As an experiment, the first B2 mission highlighted the challenges of isolated systems

During the first Biosphere 2 mission, crew members lost 16% of their body weight

Food and oxygen shortages drove the "Biospherians" to split into two factions—one seeking to bring in outside resources and another aiming to maintain isolation for the experiment's integrity. Psychological stress was exacerbated further by the increasing prevalence of insect pests.

Before Biosphere 2, the Soviet BIOS-3 system tested semi-closed ecosystems

Built from 1965 to 1972, the habitat hosted 10 experiments with crews ranging from one to three individuals who had their air recycled by algae and grew their own wheat and vegetables. However, dried meats were routinely brought into the facility to balance crew members’ diets.

Exposed concrete led to oxygen depletion within Biosphere 2

Instead of being absorbed by plants through photosynthesis to produce oxygen, significant amounts of carbon dioxide were taken up by the calcium hydroxide in the concrete, trapping the oxygen in calcium carbonate and water. This concrete was sealed before the start of the second B2 mission.

An artificial ‘lung’ protects the glass structures making up Biosphere 2

Although confined from much of the surrounding environment, B2 allows sunlight to enter, enabling its plants to engage in photosynthesis. Expansion chambers were built to protect the facility's integrity by managing changes in gas pressure resulting from temperature fluctuations.

Biosphere 2 gradually transformed into a lab modeling environmental disasters

Built to establish a self-sustaining habitat, the privately funded facility was taken over by Columbia University in 1995. Closed-system experiments were halted in favor of investigations focused on the effects of climate change, which continued after B2 was donated to the University of Arizona in 2011.

Biosphere 2 is the largest Earth science experiment ever built

The vivarium—an enclosed system including animals and plants—is sealed from below with 454 metric tons of stainless steel liner and includes an ocean habitat with more than 700,000 gallons of seawater. B2 is visited by 100,000 people yearly, including more than 10,000 K-12 students.

Read a firsthand account of a participant in the first Biosphere 2 mission

The first crew of “Biospherians” spent four months growing their own wheat and awaiting the ripening of tomatoes, onions, and peppers to make their own pizza. They also raised their own livestock, including chickens, pigs, and two goats named Milky Way and Stardust.

Biosphere 2 revealed limitations in maintaining wildlife in unfamiliar environments

Trees appeared to become weak and more prone to breaking because a lack of wind caused them to no longer need to develop stress wood. The extinction of pollinators—potentially due to an explosion in the population of longhorn crazy ants—was also unexpected.

Biological terraforming studies have been conducted at Biosphere 2

The experiments involve populating barren hillslopes within the Landscape Evolution Observatory with microbes that react with air and rock to produce molecules needed by more complex organisms. Mosses and other simple plants can then grow in these spaces, gradually making them more hospitable to humans.

A prototype greenhouse for Biosphere 2 is now part of a test habitat for Mars

The Space Analog for the Moon and Mars combines the Test Module greenhouse with a workshop, kitchen, common area, sleeping quarters, and a yard that mimics lunar and Martian surfaces. A blind crew member in SAM’s first mission, Inclusion I, helped assess accessibility in potential future space habitats.

A basement of mechanical systems—collectively called the technosphere—supports B2

Twenty-six underground air handlers heat, cool, filter and manage the humidity of the air across the biomes of Biosphere 2. The above-ground Energy Center complex provides continuous power to these and other systems, including heating and cooling water for laboratory experiments and personal use.

Questioning the results of life on K2-18b

An analysis of the atmosphere of an exoplanet called K2-18b identified the presence of biosignatures—molecules that are created by living things on Earth. This discovery may indicate life exists beyond Earth, but the lack of environmental data complicates the interpretation of results.

Astronauts on the International Space Station have tested an algae-powered bioreactor that converts carbon dioxide, water, and light into oxygen and edible, protein-rich biomass.

B2 models the interactions of air, water, soil, plants and microbes at the LEO

The Landscape Evolution Observatory at Biosphere 2 examines how factors such as climate change, water flow, weathering and community development impact landscape structures comprising 500 metric tons of crushed rock. Research is also conducted at biomes representing savannas, mangroves, coastal fog deserts, oceans and rainforests.

Research suggests the cleanliness of the ISS may make astronauts unhealthy

The International Space Station's sterile conditions deprive astronauts of the opportunity to strengthen their immune systems through microbial exposure. To address this problem, future missions may use probiotic-based cleaners and foster diverse microbes in space habitats.

China developed an artificial closed ecosystem in preparation for a future lunar base

Yuegong-1, also known as Moon Palace 1, was a Beijing facility where volunteers simulated life on a colony and conducted experiments on bioregenerative life support systems to assess their viability in an off-Earth environment. The longest experiment at the 0.04-acre facility lasted 370 days.

