Introduction
The years 2024 and 2025 represent a period of dynamic and diverse activity in human spaceflight. The landscape is characterized by a blend of established international partnerships, the rise of robust commercial operations, the steady progress of independent national programs, and the determined, if measured, steps toward returning humans to the Moon. The era sees the maturation of commercial crewed flights to low-Earth orbit, transforming what was once a groundbreaking event into a routine transportation service. This shift is the direct result of NASA‘s long-term strategy to foster a commercial marketplace in space, a strategy now bearing fruit with a regular cadence of SpaceX and private Axiom Space missions. These flights operate alongside the persistent international cooperation aboard the International Space Station (ISS) and the methodical operations of China’s Tiangong space station. Together, these parallel efforts paint a picture of humanity’s expanding presence beyond Earth, driven by a mix of national ambition, scientific curiosity, and commercial enterprise.
The International Space Station: A Global Nexus in Orbit
The International Space Station remains the primary destination for most human spaceflight activities, serving as a unique microgravity laboratory and a symbol of long-standing international cooperation. In 2024 and 2025, the station is a bustling hub supported by a mix of government and commercial vehicles from the United States and Russia.
NASA’s Commercial Crew Program: The Workhorse of LEO
NASA‘s strategy of fostering commercial partnerships to service the ISS is now in a fully operational phase. SpaceX‘s Crew Dragon has become the primary vehicle for transporting U.S. and international partner astronauts to and from the station, conducting regular crew rotation missions that are the backbone of the station’s staffing.
The SpaceX Crew-8 mission, launched in March 2024, carried a four-person international crew: NASA astronauts Matthew Dominick (Commander), Michael Barratt (Pilot), and Jeanette Epps (Mission Specialist), along with Roscosmos cosmonaut Alexander Grebenkin. Their long-duration stay aboard the ISS is dedicated to conducting over 200 scientific experiments. This research includes using stem cells to create organoid models for studying degenerative diseases, examining the effects of microgravity and UV radiation on plants at a cellular level, and testing countermeasures like pressure cuffs to mitigate the negative health effects of fluid shifts in astronauts. The crew’s mission was unexpectedly extended following issues with the Boeing Starliner flight, highlighting the dynamic nature of station operations.
The SpaceX Crew-9 mission, which followed in September 2024, had a significantly different profile that showcased the flexibility of the commercial crew model. The mission launched with only two astronauts—NASA‘s Nick Hague and Roscosmos’s Aleksandr Gorbunov—instead of the usual four. This modification was a direct response to the situation with Boeing’s Starliner. By launching with fewer crew members, the mission opened up two seats on the Dragon capsule for the return journey of Starliner astronauts Butch Wilmore and Suni Williams, who were stranded on the station. The Crew-9 mission also marked a logistical milestone, becoming the first crewed flight to launch from Cape Canaveral’s Space Launch Complex 40, a move made to accommodate the launch schedule of other high-priority missions from the primary pad, LC-39A. The Crew-9 crew, along with the two Starliner astronauts, are scheduled to return to Earth in March 2025.
The sequence of events surrounding the Starliner and Crew-9 missions provided the first real-world test of NASA‘s two-provider strategy for ISS transportation. The program was intentionally designed with two independent commercial partners, SpaceX and Boeing, to ensure redundant access to space and avoid reliance on a single vehicle, a key lesson from the Space Shuttle era. When Boeing’s Starliner encountered on-orbit anomalies that made its return with crew uncertain, the existence of a second, proven transportation system became a practical lifeline. The ability to modify the Crew-9 mission to serve as a return vehicle for the Starliner crew demonstrated that this planned redundancy was not merely a theoretical backup. It proved to be a functional and critical component for ensuring astronaut safety and maintaining the operational continuity of the space station. Without a second operational provider, NASA would have faced a far more difficult scenario with limited options for bringing its astronauts home.
Boeing’s Starliner Joins the Fleet
After years of development and delays, Boeing’s CST-100 Starliner spacecraft conducted its first crewed flight test in 2024. The mission was a major step for the Commercial Crew Program, intended to certify a second American vehicle for ISS missions.
