NASA's Devastating Plan to Retire the International Space Station: A Comprehensive Overview
The International Space Station (ISS) is on its twilight years, with retirement just around the corner in a few short years. This iconic orbital lab, home to astronauts in low Earth orbit for over 20 years, is set to meet its end in a fiery plunge through the atmosphere, leaving behind tiny remnants of its illustrious history.
NASA, along with its international partners, has devised a plan to bid farewell to the ISS. This plan involves sending the space agency's beloved orbital lab plummeting through Earth's atmosphere in 2031. Most of it will burn up due to the intense heat, but smaller fragments will remain, prompting a controlled reentry to minimize the risk of impact on inhabited areas.
After a thorough evaluation of various options in terms of feasibility and cost, NASA made an unexpected decision. They turned to the private industry, tasking them with designing a spacecraft that would drag the ISS towards its inevitable destruction. This move is a testament to the rapid advancements and capabilities of private companies in the space sector.
The ISS, at 357 feet long, is not only the largest human-made structure in space but also holds the record for the largest object to ever be deorbited. Bringing it down will be no easy feat, particularly with ensuring that its remaining debris lands a considerable distance away from populated areas.
Why bid adieu to the ISS?
NASA and its international partners began constructing the ISS in 1998. Over two decades, it has served as a pivotal platform for scientific research and demonstrations of new technologies in microgravity, often influencing innovations on Earth. The ISS is a symbol of international cooperation and peace, showcasing collaboration among space agencies from the United States, Russia, Europe, Japan, and Canada. It has hosted astronauts from 18 different countries, who have completed over 270 spacewalks.
However, with age comes wear and tear, and the ISS is no exception. Its retirement is paving the way for private companies to design their own space stations in low Earth orbit, taking over once the ISS is gone. Russia, one of the ISS's key partners, is constructing its own space station in orbit and will likely take its toys with it when it leaves. This means NASA will be left without a crucial ally in the process of decommissioning the ISS.
Disassembling the ISS bit by bit is simply not practical, as the spacecraft was never designed to be taken apart again. The process would require significant efforts from NASA, international space agencies, and astronauts, as well as a spacecraft with a cargo bay large enough to return the disassembled parts to Earth. This is a logistical and financial challenge that the agencies are unwilling to undertake, making the currently proposed plan the only feasible option.
The downward spiral
Rather than letting the ISS tumble down uncontrollably, NASA and its international partners will target a remote, uninhabited area in the ocean as its final resting place. Before the deorbit process begins, all movable goods will be evacuated from the ISS, and astronauts will evacuate the space station, leaving it empty for the first time in decades.
To begin the deorbit process, NASA will cancel the periodic orbit-raising burns that maintain the ISS's position. Eventually, the spacecraft's orbit will decay, dropping below 150 miles. This natural orbital decay, caused by atmospheric drag, will take months to gradually bring the ISS down to its end.
The SpaceX touch
For the next step, SpaceX has been tasked with designing a new deorbit vehicle. This vehicle will dock with the ISS and perform a series of deorbit burns to further lower the space station's orbit. NASA had previously suggested using Russia's Progress cargo spacecraft for the task, but that plan is now off the table.
In March, NASA released its 2024 budget proposal, which included $180 million for developing a deorbit capability for the ISS by the end of 2031. The cost of developing the ISS tug is estimated to be around $1 billion. The recently awarded SpaceX contract, worth $843 million, will cover the development of the vehicle, but not the cost of launching it. SpaceX has not shared details of its space tug design or whether it will repurpose its Dragon spacecraft or build a different one altogether.
Safe and controlled reentry
To ensure a controlled reentry, the ISS will need to execute a large reentry burn to precisely target its landing point. The thrust maneuver will ensure that the spacecraft enters an elliptical orbit and is properly caught by the atmosphere. If the maneuver is strong enough, the uncertainties of the debris footprint will play a lesser role.
Approximately 40% of the ISS is expected to survive reentry, according to Tobias Lips, managing director of satellite aerodynamics company Hyperschall Technologie Göttingen in Germany. This substantial amount of material could land in the Pacific Ocean's "spacecraft cemetery," a remote region located between New Zealand and South America, known for its isolation.
The end of an era
As the ISS descends towards a nosedive through the Earth's atmosphere at speeds reaching 17,500 miles per hour, it will begin to disintegrate. External elements such as solar panels and antennae will fall off first, followed by the main structure of the station breaking up into fragments. Most of these fragments will burn up, leaving behind 10% to 20% of the ISS's mass.
The survival of these remaining ISS fragments is still a concern. While the smaller the spacecraft, the fewer fragments that will survive reentry, larger objects are less prone to complete breakdown, making it difficult for them to fully disintegrate. This means that even if the deorbiting process is successful, debris may still pose a potential threat.
The controlled deorbiting and eventual destruction of the ISS mark the end of an era and the beginning of a new one. With the retirement of the ISS, the stage is set for private companies to take the lead in commercializing low Earth orbit.
Following NASA's decision, private companies could play a significant role in the future of space exploration. These companies might design spaceships that can drag the remains of the ISS towards its destruction, showcasing their advancements in space technology.
The controlled deorbit of the ISS could inspire future scientific research in the field of reentry physics, providing valuable data on how large objects behave upon reentry into Earth's atmosphere. This knowledge could help mitigate potential risks associated with reentry of future space missions and space debris.
