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Why Low Earth Orbit desperately needs a traffic cop

In the race for the commercialization of space, one premise is undisputed: crowds are crowding around.

From private companies to universities to the military, everyone has their eyes on the sky when it comes financially within reach. However, it is not clear how all these new orbital gadgets will coexist and fly at 17,000 miles per hour, surrounded by a high-speed minefield of rubble from humanity's previous space projects.

Aerospace Corp., a state-funded research center proposes a solution to this obstruction: Stick a small 100-gram GPS transponder on each vehicle launched to track, identify and monitor it – even if that Satellite stops working. Widely used in civil aviation and in the maritime industry, transponders have never achieved a great place in space. The current satellite tracking consists mainly of ground-based radar and optical tracking telescopes.

Aerospace prototype transponders

Source: The Aerospace Corporation

Humans have launched about 7,500 satellites since the beginning of the space age, with more than 1,500 still in service. That's a fraction of the more than 20,000 new vehicles developed by a number of space companies such as Planet Labs Inc., OneWeb, LeoSat Enterprises Inc. and SpaceX by Elon Musk.

Broken satellites often burn in the Earth's atmosphere, while some larger ships in a remote area of ​​the South Pacific are sent to extinction. Still others are flown further into space, to an orbital "cemetery", far beyond where working satellites move.

However, in many cases, the used vehicle (or parts of it) becomes hypersonic space debris and threatens other satellites with the possibility of instant destruction. Add something to those ruptured spacecraft or discarded parts, and the risk of a sudden death for any million-dollar spacecraft begins to increase. And the bonus of every new collision? Additional debris (though some look into a cleanup plan)

Today, satellite operators must manage these potential disasters (NASA calls them "conjunctions") every month or two. Soon they will become a daily routine, said Andrew Abraham, senior researcher and engineer at Aerospace.

The US Joint Space Operations Center tracks approximately 22,000 objects in orbit. The agency issued 1.2 million collision warnings in 2016, said retired Navy admiral Cecil Haney, a senior aerospace consultant and former head of strategic US command. The operators carried out 148 evasive maneuvers, in which the engines were switched off to avoid. In general, the warnings would come five days to seven days before a potential collision, said Haney.

"These operators do not want to move their satellites on a whim," he said, considering the finite fuel on board April 18, during a panel discussion at the Space Symposium in Colorado Springs, Colorado. When it comes to managing all the objects in space, and those to come, Haney warned, "It's really something we have to stick to – and in my mind that I can get away with it quickly."

More than 290 satellites Interruptions have been recorded in orbit since 1961.

Source: ESA

The transponder with a GPS module and a radio transmitter is the size of a playing card game, Abraham said. The idea of ​​Aerospace would be to report regularly on the location of a ship so that the pursuers could at any time narrow their position to a few dozen meters. The system would operate in three modes: normal, thrust (when the satellite repositioned), and debris. The last mode would be a low-power setting that would report less frequently, but up to 40 years, thanks to a small solar cell.

Such devices would incur additional costs, they would not solve the problem of what is already up there and it is not clear who would coordinate all the data they would provide. A government agency, an industrial consortium or a new commercial or non-profit organization? Maybe "volunteer satellite observers" who would share the data on a public website? Aerospace sees advantages and disadvantages for everyone, but notes that based on the approach of the maritime industry, an international body might be best. And the benefits can outweigh the cost, especially if GPS tracking can reduce orbital maneuvers and extend satellite life. (Some major satellite operators use GPS for their craft.)

A catastrophic "conjunction," such as the collision of a US communications satellite with a dead Russian satellite in February 2009, can mean not only the affected company but also the disaster Operators of other satellites. New debris increases uncertainty and requires a quick assessment to determine who has to clear his ship – and how fast. According to a 2011 NASA study, the 2009 accident, together with China's intentional destruction of a weather satellite two years earlier, accounts for more than a third of all debris in a near-Earth orbit.

Another expense for the satellite operators could be handled by these tracking devices: Gravity. Depending on their mass, size, shape, orientation and type of orbit, satellites can slowly go where they should not be. Within a few days, the position of a vehicle in a near-earth orbit may change by several tens of kilometers, making it difficult to pinpoint the exact location. For weeks, it is easy to "lose" a circulating object altogether.

The first decades of human spaceflight "relied on the" big sky "approach to avoid orbital accidents," writes Abraham. "The assumption was that the volume of space is too large compared to the volume occupied by artificial objects" so that an accident happens except very rarely, he said. However, this approach quickly becomes obsolete as more objects are thrown into space and use certain orbital slots instead of spreading more evenly around the planet.

The management of space travel now has little government oversight, though The Trump Administration has suggested that the US Department of Commerce undertake these tasks and coordinate with other nations. Greg Wyler, the founder of internet satellite company OneWeb, even suggested that civil aviation rules could be applied to satellite management.

Either way, Abraham writes: "The projected increase in launch rates eliminates the status quo as a viable option."

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