An End of an Era
In the vast, silent cold of space, 250 miles above Earth, the International Space Station (ISS) continues its relentless journey. As of November 2025, it has been home to an uninterrupted chain of human beings for over 25 years, a streak that began on November 2, 2000. It remains the largest single structure ever built in space, a 450,000-kilogram testament to human ingenuity and, perhaps more remarkably, to sustained international cooperation.
Onboard, life and work proceed with the steady, disciplined rhythm of a long-duration mission. The current seven-member crew, Expedition 73, is a microcosm of the station’s entire legacy. It includes NASA astronauts Zena Cardman, Mike Fincke, and Jonny Kim; JAXA’s Kimiya Yui; and Roscosmos cosmonauts Oleg Platonov, Sergey Ryzhikov, and Alexey Zubritsky. Together, they operate the orbiting laboratory, conducting research in microgravity, maintaining the station’s complex systems, and welcoming a steady stream of visitors. The station remains a bustling hub of activity, having recently hosted the private Axiom Mission-4 astronauts and the fresh crew of SpaceX’s Crew-11.
This scene of vibrant, multinational productivity masks a significant and irreversible reality. The International Space Station is operating on borrowed time. Even as Expedition 73 conducts its experiments, teams of engineers, diplomats, and budget analysts on Earth are deep into the active, funded, and scheduled plan for the station’s imminent destruction. NASA has officially designated this its “third and most productive decade,” a period of maximizing the scientific return before the end.
The ISS is not being allowed to fade into obsolescence; it’s being run at full capacity right up to its scheduled execution. The plan is set, the contracts are signed, and the “farewell” to this orbiting laboratory is slated for 2030. What follows will be a carefully orchestrated, multi-year maneuver to drive the massive structure out of the sky and into a remote stretch of ocean.
This is the story of that plan. It is a plan born from the physical realities of aging hardware, the unacceptable risks of an uncontrolled catastrophe, and a dramatic shift in the geopolitical landscape that has forced NASA to build a $1.5 billion insurance policy. The retirement of the ISS marks the end of a unique era of global partnership and the beginning of a high-stakes race to build its replacement.
The cooperation that defines daily life on the station – where American astronauts and Russian cosmonauts share meals and responsibilities – stands in stark contrast to the strategic realities on the ground. Down here, that very partnership has become a central vulnerability, forcing NASA to fund a new generation of American hardware specifically to retire the station, a plan that, in a final twist of interdependence, still relies on its Russian partners for a successful conclusion.
A Magnificent Machine Reaches its Limit
The decision to retire the ISS is not a reflection of its scientific utility but a cold calculation of risk versus reward. The Biden-Harris Administration’s commitment to extend station operations through 2030 was a strategic move. It enables NASA to maximize the research needed for its Artemis missions to the Moon and Mars, but its primary purpose is to buy time. The extension creates a important window for a new generation of commercial space stations to be designed, built, and launched, ensuring a “seamless transition” of capabilities from the government-owned past to a privately-operated future in low-Earth orbit (LEO).
The station, for all its success, is an aging marvel. The core elements of the United States On-orbit Segment (USOS) were originally designed with a 15-year service life. That warranty effectively expired in 2013. The fact that the station is still flying and fully operational in late 2025 is a significant testament to its robust design and the constant effort of its on-orbit crews and ground-based maintenance teams.
But the structure is showing its age. It has endured decades of mechanical stress, relentless thermal cycling – swinging from frigid cold to blistering heat every 90 minutes – and a constant peppering of micrometeoroids and orbital debris (MMOD).
The most tangible sign of this wear is a problem that has plagued the station’s Russian segment for years. A persistent air leak, first detected in 2019 in the Zvezda service module’s transfer tunnel, has become a chronic management issue. Despite multiple repair attempts by Russian cosmonauts, including the use of sealants on suspected crack locations, the leak continues. Roscosmos officials admitted in August 2025 that the problem persists, even as NASA officials have more recently described the leak rate as “stabilized” and “very small” after the latest repairs.
