End of an Era - SpaceX Dragon to Deorbit the ISS
On June 26th, NASA selected SpaceX to destroy the International Space Station. In a safe manner :D
Completed from 1998 to 2011, the International Space Station (ISS) was given an operational life of 15 years. The ISS has been continuously inhabited since November 2000. This means the ISS has currently had a life of 24 years as of writing this article.
De-orbit of the ISS is meant to happen around 2030 meaning the ISS will be twice as old as initially expected.
De-orbit
Image: ISS edited over the top of a football field. Credit: NASA
Since the ISS is the size of a football field, it's quite difficult to de-orbit such a long vehicle. After all, the last thing you want to happen is for the engines to go to full power and the ISS snaps in half, leaving everything including the de-orbiter vehicle stranded.
Approach
Now there are many ways to approach de-orbiting a vehicle. One of them could be to not even de-orbit the vehicle. Wouldn't it be nice if we could boost it to a major orbit around the Earth, effectively sealing it as a museum piece for future generations.
Well this would be nice wouldn't it. Unfortunately for us, NASA has done some number crunching.
Here is a chart from the International Space Station Deorbit Analysis Summary
Here is a chart from the International Space Station Deorbit Analysis Summary
It shows the delta V required to boost the ISS to a specific lifetime.
"However, ascending to these orbits would require the development of new propulsive and tanker vehicles that do not currently exist" - NASA
"Other vehicles would require both new certifications to fly at higher altitudes and multiple flights to deliver propellant" - NASA
NASA has concluded that no vehicle in operation currently could fulfil this operation. And any vehicle that potentially could wouldn't be able to complete the mission either since it would need to be re-certified and re-fueled in orbit.
Now I hear you say, "But Starship!" Well, the main problem is that its massive engines and size could potentially cause more problems than it solves
These are all the approaches NASA has considered. With them concluding that a controlled re-entry is the best solution to this problem.
Vehicle
Image: Dragon type vehicle de-orbiting ISS. Credit: SpaceX
Since NASA concluded that a new vehicle would be required to de-orbit it in a safe manner, NASA has chosen SpaceX's plans on how to de-orbit the vehicle.
Information:
Vehicle:
Based on Cargo Dragon
Pulled from fleet
Entirely new design of trunk
Requirements:
6 times the usable propellant and 3-4 times the power generation and storage compared to the current version of Dragon
Engines:
46 Draco engines with between 22 and 26 firing at once, producing 10,000 newtons of thrust during the final burn
Weight:
30,000kg Wet Mass
16,000kg of Propellant
Debris
Debris is a big part of de-orbiting vehicles and objects in Low Earth Orbit (LEO). Many objects have been known to survive re-entry. In 2024, the ISS released some batteries to burn up on re-entry. Spoiler: They did not burn up.
NASA Space Station Batteries Hit Florida Home After It Was Released - Tech Times
The expected footprint of the debris field will be about 2000 kilometres long but will be fairly narrow. An exact area has not been provided, but it has been hinted at that the Pacific Ocean could be used as a re-entry location.
For reference, this yellow strip on planet Earth is 2000Km long. Not that big when you put the reference as Earth.
Crew
The ISS crew will depart 6 months before the planned re-entry. Since the base vehicle is Cargo Dragon, this means humans will not be helping with the reentry operation. It will be fully autonomous, with ground controllers giving the final command to execute the reentry burn.
Conclusion
An end of an era? Certainly. The ISS has been around for what feels like forever. But is it the right decision? Absolutely. In a near coming future of private space stations the ISS is starting to show its age. With the ever growing list of problems with the space suits NASA cancels ISS spacewalk due to spacesuit coolant leak. It's only a matter of time before the ISS becomes more effort than it's worth
De-orbiting the ISS is a good thing as it will allow a new era of private space stations and make way for a more exciting future for space. The legacy of the ISS can never be forgotten and must be preserved. But it will dance it's final dance in 2030.