Steve Bannon was made CEO of the company in charge of Biosphere 2 in 1994

After providing $200M to launch and upgrade B2 before its second mission, billionaire philanthropist Ed Bass appointed the future political strategist and then financial consultant to help find new investments and bring costs under control. Fearing interference from non-science experts, Biospherians from the first mission vandalized the project.

Take a series of virtual tours of Biosphere 2

The videos provide a 360-degree view of the indoor rainforest, ocean ecosystem, Landscape Evolution Observatory, and underground technosphere. A Google Maps Street View option is available to explore additional biomes, with each associated with a different floor level on the bottom right.

As of 2025, scientists at B2 study the heat tolerance of cacao and coffee trees

The research at Biosphere 2 has led to the development of low-cost plant monitors, which can be provided to farmers worldwide to enable more precise monitoring of crops. Geodesic domes built within the ocean biome are used to investigate the best architectural structures for repopulating degraded reefs.

The setting of the comedy film ‘Bio-Dome’ was inspired by Biosphere 2

The film features characters played by Pauly Shore and Stephen Baldwin who accidentally lock themselves inside an experimental biosphere, mistaking it for a shopping mall, while searching for a bathroom. With a Rotten Tomatoes score of 4%, it is considered one of the best-worst movies of all time.

Inhabiting Mars without terraforming might be accomplished with 'worldhouses'

A network of interconnected, airtight bubbles would require several orders of magnitude fewer materials than those required to re-establish the entire planet's atmosphere to resemble Earth. However, the whole network would be compromised by a single micrometeor impact that destroys the air seal.

Agrivoltaic solutions are tested in the land around the Biosphere 2 complex

The experiments involve identifying conditions needed to grow plants beneath solar panels, which protect the plants from the harsh sunlight of the Arizona desert. Research includes a citizen science component, where satellite gardens have been installed in nearby high schools.

Watch what it’s like to spend a day on the International Space Station

Microgravity makes personal care more complex on the International Space Station, where stray, floating materials must be captured to prevent them from entering vents and clogging filtration vents. No-rinse shampoo, water pouches, and other strategies help minimize obstructions.

Oxygen is produced in the International Space Station from recycled water, which is split into hydrogen and oxygen gases using an electric current.

Civilians on short-term spaceflights can experience long-term astronaut health impacts

A collection of 44 studies—primarily based on data from a 2021 tourist trip to low Earth orbit—identified immune system disruption and some kidney damage in tourists, with women appearing to recover from space travel faster than men. Return trips from Mars may require human travelers to be on dialysis.

In 2013, an astronaut's helmet began filling with water during a spacewalk

A leak in the cooling system of Luca Parmitano's spacesuit caused water to obscure his vision and silence his radio as the International Space Station entered Earth's shadow, forcing him to feel his way back to the airlock in darkness.

Five hazards of human spaceflight

From space radiation to isolation, humans struggle when it comes to traveling and living in space. What does this mean for long-term spaceflight? This hour-long podcast episode attempts to answer that question while detailing five major spaceflight hazards.

An oxygen tank explosion forced Apollo 13 to abort its moon landing

The 1970 mission—intended to be the third lunar landing—forced astronauts Jim Lovell, Jack Swigert, and Fred Haise to focus solely on their survival. They engineered a makeshift filter to handle the carbon dioxide they produced, which exceeded the lunar module's capacity.

Technologies developed for the ISS have brought benefits to people on Earth

About 93% of water used onboard the International Space Station is recycled through filtration and purification systems that have since been used in regions lacking access to clean water. Treatments to mitigate bone loss and muscle atrophy in astronauts can also help aging adults.

Drugs in space: the pharmacy orbiting the Earth

Researchers are developing pharmaceutical solutions for astronauts, whose bodies may not respond the same way in space as they would on Earth. Similar to how microgravity causes changes to astronaut physiology, the environmental shift enables new...

Astronauts follow strict schedules to mimic Earth days and stay healthy in space

Experiencing 15 sunrises and sunsets a day while aboard the International Space Station, visitors preserve their circadian rhythms and mental health with fixed timetables. Astronauts have described sleep as living in a vacuum cleaner due to ongoing air filtration.

Mold growth in space raises the hypothesis of life being brought to Earth

Panspermia suggests that life could be carried throughout the cosmos by asteroids, comets, and other objects, but it requires organisms that can withstand the extreme cold of space travel, stellar radiation, lack of water, and intense heat of planetary impacts. The discovery of mold on the International Space Station and experiments showing it can withstand radiation in outer space-like conditions increase the plausibility of the hypothesis.

Read the NASA overview of the results of Viking’s biological experiments on Mars

Three experiments on the Viking 1 and 2 landers searched for signs of metabolic activity in soil samples, indicating the presence of microorganisms. No definitive evidence of life was found in any experiment or lander imaging.

