The Architects Who Lived on the Moon and the Ocean Floor Are Now Building the Future of Extreme Living

Two Danish architects who personally tested a lunar habitat in Arctic Greenland and lived underwater in Copenhagen Harbour are now building Europe's first operational underwater laboratory, and applying every lesson to architecture on Earth.

Landlord Ledger Publications • Profile • 2026-05-08

In the autumn of 2020, two architects flew to Moriusaq, a remote outpost in northern Greenland just south of Station Nord, dragged a shipping container up an alien beach, and spent 60 days inside a structure they had spent the previous year designing and building by hand. The temperature dropped to minus 30 degrees Celsius. Hurricane-force winds battered the carbon-fiber shell. A polar fox they named Simon investigated them from a safe distance. Sebastian Aristotelis and Karl-Johan Sorensen, co-founders of SAGA Space Architects, were living inside LUNARK: an origami-inspired lunar habitat prototype, tested in one of the most hostile environments on Earth, to prove it could sustain human life on the Moon.

A Habitat That Grows 750 Percent

LUNARK did not look like any building that had come before it. The structure was based on origami folding principles drawn from Japanese paper craft and the way a budding leaf unfolds, translated into thick carbon-fiber panels connected by compliant composite rubber hinges. From its compact transport configuration, small enough to fit inside a shipping container for the 5,500-kilometer ship journey to northern Greenland, it expanded 750 percent in volume once deployed. Two people could unfold it in roughly 10 hours using no heavy machinery. The exterior was a glossy black carbon-fiber shell, tough and lightweight, with a foam core for insulation. The interior was deliberately the opposite: warm, tactile, Nordic. A home, not a survival machine.

The most consequential technology inside LUNARK was its circadian light system. On the Moon, near the poles, sunlight is nearly constant with no natural day-night cycle to regulate sleep and cognition. Inside the habitat, SAGA installed dynamic LED panels that simulated sunrise, shifted color temperature through the day, and faded to a warm sunset at night. Aristotelis and Sorensen documented its effect on their wellbeing over the 60-day mission. The light system proved to be the single element with the largest positive impact on their psychological health during the expedition. That data eventually reached orbit. In 2023, SAGA's Circadian Light system launched to the International Space Station as part of ESA astronaut Andreas Mogensen's HUGINN Mission. As of 2025, it has been operating continuously aboard the ISS for over 1,000 days.

From Arctic Ice to Copenhagen Harbour

Three years after returning from Greenland, Aristotelis was in a wetsuit. On a September weekend in 2023, he descended into Copenhagen Harbour and entered UHAB, the Underwater Habitat for Life, a one-person structure that SAGA designed, engineered, and built from scratch in their Copenhagen workshop in a matter of months. At 7 meters depth, sealed inside a 1.8-cubic-meter pressurized capsule with a moonpool entry, he stayed for 48 hours. An onshore team of engineers and rescue divers monitored life support data in real time. The mission was a technology demonstrator: validate the subsystems, prove the concept, collect data. It succeeded on every metric.

The logic connecting LUNARK and UHAB is not accidental. NASA has used the Aquarius underwater habitat off the Florida Keys for decades as a primary astronaut training facility, because the physical and psychological conditions of living underwater, including pressure differentials, complete isolation, total dependence on engineered life support, no natural light, and confined quarters, closely replicate those of space. Aquarius, however, is in its final operational years. Europe has no equivalent. SAGA built UHAB specifically to fill that gap. The project was developed in collaboration with MIT and the University of Southern Denmark, and has been documented in a published white paper.

The Roadmap to the Ocean Floor

SAGA's underwater program has a three-stage architecture. UHAB-1, the single-person demonstrator tested in Copenhagen Harbour, proved basic subsystem viability. UHAB-2, a full-scale land-based mockup designed for four people, was delivered to the European Astronaut Centre in Cologne in early 2025. It is the same facility that now houses FLEXHab, SAGA's 28-square-meter lunar training habitat, which the studio designed for ESA's LUNA facility and which has been supporting astronaut training missions since early 2025. UHAB-2 served as the platform for a 20-day validation mission with a four-person crew, including extensive psychological and physiological evaluations conducted with MIT.

