On Monday, the International Space Station enters its 20th year of continuous human habitation, a milestone that will be celebrated by the station’s partners around the world—and of course, the handful of astronauts living in the orbiting laboratory.
It is an “incredible honor” to be up here, said NASA astronaut Kate Rubins, a member of the current ISS crew, during a teleconference from the station on Friday. “We happened to have picked a really good expedition to be up here and I think we all feel very lucky.”
“I think the most fitting tribute is for the three of us to just go take a nice long view out the cupola, look at the beautiful Earth and appreciate this amazing space station,” she continued, when asked about the crew’s plans for the anniversary.
“The celebration day will be a Monday, so probably we’ll be celebrating this day by hard work,” added cosmonaut Sergey Kud-Sverchkov, “and of course, remembering those who flew here, and who have been flying here, for 20 years. We will remember all the participants of this huge program. Thank you so much, to all.”
When the Expedition 1 crew arrived at the ISS on November 2, 2000, the station had just three core modules; it has since sprouted over a dozen more, to a total of 16. During its lifespan, the ISS has been home to over 240 people from 19 countries, the platform for more than 220 space walks, and a nonstop source of incredible Earth imagery and public engagement with space.
The station’s past is impressive, and there are ambitious plans for its future. But the world that launched this incredible technological project is not the same place that it orbits every 90 minutes today. New geopolitical alignments on Earth have had consequences that reach into space, and the emergence of the commercial space sector has offered a glimpse of markets that could reshape low-Earth orbit, where the ISS resides.
The ISS is an ever-evolving reflection of technological and diplomatic shifts, but it is also an expression of the bygone era that launched it. Now, as the station approaches its twilight years, its operations will tell us a lot about where humans are headed, both on and off Earth.
The ISS is likely to host human beings until at least 2030; its member nations have already agreed to fund it until 2024 and its operational lifespan is projected to extend many years beyond that.
Here are the three major trends that will influence the next 10 years on the station—commercialization, internationalism, and the emergence of a post-ISS vision—and what they might mean for human space exploration writ large.
Open for Business
Space commerce is an ingrained trope of science fiction, from the ore-hauling commercial spaceship Nostromo of Alien fame to the hired delivery services of Planet Express in Futurama. But despite the prevalence of private markets in our imagined idea of our space future, it has proved difficult to establish a self-sustaining economy off-Earth in real life.
“If there was a straightforward way to make money in low Earth orbit with humans, we would be doing it right now,” said Casey Dreier, chief advocate and senior space policy adviser at the Planetary Society, in a call. “The very fact that it seems to take large government expenditures up front to create the conditions where private industry might find a way to make money in low Earth orbit tells us something.”
Within the lifetime of the ISS, the commercial space sector has experienced an unprecedented growth spurt, a change that is reflected by the historic arrival of the first astronauts in a commercial space vehicle, SpaceX’s Crew Dragon, at the station earlier this year.
NASA plans to open the ISS up to more commercial activity in the coming years to channel this latent momentum. In 2019, the agency announced that it would allocate five percent of its “crew resources and cargo capability, including 90 hours of crew time and 175 kilograms of cargo launch capability” though it would place limits on amounts available to any one company, according to a statement.
The private sector has played a crucial role in spaceflight since its earliest days, especially as satellite operators and contractors on federal space projects. But the immense costs of reaching space, and the dangerous environment that awaits companies there, has kept a range of potential space markets out of reach.
If all goes to plan, though, the station will receive its first fully commercial module, developed by Texas-based company Axiom Space, by the mid-2020s. Axiom and SpaceX are also laying the groundwork to sell tickets to the station for about $52 million. NASA has reached agreements with companies such as Estee Lauder to potentially film commercial footage on the station, and has discussed options for filming a movie aboard the ISS with Tom Cruise.
Of all of these emerging markets, space tourism is the one that’s most likely to take off, according to Phil McAlister, the director of the commercial spaceflight division at NASA Headquarters.