While the leak has never posed an immediate danger to the crew – the station has ample reserves of nitrogen and oxygen to top off the atmosphere – it remains a “top safety risk,” according to NASA’s own Office of Inspector General (OIG). A September 2024 report from the OIG, (IG-24-020), which audited NASA’s management of the risks of sustaining the ISS to 2030, highlighted the leaks as a prime example of the challenges of operating the aging hardware. The report noted that the leak rate had increased to its highest-ever level in April 2024 and that NASA and Roscosmos were still working to determine the root cause.
The OIG report laid bare a catalog of dangers that NASA must manage through 2030. Beyond the air leaks, the threat of MMOD is considered a “top risk to crew safety.” The station is shielded against small impacts, but the OIG noted that NASA has effectively “accepted some risk” for larger debris, as adding more protective shielding to the station at this point is prohibitively expensive and technically complex.
The audit also pointed to a growing programmatic fragility. NASA’s ability to support the station relies heavily on a “lack of redundancy” in its transportation chain. With the retirement of the Space Shuttle, the agency depends on SpaceX for both crew and cargo resupply, creating a significant risk if that company’s vehicles were ever grounded. The OIG also highlighted the “limited options” available for evacuating a full crew in the event of a major, station-wide emergency.
But the single greatest risk to the ISS transition plan isn’t technical or mechanical; it’s geopolitical. This is the “Russian Commitment Gap,” a fundamental misalignment in the timeline that threatens the entire deorbit strategy.
Here is the problem: The United States, the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), and the Canadian Space Agency (CSA) have all formally committed to operating and funding the International Space Station through 2030.
The State Space Corporation Roscosmos, Russia’s space agency, has not.
Russia’s formal, government-backed commitment to the ISS partnership extends only through 2028. This two-year gap is not a simple bureaucratic lag; it’s a critical vulnerability that the OIG report identified in no uncertain terms. The OIG stated that without Russian participation through the very end, the “ability to conduct a controlled deorbit is unclear.”
This is because the station was designed to be interdependent. Its key systems are deeply integrated. The U.S. segment provides the station’s electrical power via its massive solar arrays, while the Russian segment provides the station’s primary propulsion and attitude control – the thrusters that keep the station stable and allow it to dodge debris or reboost its orbit.
This dependency is at the heart of the deorbit plan. Even with NASA’s new U.S.-built deorbit vehicle, the operational plan, as confirmed by NASA officials in August 2025, still relies on the Russian segment. The plan calls for the Russian segment to “do attitude control,” keeping the station pointing in the correct direction, while the new U.S. vehicle provides the main “thrusting” for the final braking maneuver.
A U.S.-Russian joint commission that met in February 2025 to discuss ISS safety reinforced this very dependency. Their joint plan calls for a two-and-a-half-year process of slowly lowering the station’s orbit, a process that cannot begin until 2028. This 2028 start date is contingent on “critical capabilities” being available, chief among them ensuring that the propellant tanks on the Russian Zvezda and Zarya modules are full.
This means that NASA’s entire $1.5 billion end-of-life strategy is contingent on full, active Russian cooperation and the health of Russian-controlled systems for two years after their formal commitment to the program ends. While Roscosmos officials, including Sergey Krikalev, have stated publicly that they expect to work with NASA through the deorbit process to 2030, the lack of a binding, intergovernmental agreement remains the single greatest political and programmatic risk to the station’s safe retirement.
The Problem of “What Goes Up”
Before NASA could develop a plan, it had to define the problem. And the problem is one of immense scale. The ISS weighs approximately 450,000 kilograms (990,000 pounds). Its main truss is longer than an American football field. This massive object is traveling at over 17,000 miles per hour, circling the globe every 92 minutes.
Its orbital path, inclined at 51.6 degrees, means it passes over a vast swath of the planet, covering areas inhabited by roughly 90 percent of the world’s population.
The nightmare scenario, and the one NASA must prevent at all costs, is an uncontrolled re-entry. If the station were simply abandoned and allowed to decay naturally, it would eventually be grabbed by Earth’s atmosphere and tear itself apart. But where it would come down would be a matter of pure chance. Its debris would scatter across its entire orbital path, creating a debris field potentially thousands of miles long. Such an event would violate the long-standing U.S. government standard, which mandates that the risk of human casualty from a re-entering object must be lower than 1-in-10,000. An uncontrolled ISS re-entry would fail this test spectacularly.
