#INTERNATIONAL SPACE STATION DECOMMISSION SERIES#
The remaining descent will be more rapid, but controlled by a series of spacecrafts sent to attach and steer the structure as it begins to plummet towards Earth. The ISS will then be gently decelerated by onboard thrusters, causing its orbiting altitude to gradually lower over the course of a few months. In the planned, controlled, de-orbit operation for the ISS, newly built modules will first detach from the main structure and remain in orbit to eventually recombine as parts of future space stations. Experts estimate that if it were to crash down uncontrolled in a metropolitan area, the worst case scenario could be on the scale of a “9/11 event”. The ISS is too large to satisfy the design for demise principle, which is why we need special operations for de-orbit. Objects that fall freely from orbit must disintegrate into tiny pieces to make sure they don’t pose a danger to people on the ground. While no one was harmed, this led to reforms and “design for demise” guidelines.ĭesign for demise is an important principle for the engineering of satellites and other orbiting space infrastructure. In 1979, Nasa’s Skylab station was not re-fuelled in time and came crashing down, out of control, leaving chunks of the station scattered across Australia. In fact, it would not be the first space station to fall out of the sky. If degradation or unplanned damage occurs before the official decommissioning, a free-falling ISS poses serious dangers. While Nasa has committed to maintaining the station until 2030, its partner organisations are yet to officially sign on, meaning the final decision to de-orbit will depend on politics as much as engineering. Despite this, Nasa assesses there is “high confidence” the station will see it through to the end of 2030. In 2016, a fly-away speck of paint chipped a window, and just last year, ISS crew went into evacuation standby when Russia obliterated a dead satellite with a missile, causing thousands of pieces of debris to fly by the station at 5km per second. The rise of flying space junk also poses unplanned and catastrophic risk of destruction. Space radiation chars the transparent glass on the solar cells which are used to power the station, and repeated docking and undocking causes gradual structure degradation, which will ultimately lead to its demise. These thermal extremes cause cyclic expansion and contraction which wears the material. For every orbit around the Earth, the ISS gets scorched by solar radiation on one side, and freezes on the other. It is used to test future spacecraft technologies and to study health effects of long term spaceflight for the possibility of future human exploration of the solar system.ĭespite onboard research gaining momentum, Nasa has noticed signs of infrastructure and components slowing down. The ISS also helps to monitor Earth’s ecosystems and natural disasters in real time. Research in the so-called microgravity environment of the ISS has yielded breakthroughs in drug discovery, vaccine development and medical treatments in the last decade. It is visible by the naked eye from Earth while it completes its 16 daily orbits, passing 400km above the Earth’s surface. The monumental conglomerate structure now stretches the length of a football field and is the largest human-made object in space. The modules and parts of the ISS have been built progressively by many different countries, only coming into contact for the first time in space.
The ISS has enabled one giant leap for science and collaboration across mankind, involving five different space agencies (US, Russia, Europe, Canada and Japan).
It has already been in operation for 21 years, and Nasa has given the go-ahead for one more decade, thereby doubling its total planned time in orbit. Originally commissioned for a 15-year lifespan, the ISS is outliving all expectations. Finding Point Nemo will be the final stop in a complex and multi-staged mission to transition the operations of the ISS to new commercial space stations, and to bring the remaining structure safely down to Earth.
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