“The more people who have that experience, the more they’ll identify new ways to use space, and the more they will inspire others to also want to go,” McAlister said in an email. “That’s why I have worked so hard to enable commercial crew because I feel so passionately it will change the paradigm; change the arc of human spaceflight. That’s the big one.”
While space tourists have already flown to the ISS, these private flights may become much more common in the coming years. In addition to changing the activities and dynamics of the ISS, these flights will require a new legal and ethical infrastructure that may influence human spaceflight for many decades to come.
“As a private company or as a private individual wanting to pay for a ticket to go to space, there’s no guarantees,” said Sara Langston, assistant professor of spaceflight operations at Embry-Riddle Aeronautical University, in a call. “This is one reason we call them spaceflight ‘participants’ and not ‘passengers’.”
“If you say passenger there actually are rights, duties, and obligations between the transportation provider and the customer who has to pay for a ride,” she continued. “We call this the laws of common carriage and this goes all the way back to Medieval times, so there’s lots of precedents for that. But Congress said in 2004 that spaceflight is not common carriage.”
In other words, human spaceflight is considered inherently dangerous, so space lawyers are currently busy establishing legal frameworks for issues such as liabilities and informed consent, as it pertains to space tourism.
In addition to customers looking to buy a trip to the ISS, companies are also interested in using the station’s unique microgravity environment from companies looking to develop technologies.
For instance, Connecticut-based company Lambda Vision recently flew some of its artificial retinas to the station, and several biomedical and pharmaceutical companies have tested out “exomedicine” projects on the ISS.
Meanwhile, Florida-based company Made in Space has helped pioneer commercial 3D-printing and manufacturing techniques on the ISS, and startups such as AstroGrams hope to build a market for affordable collectibles and memorabilia that have been to the ISS.
NASA does not expect these ventures to help bankroll the station’s costly operations in the near term—just the opposite.
“NASA is subsidizing the cost to enable new markets to emerge and with the goal that NASA will ultimately be one of many customers,” said McAlister. “We do expect we will eventually move to full cost recovery, but the goal of these activities is more about enabling commercial demand than it is to subsidize the station.
“A competitive market will drive down costs for NASA, that will free additional resources for NASA to use for deep space exploration,” he added.
Likewise, NASA’s role as a public agency means that it walks a “fine line,” Langston said, when arbitrating what commercial activities to support on the ISS, and how the station’s resources will be used by companies.
“It goes against public policy for private companies to gain profit or financial benefit from public funds, so NASA does have to be very careful of what they allow commercial companies to do or what they allow their astronauts to do for private gain,” she noted.
The Geopolitics of Human Spaceflight
You can trace the origin of the ISS back to many different moments in history, but the 1975 orbital handshake shared between NASA astronaut Thomas Stafford and Russian cosmonaut Alex Leonov during the American-Russian Apollo-Soyuz mission stands out. The symbolic gesture set the stage for an astonishingly resilient partnership in space between two long-time rivals that frequently butt heads on Earth.
“The U.S. and Russia have a long, productive history of cooperation in human and robotic space exploration,” said Robyn Gatens, acting director of the International Space Station at NASA Headquarters, in an email. “In addition to nearly 20 years of crews on the International Space Station that of course includes Russians, there are Russian instruments on operational NASA science missions on the Moon and Mars.”
While there are disagreements on broader space policies between the nations, it’s likely that the American-Russian partnership on the ISS will survive as long as the station itself.
“It’s very hard to pick up your space station and go home when you are joined together so tightly”
“This type of geopolitical shared goal is, I think, the best spinoff from space,” Dreier said. “It forces people to continue working together because they do have a shared goal to protect the lives of the astronauts and cosmonauts that share the station.”
“It’s rare, these days, to have that forced cooperation,” he added. “It’s honestly one of the best consequences of why we spend money in space” because “it’s very hard to pick up your space station and go home when you are joined together so tightly.”