This is not a theoretical concern. The history of space stations is defined by two very different endings, which serve as the two guiding precedents for NASA’s plan.
The first is the chaotic and embarrassing end of Skylab, America’s first space station. Launched in 1973, the 76-tonne station was abandoned in 1974. NASA had little ability to control its attitude or orbit, and as its orbit decayed faster than anticipated, a global media “fever” erupted in 1979. Newspapers sold “Skylab insurance,” and betting pools were organized to guess the impact zone. NASA controllers did their best to orient the station to minimize risk, but the re-entry was ultimately uncontrolled. On July 11, 1979, Skylab came down, showering debris across the Indian Ocean and a sparsely populated region of Western Australia. The Shire of Esperance famously fined NASA $400 for littering. No one was hurt, but the incident was a public relations disaster that served as a powerful lesson in the dangers of orbital negligence.
The second precedent is the 2001 deorbit of Russia’s Mir space station. Mir was a 130-tonne modular station, the spiritual predecessor to the ISS. By 2000, it was well past its design life and suffering from numerous failures. Rather than risk a repeat of Skylab, the Russian space agency, Rosaviakosmos, planned a precise and controlled deorbit. They launched a specially modified, uncrewed Progress M1-5 cargo ship – nicknamed the “Hearse” – which docked to the aging station. On March 23, 2001, the Progress fired its engines in a series of carefully timed burns, steering the massive station on a precise trajectory. Mir broke apart exactly as planned over the remote South Pacific, ending its 15-year career in a fiery, controlled plunge.
Mir is the model. Skylab is the nightmare.
The challenge for NASA and its partners is that the ISS is a problem on an entirely different scale. It is roughly 3.5 times more massive than Mir and nearly six times more massive than Skylab. Its sheer size and complexity, spanning a huge area, make its atmospheric disintegration far more complex to predict and control.
In planning the station’s retirement, NASA’s own analysis laid out all the alternatives. Every option, save for one, was deemed either impossible, too expensive, or unacceptably dangerous.
- Disassembly and Return: This is the most common public question: why not bring it home in pieces, perhaps for a museum? The answer is that the station “was not designed to be easily disassembled” in space. It was built like a ship in a bottle, with components intricately connected. Taking it apart would be at least as complex as building it, which required 161 separate spacewalks. It would also require a vehicle with a cargo bay the size of the retired Space Shuttle, a capability that simply no longer exists.
- Boosting to a “Graveyard Orbit”: Why not push it up into a higher, more stable orbit and leave it there? This, it turns out, would be the most dangerous option of all. The ISS already orbits in a region with significant debris risk. NASA’s analysis showed that boosting it to a higher altitude of 800 kilometers would drastically increase the risk of a catastrophic debris strike. The mean time between a mission-ending impact would shrink from 51 years to less than 4 years. The ISS would become a massive, orbiting target, and a collision at that altitude could shatter it into a cloud of shrapnel, “potentially eliminating access to LEO for centuries.”
- Commercial Takeover: Could a private company take over the station? NASA looked for feasible proposals and received none. The hardware is a mix of 1990s-era designs, internationally owned, and so deeply integrated that it would be cheaper for a company to simply launch its own new, modern station.
The analysis led to a single, unambiguous conclusion. The only responsible, safe, and feasible option is a controlled re-entry, a Mir-style plunge on a scale never before attempted.
This decision carries a powerful lesson for the future of space exploration. The International Space Station was a marvel of “design for assembly,” but it had no integrated, funded “design for disposal.” The $1.5 billion U.S. Deorbit Vehicle is the bill for that design oversight, a massive, unbudgeted-for expense that exists for the sole purpose of safely cleaning up the previous generation’s triumphant mess.
Point Nemo: The Spacecraft Cemetery
With the “how” decided, the next question was “where.” To safely dispose of a 450-tonne object, NASA and its partners needed to find the largest, most isolated, and least-trafficked place on the planet.
They found it in the South Pacific Ocean.
The official designation for the target area is the “South Pacific Oceanic Unattended Area.” It’s a vast stretch of international water known colloquially as “Point Nemo.” Named after the submarine captain from Jules Verne’s “Twenty Thousand Leagues Under the Sea,” Point Nemo is the “oceanic pole of inaccessibility.” It is the single point on Earth’s oceans that is farthest from any land. The nearest human beings are often the astronauts passing overhead in the ISS itself.
