What is the lifespan of a Starlink satellite? How are they disposed of after retirement?

Okay, let's talk about the lifespan of Starlink satellites and their "fate" after retirement. This is indeed a point of great concern for everyone, especially with so many satellites in the sky.

How Long Do Starlink Satellites Last?

Simply put, a Starlink satellite has a designed lifespan of approximately 5 to 7 years.

You might find it strange why this is so much shorter than traditional communication satellites that can last for ten or twenty years. This is mainly determined by its unique mode of operation:

1. Very Low Orbit: Starlink satellites operate in what is called "Low Earth Orbit" (LEO), only about 550 kilometers from the ground. In contrast, many traditional "dish" TV signal satellites are in geostationary orbit at an altitude of 36,000 kilometers.
2. Requires Constant Thrust: At an altitude of 550 kilometers, although the air is extremely thin, there is still a faint drag. To avoid falling, the satellite must, like driving on a highway, continuously activate its ion thrusters, expelling krypton gas to "push against the wind" and maintain its orbital altitude and speed.
3. Fuel Determines Lifespan: The lifespan of a satellite basically depends on how long the fuel (krypton gas) it carries can last. Once the fuel is depleted, it can no longer maintain its orbit, which means its "life" has come to an end.

Designing a shorter lifespan also has an advantage: rapid iteration. Space technology is developing rapidly, and new satellites launched every few years will have significantly better performance than older ones.

How Are They Handled After Retirement? Do They Become Space Debris?

This is a very crucial design in the Starlink program, and also the most concerning issue for everyone. From the very beginning, SpaceX designed a highly responsible deorbiting process, with the core idea being: active deorbiting and complete incineration in the atmosphere.

The specific process is like arranging a "dignified funeral" for the satellite:

• Step One: Planning the Descent When a satellite's fuel is about to run out, or an irreparable malfunction occurs, ground control initiates its deorbiting procedure.

• Step Two: Active Braking The satellite uses its last remaining fuel to reorient its thrusters and perform a series of "burns" or "braking maneuvers." This operation reduces its orbital velocity.

• Step Three: Atmospheric Re-entry Once its speed slows down, Earth's gravity "pulls" it down from its original orbit, causing its orbital altitude to continuously decrease, eventually plunging into Earth's atmosphere like a meteor.

• Step Four: Incineration When the satellite enters the dense atmosphere at extremely high speed, it experiences intense friction with the air, generating temperatures of several thousand degrees Celsius. During this process, the entire satellite (composed of aluminum, composite materials, etc.) will be completely burned up and vaporized, like a shooting star streaking across the night sky. Ultimately, nothing will remain, and no debris will fall to the ground and hit anyone.

Advantages of this Method

This "self-destruction" mode is currently the most environmentally friendly and responsible way to handle low Earth orbit satellites. It stands in stark contrast to how traditional high-orbit satellites are handled: many older satellites, after retirement, can only be pushed into a higher, unused "graveyard orbit," where they become permanently floating space debris.

Furthermore, even if a Starlink satellite suddenly "dies" in space and loses all communication, due to its very low orbit, atmospheric drag will naturally pull it down within a few years, eventually leading to its incineration. This fundamentally prevents it from becoming a long-term space safety hazard.