Scientists find way to track space junk in daylight

Phys.org  August 4, 2020 Utilizing a higher-powered laser, space debris laser ranging detects diffuse reflections from defunct satellites or rocket bodies up to 3000 km. So far space debris laser ranging was only possible within a few hours around twilight while it is dark at the satellite laser ranging station and space debris is illuminated by the sun. An international team of researchers (Austria, Spain, Germany) has extended the visible window using a combination of a telescopic detector and filter to increase the contrast of objects as they appear against the sky during the day. Overall, the new technique could […]

Using sunlight to save satellites from a fate of ‘space junk’

EurekAlert  June 16, 2020 Satellites are almost always illuminated by the sun, apart from short transitions to Earth’s shadow. According to researchers at Purdue University the light that a satellite reflects can help reveal the solution to a structural malfunction. The proposed method calls for using telescopes on Earth to collect the light reflected by a satellite or one of its parts. Changes in the brightness of a “dot” over time are recorded as light curves and processed and used to extract information about an object’s appearance or rotational state. However, the more complex an object is, the harder it […]

Solving the space junk problem

Phys.org  May 25, 2020 According to a team of researchers in the US (Middlebury College, University of Colorado) the current methods of capturing debris or deorbiting old satellites might motivate operators to launch more satellites—further crowding low-Earth orbit, increasing collision risk, and raising costs because they don’t change the incentives for operators. Instead, the researchers propose an international agreement to charge operators “orbital-use fees” for every satellite put into orbit. Orbital use fees would also increase the long-run value of the space industry. It could be straight-up fees or tradeable permits, and they could also be orbit-specific since satellites in […]

Lasers learn to accurately spot space junk

Phys.org  December 24, 2019 Scientists have developed space junk identification systems, but it has proven tricky to pinpoint the swift, small specks of space litter. Researchers in China trained a back propagation neural network to recognize space debris using two correcting algorithms. The Genetic Algorithm and Levenberg-Marquardt optimized the neural network’s thresholds for recognition of space debris, ensuring the network wasn’t too sensitive and could be trained on localized areas of space. The team demonstrated the improved accuracy by testing against three traditional methods. The observation data of 95 stars was used to solve the algorithm coefficients from each method, […]

A deorbit kit for satellites based on low work-function tethers

Phys.org  June 12, 2019 A European research project, called E.T.PACK, is developing a new system for deorbiting space satellites without using on board power and fuel using low work-function tether. It consists of 50 microns thick, 2 cm wide aluminum that is several kilometers in length. It would be rolled up in a reel during the launch of the satellite. Aluminum must have the ability to emit electrons when it is heated. The tether transforms orbital energy into electrical energy while it deorbits the satellite without using any type of fuel. It uses natural resources in the space environment, such […]

Watch a harpoon successfully spear a piece of space junk

MIT Technology Review  February 15, 2019 Right now there are more than 7,600 tons of space junk floating around our planet. Researchers in the UK created a satellite called the RemoveDEBRIS which fired a harpoon at 20 meters a second at a separate satellite panel that it was holding at the end of a boom. The harpoon succeeded in stabbing and capturing the item. Last year the team also “accurately fired a giant net” https://www.technologyreview.com/the-download/612174/satellite-uses-giant-net-to-trap-spinning-bit-of-space-junk/ at a satellite to capture it and tested out a lidar- and camera-based system for identifying space junk. The final test by RemoveDEBRIS in March […]

Why space debris cleanup might be a national security threat

Phys.org   November 13, 2018 From the 23,000 pieces of debris in Earth orbit that are larger than 5-10 centimeters that we can track and catalog, to the hundreds of millions that we cannot, there is little question that both big and small objects whizzing around at lethal speeds endanger the prospects for civilian, commercial and military missions in outer space. Both the old and new space powers can easily cloak their military intentions in legitimate concerns about, and possibly commercial solutions to, debris hazards. And there are now a number of open assessments about space junk removal technologies  that can […]

Plasma thruster: New space debris removal technology

Phys.org  September 28, 2018 Ejecting plasma beam from the satellite to impart a force to the debris to decelerate it so that it re-enters the Earth’s atmosphere and burning up naturally, accelerates the satellite in the opposite direction, which makes it difficult to maintain a consistent distance between debris and the satellite. An international team of researchers (Japan, Australia) demonstrated that the bi-directional ejection of plasma plumes from a helicon plasma thruster can yield the space debris removal operation using a single propulsion system. In laboratory experiments, the plasma thruster was precisely controlled with a magnetic field and gas injection. […]

A satellite with a harpoon, net and drag sail to capture space junk is in orbit and will be tested soon

Phys.org  June 29, 2018 NASA is experimenting with the RemoveDebris spacecraft deployed from the ISS, to conduct a series of active debris removal (ADR) technology demonstrations starting in September 2018. Two CubeSats are launched as artificial debris targets to demonstrate some of the technologies. First CubeSat will inflate its onboard balloon to simulate a larger piece of junk. The RemoveDebris spacecraft will then deploy its net to capture it, then guide it into the Earth’s atmosphere where the net will be released. The second CubeSat will be used to test the mothership’s tracking and ranging lasers, its algorithms, and its […]