Evidence suggests some of the Challenger's crew may have been alive after the explosion

Recovery of the intact crew cabin and later analysis of flight data led investigators to conclude the astronauts likely survived the initial breakup and remained alive during the roughly two-minute descent before the cabin struck the ocean.

How do astronauts battle loneliness and depression?

You’re stranded hundreds of miles away from your friends and family, constantly surrounded by coworkers who also are your roommates, and you’re only allowed the shortest of walks outside. There’s also no takeout, and gravity has essentially broken up with you. You might need a little help adjusting mentally. That’s where space psychologists and psychiatrists step in, according to this article.

NASA uses extreme Earth environments to prepare for space exploration

Analog missions in volcanic terrains and craters mimic Martian and lunar environments. Crew members operating in these missions, including at sites in Utah, Nevada, Arizona, and Hawai'i, test suits and specialized space instruments under simulated conditions.

The Russian Federal Space Agency enabled the first space tourism journey

NASA refused to take Dennis Tito, who had no formal training as an astronaut, up to the International Space Station. Instead, the American engineer and entrepreneur traveled aboard the Soyuz TM-32 mission and described the initial experience of microgravity after engine shut-off as the "most spectacular" part of the flight.

Tardigrades have not been shown to survive all space conditions at once

A 2007 mission launched several species into low-Earth orbit, exposing them to microgravity in temperature-controlled modules. Survivability rates were high for microgravity exposure alone, but plummeted when combined with exposure to the full UV spectrum and the vacuum of space.

Prolonged space travel significantly impacts multiple human body systems

Astronauts can lose 20% of their muscle mass after two weeks and 10% of their bone mass after six months in space. Decreased sharpness of eyesight and changes in neural connectivity, brain structure and gut bacteria have also been observed.

The inhabitability of the Martian environment presents significant colonization risks

Terraforming the thin atmosphere, toxic dust, extreme cold, and lack of magnetic field is infeasible, given limitations to the size of what can be sent to Mars. NASA and SpaceX are instead exploring creating underground shelters.

Blue Origin, Jeff Bezos’ aerospace company, sent its first passengers to space in 2021

Founded in 2000, Bezos spent many years working on the company as a side project before it became more well-known around 2004, when a plot of land in Texas was purchased as a launch site for the company’s rockets. He has said that the goal of Blue Origin is to build “reusable space vehicles.” This resource details what passengers experience from takeoff to landing on a Blue Origin flight.

Hear the story of a cosmonaut stranded in space after the Soviet Union collapsed

When the USSR dissolved in 1991, cosmonaut Sergei Krikalev was still aboard a space station—forcing him to remain in orbit for months longer than planned. This limited podcast series recounts the event, hosted by astronaut and pop star Lance Bass.

Explore a timeline of the International Space Station National Lab

In 1984, President Ronald Reagan called for establishing a human presence in space, which began with NASA astronaut Bill Shepherd and Russian cosmonauts Yuri Gidzenko and Sergei Krikalev on November 2, 2000. Humans have continuously occupied the ISS every day since.

The origin of cyborgs

The term "cyborg" was coined in a 1960 academic paper discussing what alterations humans would need to undergo to survive in extraterrestrial environments, a venture far "more logical than providing an earthly environment" in space. According to authors Manfred E. Clynes and Nathan S. Kline, Cyborgs with a capital C have incorporated exogenous components that extend their ability to adapt to new environments. Read the paper here.

Wind helps trees develop resistance to collapse

Scientists at Biosphere 2 found that trees grew faster in the facility than those in the wild but collapsed more quickly when replanted outdoors. Researchers uncovered that trees build resistance when pushed and pulled due to wind stress, strengthening their foundational root systems.

It is impossible for astronauts to burp in space

Due to Earth's gravity, liquids and solids sink in our digestive system, while gases rise, allowing them to be forced back up the esophagus to be expelled through burping. In the microgravity environment of the International Space Station, burping would result in vomiting if it were possible.

Hubble overcame early optical failure and became a critical scientific instrument

The flaw in Hubble's mirror was smaller than the width of a human hair, but fixing it required a space mission as complex as a Hollywood rescue story—with astronauts installing corrective optics like contact lenses for a giant eye in the sky.

Explore what Challenger was supposed to do on its mission

STS-51L's planned seven-day mission included deploying satellites, studying Comet Halley, conducting fluid dynamics experiments, and broadcasting live lessons from orbit—routine scientific and educational tasks that were never carried out after the shuttle was lost shortly after launch.

The Challenger disaster grounded the space shuttle fleet for nearly three years, exposed deep flaws in NASA's leadership, and prompted significant changes to the agency's safety oversight and decision-making culture.

An unedited interview with the first person to float freely in space

Astronaut Bruce McCandless was the first person to ever float freely in space, completely untethered from a shuttle. How did he enter the field? What are his thoughts on current space travel? Listen to his experience and opinion firsthand in this 19-minute video.