International space station – product of multinational collaboration

On June 5, a United Launch Alliance Atlas V rocket carrying the Boeing Starliner spacecraft was successfully launched from Space Launch Complex 41 at Cape Canaveral Space Force Station.

It was the first crewed flight of the Starliner, with veteran astronauts Barry "Butch" Wilmore and Sunita "Suni" Williams on board.

The Starliner docked with the International Space Station (ISS) the following day. After extensive checks to verify airtight seals, the hatches were opened and Wilmore and Williams floated into the lab complex to an enthusiastic welcome from the seven resident crew members: cosmonauts Oleg Kononenko, Nicolai Chub and Alexander Grebenkin, along with NASA astronauts Matthew Dominick, Michael Barratt, Jeanette Epps and Tracy Dyson.

The Boeing Starliner is a human-grade space capsule designed to take astronauts to and from the ISS. Boeing began work on the capsule in 2014, when it signed a US$4.2 billion contract with NASA under the agency’s commercial crew programme.

The ISS is a large space station assembled and maintained in low earth orbit by the collaborative efforts of five space agencies and their contractors: NASA (US), Roscosmos (Russia), JAXA (Japan), ESA (Europe), and CSA (Canada). The ISS is the largest space station ever built.
The ISS programme brings together international flight crews, multiple launch vehicles, globally distributed launch and flight operations, training, engineering, development facilities, communications networks and the international scientific research community.

The space station was officially approved by president Ronald Reagan and a budget approved by the US Congress in 1984. NASA administrator James Beggs immediately set out to find international partners who would co-operate on the programme. Canadians, Japanese and many nations of the European Space Agency began to participate soon after.

In 1993, during a redesign of the ISS, the Russians were invited to participate.

As the ISS is a multi-national collaborative project, the components for in-orbit assembly were manufactured in various countries around the world. In the mid-1990s, the US components Destiny, Unity, the Integrated Truss Structure and the solar arrays were fabricated at the Marshall Space Flight Centre in Huntsville, Alabama and the Michoud Assembly Facility in New Orleans. These modules were delivered to the operations and checkout building and the space station processing facility (SSPF) for final assembly and processing for launch.

The Russian modules, including Zarya and Zvezda, were manufactured at the Khrunichev State Research and Production Space Centre in Moscow. Zvezda was initially manufactured in 1985 as a component for Mir-2, but Mir 2 was never launched and instead became the ISS Service Module.

The European Space Agency (ESA) Columbus module was manufactured at the EADS Astrium space transportation facilities in Bremen, Germany, and by many other contractors throughout Europe. The other ESA-built modules – Harmony, Tranquility, Leonardo and the Cupola – were initially manufactured at the Thales Alenia space factory in Turin, Italy. The structural steel hulls of the modules were transported by aircraft to the Kennedy Space Centre SSPF for launch processing.

The Japanese Experiment Module Kibō, was fabricated in various technology manufacturing facilities in Japan, at the NASDA (now JAXA) Tsukuba Space Centre, and the Institute of Space and Astronautical Science. The Kibo module was transported by ship and flown by aircraft to the SSPF in Florida.

The mobile servicing system, consisting of the Canadarm2 and the Dextre grapple fixture, was manufactured at various factories in Canada and the US under contract by the Canadian Space Agency. The mobile base system, a connecting framework for Canadarm2 mounted on rails, was built by Northrop Grumman.

The assembly of the ISS, a major endeavour in space architecture, began in November 1998. Russian modules launched and docked robotically, with the exception of Rassvet. All other modules were delivered by the space shuttle, which required installation by ISS and shuttle crew members using the Canadarm2 (SSRMS) and extra-vehicular activities (EVAs).

By June 2011, 159 components had been added during more than 1,000 hours of EVA. There had been 127 spacewalks originating from the station and the remaining 32 were launched from the airlocks of docked space shuttles.

The ISS provides a platform to do scientific research, with power, data, cooling, and crew available to support experiments. Small uncrewed spacecraft can also provide platforms for experiments, especially those involving zero gravity and exposure to space, but space stations offer a long-term environment where studies can be done potentially for decades, combined with ready access by human researchers.

The ISS simplifies individual experiments by allowing groups of experiments to share the same launches and crew time. Research is done in a wide variety of fields, including astrobiology, astronomy, physical sciences, materials science, space weather, meteorology; and human research, including space medicine and the life sciences.

Scientists on earth have timely access to the data and can suggest experimental modifications to the crew.

If follow-on experiments are necessary, the routinely scheduled launches of resupply craft allow new hardware to be launched with relative ease. Crews fly expeditions several months long, providing approximately 160 person-hours a week of labour with a crew of six, though a considerable amount of crew time is taken up by station maintenance.

Perhaps the most notable ISS experiment is the Alpha magnetic spectrometer (AMS), which is intended to detect dark matter about the universe. According to NASA, the AMS is as important as the Hubble space telescope. In April 2013, scientists reported that the AMS might have detected hints of dark matter.

According to the scientists, "The first results from the space-borne Alpha magnetic spectrometer confirm an unexplained excess of high-energy positrons in earth-bound cosmic rays."
China and India are not participants in the ISS programme. China has built its own space station, Tiangong, whose core module was launched in April 2021. Tiangong has been permanently crewed since December 2022.

India proposes to build an orbital space station, the Bharatiya Antariksha Station, with a planned completion date of 2035. It will maintain an orbit of approximately 400 kilometres above the earth, where astronauts could stay for 15-20 days.

For more information about the International Space Station assembly elements visit https://www.nasa.gov/international-space-station/international-space-station-assembly-elements/