The Starliner capsule, named Calypso, launched aboard a United Launch Alliance Atlas V rocket on June 5, 2024, from Cape Canaveral, Florida. Onboard were two veteran NASA astronauts, Butch Wilmore and Suni Williams. The launch was historic, marking the first time a crew had flown on an Atlas rocket since Gordon Cooper’s Mercury-Atlas 9 mission in 1963. The spacecraft successfully docked with the ISS on June 6.
However, the mission, which was planned to last about eight days, was quickly complicated by technical problems. During its approach to the station, the spacecraft’s service module experienced five separate helium leaks in its propulsion system. Compounding this issue, five of its 28 reaction control system (RCS) thrusters, which are used for maneuvering, failed to operate correctly. While ground controllers were able to recover four of the thrusters through a series of resets, the unpredictable behavior of the propulsion system raised serious questions about the vehicle’s condition and its ability to safely perform the de-orbit burn and re-entry.
What was meant to be a short test flight turned into a long-duration stay. The mission was repeatedly extended as engineers on the ground worked to understand the root cause of the anomalies. After more than two months of intensive analysis, on-orbit testing, and simulations, NASA made the call that the risk of returning the crew aboard the Starliner was too high. The decision was made to bring Wilmore and Williams back to Earth on a different spacecraft—SpaceX‘s Crew-9 Dragon. The Starliner capsule undocked from the ISS without a crew on September 6 and performed a successful autonomous landing at the White Sands Space Harbor in New Mexico on September 7, 2024.
While the mission did not achieve its primary objective of a crewed round trip, the unexpected extended stay provided an invaluable engineering dataset. The long duration on orbit allowed engineers to gather a wealth of information on the vehicle’s performance that would have been impossible to obtain during a short flight. This included data on the long-term performance of the spacecraft’s batteries, which were successfully recharged by the ISS, the thermal degradation of components over time, and the behavior of the troubled propulsion system under real space conditions. This unplanned long-duration engineering trial, born from mission anomalies, supplied critical information that will be used to fix systemic issues and certify the Starliner for future operational flights.
Roscosmos Soyuz Operations
Russia continues to provide reliable transportation to the ISS with its venerable Soyuz spacecraft, maintaining a crucial role in the international partnership. The Soyuz missions in 2024 continued the practice of crew swaps and short-duration flights for international partners.
The Soyuz MS-25 mission launched on March 23, 2024, carrying a three-person international crew. The crew consisted of Roscosmos cosmonaut Oleg Novitsky, NASA astronaut Tracy Caldwell-Dyson, and Maryna Vasileuskaya, a spaceflight participant from Belarus. The flight made Vasileuskaya the first Belarusian woman to fly in space. Following a short stay, Novitsky and Vasileuskaya completed a 13-day mission, returning to Earth aboard the Soyuz MS-24 capsule that was already docked at the station. Caldwell-Dyson remained on the ISS to begin her long-duration expedition.
Later in the year, the Soyuz MS-26 mission launched on September 11, 2024. It transported Roscosmos cosmonauts Aleksey Ovchinin and Ivan Vagner, along with veteran NASA astronaut Donald Pettit, to the station for a long-duration stay. Their launch briefly set a new record for the most people in orbit at one time—19 individuals—when factoring in the crews of the ISS, China’s Tiangong station, and the private Polaris Dawn mission. The Soyuz MS-26 crew is scheduled to remain on the station until their return to Earth in April 2025.
These missions underscore the quiet but deep operational interdependence between the United States and Russia in space. Despite significant geopolitical friction on the ground, the partnership aboard the ISS remains pragmatic and highly integrated. The practice of “seat swapping,” with American astronauts regularly flying on Soyuz and Russian cosmonauts on Crew Dragon, is not merely symbolic. It is a technical and safety imperative. This arrangement ensures that there are always crew members on the station trained to operate both types of spacecraft, which serve as “lifeboats” in case of an emergency. It also guarantees that both nations retain access to the station should one of their transportation systems be temporarily unavailable. This practical, day-to-day cooperation, which includes direct coordination on technical issues like managing a leak in the station’s Zvezda module, persists as a functional necessity for the continued safe operation of the orbiting laboratory.
