Space

Dangling tape could be used to de-orbit old satellites

Dangling tape could be used to...
According to NASA, there are over 500,000 pieces of space debris currently orbiting our planet
According to NASA, there are over 500,000 pieces of space debris currently orbiting our planet
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According to NASA, there are over 500,000 pieces of space debris currently orbiting our planet
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According to NASA, there are over 500,000 pieces of space debris currently orbiting our planet

In order to at least begin addressing the growing problem of space debris, numerous groups are now looking into methods of de-orbiting satellites once their operational lives have ended. One of the latest approaches involves getting the spacecraft to dispense a long strip of sunlight-catching tape, instead of using their own propellant.

The technology is being developed via the three-year European Union E.T.PACK project, led by Spain's Universidad Carlos III de Madrid.

It would involve equipping satellites with a rolled-up strip of aluminum tape, prior to launch. Known as a low work-function tether, that tape would be several kilometers long but just 2 cm wide (0.8 inches) and only 50 microns thick – that's thinner than a human hair. It would additionally be coated with a thermionic material, which would emit electrons when heated by sunlight.

Once they were at the end of their mission, the orbiting satellites would allow that tape to unravel out of them, exposing it to the sun and to Earth's geomagnetic field. Thanks to a phenomenon known as Lorentz force, which is defined as the force exerted by a magnetic field on a moving electric charge, that tape would then generate electricity. That current would in turn be relayed to the satellite, where it would power up onboard electric thrusters to push the spacecraft down and out of orbit.

It is hoped that E.T.PACK will culminate in the creation of a tether kit, that could be added to and tested on satellites in a subsequent project.

"A low work-function tether transforms orbital energy into electrical energy while it de-orbits the satellite without using any type of fuel," says project coordinator Gonzalo Sánchez-Arriaga. "Unlike current propulsion systems, a low work-function tether does not need propellant and uses natural resources in the space environment, such as the geomagnetic field, ionospheric plasma and solar radiation."

Sources: Universidad Carlos III de Madrid, E.T.PACK

5 comments
Quercus
So as their orbits decay they trail lengths of thin aluminium tape - "several kilometres long" - which, presumably, eventually burns up in the atmosphere as the satellite breathes its last and also burns up. Or does it come crashing down to earth? Depends how big it is presumably. If this idea catches on, the top of the atmosphere will eventually be criss-crossed with alloy tapes as increasing numbers of satellites expire and all sorts of additional crap is added to the atmosphere. There has got to be a better way.....
Altairtech
All satellites already have on-board stabilization jet thrusters. Just one shot in the correct direction is enough to de-orbit the satellite. Why create a complicated "solution" that is redundant and that will leave more stray objects in space?
Brooke
Hi Mike: The article muddled how this works. There are two modes of operation. In one mode the satellite is slowed down allowing it to burn up as it reenters the atmosphere. Hi Altairtech: A common problem is that the computer dies or the existing thrusters run out of fuel. This is a passive system that can either deorbit or boost a satellite without using any fuel. Read the actual article at: https://etpack.eu/
Cody Blank
I was really hoping this was just a "slap some duct tape on it" sorta thing, but rad science non the less.
Rino Torino
Cannot understand. The tape is used to power electric thrusters, but satellites already have solar panels. Why shoudn't use them as a power source for thrusters?