Portugal Cork | Warren C. Volles

Sustainable Cork Engineering in Portugal:
From Wine to Rockets

While visiting the Cortiçarte cork factory, I learned that cork is a sustainable material used in many products including those in the expanding field of aerospace engineering. Its lightweight, fire-resistant, and insulating properties make it especially valuable for spacecraft components.

Portugal is the world's leading cork producer. It has 737,000 hectares, or 34% of the world's forests, where cork oak trees grow. Portugal produces about half of the world's cork supply. A significant portion of Portuguese cork is exported, mainly to the European Union, the United States, and China.

The cork processing factory Cortiçarte, located in Azaruja, Portugal, was established in 2000. Cortiçarte is one of the innovators in the cork industry. The company oversees the entire cork process, from harvesting the cork out of the forests to processing and transforming it into various products. They are committed to making cork a practical and sustainable material.

Cork comes from the bark of cork oak trees, Quercus suber, that are mainly found in the warm climates of the Mediterranean area. The bark is collected every nine years using an environmentally sound method that does not harm the tree. In fact, cork oaks can live up to 200 years.

The harvested bark is processed in factories before being made into products from wine stoppers to fashion items, furniture, flooring materials, and even space industry components.

In fact, cork has been used from the 1960s to today in multiple parts of spacecraft, including as insulation for solid fuel tanks, linings in engines, nose cones, and as part of the heat shields in space capsules.

Cork has properties that make it a great choice for insulating rockets against the intense heat generated during launch and atmospheric re-entry.

1960s

Historically, cork materials have been used for insulation in spacecraft since the 1960s, starting with the early Scout rockets. This practice continued with the Mercury and Gemini spacecraft and later with the Saturn V, Apollo, Space Shuttle, Titan, Pegasus XL, and Delta IV programs.

today

Cork is used in SpaceX rockets and NASA's Artemis program. In 2025, NASA's Space Launch System will carry astronauts in the Orion spacecraft to the Moon's South Pole during the third Artemis mission. This rocket will benefit from cork insulation since it will face the intense heat of launch and extreme temperature variation in deep space.

Properties of Cork

Cork is lightweight and a good insulator because of its cellular structure, which is 70% air by volume.

Cork is able to withstand extreme temperatures, which can range from -423°F (-253°C) to over 200°F (93°C) during space travel.

Additional Insights

As a rocket ascends, it generates intense heat due to air resistance and the combustion of fuel. However, the cryogenic fuel that powers it—typically a combination of liquid hydrogen and liquid oxygen—must remain extremely cold to stay in liquid form. If temperatures climb too high, the fuel would vaporize, potentially disrupting the launch or damaging the vehicle. To manage this contrast between extreme external heat and the need for internal cooling, engineers use advanced insulation materials. One of these is cork, which is naturally lightweight, fire-resistant, and an excellent thermal insulator.

References

Cork Industry Federation. (2024, January 24). Why is cork needed in space? https://cork-products.co.uk/why-is-cork-needed-in-space/

Cork Quality Council. (n.d.). Industry statistics. https://www.corkqc.com/pages/industry-statistics

Corticarte. (n.d.). About us. https://corticarte.pt/

De la Cuetara, I., Rand, B., McDonald, J., Schlosberg, J., & Pereira, I. (2024, April 25). Power of cork key to climate change fight, scientists say. ABC News. https://abcnews.go.com/International/power-cork-key-climate-change-fight-scientists/story?id=105688608

Latham, K. (2023, December 29). Champagne stoppers in space: How cork will protect the next spacecraft to visit the Moon. BBC. https://www.bbc.com/future/article/20231228-champagne-stoppers-in-space-how-cork-will-protect-the-next-spacecraft-to-visit-the-moon

Noal Farm. (2022, December 3). How it's made wine cork - Harvesting 50 million cork wine and making process in factory [Video]. YouTube. https://www.youtube.com/watch?v=kDmiQWW6XSM