The Commercialization of Space Access
A new model for human spaceflight is rapidly maturing, where private companies sell seats and full missions to national space agencies, research institutions, and private individuals. Axiom Space, in partnership with SpaceX, is at the forefront of this movement, organizing multi-day missions to the ISS for a new generation of spacefarers.
Axiom Mission 3 (Ax-3), which launched in January 2024, was a landmark flight: the first all-European commercial astronaut mission to the ISS. Commanded by former NASA astronaut Michael López-Alegría, who now works for Axiom, the crew included Pilot Walter Villadei of the Italian Air Force, Mission Specialist Alper Gezeravcı, who became the first astronaut from Turkey, and Mission Specialist Marcus Wandt of Sweden, the first European Space Agency (ESA) project astronaut to fly on a commercial mission. The 21-day mission was heavily focused on science. The crew conducted more than 50 different experiments, investigating topics ranging from the growth of cancer organoids and the aggregation of proteins related to Alzheimer’s disease to the application of genetic editing techniques on plants in microgravity.
The Axiom Mission 4 (Ax-4), which launched in June 2025, will continues this trend of government-sponsored commercial flights. The mission is commanded by Peggy Whitson, Axiom’s Director of Human Spaceflight and a former NASA astronaut who holds the record for the most time in space by an American. The crew is exceptionally diverse, featuring pilot Shubhanshu Shukla from the Indian Space Research Organisation (ISRO), and mission specialists from Poland and Hungary. This flight will mark a return to human spaceflight for India, Poland, and Hungary after more than 40 years. Ax-4 is set to be the most research-intensive Axiom mission yet, with over 60 scientific experiments and outreach activities planned, representing contributions from 31 different countries.
These Axiom missions signify a new paradigm for how countries can participate in human spaceflight. Nations that do not have their own crewed launch systems can now purchase “spaceflight-as-a-service.” This model allows them to fly their own astronauts and conduct nationally important research in orbit by buying a seat on a commercial flight. While the ticket price is substantial, it is a small fraction of the immense cost and decades of development required to create a sovereign human spaceflight program from scratch. This approach effectively democratizes access to low-Earth orbit, enabling more countries to reap the scientific, technological, and inspirational benefits of sending their citizens to space. Axiom isn’t just selling space tourism; it’s selling participation in the global space enterprise.
New Frontiers in Commercial Spaceflight
Beyond servicing the ISS, the commercial sector is beginning to conduct ambitious missions of its own, operating independently of any government space station and pushing the boundaries of what’s possible in Earth orbit.
Polaris Dawn: Pushing the Envelope
The Polaris Dawn mission, which flew in September 2024, was a privately funded flight that showcased the growing capabilities of commercial spaceflight. Funded by billionaire Jared Isaacman and operated by SpaceX, the mission was not a trip to a space station but a free-flying technology demonstration with a set of challenging objectives.
The five-day mission launched on September 10, 2024, with a four-person crew: Commander Jared Isaacman, Pilot Scott Poteet, and Mission Specialists Sarah Gillis and Anna Menon. The flight plan was designed to test the limits of the Crew Dragon spacecraft and its human occupants. The capsule was sent into a highly elliptical orbit that reached a peak altitude of 1,408.1 kilometers. This was the highest Earth orbit ever flown by a crewed spacecraft, breaking a record set by the Gemini 11 mission back in 1966. This trajectory intentionally took the crew through parts of the Van Allen radiation belts, providing a unique opportunity to gather data on the effects of space radiation on the human body.
The mission’s most anticipated objective was the first-ever commercial extravehicular activity (EVA), or spacewalk. At an altitude of about 700 kilometers, crew members Jared Isaacman and Sarah Gillis opened the hatch of the Dragon capsule and exposed themselves to the vacuum of space. They tested a new generation of EVA suits designed and built by SpaceX. These suits are an evolution of the sleek, single-piece suits worn inside the capsule during launch and landing. The successful test of these new suits is a key step toward developing a scalable design that can be mass-produced for future long-duration missions on the Moon and Mars.
In addition to these milestones, the crew conducted a suite of scientific and technical experiments. They were the first to test Starlink‘s laser-based communications system in space, a technology that will be needed for high-bandwidth data links for future lunar and Martian outposts. They also carried out a range of medical research projects in collaboration with leading research institutes, focusing on health risks for long-duration spaceflight such as decompression sickness and Spaceflight Associated Neuro-Ocular Syndrome (SANS), a condition that affects astronauts’ vision.
