The ISS marks 2 decades of continuous human presence

The International Space Station has just crossed 20 years of continuous human presence as its unbroken string of expedition crews continue to perform a wide range of scientific research aboard this multinational outpost.

Expedition 1 launched to the outpost on Oct. 31, 2000, and docked two days later on Nov. 2. Their job primary job was to begin setting up shop for what would become the longest stretch of continuous human presence in space. Since then, 64 crews of called the ISS home.

Throughout the years, these crews have performed thousands of experiments in areas such as 3D printing, cancer treatment research, materials science, human studies, and so much more!

The Expedition 64 crew. Credit: Orbital Velocity

The largest human-built object in space

At roughly the size of a football field, this $150 billion multinational outpost circles Earth at 28,000 kilometers per hour, orbiting the planet every 90 minutes at an altitude of 400 kilometers.

Astronauts and cosmonauts aboard experience 16 sunrises and sunsets each day as they work on science experiments and perform station maintenance.

The station itself can be seen by nearly every person on the planet as it soars overhead as the brightest object in the night sky, save for the Moon.

While its origins go back farther, today’s ISS was conceived in 1993 when the United States and Russia agreed to merge their space station projects to form a single international outpost.

In total, five space agencies representing 15 countries agreed to work together to build, maintain and service the outpost: NASA, Roscosmos, the European Space Agency, the Canadian Space Agency and the Japan Aerospace Exploration Agency.

The International Space Station is roughly the size of an American football field. Credit: NASA

Built between 1998 and 2011, the 400-metric-ton ISS has over a dozen habitable modules with a living space comparable to a five bedroom house.

It stretches some 109 meters by 73 meters with its eight massive solar array wings, which produce between 84 to 120 kilowatts of electricity, enough to power more than 40 homes!

Assembling the ISS required more than 40 launches, including 36 space shuttle flights and several Russian Proton and Soyuz rockets.

Since the year 2000, rotating expeditions of between two and six people have continually occupied the outpost with seven person crews expected to begin as early as later this month.

During construction, much of the crew time was spent assembling and maintaining the station. Today, more than 20,000 hours each year are dedicated to science and research activities.

As of November 2020, some 240 people from 19 countries have visited the ISS with many traveling there multiple times.

The station was designed to be an orbiting research laboratory, observatory and factory with the potential to facilitate future missions to deep space destinations like the Moon or Mars.

Nearly 3,000 research investigations have been performed at the ISS. Credit: NASA

‘Off the Earth, for the Earth’

Since 1998, nearly 3,000 investigations aboard the ISS have generated some 2,100 scientific publications in a wide range of fields with even more spinoff research in non-space industries, according to NASA.

Research areas include materials science for better manufacturing techniques on Earth, space-based vaccines, remote sensing technologies for disaster response and more.

For example, advanced water filtration, which is needed for long-duration deep space missions, has led to advancements in purification systems on Earth for places like sub-Saharan Africa.

Investigations with robotics and haptic feedback techniques are helping to advance telemedicine applications and even make better products for paraplegics.

Even everyday clothing stands to benefit from ISS research.

Because microgravity changes the way heat and sweat are absorbed into astronauts clothing, high-performance fibers are being tested for comfortability, potentially leading to better textiles for gym use or even extreme conditions on Earth.

Like any scientific research, it can be difficult to justify space-based studies because of the amount of time it can take before effects reach the marketplace for the majority of people.

However, there are near-term benefits, including the creation of high-tech jobs as well as the education and inspiration of tens of thousands of youth across the world in pursuit of careers in science, technology, engineering and math.

A hub of new commercial activity

NASA has been in the process of commercializing aspects of the ISS since the mid-2000s by helping with the development of commercial cargo and crew spacecraft to service the outpost.

Additionally, commercial research opportunities aboard the station were formed when the ISS U.S. National Lab was established in 2005 with the goal to expand the U.S. economy in space-based research, applications and operations.

As of 2019, NASA says there are nearly 50 companies, such as NanoRacks, conducting research aboard the outpost with 11 of those installing 14 commercial facilities.

That is set to expand as a commercial airlock is scheduled to fly to the outpost later this year, allowing even more experiments to be deployed from the ISS.

Now with NASA taking aim on the Moon, the agency is looking to private companies to take up the bulk of responsibility for low Earth orbit access and research.

While government funding for the outpost is currently expected to run through 2024, there is a possibility of extending that into the late 2020s. Regardless, the ISS is closer to its end than its beginning.

Add in the outpost’s enormous operating costs — nearly $4 billion a year — and it's hard to see the ISS itself being commercially operated.

It’s more likely cheaper private space stations would assume some or all of the capabilities of the current outpost.

A rendering of Axiom Space’s proposed commercial modules attached to the ISS. Credit: Axiom Space

In June 2019, NASA announced plans to allocate and sell some of its annual ISS resources for private astronauts and even more commercial usage in order to support the development of a sustainable low Earth orbit economy.

This is starting with companies utilizing existing facilities with the hope private modules could be added to the outpost in the near-future with free-flying platforms orbited soon after to begin transitioning capabilities and assets.

The long-term goal is for all ISS capabilities to be handed off to the private sector with NASA purchasing services and access to commercial space stations when and where needed.

Already companies are taking advantage of this with Axiom Space contracted to add commercial modules to the ISS within the next few years.

Additionally, SpaceX is looking to send private astronauts and spaceflight participants to the outpost in their new Crew Dragon spacecraft as early as 2021.

The International Space Station as seen from the departing crew of Soyuz MS-08 in October 2018, a month-and-a-half before the 20th anniversary of the launch of the outpost’s first piece: Zarya. In November 2020, the program celebrated 20 years of continuous human presence aboard the ISS. Credit: NASA/Roscosmos

The legacy of the ISS as it enters its 3rd decade of operations

The International Space Station taught humanity how to assemble and maintain large objects in orbit for long periods of time and is helping us better understand the effects of long-duration spaceflight.

Moreover, the research being conducted aboard stands to improve the lives of millions, if not billions worldwide.

One of the outpost’s biggest accomplishments is not scientific in nature, but geopolitical. For more than two decades, the ISS has been a model for international cooperation.

During these last 20 years, the United States' relationship with Russia has been mixed, at best. Even so, cooperation on ISS-related activities has not been affected in any significant way.

There are a number of reasons for this, including the mutually-beneficial relationship between NASA and Roscosmos.

NASA, Roscosmos, the European Space Agency, the Japan Aerospace Exploration Agency and the Canadian Space Agency are showing that international cooperation in space can transcend the problems of Earth.

The outpost’s most lasting legacy, however, likely to be its critical role as a destination for a fledgling commercial space industry as it begins to take over the reigns of infrastructure and research in low Earth orbit, allowing governments to focus time and money on deep space exploration projects.