That said, Russia and the U.S. are no longer the only powers on the crewed spaceflight scene. China has made huge strides in its human space program over the past 20 years: the nation launched its first astronaut, Yang Liwei, in 2003, and is on track to establish a permanent space station in 2022.
While China has expressed interest in joining the ISS coalition in the past, the United States has barred it from sending astronauts to the station, or participating in ISS research, due to national security concerns. (The two nations collaborate on a range of other space-related issues beyond the ISS, including Earth science, lunar science, and space debris).
“I think it would be a good thing to engage them on the ISS, but that ship has sailed a little bit,” Dreier said.
“They don’t need the United States,” he noted. “They are building their own space station, and they have independent access for humans to space. They are only the third country to do that.”
While China and the U.S. are not likely to cooperate on crewed space missions in the near term, many other nations have honed their own space programs in the 20 years since the ISS has been operating. India, South Korea, and the United Arab Emirates, for instance, may send more of their astronauts the ISS in the next decade, which could expand the diversity of the station crew and lead to a more multifaceted space environment in the future.
”By partnering with other nations, NASA is able to engage the best scientific minds, as well as share the cost and risks of investments in ambitious missions,” said Gatens. “NASA’s international partnerships are also an important part of global diplomacy, leveraging activities in space to bring nations closer together here on Earth. We recently made an agreement with the United Arab Emirates to train their astronauts, one of whom already has flown to space.”
What Comes After the ISS?
The ISS has been flying for decades, and may remain a home to humans until the 2030s. But like any lived-in and well-loved home, it will eventually reach the end of its lifespan and need to be torn down—or deorbited, in this case. One day, a crew of astronauts will undock from the ISS for the last time, abandoning its modules to burn up in the same skies that it used to glide above, catching sunlight that made it shine on dark, clear nights.
By the time the ISS is destroyed in a (hopefully) controlled reentry into the atmosphere, NASA thinks that other crewed stations will have deployed in space to take up its mantle.
“Our goal is to have an uninterrupted presence in low-Earth orbit, to be able to transition from the station to other platform(s) where we can continue working in low-Earth orbit,” McAlister said.
In addition to keeping humans in low-Earth orbit, NASA is already working towards the deployment of a human habitat called Lunar Gateway, a smaller space station that would orbit the Moon and provide a platform for human exploration of the lunar surface.
“NASA right now is beginning the process of returning humans to deep space in the vicinity of and on the Moon with the Artemis program,” Dreier said. “There’s a serious effort and I think this has been a little bit underappreciated how much work NASA and others have been putting into these broad international agreements.”
There are still many contentious debates to be had about the exploration of the Moon, especially regarding resource utilization on the lunar surface, but NASA is working toward a vision of international cooperation on the Lunar Gateway that is modeled on the ISS coalition. NASA hopes to establish the Lunar Gateway in orbit around the Moon by 2028, and use the orbiting habitat as a platform to expand human exploration of the lunar surface.
“The goal for the future is that we’ll have commercial stations in low-Earth orbit that are tailored to specific market needs, including NASA’s needs, and that we’ll carry our international partnerships forward to the Gateway in orbit around the Moon and continued deep space exploration as we go together with commercial and international partners,” said Gatens.
In this way, the central legacy of the ISS—an orbital embodiment of what is possible when nations work together—hinges on whether this multilateral spirit in space can outlive the station itself.
“Space is an equalizer in many ways,” Langston said. “It doesn’t matter where you come from, what language you speak, what culture you come from—math and sciences brings people together. Everybody is interested in the beneficial outcomes of conducting science and exploration activities.”
A generation of young adults have never experienced an unpeopled spacescape, thanks to the orbital relay race that continues aboard this most storied off-Earth outpost. The next decade will determine whether humans can maintain and expand our presence beyond our planet, because our current life raft cannot float forever.