'Water grave' will bury the ISS station in the future

NASA will drop the International Space Station into an uninhabited sea called Point Nemo in 2031.

Point Nemo is located 4,800km off the coast of New Zealand and 3,200km north of Antarctica. It is so far away from land that the closest people to this area are the astronauts on the International Space Station (ISS) - flying at an altitude of 420km above Earth. When decommissioned in 2030, the ISS will crash into that remote location, like other space stations, satellites and debris. Point Nemo is considered the grave for objects in space.

The ISS station will operate until the end of 2030.

Many space powers have dumped space debris in the area around Point Nemo, named after Captain Nemo in the novel "Twenty Thousand Leagues Under the Sea" by Jules Verne from the 1970s. Also known as Extreme Impossible Approaching over the ocean or the No-man's Zone in the South Pacific, the exact coordinates of this world's most remote location were calculated by Russian-Canadian engineer Hrvoje Lukatela in 1992.

More than 263 pieces of space junk have sunk into Point Nemo since 1971, including Russia's Mir station and NASA's first space station, Skylab, according to 2019 research. The debris is not an intact record of the calendar. space travel history which is debris scattered over large areas. "This is the largest ocean without any archipelago. It's also the safest area for debris to be re-entered into the atmosphere," said Holger Krag, director of the Agency's Office of Space Safety Programs. European Space Agency (ESA), said.

Point Nemo has almost no trace of human life. In addition to space debris on the seabed, microplastics were discovered in the sea water here when the Volvo Ocean Race yacht passed through the area in 2018. Space junk like old satellites fell back into the Earth's atmosphere the ground every day, though most of it goes unnoticed because the debris burns up long before it hits the ground. Only debris as large as spacecraft or rocket parts can pose a minor threat to people and infrastructure on the ground. Space agencies and operators must plan carefully in advance to ensure that the debris lands on Point Nemo.

In the case of the ISS station, NASA says the station will begin maneuvers to leave orbit in early 2026, lowering altitude to fall to Earth in 2031. The exact time of the operation depends on the solar cycle. sky and its impact on the Earth's atmosphere. Active sun often causes Earth's atmosphere to expand and increase drag on the ISS station, according to NASA.

The space agency and commercial operator must also notify the aviation and shipping authorities, typically in Chile, New Zealand and Tahiti, of the location, time and area of ​​the debris area. fall down. Authorities will issue notices to planes and ships. According to Krag, a big problem is a lot of debris from the rocket stage and spacecraft falling out of control into the Earth's atmosphere. In June 2021, NASA criticized China for being irresponsible after debris from a Long March 5B rocket fell into the Indian Ocean.

Long March 5B rocket is 33 m high and weighs more than 18,000 kg, launching the module of the Chinese space station into orbit on April 29, 2021. After running out of fuel, the rocket fell out of control through space until it was sucked in by Earth's gravity. Krag said that an average of 100-200 tons of space junk falls out of control through the Earth's atmosphere each year.

At least 26,000 pieces of space junk orbit the Earth the size of a felt ball or more, which could destroy a satellite if a collision occurs. More than 500,000 pieces of debris large enough to damage spacecraft or satellites. More than 100 million pieces of debris the size of a grain of salt could puncture a space suit.

Letting space junk fall to the bottom of the ocean at Point Nemo is the least extreme option, says Vito De Lucia, a professor of law at the Norwegian Center for Sea Law at the University of the Arctic. However, we don't know much about the deep-sea environment in this area. Some studies say that due to ocean currents in the area, Point Nemo is not really biodiverse. Oceanographer Autun Purser, a postdoctoral fellow at the Alfred Wegener Institute in Bremerhaven, Germany, shared that he has been close to Point Nemo and the seabed is home to sea cucumbers, octopus and exotic fish.

Krag says space debris that ends up in the ocean is usually made of stainless steel, titanium or non-toxic aluminum. "The orbital debris does not float, but sinks deep and does not pose a danger to ships. Compared to many lost containers and shipwrecks, the amount of space junk's hardware is quite small," Krag said.