The Polaris Dawn mission was more than just a private adventure; it functioned as a privately funded research and development platform for technologies that are directly applicable to future government-led deep space exploration. By flight-testing new EVA suits, gathering data on high-altitude radiation exposure, and demonstrating new communication systems, the Polaris program is effectively accelerating the development of capabilities that NASA will require for its Artemis missions. This creates a symbiotic relationship where NASA’s future needs help shape the direction of private endeavors, and those private missions, in turn, can move quickly to develop and prove the very technologies the agency needs, de-risking them for future use on the Moon and Mars.
China’s Tiangong Space Station: A Permanent Outpost
While much of the world’s attention is on the ISS, China is methodically operating its own independent space station, Tiangong. Throughout 2024 and 2025, the China Manned Space Agency (CMSA) has maintained a continuous human presence aboard the orbital outpost, conducting regular crew rotations and a packed schedule of scientific research.
China’s operational model relies on overlapping missions, where a new three-person crew arrives aboard a Shenzhou spacecraft before the previous crew departs. This ensures a seamless handover of station operations. In late 2024, the Shenzhou-18 crew was relieved by the Shenzhou-19 crew, which consisted of Commander Cai Xuzhe and first-time astronauts Song Lingdong and Wang Haoze. Their six-month mission, which concluded in April 2025, was packed with activity. The crew conducted 86 different science experiments and performed multiple spacewalks, including one that set a new record for the longest in Chinese history at over nine hours. During their EVAs, they installed protective shielding to guard the station against impacts from small space debris.
The Shenzhou-20 crew, comprising Commander Chen Dong and first-time taikonauts Chen Zhongrui and Wang Jie, launched in April 2025 to take over station operations. They are scheduled to be relieved by the Shenzhou-21 crew in October 2025.
The scientific work being done on Tiangong is notable for its focus. Unlike the ISS, which serves a multi-national consortium with a wide array of research interests, the activities on Tiangong appear to be strategically aligned with China’s long-term space exploration goals. The experiments are not just for general scientific inquiry; many are explicitly designed to solve challenges related to China’s next major objective: landing taikonauts on the Moon by 2030. For example, the Shenzhou-19 crew oversaw experiments exposing simulated lunar soil bricks to the space environment to test their viability as a construction material for a future lunar base. Other research involved studying the growth of fruit flies in a low-magnetic field to better understand how life might adapt to the lunar or Martian environments. This clear, methodical alignment of research with national goals shows that Tiangong is not just a laboratory in orbit; it’s a critical proving ground and stepping stone for China’s ambitious lunar program.
The Journey Back to the Moon
After a hiatus of more than 50 years, NASA is leading a multinational effort to return humans to the lunar surface through its Artemis program. The coming years are focused on a series of flight tests to prove the hardware and procedures needed for this historic undertaking.
Artemis II: A New Generation’s Lunar Voyage
Artemis II is the first crewed mission of the program and represents the first time astronauts will travel to the vicinity of the Moon since the Apollo era. The mission is a flight test designed to validate the capabilities of the Orion spacecraft and its powerful Space Launch System (SLS) rocket.
The roughly 10-day mission will send a crew of four on a journey around the Moon and back to Earth. It will be a thorough checkout of the Orion’s critical systems, including its life support, communication, and navigation capabilities, in the deep space environment. The international crew selected for this historic flight consists of NASA astronauts Reid Wiseman (Commander), Victor Glover (Pilot), and Christina Koch (Mission Specialist), along with Canadian Space Agency astronaut Jeremy Hansen (Mission Specialist).
The mission was originally planned to launch in late 2024, but NASA has since revised the schedule, targeting September 2025 for liftoff. The delay was driven by a safety-first approach, allowing engineers more time to resolve technical issues that were discovered following the uncrewed Artemis I flight in 2022. These included unexpected erosion of the Orion capsule’s heat shield during re-entry and challenges with components in the life support system, specifically related to a battery and circuitry for air ventilation and temperature control.
