The recent invasion of Ukraine by the Russian Federation is nothing short of a tragedy, particularly for the Ukrainian people, but also for the various ways it has broken down decades of political infrastructure meant to promote international peace and cooperation. And that includes cooperation between national scientific agencies on important research. A major scientific project that has been in the news for how this war has affected it is the International Space Station. So let’s discuss how the International Space Station works, both technically and politically, and how this breakdown will affect research on and off the station.
ISS
At 73 meters (~240 feet) across, the International Space Station is the largest artificial satellite in Earth orbit. It orbits between 415 and 420 kilometers (roughly 260 miles) above sea level, which it maintains by traveling 7.66 kilometers per second, (about 25 times the speed of sound) enough to circle the planet every 90 minutes. Starting on 20 November 1998, it was assembled in orbit over the course of a decade from over 40 modules. It can house a crew of seven and has been continuously crewed since 31 October 2000. Additional details about its structure and its pieces can be found in this video by Jared Owen.
The ISS serves as a laboratory for experiments that require conditions not found on Earth. Much of this research is directly related to space travel itself, from the effects of space travel on the human body and other organisms to spacecraft systems and materials, which will all be important knowledge for future space missions. But the zero-gravity environment also makes possible certain experiments where gravity would be a source of error, in fields such as protein crystallization, fluid dynamics, and quantum mechanics. Cosmic radiation is another thing that cannot be easily studied on Earth, so experiments are performed on how radiation affects organisms and materials and on what types of particles are being produced in deep space. And due to the station’s vantage point, observations can be made of deep space and Earth’s atmosphere and surface. Several drugs have been developed using data from protein crystals grown on the ISS (one way to determine the structure of a protein is to create crystals of that protein, and better crystals are grown in zero gravity) and camera monitoring of the Earth’s atmosphere, oceans, and vegetation provide useful information for everything from climate models to disaster relief. These experiments are designed by the space agencies in the ISS program, equipment is built and transported to the station, and the experiments are performed by those aboard the station or by those on the ground via radio. This page from NASA provides descriptions of several experiments done on the ISS in the past 20 years and why they were best performed in space.
The legal structure that governs the space station is a multi-layered series of agreements between the space agencies of the United States (NASA), Russia (Roscosmos), Canada (CSA), Japan (JAXA), and the member states of the European Space Agency (ESA). Each partner nation has built modules for the station, is responsible for maintaining their modules and running them from the ground, and retains legal ownership over their modules. The amount of usage each nation is allowed from each other’s lab facilities and the amount of ownership each nation has over the intellectual property of data is determined by pre-existing agreements. While there is one European and two Japanese modules, all of which are laboratory facilities, and a robotic arm provided by Canada, most of the station’s sixteen habitable modules and basic utilities were built and launched by the United States and Russia. The station is divided into distinct American and Russian halves, due in large part to the complexity of maintaining and running the station. No one crew member needs to be an expert in all of the station’s systems, they just need to be an expert in the modules their country launched and that they’ve trained with. While astronauts from each country are allowed to move between each half, (meals are usually eaten in one of the Russian modules) repairs and maintenance are performed by astronauts from the country who built the module and experiments launched by each country are usually performed in that country’s lab facilities by that country’s astronauts unless there is a pre-arranged agreement. Flight control and station-keeping is solely provided by the Russian half of the station whereas the majority of electricity is generated by the American half.
Invasion Effects
With Russia isolating itself from the world stage due to the invasion of Ukraine and with international sanctions specifically targeting their aerospace industry, there is now significant concern that Russia might pull out of the ISS international agreement. Dmitry Rogozin, the politician appointed as head of Roscosmos, has made several threats in the past month to pull out of the ISS agreement, cut off other nation’s access to the ISS, or let the ISS deorbit and crash over other nations. This is not the first time that Rogozin has made these kinds of comments. He made similar threats during the 2014 Crimea invasion, so most experts regard these recent threats as hollow. So far, no actual substantive plan for Russia to withdraw from the ISS have been put forth and cooperation between NASA and Roscosmos has continued throughout the invasion. Though this is the highest period of tension between the two nations since the ISS was created, the two agencies have maintained a professional and cooperative relationship through previous periods of political tension. Outright sabotaging the station would have no strategic benefit and would hurt Russia’s image even further.
While actively sabotaging the station is considered very unlikely (though not impossible), the possibility of Russia discontinuing its support of the station is a more reasonable concern. The biggest problem here is that all station-keeping is managed by the Russian half of the station. To understand this concept, I should explain how orbits work. As I’ve said before, the station is only about 420 km (260 miles) above sea level, so it is still being pulled down by Earth’s gravity. But the station is moving to the side at 7.66 km per second, so it moves out of the way of the Earth before it can hit. A good way to picture this is how Issac Newton did when he first described the concept. Imagine a cannon firing a cannonball along a path parallel to the ground. The cannonball will continue moving forward at the same speed while gravity pulls it downward until the ball hits the ground, creating a path with a steep curve. Fire the cannonball faster, and it will be able to move further before the ball hits the ground, creating a path with a gentler curve. Fire the cannonball fast enough, and the curve of the cannonball’s path will be as gentle as the curve of the planet, meaning the cannonball will never get any closer to the surface. This is how all orbits work, from satellites around the Earth to the Earth’s orbit around the Sun.
