Space

ESA's potential space garbage collector nets itself a drone

ESA's potential space garbage ...
The net gun was demonstrated using a drone as a target
The net gun was demonstrated using a drone as a target
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The net gun loaded
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The net gun loaded
The net gun being tested in zero gravity
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The net gun being tested in zero gravity
The net gun fired
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The net gun fired
The net gun was demonstrated using a drone as a target
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The net gun was demonstrated using a drone as a target
The drone tangled in the capture net
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The drone tangled in the capture net
A robotic capture arm is one option
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A robotic capture arm is one option
Artist's concept of the capture net in action
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Artist's concept of the capture net in action
Clean Space infographic
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Clean Space infographic

ESA has provided a preview of its plan to net space debris by unveiling a prototype net gun designed to envelope and capture tumbling dead satellites. Wojtek Gołebiowski of Poland's SKA Polska, which is developing the gun under a contract with the space agency, used a small version to target and take down a low-flying drone at the Industry Days event for ESA's Clean Space initiative.

ESA says that because the net gun is designed to be used in zero gravity, the device was fired at low power, shooting out a net of multi-colored strands to aid camera tracking and computer models of how it behaves. The video of the demonstration shows the gun capturing the drone or knocking it out of the air at short range.

Space debris is a major problem of the 21st century that only threatens to get worse. Depending on how debris is defined, there are tens or hundreds of thousands of manmade objects in orbit about the Earth. These range in size from tiny particles if solid rocket residue to dead satellites the size of a bus. As the 2009 collision between the Iridium 33 and Kosmos 2251 satellites demonstrated, this debris can result in collisions that can create additional thousands of fragments that can cause even more damage in a cascade effect.

Artist's concept of the capture net in action
Artist's concept of the capture net in action

The Clean Space initiative is aiming to reduce the problem by removing larger pieces of debris, such as defunct satellites. ESA says that this has never been attempted before – especially with an automated system. To accomplish a clean up operation, ESA is developing new adaptive guidance, navigation, and control systems, as well as image recognition and on-board processing capabilities.

A key problem is how to capture satellites that have started to tumble as their attitude controls systems fail. This involves learning more about this tumbling behavior and developing devices to actually grab and despin the satellite. For this, ESA is looking at two methods. The first is a robotic arm and the other is the net gun, which fires a square net with weights on the end that envelops the target, so it can be despun and secured.

The net gun loaded
The net gun loaded

The end goal of the initiative is an orbital mission called e.deorbit, which will involve a rendezvous with a dead ESA satellite in a low, near-polar orbit at an altitude of 800 to 1,000 km (500 to 622 mi). The disposal satellite will grapple with the target, then slow it down for a controlled re-entry and burn up in the atmosphere.

ESA says that e.deorbit is seeking approval at the ESA Council at Ministerial level late this year, with a projected launch in 2023.

The video below shows the capture net in action.

Source: ESA

Clean Space: Netting a satellite

5 comments
Future3000
Sometimes I think this "scientists" were paid to make me laugh (or cry)! To take down a debris satellite by sacrifice the disposal satellite is like hunting Moby Dick by sinking the whaling ship! Biggest waste of money! Seems ESA can do this! Better build a lightweight "Decelerate-Disposal-Satellite" shaped like a big bucket (or container), propelled by solar cells and EM-thruster, detecting and overtaking automatically spacedebris, brake a little bit till debris caught into "bucket", search and collect next debris 'till "bucket" is full, decelerate slowly (now heavy) Disposal-satellite via EM-thruster, release debris, now too slow to stay in orbit... a few days later, debris burn up in the atmosphere. Meanwhile "Disposal-satellite" (now lighten) accelerate via EM-thruster back into orbit, search next debris and so on, cleaning space for the next hundred years... This system will be scalable, so biggest satellite could be caught! If you pay it, we will build it for you! (and yes, we have such amazing technologies, we're a group of independent German space- and aircraft engineers) Space garbage disposal, a new future job? Probably. Watch movie "Gravity"
MattII
Well that's cube-sats dealth with, now for everything else.
Sean Reynolds
Okay, not to rain on anyone's parade... I love shooting drones down as much as the next guy. Satellites are flying around the earth using momentum, not propellers. The net would have to have enough force to change the momentum of the satellite, it's not enough to simply hit it with a net. The point being, its the mass of the object you hit the satellite with that changes its course, and this net doesn't look very massive. Now if you told me you wanted to fly a craft with giant nets like a fishing boat and collect debris, then I'm with you, but shooting debris with a net doesn't actually do very much unless the mass of the debris and the mass of the net are very similar.
Bob Flint
As Sean has mentioned the mass of the "Hunter satellite must be bigger than the "Prey satellite, that plus the force of ejection of the net will push back on the hunter, perhaps enough to miss the target, and "if" it manages to snag now needs to expend more fuel to bring both down, and burn up. Otherwise you have just added more junk up there, and presumably the hunter is sent up with self destruct to lower it's orbit with or without capturing prey...
RichardU
I had a good laugh at this one, as the guys early have said, they have not taken into consideration the mass of the object. Plus will each satellite have just one net, in so its very expensive way of getting debris out of orbit. If it could bring down say 10 or 20 that might be worth considering.