SpaceX Starlink satellites may pose a problem for terrestrial astronomy


Last week, SpaceX launched the first 60 satellites of the future network of low-cost satellite Internet Stralink, which will have up to 12,000 vehicles. The launch of compact satellites weighing 227 kilograms passed without any problems. 

And residents of many parts of the world were even lucky enough to watch the “train” of vehicles flying in a row in low near-earth orbit. But, of course, all these, as well as future vehicles will be located in the orbit of our planet not in such orderly rows. And this, in turn, raises serious concerns among astronomers, who believe that the satellites Ilona Mask can create difficulties in the work of many telescopes around the world.

As Space.com points out, satellites themselves, because of their compactness, do not have strong reflectivity and are not so clearly visible in the sky with the naked eye. And as soon as the apparatuses are distributed in orbit, they will become even dimmer. But the problem is that astronomers are used to relying not only on their own eyes, but also on very sensitive equipment.

According to astronomer Alan Duffy of Swinburne University of Technology (Australia), the existing orbital constellation of satellites is already creating some problems for ground-based telescopes.

“Satellites do create difficulties for scientific observations, but astronomers have developed clever methods that allow them to be solved,” commented Duffy.

“Optical telescopes, for example, the same Pan-STARRS, automatically“ mask ”the satellites flying in their field of view on images. However, radio telescopes, such as the Australian ASKAP, have more difficulty. It is necessary to maneuver between frequencies, because otherwise the equipment can be “blinded” by bright navigation satellite signals, like the same GPS, ”the scientist explains.

According to the United Nations Office for Outer Space Affairs, there are 5,162 man-made objects in near-Earth orbit right now, 2,000 of which are actively exploited. Additional deployment of a network of 12,000 satellites will be unprecedented in all respects.

Starlink satellites will kill ground-based radio astronomy
The environment in which we live is filled with all kinds of radio waves: signals from Wi-Fi stations, cell phone towers, wireless networks, emitting a huge amount of radio noise, and so on. But satellites present an even more serious problem for radio telescopes than any other ground equipment.

“The full deployment of the Starlink satellite network will probably mean the end for terrestrial microwave radio telescopes, which are used to search for very weak radio signals,” adds Duffy.

“The tremendous benefits that global satellite coverage has offered unfortunately outweigh the benefits astronomy offers. Therefore, we can most likely lose the possibility of observing the residual luminescence after the Big Bang and the outbursts of the birth of new stars from the Earth. ”

According to Duffy, Starlink satellites are bound to cause radio interference during observations. The scientist believes that humanity “should build a radio telescope on the far side of the moon”, where it will be shielded from all this radio noise coming from our planet and its near-Earth space.

By the way, it does not seem that a solution to radio interference problems that would interfere with astronomical observations was found in SpaceX itself.

Last year, the astronomer of the National Radio Astronomy Observatory of the USA Harvey List sent a letter to the Federal Communications Commission (FCC), in which he expressed serious concern about the Starlink project.

According to Liszt, coordination between several national observatories and SpaceX company “ended futilely around mid-2017, after a preliminary and rather superficial assessment by radio astronomers of probable problems and the ways in which SpaceX plans to solve them.”

One of the reasons for this passivity in resolving this issue may be explained by the fact that SpaceX itself may consider these 60 first launched Starlink satellites as test ones. Allegedly, with the project to the end, nothing is clear yet, so you should not hurry. In addition, in 2015, various experts and industry analysts questioned the profitability of such projects as Starlink. However, the company has already confirmed via Twitter that it plans to launch up to six launches in 2019, within which new satellites will be launched.

Satellite Internet SpaceX – even more space junk
The problems that Starlink satellites can create are connected not only with radio astronomy, but also with space ecology. Twelve thousand satellites are a huge pile of potential new space junk.

“SpaceX is proposing to place 12,000 new satellites in low-Earth orbit where the bulk of space debris is located. Running all of these devices in just a few years will actually increase the total mass of garbage by 40 percent. It took 60 years for mankind to accumulate such volumes in orbit. A huge increase in space debris is awaiting us, ”said Alice Gorman, a space archaeologist from Flinders University (Australia).

In fairness, it is worth noting that SpaceX back in 2017 filed a patent with the FCC, which described ways to solve probable problems with space debris due to its satellites, as well as methods for quickly removing devices from orbit, whose lifetime (5-7 years) will be coming to an end.
“The satellites will be diverted from a low near-earth orbit to a burial orbit, after which they descend into the earth’s atmosphere and burn in it completely about a year after the end of their mission,” the company explained then.

But this is unlikely to help if, even before the end of its service life, a satellite or company satellites will be damaged as a result of a collision with other space debris that is present in low Earth orbit. And as the practice of the International Space Station has recently shown, just a small grain of sand is enough to create big problems for a spacecraft.

“If the SpaceX methods do not work, then according to the company’s assumptions, it will take about 5 years to independently descend into the atmosphere of a failed satellite. This is a huge amount of time for which anything can happen. During this time, a non-working satellite can be destroyed to the ground by collisions with other objects of space debris, which again will lead to an increase in its volume in orbit, ”explained Gorman.

Just one such incident can trigger a cascade of destructive events, the so-called Kessler syndrome — a hypothetical development in near-earth orbit, described in detail by NASA consultant Donald Kessler back in 1978, when space debris resulting from numerous launches of artificial satellites leads to complete unsuitability near space for practical use.

“They often close their eyes to the problem of space debris. According to one estimate, at least 40 percent of all space missions and launches are not following the UN guidelines for reducing the appearance of new garbage in orbit, ”Gorman says.

“SpaceX offers the right steps to de-orbit spent satellites, as well as methods to avoid collisions. But how it will work in practice with so many new satellites is a question. ”

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