Of course, this only works if the thing in orbit never changes its speed. But that’s to be expected; an object in motion stays in motion with the same speed and direction unless acted upon by an outside force. It’s only on Earth where things slow down overtime because they have to move through the air, which pushes against the moving object as it moves and slows the object down. But Earth’s atmosphere doesn’t have an altitude where it just stops. The atmosphere becomes thinner and thinner as it gets further from the planet’s surface until it becomes too thin to distinguish from interplanetary space. In low earth orbit, where the ISS orbits, the air pressure is about 0.007% of what it is at sea level. This is essentially the vacuum of space for most purposes, but it is still thick enough to create measurable drag forces. These drag forces are enough to very slowly reduce the station’s speed and cause its orbit to sink by about two kilometers closer to Earth every month. To combat this, the Zvezda module on the Russian half of the station has a series of small rockets that can speed the station up and raise its orbit. All of these speed boosts are controlled by Roscosmos from the ground, just as all module’s functions are controlled by the agency who launched them. The fear now is that if Roscosmos pulled out of the ISS agreement, it would leave the ISS without the ability to perform these boosts. If this happened, it would take about 15 months for the space station to sink low enough that it re-enters the atmosphere and burns up. There would be more than enough time to evacuate the crew from the station, but the station itself would be destroyed.
While Rogozin has made threats to disconnect the Russian half of the station from the rest and let it deorbit, this almost certainly won’t happen. Disconnecting the two halves of the station would require thought-out planning and the support of the other members of the ISS agreement. Even if it could be done, the Russian half is dependent on the American half for electricity, so it would be functionally useless as an independent space station. The more likely outcome of a Russian pullout of the agreement would be for them to simply stop sending crews and supplies to the ISS and stop supporting their modules from the ground. If this happens, NASA and the remaining ISS partners would have to find another way to reboost the station. Before they were retired in 2011, space shuttles were able to provide reboosts when they were docked with the station, and there are plans for how to do this using other visiting vehicles. But that would make the station more dependent on these regular resupply ships, which gets to the bigger problem created by a potential Russian pullout.
Of the 26 crewed and uncrewed rocket launches to the ISS that have occurred since the introduction of SpaceX’s Crew Dragon vehicle in 2020,* half of these were launched from Russia’s Baikonur Cosmodrome. Additionally, the ESA regularly buys and launches Russian Soyuz rockets from Europe’s Guiana Space Center and several American rocket-building companies buy engines from Russia. In response to sanctions, Russia has stopped selling rockets and rocket components to other nations, which will impact the frequency of launches from these nations. Whie NASA and the other ISS partners have said they are determined to keep the ISS running without Russia if necessary, keeping the station staffed and supplied without one of its biggest partners would be a significant logistical hurdle, especially on such short notice.
In theory, the ISS could be managed without Russia with enough planning and political will. But the timing for this conflict creates one final challenge. At almost 30 years old, the ISS is starting to show its age. With impacts from space debris, stresses from rockets docking and undocking, and thermal stresses created by experiencing a sunrise or sunset every 45 minutes, the effort to repair and maintain the station is becoming more onerous. In January, NASA announced plans to retire the ISS in 2031, deliberately deorbiting the station and letting it burn up in the atmosphere before crashing into the South Pacific. Over the next ten years, new modules from ISS partners and private companies will dock to the station to experiment with various commercial uses for orbiting space stations in the future. The techniques and data generated by these experiments are planned to lead to more space stations being launched for scientific and industrial uses. Before the ISS is deorbited, these new modules will be disconnected from the station and will become an independent space station. But this plan depends on the station being safe to use through to 2031. While NASA, ESA, JAXA, and CSA have performed routine inspections on their modules and have guaranteed their safety through to the end of the station’s life, Roscosmos has fallen behind on inspecting their modules in recent years. As of now, the safety of the Russian modules can only be guaranteed through to 2024, and if Russia pulls out of the station, there will be no extension of this window. While replacements for the Russian propulsion modules could be launched, it’s harder to financially justify building and launching modules that will see less than 10 years of use. If Russia does decide to pull out of the ISS agreement, it would change NASA’s financial calculations and could lead to the station being retired far earlier than planned, ruining these existing plans for developing the future of orbital space stations.
Importance of Collaboration
None of this is to say that Russia will definitely pull out of the International Space Station. While politicians in Roscosmos have made threats, the organization itself is continuing to collaborate with its partners. Russian cosmonauts on the ISS have so far maintained their friendly relationships with the rest of the crew and some have even spoken out against the invasion. Additionally, the ISS is currently the only platform Russia has for manned missions to space and with the economic downturn created by the invasion of Ukraine and subsequent sanctions, Russia can’t build another such platform in the near future. For the first nation that reached space, losing access to it would be a serious loss of prestige.
But we are already seeing the effects of this breakdown of cooperation in other areas. Two days after the invasion of Ukraine started, the eROSITA x-ray telescope had to be shut down. This telescope, built to survey distant galaxies over the course of seven years, was built by a German institute and incorporated into a Russian observatory satellite. With collaboration between the two nations shut down, the telescope is not taking measurements until further notice. The ExoMars mission, a collaboration between ESA and Roscosmos to find signs of life on Mars, has been suspended shortly before the planned launch of a rover later this year. And with Russian rockets no longer available, various satellite programs are now looking for other launch vehicles.
The point I want to make with all of this is the importance of collaboration to the scientific process. The reason why scientists publish the findings and the designs of their experiments is so that other scientists can try to replicate their studies. The more scientists who perform the same experiment and get the same results, the less likely the results are to be from bias. And of course, collaboration on engineering challenges such as the International Space Station allows us to pool our collective knowledge and resources and use them to their fullest. And while this is certainly not the biggest tragedy created by this war, I think it’s worth noting how much of science, and of so much else, is dependent on peaceful cooperation.
For More Details
*The reason why I’m only counting launches since the introduction of the Crew Dragon is that before this, NASA astronauts were dependent on Russian Soyuz launches to travel to the ISS. Before 2020, far more launches to the ISS were done by Russia. So I’m only counting recent launches for this example because they’re more representative of launches for the foreseeable future.
Comments