This significant isolation makes it the world’s “spacecraft cemetery.” It is the designated dumping ground for high-risk space hardware. When Russia deorbited the Mir station in 2001, this is where it was aimed. It has since been the target for hundreds of other defunct satellites and cargo vehicles.
The final re-entry of the ISS won’t be a single, pinpoint splashdown. The station is so large that it won’t burn up completely. As it descends through the atmosphere at hypersonic speeds, it will be subjected to unimaginable heat and aerodynamic forces. It will break apart.
Most of the station’s mass, particularly the lighter structures and the massive solar arrays, will “incinerate, melt, or vaporize.” But denser, heat-resistant components, like the titanium propellant tanks or the thick-walled Russian-built modules, are expected to survive the fiery re-entry. These pieces will continue on a ballistic path.
The result is a “debris footprint,” a long, narrow ellipse of debris scattered along the station’s final ground track. NASA’s objective is to control the station’s final burn with enough precision to ensure this entire debris footprint, which could be up to 6,000 kilometers (over 3,700 miles) long, falls within the uninhabited waters of the Point Nemo region.
This is the non-intuitive reality of a “controlled” deorbit on this scale. “Control” doesn’t mean landing on a dime. It means precisely placing a 6,000-kilometer-long trail of debris in the only part of the planet that is empty enough to safely contain it. Any surviving fragments will be left to “harmlessly settle on the ocean floor,” where NASA’s environmental impact analysis projects no substantial long-term effects.
A New Plan for the Final Push
The plan to hit this 6,000-kilometer target has undergone a radical and expensive transformation.
For years, NASA and its international partners had studied a deorbit plan that relied on Russia. The baseline strategy involved using “up to three Roscosmos Progress spacecraft.” These uncrewed cargo ships, which regularly fly to the station, would dock to the Russian segment and fire their engines in unison, just as the single Progress “Hearse” did for Mir.
This plan was abandoned for two critical reasons. First, as the partners studied the complex physics, they concluded that the Russian segment of the ISS “is not designed to manage three Progresses firing at the same time.” The combined thrust and structural loads created too much risk. The agencies agreed that a new, single, “more robust” spacecraft was needed to provide a greater margin of safety.
The second reason was geopolitical. The original “three Progress” plan was detailed in NASA’s ISS transition report issued in January 2022. Just weeks later, Russia invaded Ukraine, and the U.S.-Russian relationship deteriorated to its lowest point since the Cold War. The plan, which placed the safety of the entire $150 billion, U.S.-led asset in the hands of Roscosmos, suddenly became a significant strategic liability.
This combination of technical and geopolitical risk forced NASA to make a strategic pivot: America would build its own vehicle.
This is the U.S. Deorbit Vehicle (USDV). It is a $1.5 billion solution to the deorbit problem.
In June 2024, after a competitive bidding process where the only other offeror was Northrop Grumman, NASA announced it had selected SpaceX to design, develop, manufacture, and deliver this one-of-a-kind spacecraft.
The program’s budget has been a source of confusion. The contract awarded to SpaceX is valued at up to $843 million. The total $1.5 billion figure, which NASA leadership has used when briefing Congress, represents the total project life-cycle cost. This larger sum includes the $843 million spacecraft, plus the cost of a dedicated heavy-lift launch vehicle, the complex integration of the vehicle with its rocket, and all mission operations.
Because this was an unforeseen expense, it was not in NASA’s long-term budget. The agency has had to request new funding, including $109 million in its Fiscal Year 2025 budget request, to keep the program on schedule. NASA officials have advocated for the USDV in emergency appropriations bills, underscoring the geopolitical urgency of securing an independent deorbit capability. The $1.5 billion is, in effect, the price of an insurance policy that guarantees NASA can safely deorbit the station and protect the world’s population, regardless of political turmoil.
The spacecraft SpaceX is designing is a “monster,” as described by those involved. It is a custom-built, heavily modified version of its flight-proven Cargo Dragon capsule. It’s important to note that while SpaceX is building the vehicle, NASA will own and operate it. SpaceX is the contractor; NASA will be the pilot.