This deliberate, safety-focused pace, even at the cost of timeline-based milestones, reflects a core philosophy within NASA’s modern deep space exploration efforts. Rather than pushing to meet an aggressive deadline, the agency is publicly acknowledging complex technical hurdles and adjusting its schedule to ensure they are fully resolved. This cautious approach is a direct legacy of lessons learned from past spaceflight tragedies and shows a prioritization of engineering rigor over schedule pressure.
The successful completion of Artemis II is the final major test before a landing is attempted. The following mission, Artemis III, is now scheduled for September 2026. It is planned to land the first astronauts of this new era, including the first woman, near the Moon’s South Pole. The success of Artemis III hinges not only on the performance of the SLS and Orion but also on the readiness of SpaceX’s Starship, which has been selected as the Human Landing System (HLS) and must complete an unpiloted demonstration landing on the Moon before it can carry a crew.
The Expanding Club of Spacefaring Nations
While the United States, Russia, and China remain the only countries with independent human spaceflight capabilities, other nations are actively working to join them, and they are using innovative strategies to do so.
India’s Gaganyaan Program
The Indian Space Research Organisation (ISRO) is moving forward with its Gaganyaan program, an ambitious initiative to develop and launch an Indian crewed spacecraft into orbit. A successful mission would make India only the fourth nation in the world to achieve this feat independently.
After a series of programmatic delays, ISRO has declared 2025 the “Gaganyaan Year” and is preparing for a series of critical test flights. The first uncrewed orbital flight of the Gaganyaan spacecraft, known as G1, is scheduled for late 2025. This mission will not carry astronauts but will instead fly a humanoid robot named Vyommitra to test the vehicle’s life support and flight systems in orbit. This flight is a crucial step in a series of tests that must be completed before a human crew can fly. The first crewed Gaganyaan mission is now anticipated to launch in 2027. The four astronaut-designates, all experienced pilots from the Indian Air Force, have already completed their initial training in Russia and are now undergoing mission-specific training at ISRO’s facilities in India.
In a move that reflects the changing landscape of space exploration, India is pursuing a hybrid strategy to achieve its human spaceflight goals. While methodically developing its own sovereign launch vehicle and capsule, ISRO is also taking advantage of the new commercial space ecosystem to gain immediate, hands-on flight experience for its astronaut corps. As part of a collaboration with NASA and Axiom Space, ISRO astronaut Shubhanshu Shukla will serve as the pilot for the Axiom Mission 4 flight to the ISS in 2025. This is a pragmatic shortcut that allows India to gather invaluable operational data. The experiments Shukla will conduct aboard the station in fields like space medicine, life support, and human physiology are designed to directly feed back into and support the Gaganyaan program. This dual-track approach is highly efficient, allowing India to advance its human spaceflight knowledge base and train its astronauts in a real microgravity environment in parallel with its own hardware development. This strategy should help accelerate the overall program and reduce risks for the eventual first crewed flight of Gaganyaan.
Summary
The period of 2024-2025 is marked by a significant evolution in how humanity accesses and operates in space. In low-Earth orbit, commercial services have come of age. The regular cadence of SpaceX crew rotation flights and the emergence of private, nationally-sponsored astronaut missions from companies like Axiom Space show that the commercial model for space transportation is now a mature and reliable system.
This period also provided a stark lesson in the value of redundancy. The technical challenges faced by Boeing’s Starliner during its inaugural crewed flight led to an unprecedented situation, but the availability of a second, operational commercial vehicle from SpaceX provided a safe and flexible solution for the stranded crew. This event validated NASA’s two-provider strategy in a very real way.
China’s Tiangong space station continues its steady and methodical operations. With regular crew rotations and a science agenda clearly focused on supporting its long-term lunar ambitions, Tiangong stands as a testament to a focused, state-driven space program with clear goals.
NASA’s Artemis program continues its deliberate march back to the Moon. The schedule adjustments for the Artemis II mission underscore a safety-first philosophy, prioritizing engineering diligence over adherence to ambitious timelines as it prepares for the first crewed lunar flyby in more than half a century.
The Global participation in space is clearly expanding. The diverse, international crews flying on commercial Axiom missions and the determined progress of India’s Gaganyaan program, which cleverly blends sovereign development with commercial partnerships, signal a future in space that is increasingly diverse and multipolar.
