The International Space Station will have an expensive funeral

The first permanent crew aboard the International Space Station (ISS) reached orbit in 2000, two years after the first two modules were placed there. For more than 22 years, there has not been a day without a human being on board the station. It is estimated that the construction of the orbiting laboratory over the years has cost nearly 100 billion US dollars, and the annual operation of the station costs member states nearly 2 billion US dollars. However, even with such expenses, it is impossible to keep the station in orbit indefinitely. Originally, plans called for the project to be completed and the station destroyed in the upper atmosphere in 2016. In 2015, the space station program was extended through 2020. In the following years, the project was extended twice more, to determine in January 2022 that the station would finish. Its operation is in 2030 and it will be withdrawn from orbit into the upper atmosphere in January 2031.

This time we cannot count on extending the project due to the fact that the station is slowly starting to fail. There are more and more problems with the tightness of individual units and the equipment installed on them. Extending the program beyond 2030 would simply be dangerous for the crew aboard the station.

NASA begins preparations for the final mission

In NASA’s 2024 budget proposal, which was published in early March, you can find an item described as “preliminary development work on the throttle unit.” We are talking about a special unit that, after being launched into orbit at the end of 2020, will brake the space station in a controlled manner, making it lower and lower. The plan is for the space station to eventually enter Earth’s atmosphere over the Pacific Ocean. Of course, some of the station will burn up during the flight through the atmosphere, but some will survive and have to fall near the inaccessible pole of the ocean, also known as Point Nemo, more than 2,500 km from the nearest land.

NASA is requesting $180 million from lawmakers in 2024 for this. Of course, this amount does not cover the construction or launch of the module into orbit. According to current estimates, the total cost would be around $1 billion.

The problem is that until recently, the plan was to deorbit the space station with the help of the Russian Progress cargo ship, which could handle this task. However, the geopolitical situation on Earth makes it impossible to be sure if Progress will be available in 2030. Thus, NASA wants to have its own backup unit.

But do you have to spend a lot?

A billion dollars for a private deorbit may seem like a lot, but after all, half of the annual budget that goes for years is spent on space station maintenance. After all, no one wants a space station to lie uncontrollably in an indefinite place on Earth after three decades of resounding success.

Pulling anything out of orbit is a very difficult task. The space station, located at an altitude of 400 km above the Earth, circles our planet in just 93 minutes, so it moves above the Earth’s surface at a huge speed. So assuming we were simply running the throttle engines and nothing else, we wouldn’t have been able to locate the landing site until the very end. The upper atmosphere is subject to constant fluctuations. Depending on atmospheric conditions, temperature, pressure, sometimes the point at which the atmosphere controls the throttle of a space object is higher and sometimes lower. In a way, it’s like trying to land a seaplane in rough seas. It is not known when the plane will touch the surface of the water. It will depend on the current state of the sea.

Using a special braking module allows you to design the trajectory of entry into the atmosphere so that the station will land near Point Nemo, where it will not threaten anyone on the surface of the Earth. It might be worth any price.