The design itself is a powerful example of brute-force engineering driven by a tight deadline. NASA needs the USDV delivered and ready for launch by mid-2029. There is no time to invent and test a new, exotic, high-efficiency propulsion system.
SpaceX’s solution is to use what works and multiply it. The USDV will be based on the familiar Dragon capsule but will feature a significantly “enhanced trunk section.” This unpressurized lower section, which normally carries external cargo and solar panels, will be transformed into a massive propulsion module. It will be packed with a “whopping” 46 Draco thrusters. A standard Cargo Dragon, by comparison, has 16.
These 46 thrusters, firing in concert, will generate approximately 10,000 Newtons of force. This raw power is not for orbital finesse; it’s for control. It’s the muscle needed to “fly the entire space station” as a single unit, giving NASA ground controllers the authority to steer the 450-tonne conglomeration and, critically, to fight the immense aerodynamic torques that will try to send the station tumbling as it descends into the upper atmosphere. It is not a scalpel; it’s a cosmic tugboat, the most powerful ever built, designed for a single, fiery, one-way trip.
The Long Goodbye: A Step-by-Step Timeline
The deorbit of the International Space Station won’t be a single event. It will be a “long goodbye,” a slow, multi-year process set to begin in 2028. Based on NASA’s “Concept of Operations” and public statements, the timeline is a complex ballet of orbital mechanics and international cooperation.
Phase 1: The Slow Descent (Mid-2028 to Mid-2029)
The process will begin in mid-2028. This is the date the U.S.-Russian joint commission has targeted to have the Russian segment’s propellant tanks full and all “critical capabilities” ready. From its operational altitude of around 400 kilometers, ground controllers will stop reboosting the station. It will be allowed to “drift down,” its orbit slowly and naturally decaying due to the faint pull of atmospheric drag. This descent will be augmented by periodic, planned burns from the Russian segment’s thrusters.
Phase 2: The Tug Arrives (Mid-2029)
While the station slowly descends, the U.S. Deorbit Vehicle will be launched on a heavy-lift rocket. Sometime in mid-2029, it will rendezvous and autonomously dock with the ISS, likely attaching to the forward-facing port of the Harmony (Node 2) module. Once docked and checked out, the USDV will go dormant. It will remain attached to the station for more than a year, a silent passenger waiting for its one and only command.
Phase 3: The Final Crew Departs (Mid-2030)
By mid-2030, the station’s altitude will have decayed to approximately 220 kilometers (136 miles). This is a critical threshold. This altitude is the lowest that human-rated spacecraft, like the SpaceX Crew Dragon, are certified to safely fly. It is also the altitude where the station’s primary stability system – its massive, spinning Control Moment Gyros (CMGs) – will become ineffective. The gyros, which keep the station stable by spinning internally, will no longer be powerful enough to counteract the growing force of atmospheric drag.
At this point, the final expedition crew conducts “passivation” procedures. They will shut down non-essential systems, vent any remaining toxic fluids or high-pressure gasses to make the station inert, and configure the complex for its final, uncrewed phase. They will then board their spacecraft, undock from the ISS for the last time, and return to Earth.
For the first time in 30 years, there will be no human presence in low-Earth orbit.
Phase 4: The Zombie Station (Mid-2030 to Early 2031)
This is the most dangerous and complex phase of the entire mission. For its final six months, the 450-tonne ISS will become the largest “zombie” satellite ever flown, operated entirely by remote control from the ground.
Flying through the “thicker” air at 220 kilometers and below, the station will be unstable. It will require constant propulsive firing to keep it from tumbling. This is where the plan’s single greatest point of failure lies.
The operational plan, as of late 2025, is a hybrid one. It calls for the Russian segment’s thrusters to provide the “attitude control” (keeping the station pointed correctly) while the new U.S. Deorbit Vehicle provides the main “thrusting” for the major orbit-shaping burns.
This plan’s success is entirely contingent on Russian cooperation in 2030 and 2031, two years after their formal commitment to the program expires. If, during this final six-month, uncrewed phase, the Russian systems were to fail or their cooperation were to cease, the station could lose attitude control. It could begin to tumble, making it impossible for the USDV to execute its final burn correctly. This is precisely the risk NASA’s OIG warned about, and it remains the central, unresolved geopolitical gamble in the entire deorbit strategy.
