You might think that launching a satellite is the hardest part of its lifecycle. But it’s not only a challenge to get a satellite into orbit — you also have to decide what to do with it when it no longer works. Abandoned satellites contribute to the problem of space debris, making it more difficult and more dangerous to launch other satellites or spacecraft in the future.
To tackle this problem, a company called Tethers Unlimited has demonstrated a cheap and lightweight solution for safely disposing of satellites once they are no longer required. The solution involves a 230-foot-long strip of conductive tape deployed from the satellite which pulls it into a lower orbit, called, delightfully enough, Terminator Tape.
An illustration of the Terminator Tape in action. Tethers Unlimited
To test out the system, Tethers Unlimited attached a Terminator Tape module to the Prox-1 CubeSat, launched last June. The module weighs just two pounds and is about the size of a notebook, and can be attached to the outside of the satellite. Once Prox-1 was no longer required, the module was activated by an electric signal which can be either pre-set to a certain time or triggered by the satellite itself.
When the module is activated, the conductive tape is deployed like a tail from the satellite. This tape creates drag from its interactions with both gravity and the Earth’s magnetic field, gradually pulling the satellite into a lower orbit. As its orbit lowers, eventually the satellite will burn up in the planet’s atmosphere.
Satellites naturally fall into lower orbit when not powered, but this happens very slowly. With the assistance of the Terminator Tape, the satellite being tested fell 24 times faster than it would usually.
“Three months after launch, as planned, our timer unit commanded the Terminator Tape to deploy, and we can see from observations by the U.S. Space Surveillance Network that the satellite immediately began de-orbiting over twenty-four times faster,” Rob Hoyt, CEO of Tethers Unlimited, said in a press release.
“So, instead of remaining in orbit for hundreds of years, rapidly removing dead satellites in this manner will help to combat the growing space debris problem. This successful test proves that this lightweight and low-cost technology is an effective means for satellite programs to meet orbital debris mitigation requirements.”
The next step for Tethers Unlimited is to test two identical satellites side by side, one with the Tether Tape and one without, to see exactly how effective the system is.