleagues, 2026) reports recovery of metastable ritonavir Form III made in orbit. Control samples of Forms I, II and III and amorphous ritonavir also flew and returned, and the authors describe their physical and chemical stability as excellent compared with Earth-held reference samples. Seven of the study's fifteen authors list a Varda Space Industries affiliation.

Varda's W-7 mission, with a launch date of 20 October 2026 on the company's mission page, is designed to test whether microgravity can produce a crystal form of a PROTAC cancer drug with better solubility. The page describes the aim and gives no results.

NASA's Fabrication of Amorphous Metals in Space (FAMIS) investigation planned to process tungsten-reinforced bulk metallic glass samples in a furnace on the International Space Station and analyse them after return. The NASA page, last updated in May 2023, reports no results. NASA's June 2025 researcher guide says that reducing gravity-related heat and mass transport can help separate those effects during solidification. It credits ISS materials science experiments with contributing to improved mathematical models for predicting material properties during processing on Earth.

What the evidence says

Each statement is typed by the strength of its evidence and linked to the source that supports it.

Limitations and open problems

• Metal and other non-polymer processes are still being developed, so in-orbit production is narrower than polymer printing (Hoffmann and Elwany, 2023).
• The ZBLAN quality claim is not yet verified. NASA says fibre quality can only be fully assessed after the samples return to Earth (NASA, 2024).
• A long production length does not by itself show better fibre. NASA says the quality goal can only be judged after the samples return to Earth (NASA, 2024).
• Varda's crystallisation result is company-reported, and the page gives no yield, purity or measurement method (Varda, 2024).
• Material must be returned to Earth for testing, which adds logistics and time (NASA, 2024).
• The InAsSb result is one small crystal of one composition, measured under research conditions. It is not a finished infrared device or a production process (Huang and colleagues, 2026).
• The InAsSb authors attribute the high electron concentration to vacancies and state that high-quality terrestrial growth is still needed (Huang and colleagues, 2026).
• The ritonavir study addresses survival and stability after flight. It does not establish a clinical benefit or a production process. Seven of its authors list a Varda Space Industries affiliation (Bauser and colleagues, 2026).
• Varda's W-7 page describes the aim of its solubility experiment and gives no results, so the outcome is not yet known (Varda, 2026).
• The NASA FAMIS page reports no results and was last updated in May 2023, so its status may be out of date (NASA, FAMIS investigation page).
• The sources reviewed here do not give verified production costs or throughput for any in-space manufacturing process.

Possible future uses

Timeline

1. 2014Polymer printing is demonstrated in space, as noted in a 2023 review of in-space additive manufacturing. Sources: [2]
2. 17 Sept 2018NASA's in-space manufacturing project sets out a plan for a multimaterial fabrication laboratory on the International Space Station, planned for the early 2020s. Sources: [4]
3. Feb 2023Hoffmann and Elwany's review of in-space additive manufacturing appears in issue 2 of the Journal of Manufacturing Science and Engineering. Sources: [2]
4. 21 Feb 2024Varda's W-1 capsule reenters after growing ritonavir crystals inside the capsule, according to the company. Sources: [3]
5. 25 Mar 2024NASA reports ZBLAN optical fibre drawn on the International Space Station, with more than 1,141 metres drawn in a single day. Sources: [1]
6. 25 Feb 2026A peer-reviewed study reports an InAsSb single crystal grown aboard the China Space Station, with fewer dislocations and a more uniform composition than a 1-g sample. Sources: [5]
7. 8 Apr 2026A peer-reviewed study reports recovery and stability of ritonavir Form III made in orbit and returned to Earth. Seven of its authors list a Varda affiliation. Sources: [6]
8. 20 Oct 2026Varda gives 20 October 2026 as the launch date of its W-7 mission, which is designed to test whether microgravity can produce a more soluble crystal form of a PROTAC cancer drug. No results are reported. Sources: [7]

Futures this could help bring about

How far away?

A permanent base on the Moon

Engineering prototypes · 2 of 6 steps done

How far away?

A self-sustaining settlement on Mars

Science unproven · 3 of 9 steps done

How far away?

Making things in orbit that can't be made on Earth

Engineering prototypes · 3 of 6 steps done

How far away?

Terraforming Mars

Science unproven · 4 of 13 steps done

Related breakthroughs

• Polymer and water lenses shaped by surface tension on ISS, preprint reports (7 Oct 2025)
• ESA-built demonstrator prints first metal part on the ISS (6 Sept 2024)

Glossary

ZBLAN

A fluoride glass used to make some optical fibres. NASA's investigation studies drawing it in microgravity, where crystal growth is slower.

Microgravity

The near-weightless condition in orbit, where gravity-driven convection and settling are greatly reduced.

Additive manufacturing

Building a part layer by layer from a material such as a polymer, metal or ceramic, rather than cutting it from a solid block.

Drawing (optical fibre)

Pulling a heated glass rod or preform into a long, thin fibre.

Dislocation

A line-shaped defect in the regular atomic arrangement of a crystal. Dislocation density is the number of these defects per square centimetre.

Electron mobility

How easily electrons move through a semiconductor under an electric field, measured in cm²/V·s. Higher values generally mean better electrical quality.

Crystal form (polymorph)

A different solid arrangement of the same molecules. Different forms of one drug can differ in solubility and stability.

Bulk metallic glass

A metal alloy cooled quickly enough to solidify without an ordered crystal structure.

PROTAC

A type of drug molecule designed to tag a disease-causing protein so that the cell breaks it down.

Sources

1. government report
   Optical Fiber Production
   NASA, 25 Mar 2024. Accessed 21 Oct 2026.
2. review article
   In-Space Additive Manufacturing: A Review
   Miguel Hoffmann, Alaa Elwany. Journal of Manufacturing Science and Engineering, Feb 2023. DOI: 10.1115/1.4055603. Accessed 21 Oct 2026.
3. company announcement
   W-1
   Varda Space Industries, Feb 2024. Accessed 21 Oct 2026.
4. conference paper
   NASA's In-Space Manufacturing Project: Toward a Multimaterial Fabrication Laboratory for the International Space Station
   Tracie Prater, Niki Werkheiser, Frank Ledbetter et al.. NASA Technical Reports Server (AIAA Space Forum), 17 Sept 2018. Accessed 21 Oct 2026.
5. peer reviewed paper
   Microgravity-enabled growth of uniform InAsSb bulk single crystal
   Jidong Huang, Huaiwen Zheng, Zhigang Yin et al.. npj Microgravity, 25 Feb 2026. DOI: 10.1038/s41526-026-00581-5. Accessed 21 Oct 2026.
6. peer reviewed paper
   A study on the stability of ritonavir form III processed in orbit and returned to Earth
   Haley C. Bauser, Pamela A. Smith, Stephan D. Parent et al.. npj Microgravity, 8 Apr 2026. DOI: 10.1038/s41526-026-00594-0. Accessed 21 Oct 2026.
7. company announcement
   W-7
   Varda Space Industries, 20 Oct 2026. Accessed 21 Oct 2026.
8. government report
   Fabrication of Amorphous Metals in Space (FAMIS)
   NASA, 22 May 2023. Accessed 21 Oct 2026.
9. government report
   A Researcher's Guide to: Microgravity Materials Research
   NASA, 17 Jun 2025. Accessed 21 Oct 2026.

Revision history

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