Decommission of ISS

News: The National Aeronautics and Space Administration (NASA) has announced plans to retire and decommission the International Space Station (ISS) by 2031.

What is the ISS?

  • The ISS was launched in 1998 as part of joint efforts by the U.S., Russia, Japan, Canada and Europe.
  • The idea of a space station originated in the 1984 State of the Union address by former U.S. President Ronald Reagan. The space station was assembled over many years, and it operates in low-earth orbit.
  • Since its inception, it has served as a laboratory suspended in space and has aided multiple scientific and technological developments. The ISS was originally built to operate for 15 years.
  • A space station permits quantum leaps in research in science, communications, and in metals and lifesaving medicines which could be manufactured only in space. ISS has consistently maintained human presence for the past 21 years, providing astronauts with sophisticated technologies for scientific research.

Reasons:

  • The space station has already surpassed that checkpoint by being active for 21 years, with plans to continue operations till 2030.
  • 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.
  • This 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.

Procedure to de-commission:

  • 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 civilisation. The space agency will use the dual method of natural orbit decay and a re-entry manoeuvre to bring an end to the ISS as we know it.
  • 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.
  • It would then lead to Point Nemo over the South Pacific Oceanic Uninhabited Area (SPOUA). Dissembling process would have posed huge logistical and financial challenges.