UHAB-3 is the endgame: a fully operational underwater habitat designed for four-person crews, anchored to the seabed at depths of up to 30 meters, with a dedicated mission control unit. The target deployment is 2027, in some of Europe's coldest open waters, where it will serve as both an ESA astronaut training facility and a marine research station. The habitat will be self-sustaining and airtight, featuring high-pressure backup air reserves, 10 square meters of livable floor space, polycarbonate viewports, and SAGA's proprietary Raven sensor network feeding into their Habitat OS called Odin. DTU, the Technical University of Denmark, has identified strong research collaboration potential, and the Danish National Defence Technology Centre has noted defence applications for the platform.

The need is concrete. Aquarius, the only existing operational underwater habitat in the world, has been running since 1993 and is approaching end of service. The gap it will leave is not merely symbolic. Astronaut training programs, marine biologists, oceanographers, and climate researchers have all depended on it. UHAB-3 would be the first purpose-built European successor.

FLEXHab and the ISS: A Studio With Operational Hardware

SAGA's biography already has more operational hardware in active service than most architecture firms accumulate in a generation. Beyond the ISS circadian light system and the UHAB program, the studio designed FLEXHab: the astronaut training habitat at the European Astronaut Centre's newly constructed LUNA facility in Cologne, Germany. FLEXHab is a 28-square-meter prefabricated structure with a 3D-printed facade made from glass-fiber-reinforced polymer, upcycled wood composite interiors, a laboratory, sleeping quarters, a galley with stowable dining furniture, and an EVA airlock simulation bay. It can support four astronauts for up to 30 days. Its circadian lighting system is identical in principle to the one operating on the ISS. The first training missions began in early 2025.

SAGA also co-founded 3DCP Group in 2021, now the largest 3D construction printing company in Northern Europe. The studio holds multiple world records in large-scale additive manufacturing, including the largest 3D-printed structure in Scandinavia and the largest in Central America (the Mirador Pavilion). Their Skovsporet development in Holstebro, Denmark, comprising 36 student apartments across six buildings and printed on-site using a COBOD BOD3 printer with low-carbon FUTURECEM concrete, is recognized as Europe's largest 3D-printed housing development. The printing phase for all 36 units concluded in late 2025, with handover to residents scheduled for August 2026.

What Space Architecture Does to Earth Buildings

The connection between SAGA's extreme-environment work and their residential practice is not rhetorical. It is methodological. The same tools, including topology optimization, generative design, 3D printing, and biogenic digital fabrication, that produced LUNARK's carbon-fiber origami shell and FLEXHab's parametric facade are now producing housing in Denmark and private residences in Vietnam. Their EcoNeo house is a 35-square-meter summerhouse built entirely from biogenic materials using digital fabrication methods, capable of accommodating a family of six with a sauna. Their Eden Villa in Vietnam, a 750-square-meter private residence, features the world's largest electrochromic glass dome. The logic running through all of it is what SAGA calls Terra-Tech: extreme constraints create better methods, and better methods make better buildings, wherever they are.

For investors and developers watching where residential architecture is going, the SAGA story offers a sharper version of a question the market is already beginning to ask. Housing is one of the largest asset classes in the world. The methods used to produce it, traditional construction with long lead times and significant material waste, have not changed substantially in decades. The firms that will change them are not coming from within the industry. They are coming from aerospace, from digital fabrication research, from places where the cost of failure is not a budget overrun but a life-support failure at minus 30 degrees or 30 meters below sea level. The discipline those environments enforce on design produces tools with very wide application. SAGA has been stress-testing those tools, literally, since 2020.

The full-scale underwater habitat planned for European waters represents the next proof point. If UHAB-3 operates as designed, four people living and working at 30 meters depth in cold northern seas for extended durations, training for moon missions and conducting marine science, then the technologies that made it possible: the life support architecture, the sensor networks, the materials, the psychological design, become available for a second purpose. The same origami logic that let two architects unfold a lunar home in the Arctic could fold into a building envelope that prints itself on a Danish street. It already has.