NASA is celebrating a quarter-century since the launch of the first two modules of the International Space Station (ISS), which marked the beginning of a global collaboration in space exploration. Over the years, the ISS has become a microgravity laboratory hosting 273 people from 21 countries and accommodating more than 3,700 research and educational investigations from 108 countries.
The official partners in the ISS project include:
- Canada: The Canadian Space Agency (CSA) was established in 1989, and Canada, having previously contracted satellite deployment through the U.S. Space Shuttle, saw participation in the ISS as a way to boost its emerging space industry. Canada contributed the “Mobile Servicing Centre,” which evolved into the iconic CanadArm and CanadArm2.
- European Space Agency (ESA): A multinational agency, ESA planned to contribute the Columbus research facility. This included a pressurized microgravity research laboratory, a self-contained research module, an automated polar orbit platform, and a space tug. These components were subcontracted to various space enterprises across Europe.
- Japan’s National Space Development Agency (now JAXA): Japan planned to contribute a sophisticated laboratory with a large pressurized module, an expose platform for unpressurized payloads, and remote-controlled manipulators to service payloads. These elements aimed to enhance the scientific capabilities of the space station.
- United States of America: As a leading space agency, NASA took on a significant portion of the construction cost of the ISS. Planned contributions included an integrated truss structure, a mobile servicing system transporter, propulsion systems, docking systems, airlocks, and guidance systems. The U.S. also faced challenges, such as disagreements over the station’s design and attempts to create a Crew Return Vehicle for emergencies.
- Russia: After the collapse of the Soviet Union, Russia joined the project through agreements with the U.S., which involved Russian cosmonauts working on American experiments. Initially viewed with concerns about cost overruns, Russia later took on a larger share of the costs as its space program regained stability.
On November 20 and December 4, 1998, Zarya and Unity were launched as the first two ISS modules. The space shuttle Endeavour STS-88 crew, in December 1998, successfully captured the Zarya module with the robotic arm and connected it to Unity. This marked the beginning of the ISS’s construction, and engineers from around the world collaborated to ensure the success of this ambitious project.
Since the historic joining of Zarya and Unity, the ISS has undergone significant expansion with contributions from its international partners. The station received its first long-duration residents, Expedition 1, in November 2000. Since then, international teams have maintained a continuous human presence on the ISS, conducting operations, maintenance, spacewalks, and groundbreaking research across various scientific disciplines.
The ISS has become a bustling orbital outpost and microgravity laboratory, accommodating diverse activities, including cargo and crew visits, spacewalks, scientific investigations, technology demonstrations, commercial ventures, public outreach, and STEM initiatives. The utilization and advancements achieved on the ISS have yielded substantial benefits for humanity.
In the years following the launch of the first two modules, ISS crews have conducted thousands of experiments, leading to biomedical and technological spinoffs. A notable milestone was the “Year in Space” mission, where Scott Kelly and Mikhail Kornienko spent nearly a year on the ISS. Scott Kelly’s twin brother, Mark Kelly, served as a control for a series of biomedical experiments. The ISS has also hosted the first crews brought by privately owned spacecraft, such as the SpaceX Crew Dragon.
As of Expedition 70, which arrived on September 27, 2023, and is set to depart in spring 2024, the ISS continues to play a crucial role in advancing human understanding of space and fostering international collaboration in space exploration.