In recent years, the odds of orbital collisions has doubled due to all the debris, large particles, and just plain scrap flying around in orbit. These are fragments left from launches as well as from collisions between other objects already in orbit. The Economist is reporting that several methods for de-oribiting space junk are being tested, with the goal to get a handle on the problem while there is still time to do so. So far, nets, harpoons, and magnets are among the options which have been considered.
In the first test, the servicer will use springs to push the pod out and then, once it is ten metres away, will approach it again, lock onto the docking plate using an arm fitted with a magnetic head, retract the arm and pull it back to the servicer. For the second test, it will push the pod at least 100 metres away before its starts approaching it. A reaction wheel and a set of magnetic torque-generators will then put the pod into a tumble involving all three axes of motion, at a speed of half a degree a second.
This is, as it were, an important twist—for chunks of orbiting debris typically spin in this fashion. A real deorbiting mission will therefore have to deal with such spinning objects. Markings on the pod will help the servicer work out its prey’s motion. Using eight thrusters, it will manoeuvre itself until those markings appear, to its sensors, to be stationary. This will mean its motion exactly matches that of the tumbling pod, and that the magnetic head can therefore be extended to do its job.
For the third capture test, the servicer will first use its thrusters to back off several kilometres from the pod, putting the pod beyond sensor range. Then it will search for it, as would need to be the case if it were hunting for a real derelict spacecraft.
For all the technological prowess these tests will require, however, real derelicts pose a greater challenge than dummy ones. For one thing, unlike Astroscale’s pod, few spacecraft have been designed to expedite their own removal. Also, those objects which most need removing are dangerously heavy. A spacecraft that miscalculates while attempting to capture such a piece of tumbling debris could be smashed to smithereens, thus contributing to the problem it was supposed to be solving.
It is apparently enough to remove the larger objects to achieve significant gains in safety.
Alternate Article Source (no paywall): Stuff.co.nz.
Previously:
(2019) Technology to Easily Deorbit Satellites in Development
(2019) Space Harpoon Pitched and Snags Target
(2017) A Satellite May be Falling Apart in Geostationary Orbit
Related Stories
Submitted via IRC for Bytram
On the morning of June 17, the Luxembourg-based satellite operator SES lost control of a large satellite in geostationary space, nearly 36,000km above the Earth's surface. Shortly after, the satellite operator began working with another company that specializes in space situational awareness to track the drifting machine, AMC-9. A few days ago that company, ExoAnalytic Solutions, saw the AMC-9 satellite begin to fragment.
"We have seen several pieces come off of it over the past several days," ExoAnalytic's chief executive officer, Doug Hendrix, told Ars. "We are tracking at least one of the pieces. I would hesitate to say we know for sure what happened."
Sunday 11am ET Update: In response to a query from Ars, the AMC-9 satellite's operator, Luxembourg-based SES, issued the following statement on Sunday morning:
In the early hours of 1st July, the SES Satellite Control reestablished contact to AMC-9. SES and the satellite manufacturer Thales are working around the clock to evaluate the status and define the next steps.
Tracking information received on 29 June had suggested that at least two separate objects were located in the vicinity of AMC-9. Their source has still to be determined. The new piece of information was included by Thales and SES in their investigations.
Kessler syndrome?
Source: A satellite may be falling apart in geostationary orbit
SES's AMC-9 satellite drifting after anomaly
The research project called RemoveDEBRIS is
an effort to test various space junk removal technologies. The project, which involves a 220-pound satellite in low Earth orbit, is being led by the University of Surrey
In its third test, the project successfully snatched a piece of debris using its space harpoon. The harpoon shot out at 65 feet per second/20 meters per second (0.0007% of the maximum velocity of a sheep in a vacuum) its space-harpoon-claws successfully digging into the target and gaining a firm lock.
Previously, the satellite deployed a net to capture a simulated piece of space junk, and a laser-based camera system was used to locate a floating chunk of space debris. A fourth and final experiment will be conducted in March, when the satellite will pump the brakes by deploying a small sail.
