How withdrawing from the ISS could impact marine life

After more than two decades of scientific service, the International Space Station (ISS) should say a final farewell. The research center has allowed us to expand our understanding of the Earth, the solar system and beyond. More than two hundred astronauts have visited the station, while researchers have conducted thousands of experiments and studies, from researching the origin of stars to understanding the impacts of space on the human body. This space laboratory has touched and transformed almost every major scientific discipline.

Earlier this year, NASA announced plans for the station’s eventual retirement in 2031, but the 450-ton lab is unlikely to face a quick demise. After operations are completed, most dead satellites drift out of orbit and eventually burn up in Earth’s atmosphere.

However, most of the ISS will sink in Point Nemo, a remote region of the Pacific Ocean so far from Earth that many scientists call it a “space graveyard”, after the number of spacecraft buried in the grave. watery.

The isolated expanse of ocean is an ideal place for a spacecraft to crash without causing potential harm to humans or destruction to cities, as described by NASA in the ISS transition plan. The name “nemo” is Latin for “person” and, as its nickname suggests, it is uninhabited by humans. In fact, it is the farthest point of any landmass on Earth.

Point Nemo lies at 48°52.6′S 123°23.6′W in the Pacific Ocean. Google Earth

There is virtually no life in the nutrient-poor waters – the lack of biological diversity is one of the reasons Point Nemo is used as a galactic dumping ground. At one time, Point Nemo offered a perfect blank canvas to study a deep underwater location completely untouched by the human environment, says Leila Hamdan, associate director of the university’s school of ocean science and engineering. of southern Mississippi. Hamdan studies the biogeography of the deep sea, in particular how shipwrecks alter the biodiversity of the ocean floor.

But big tech exposed to the elements of space presents a whole different set of unknown variables. As the clock ticks on the impending aquatic fate of the ISS, some wonder how space exploration ultimately impacts marine life.

“Before we even have the technology to go [to Point Nemo]and put deep submersibles in the ocean and collected samples there, we already put the relics of space exploration there,” says Hamdan.

According to Hamdan, it is unclear whether the long-term effects of launching satellites into the ocean have a positive or negative impact on marine wildlife and local ecology. But shipwrecks could offer clues, she says.

When a ship runs aground, the microbes that surround the wreckage tend to be more diverse and play an important role in keeping the environment healthy. However, unlike ships that sail across the sea, these Earth-orbiting structures have traveled through space. The ISS, for example, contains decades of experimental equipment, materials and even traces of altered human DNA. It’s unclear what kind of long-term effects the craft — and what they’re carrying — will have on Earth’s seabed.

“It will be a very large human structure with a lot of human material, which is now resting on the seabed,” she says. “It would be naive to think that this is not going to change the ecology that is present.”

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Space debris is just one type of marine debris that contributes to the growing and widespread pollution of Earth’s oceans. According to the Office of Coastal Management, more than 800 marine species have been injured, sickened or died from consumer plastics, metal, rubber, paper and other debris. While the ISS is larger than most trash in the ocean, other experts worry less about its immense size compared to other sunken trash.

“If you look at the volume of the International Space Station, it’s nothing compared to an oil tanker,” says Cameron Ainsworth, associate professor of physical oceanography at the University of South Florida’s College of Marine Science. An average 700-foot-long tanker easily exceeds the ISS’ end-to-end length of 356 feet, making the station equivalent to “a few tons of aluminum crashing into the ocean, which won’t have no more impact than a sinking ship.”

But as Earth’s orbit becomes increasingly cluttered with a host of space junk, those few hundred pounds of debris per craft will eventually pile up.

“The ocean is not an unlimited repository for all of our space junk,” says Erik Cordes, professor and vice president of biology at Temple University. Cordes, who was one of many experts called in to help after the 2010 Deepwater Horizon oil spill, knows all too well the damage human activities can have on marine life.

While he understands the appeal of landing decommissioned spacecraft as far away from people as possible, Cordes says there are a lot of “unpredictable” consequences to dropping tons of scientific equipment into an area that scientists don’t. don’t know enough.

“People usually think of the deep sea as one big, muddy, barren desert, and it really isn’t,” he says. “The more we explore, the more we begin to discover some truly incredible habitats, ecosystems and animals at the bottom of the ocean.”

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Marine scientists often have to resort to guesswork about what’s lurking on the ocean floor, Cordes says. But until they have real data, such as high-resolution maps and images to scan the deepest parts of the seafloor, more work is needed before it becomes possible to predict the impact. term, if any, of falling satellites into the Earth’s oceans.

NASA states in the ISS teardown debrief that impacts to marine life are likely to be minimal: “During descent through Earth’s atmosphere, the space station would burn, shatter and vaporize into fragments of varying sizes. Some station fragments [sic] would likely survive the thermal stresses of reentry and fall to Earth. The environmental impacts of this debris in the predicted impact area are expected to be low. »

When PopSci contacted NASA and other government agencies for comment, they said there was no official effort to track space debris after it fell into the ocean. There is still time to explore other avenues or implement marine habitat monitoring before the ISS begins its decommissioning plans in 2030. NASA writes in the transition plan that it will continue “ Investigate alternative footprint targets and ground paths for station disposal to minimize risk. for [sic] The population of the Earth. But until scientists know more, it’s a waiting game.

“I think with all the money we’re spending putting this thing out there,” Cordes says, “we should spend some money to find out what happens when it comes back down.”

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