Decommissing the International Space Station

Last Updated24/02/2022

The ISS was launched in 1998 as part of joint efforts by the U.S., Russia, Japan, Canada and Europe.
It operates in low-earth orbit.
The ISS has served as a laboratory suspended in space and has aided multiple scientific and technological developments.
ISS has consistently maintained a human presence for the past 21 years, providing astronauts with sophisticated technologies for scientific research.

The space station has already surpassed that checkpoint of 15 years by being active for 21 years, with plans to continue operations till 2030.
However, the limitations on the life-cycle of the station are catching up. The ISS goes through 16 rotations of the earth per day, causing extreme temperature changes on the exterior.
The side facing the sun can get heated up to 121°C while the temperature on the opposite, darker side can fall to –157°C, causing intense expansion and contraction of the building material.
The orbital thermal cycling, coupled with dynamic loading, affects the longevity of the primary structure of the space station.
The technical lifetime is also limited by parts like radiators, modules and truss structures that tend to degrade over time.

NASA plans to remove the ISS from its orbit around the earth and eventually plunge it into the ocean at a point farthest from human civilization.
The space agency will use the dual method of natural orbit decay and a re-entry maneuver to bring an end to the ISS.
According to the plan, the earth’s natural atmospheric drag will be used in lowering the altitude of the ISS while setting up the de-orbit.
The space station operators will then provide the final push to it to lower the structure to the maximum possible height and ensure safe re-entry into the earth’s atmosphere, leading it to Point Nemo over the South Pacific Oceanic Uninhabited Area (SPOUA).
The exterior of the modules is expected to melt while re-entering the earth’s atmosphere. The exposed internal hardware is also expected to burn or vaporize during the process.
It is believed that denser components like the truss sections will survive the re-entry and fall into the SPOUA.

NASA claims that the debris of the ISS that survives the re-entry will settle on the ocean floor and not cause any substantial long-term impact.

As the ISS plans to end operations in space, new players are already lining up to replace it.
In January 2022, China announced that its space station will be ready for operations this year.
Blue Origin, the aerospace company founded by Jeff Bezos, has also announced its plans to build Orbital Reef, a commercially developed, owned, and operated space station in low-earth orbit. Blue Origin is working alongside Sierra Space on the project.