At this point the satellite, and its low orbit loot, will plunge to Earth to burn up in the atmosphere.
The U.S. Space Surveillance Network estimates that around 29,000 objects larger than 10 centimeters are currently floating in Earth orbit, some at speeds approaching 10 kilometers per second, or 6 miles per second.
These bits and bobs can smash into other items in orbit creating even more debris in a cascading Earth enveloping satellite and astronaut destroying shower of doom referred to as the Kessler syndrome, named after Donald J. Kessler who first proposed it in 1978.
Lunar orbit is looking like a better place to be.
Previous Coverage: SpaceX Launches CRS-14 Resupply Mission to the ISS and Space Junk Removal Testing Craft Ejected From the ISS
Space debris is a constant threat to astronauts, satellites, space stations, and billionaire tourists. Gonzalo Sánchez and his colleagues of the E.T. PACK Project have come up with an approach that can be used to deorbit satellites in the future.
The ESA's Space Debris Office estimates that there are over 34,000 pieces of large debris in Low Earth Orbit consisting of dead satellites, boosters, dropped wrenches, paint flecks and all manner of other assorted junk. At some difficult to predict point in the future it is possible, as the amount of this debris increases, for a cascading effect known as the Kessler syndrome to occur making Low Earth Orbit extremely dangerous and effectively closing it off for use.
The new satellite deorbiting technology is intended to help avoid this outcome and is called the Electrodynamic Tether technology for Passive Consumable-less deorbit Kit (E.T.PACK) system.
The key to this system is a low work-function tether that consists of a strip of aluminum tape coated with a special material that allows it to emit electrons when illuminated by the Sun. This causes the tether to become attracted to Earth's magnetic field via the Lorentz Force, effectively lowering its altitude until it burns up in Earth's atmosphere.
The tether itself would measure 2 cm (0.8 in) in width, 50 microns in thickness, and several kilometers in length. During the launch of the satellite, the tether would be rolled up in a reel and only deployed once the satellite was in orbit. In this way, future satellites would be able to self-destruct and not become part of the space debris problem.
The project, which is funded by the European Commissions is expected to conclude in three years culminating in a prototype for a demonstration flight. The technology has captured the interest of the ESA and various space industries.
(Score: 2) by Hartree on Thursday January 14 2021, @02:53AM (1 child)
Is that anything like Holy Shit?
(Score: 0, Funny) by Anonymous Coward on Thursday January 14 2021, @03:15AM
Is it Runaway Space Crap? Or just the usual?
(Score: 3, Interesting) by takyon on Thursday January 14 2021, @04:34AM (3 children)
Cheapass Starship Trash Collector
Alternatively, launch a satellite that can change its orbit gradually with ion engines to match debris, and uses solar panels to charge up lasers and shoot it. The debris heating and shedding material could help push it downward.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 3, Touché) by c0lo on Thursday January 14 2021, @04:49AM
Don't wait for a collision to shed material from the target, do it proactively in the most expensive way possible (grin)
https://www.youtube.com/@ProfSteveKeen https://soylentnews.org/~MichaelDavidCrawford
(Score: 2, Interesting) by Anonymous Coward on Thursday January 14 2021, @06:25AM
Spread lasers across a continent so that you can get plenty of light up into space without ionizing the air. For example, the USA could locate 1 laser next to each power plant. The EU could do likewise. Whenever electrical power is cheap, fire the lasers.
Every laser fires at once, aiming west for the typical orbit. (hit the satellite head-on) Use a series of extremely short coordinated pulses. The high energy can knock multiple electrons off of each surface atom, causing it to get blasted loose without having much heat sink into the object. This causes two effects. First, the satellite turns to vapor. Second, thrust is generated. That thrust can help deorbit a satellite. Hit the satellite every time it rises in the west (or otherwise as appropriate for strange orbits) and eventually it will be gone.
(Score: 2, Funny) by multistrand on Thursday January 14 2021, @06:44AM
Orbital skeet.