Phase 5: The Final Burn (Early 2031)
Assuming cooperation holds and the station is stable, ground controllers at NASA will begin the final sequence.
- Orbit Shaping: The USDV will fire its 46 thrusters in a series of powerful burns. These are not to deorbit the station yet, but to change its orbit from a 220-kilometer circle to a pronounced ellipse, with a low point (perigee) of around 145 kilometers.
- The Plunge: At the precise moment, calculated to align the station’s path with the Point Nemo target zone, NASA will send the final command. The USDV will ignite its thrusters for one last, continuous burn, lasting between 40 and 60 minutes.
- The Point of No Return: This final, massive braking maneuver will push the station’s perigee down to just 50 kilometers (31 miles). At this altitude, atmospheric capture is irreversible. There is no going back.
Phase 6: The Fiery Descent (The Breakup)
In its final moments, the station will hit the upper atmosphere.
- At an altitude between 110 and 120 kilometers, engineering models predict the station’s massive “wings” – its solar arrays and radiators – will be the first to go, shearing off from the main truss.
- Between 84 and 100 kilometers, the pressurized modules will begin to rupture and disintegrate.
- The station will cease to exist as a single object, becoming a 6,000-kilometer-long trail of fire and debris arcing across the pre-dawn or post-dusk sky over the most remote ocean on Earth.
The “LEO Gap” and the Race for a Successor
The 2030 retirement of the ISS is not just an end-of-life plan; it’s a strategic pivot. NASA is getting out of the business of being a landlord in low-Earth orbit. The agency has been clear: it will not build an “ISS 2.0.”
Instead, NASA’s new model is to be one of many customers in a robust, commercial marketplace. The plan is to buy services – crew time, research rack space, data bandwidth – from privately owned and operated space stations, just as it currently buys cargo and crew transportation services from SpaceX and Boeing.
This new initiative is the Commercial LEO Destinations (CLD) program. NASA has already invested hundreds of millions of dollars to stimulate the development of these private stations. In July 2025, the agency issued a revised directive for “Phase 2” of the program, signaling an acceleration of the acquisition strategy to “ensure mission continuity” and get a successor in orbit as fast as possible.
The urgency is driven by a strategic nightmare known as the “LEO Gap.”
The LEO Gap is the potential, or even likely, period between the ISS’s deorbit in early 2031 and the date a new commercial station becomes fully operational. A gap would, at a minimum, mean the U.S. has no human presence in LEO for the first time in three decades.
But NASA’s OIG reports warn the consequences would be far more severe. A gap would be catastrophic for NASA’s deep-space exploration ambitions. Critical, long-duration research into human health and life-support systems, which is required for Artemis missions to the Moon and Mars, will not be completed by the 2030 deadline. This research can only be done in a microgravity laboratory. If there is no station, that research halts, crippling the Artemis timeline.
Furthermore, the OIG warned that a significant gap could cause the “nascent low-Earth orbit commercial space economy” to “collapse,” as the new ecosystem of research and manufacturing companies finds itself with no destination.
The 2030 deadline has triggered a high-stakes race against the clock. As of November 2025, three main contenders are vying to be that successor, each with its own unique approach and its own significant vulnerabilities.
Contender 1: Axiom Space
Axiom is, in many ways, the front-runner. Its business model is the most integrated with the ISS’s final years. The plan is to build its own modules, launch them, and first attach them to the ISS. Then, just before the ISS is deorbited, Axiom Station will detach and fly free as an independent platform.
Axiom has proven its flight-operations expertise, having successfully flown four private astronaut missions to the ISS: Ax-1, Ax-2, Ax-3, and Ax-4. The most recent mission, Ax-4, flew in the summer of 2025.
But the company is facing what has been publicly described as a “severe cash crunch.” Reports in late 2024 detailed “dire financials” and suggested its high-profile private missions are currently operating at a loss. The launch of its first module has been delayed to 2026. This “unstable business situation” has cast significant doubt on Axiom’s ability to self-fund the multi-billion-dollar development of its station. Axiom’s primary risk is financial.
Contender 2: Orbital Reef
This is the heavyweight partnership of Blue Origin and Sierra Space. Their vision is for a “mixed-use business park” in orbit, a large-scale destination for research, tourism, and manufacturing.
