قالب وردپرس درنا توس
Home / Science / NASA opposes the new megaconstellation, citing the risk of a “collison disaster”

NASA opposes the new megaconstellation, citing the risk of a “collison disaster”



Dash across the night sky.
Enlarge / Sixty Starlink Internet communications satellites from SpaceX are seen in the night sky in Vladivostok.

NASA has officially commented (PDF) on a request from a US company to build an ultrasonic satellite at an altitude of 720 km above the Earth̵

7;s surface, citing concerns about the collisions. This appears to be the first time NASA has publicly commented on such an application to reach the market, an application pending the Federal Communications Commission.

Samantha Fonder wrote: “NASA sent this letter during public opinion with the aim of providing a better understanding of NASA’s interest in their assets in orbit, in order to minimize risk. risk of collision for the common good of all involved “. an engineer for a space agency.

The problem is the plans launched by AST & Science, which intend to build a constellation of more than 240 large satellites, essentially deploying “cell towers” in space to provide 4G broadband connectivity. and possibly 5G directly to mobile phones on Earth. The Midland, Texas-based company calls its constellation “SpaceMobile” and has raised around $ 120 million.

The space agency feels compelled to comment on the AST’s proposal for a number of reasons. Most notably, the proposed altitude for the constellation SpaceMobile is located near “A-Train”, a group of 10 Earth science monitoring satellites operated by NASA and the US Geological Survey, as well as partners in France and Japan. “Historical experience with the constellation A-Train has shown that this particular space tends to create a large number of connections between objects in space,” the NASA letter wrote.

They are also large

The satellites are also very large. To provide the service, AST plans to build spacecraft with large diverging array antennas – 900 square meters. According to NASA, when planning potential links to other satellites and debris in this orbit, this would require a “hard object radius” of 30 meters, or 10 times greater. times compared to other satellites.

NASA says it is proposed that traveling around the constellation SpaceMobile would be heavily taxed. “For a completed constellation of 243 satellites one can expect 1,500 mitigation actions per year and perhaps 15,000 planned activities,” the space agency stated. “This would be the equivalent of four drills and 40 active planning activities on any given day.”

Finally, the space agency is concerned because the AST has never remotely made a satellite the size of vehicles 1 ton or larger that would reside in its constellation. Given this inexperience, it is expected that 10% or more of the satellites could fail, making them unable to maneuver to avoid a collision. NASA sees the risk of a catastrophic collision as “unacceptably high.”

NASA submitted its comments on October 30, and the comment period ends on Monday. Most other comments on the AST application support.

In response to Ars’s question about NASA’s filing, the AST said it will work with NASA to improve their concerns. “We have reviewed NASA’s letter and are confident we can work with them to address their concerns, including providing AST’s constellation design clarification for strong management. orbital debris, keeping NASA and other orbital assets safe, ”said Raymond Sedwick, Head of Systems Scientist at AST.

What is the FCC?

So why did this matter before the Federal Communications Commission? Responsibilities for US space operations are scattered across a number of federal agencies, but the FCC administers the spectrum. In this case, the AST got a license to use spectrum in the V-band from Papua New Guinea (yes, that’s legal). But to access the US market and sell its services, the AST still has to apply for an FCC authorization.

When it comes to megaconstellations – including SpaceX’s Starlink, OneWeb and others – FCC have is looking at the debris problem of bringing hundreds, if not thousands, of new satellites into low Earth orbit. Therefore, it will be interesting to see in which direction the FCC addresses this issue since the federal agency has two competing interests.

In general, the FCC has made it easy to license spectrum for satellite operators. Brian Weeden, a satellite expert at the Secure World Foundation, said: “I don’t know any examples of the FCC refusing such a license. “They are trying to be business-friendly and encourage companies to do business in America.”

However, the FCC has been using its spectrum agency to review rules that could minimize debris by requiring satellite operators to compensate the government against potential accidents as well. like having the ability to maneuver their vehicles. The comment period for these proposed rules, first published in April, ended last month. It is not clear what the final rules will look like, but the satellite operators have described some of the ideas as too complicated.

In the end, it is not clear how the FCC will handle NASA concerns, which know a thing or two about space and is speaking out for the first time.

In the big picture, Weeden said, this combination of NASA and AST is clearer evidence that the US government – and other astronaut countries of the world – needs to do better to make sure that Earth’s low orbit remains debris-free as possible. There is no government agency specifically responsible for ensuring Earth’s low orbit remains safe, and existing models are not fully capturing the threat from new and old satellites. second segment of the used missile and known debris. So in a sense, with all the megaconstellation flying into space today, regulators are flying in the dark, he said.

“We should have done a lot of this work over the past 10 years,” he said. “From a government policy surveillance perspective, we are behind the power curve.”


Source link