Point Nemo: What’s in the “Space Graveyard”
Point Nemo is the most remote and distant place from any solid ground on our planet, and also the graveyard of spacecraft, space stations, and other large space objects that have been decommissioned. The region is known as the “Uninhabited Area of the South Pacific Ocean”.
The location is known to be quite remote. Point Nemo is located at 48⁰25.6′ in south latitude and 123⁰23.6′ in west longitude. In addition, the people closest to the region are those aboard the International Space Station (ISS), which orbits the Earth at an altitude of about 400 km. From Point Nemo to the mainland, in Southern Antarctica, it is about 2,700 km.
As there are no islands nearby and few commercial vessels pass through the site, it is used to safely dispose of old spacecraft, without exposing people and buildings to the dangers of possible falling debris. Because of this, the South Pacific Uninhabited Area has become a large space graveyard, covering 3,000 km from north to south and 5,000 km from east to west.
The site is between the bathyal zone and the abyssal zone, approximately 4 km below where the waves form. Also, as the area is dark, it has few fish and is home to sea sponges, starfish, squid, octopus, and other animals, which live amid the space debris.
The space graveyard
Due to the action of gravity, leaving space vehicles in Earth orbit indefinitely is very dangerous. That’s because the mass of the Earth exerts the gravitational attraction on everything that is in orbit and little by little attracts these objects. Because of this, if not disposed of properly, cargo ships, satellites and even the International Space Station can uncontrollably enter Earth.
Although this process burns the object, the debris that remains is dangerous to terrestrials. For this reason, the space agencies responsible for the craft notify maritime and aviation authorities in Chile and New Zealand, which share responsibility for traffic in the South Pacific Uninhabited Area, informing them of the time and place at which the debris will fall.
Soon after, controlled re-entry begins. Objects enter the atmosphere towards the ocean floor. At this time, maritime and aviation authorities must advise aircraft and vessel commanders to avoid the location.
“Even at controlled entrances, there is no exact landing point,” said Holger Krag, director of the Office of Space Debris at the European Space Agency (ESA). Krag adds that for this reason, large areas are needed. “The nature of the breakup process [of the ships] is why we need a really big area, to make sure all the fragments fall into it, because they don’t fall in one place.”
Between 1971 and 2016, space agencies around the world disabled around 260 spacecraft at the site. At Point Nemo, there are submerged remains of former Soviet space stations, Russian supply ships, European Space Agency cargo ships, and others from the United States. It is estimated that their debris is 1 km away because the entrance of a large spacecraft can extend over an area of 1,601 km.
Impacts on Point Nemo’s marine life
Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center, reports that space vehicles are currently being driven to other locations. “Some of the Russian ships go to the Indian Ocean, while others go to the North Atlantic, like the Baffin Bay,” he said.
It is worth mentioning that the current objective of the space industry is to reduce the amount of debris in space, to reduce interference with communication systems on Earth and the risks in space explorations.
This means that objects that are in space will have to come down at some point. On the other hand, the impacts that objects cause on ocean ecosystems is unknown. This is because there are few studies that study the impacts of space debris.
Space archaeologist at Flinders University, Alice Gorman, explains that while various parts of spacecraft burn as they return to Earth, more robust parts, such as fuel tanks, can be problematic depending on the compound they carry. “Some spacecraft fuels are toxic – hydrazine, for example. But cryogenic fuels are not”, highlighting that hydrazine is one of the main materials used today.
Despite the environmental impacts, there is no safer option for disposal. “If we left [objects] in orbit without fuel to help maintain their positions, this craft would descend and we would have no control over where they land.”
For Dr. Brad Tucker, an astronomer at the Mount Stromlo Observatory, this is not the best solution. “Actually, we don’t like her. It’s the least bad option we have,” he adds. In addition, he explains that the region is known for having practically an artificial reef formed by pieces of space objects.
The Alfred Wegener Institute researcher, Autun Purser, explains that because of the ocean currents, the place has animals, but not a great biological diversity. While Holger Krag, director of the Space Security Program at ESA, claims that most objects discarded there were non-toxic.
Spaceships that are at Point Nemo
The Point Nemo Space Cemetery is home to more than 140 cargo ships from Russia, space cargo vehicles from Japan, automated transfer vehicles from Europe and space stations from the former Soviet Union.
Among the stations in the cemetery is Mir, which was launched in 1986 by the former Soviet Union. The station was deactivated in 2001 and deorbited by a Russian Progress spacecraft. About 25 tons of the material resisted and sank into the ocean. Furthermore, it entered the atmosphere at about 99 km altitude and began to disintegrate at 95 km.
Another space station buried at the site was China’s Tiangong-1. It was part of a project aimed at building a station with several modules. Despite the fact that in 2012 Tiangong-1 went into hibernation, the Chinese authorities managed to keep it running for a while longer. However, in 2016 the country lost contact with the station and as it could not control it, it returned to Earth. Components that survived re-entry into Earth plunged thousands of kilometers into Point Nemo.
Jules Verne, the European Space Agency’s (ESA) first automated transfer vehicle (ATV), was decommissioned in 2009 after carrying out activities in the orbiting laboratory, ISS. It broke up approximately 75 km above the Space Cemetery, and it took 12 minutes for the remains to sink into the Pacific.
Although the International Space Station (ISS) has been orbiting in space for 20 years and its components show signs of wear, NASA has said it intends to keep it active until 2030. After that, it will return to Earth in a dive at Point Nemo.