As of 2025, Orbital Reef is deep in the design and testing phase. In April 2025, Blue Origin completed a key “human-in-the-loop” milestone, using full-scale mockups of the station’s interior to have test subjects walk through day-in-the-life operations, from cargo transfer to worksite setups.
But the program has been dogged by schedule delays. Its Preliminary Design Review (PDR), an important engineering milestone, was pushed from 2023 into mid-2024. While the partnership has immense resources, its risk is schedule. It is not clear if it can get its complex, multi-module station built and flying by 2030.
Contender 3: Starlab
Starlab is a global joint venture led by U.S.-based Voyager Space and European aerospace giant Airbus. The partnership also includes Japan’s Mitsubishi Corporation and Canada’s MDA Space, the company that built the Canadarm.
This team is moving quickly. It is on track to hold its Critical Design Review (CDR) in late 2025 and made a high-profile appearance in October 2025 at the International Astronautical Congress in Sydney, displaying a full-scale mockup of its interior.
Starlab’s entire strategy is built on a “single launch” concept. They have selected SpaceX’s Starship – the most powerful rocket ever built – to launch the entire station on a single flight. This “No Assembly Required” approach would, if successful, leapfrog the competition, bypassing the years of complex, one-piece-at-a-time orbital assembly that defined the ISS. This is Starlab’s greatest strength, but also its greatest risk. Its success is tied completely to the flight-readiness and reliability of Starship, a vehicle that, in 2025, is still in its early operational life. Starlab’s risk is technical dependency.
This race to replace the ISS has become a trilemma for NASA. The agency is betting on three different horses, each with a major, distinct vulnerability: one financial, one schedule-based, and one dependent on a next-generation rocket. All NASA can do is offer funding and expertise, and hope that at least one of them crosses the finish line before 2031.
Intriguingly, the partners involved in Starlab – American, European, Japanese, and Canadian – look just like the government agencies that built the ISS. This suggests that the model of international cooperation is not dead. It’s simply evolving. The future of LEO is shifting away from 20th-century intergovernmental treaties and toward a 21st-century model of agile, globalized, commercial partnerships.
Summary
The International Space Station, a 25-year-old symbol of human presence in the cosmos, is now in its final chapter. Its retirement, set for 2030, and its subsequent deorbit in early 2031 are not an epilogue but a necessary, dangerous, and significantly complex pivot to the next era of space exploration.
The 450-tonne, football-field-sized laboratory cannot be left in orbit, where it would become a catastrophic debris risk. And it cannot be brought home. The only viable path is a controlled, fiery plunge into the planet’s most remote location, the “spacecraft cemetery” at Point Nemo.
The original plan, which relied on Russian Progress vehicles, has been superseded by a $1.5 billion, U.S.-led effort. This new strategy is centered on the U.S. Deorbit Vehicle, a “monster” tugboat being built by SpaceX, designed with 46 thrusters to give NASA the brute force required to fly the massive station into its final, destructive entry.
This $1.5 billion vehicle is the price of an insurance policy, one that became non-negotiable in the wake of geopolitical tensions. Yet, in a final, defining irony, the deorbit plan still depends on Russian cooperation. The operational timeline, as of late 2025, requires the Russian segment to provide critical attitude control for the station during its final, six-month uncrewed “zombie” flight, two years after Russia’s formal commitment to the partnership ends.
This reliance, coupled with the technical challenge of remotely flying a 450-tonne object as it’s being ripped at by the atmosphere, represents the two greatest risks to a safe conclusion.
As NASA prepares to close the book on the ISS, it is racing to write the first chapter of the next. The agency is attempting to foster a new commercial marketplace in LEO, but it is running out of time. The retirement of the station has set a hard deadline, forcing a high-stakes competition between private ventures, all of whom face significant financial, schedule, or technical hurdles.
The deorbit of the ISS is the expensive and necessary first step, clearing the sky for what comes next. But it also starts the clock on the “LEO Gap,” a potential void in U.S. human spaceflight that could ground critical research for the Moon and Mars and leave the nascent LEO economy without a home. The station’s final, fiery orbit is not just the end of a mission; it’s the starting gun for the race to replace it.
