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5 days beneath the waves: What it's like to live in an underwater 'space station'
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- DeepHorus
A four-person crew completed a five-day simulated space mission 22 feet beneath the ocean surface in the Jules’ Undersea Lab near Key Largo, Florida. The SEA STAR mission studied challenges astronauts may face on long-duration space missions. The crew lived and worked underwater without returning to the surface until the mission ended.
The habitat was built in the 1970s as “La Chalupa,” a mobile facility designed for aquanauts living and researching underwater for more than 24 hours in saturation. It was originally housed in a barge 20 feet wide and 60 feet long and could be flooded, submerged, and moved between sites. It now hosts missions near Key Largo, including a NASA 30-day project and two world-record stays of 73 and 100 days.
Inside, the station includes a galley with a kitchen and dining/work area, a toilet and shower, a moon pool entrance, and a bedroom with two bunk beds. Three windows offer views of the green surrounding water. NASA-origin communications and umbilical cables provided air, fresh water, and power, while a direct line to Mission Control supported emergencies.
The crew followed an International Space Station-style schedule. Each member managed research projects and daily tasks including cooking, medical checkups, cognitive tests, maintenance, and repairs. The commander coordinated work, and the team conducted “spacewalks” as scuba exploration dives.
The mission’s value lies in its realism. Space research remains rare and expensive, so analog habitats let scientists observe teamwork, stress, and operational challenges under extreme but controlled conditions. The underwater setting mimics the isolation and confinement of long-duration spaceflight.
The experience was described as surprisingly peaceful, with only life-support systems audible beyond crew-made noise. That quiet isolation resembles what a future Mars habitat might feel like. Such tests can inform training and habitat design for astronauts preparing for farther journeys.
