While offering immense advances in terms of Internet connectivity, the new generation of BlueWalker 3 satellites from the American company AST SpaceMobile is also the source of some of the most significant light pollution in space. This is the worrying observation of a study published in the journal Nature on September 23 and broadcast by the media The edge.
According to this work, the giant, capable of offering a fast Internet connection to a smartphone from any point on the globe, is one of the current objects that generates the most light in space. However, this could hamper the work of astronomers by making it difficult to observe the sky and create a worrying precedent.
A promising technology
The megasatellite from AST SpaceMobile, a space company specialized in Internet access, was sent to low Earth orbit (OTB) in September 2022 by SpaceX’s Falcon 9. The objective is to test a technology that allows direct 4G and 5G Internet access to mobile phones – without any equipment on the ground – and thus compete with SpaceX’s Starlink satellites.
And the number of contracts signed by AST SpaceMobile with mobile operators, such as Vodafone or T-Mobile, demonstrate the current appetite for this type of technology. Orange also chose the Texan company and BlueWalker 3 to improve Internet access for its customers in some of its African markets. Last June, the company indicated that it had succeeded in its bet, by managing to transmit a 4G LTE signal from space to a smartphone.
As bright as the brightest stars
Despite these promising results, since its launch into orbit, the innovative 1,500 kg machine, carrying 64 m2 of reflective antennas, has rotated around the Earth, generating a problematic light source. Observations of the satellite over 130 days from six different countries showed that it was as bright as Procyon and Achernar, which are among the brightest stars. An observation that, however, varies depending on the position of the BlueWalker 3 with respect to the sun.
The satellite also generates light trails in astronomical observation images.
A risk raised, since last year, by several scientists, such as the astrophysicist at the Côtes d’Azur observatory, Eric Lagadec, on X (formerly Twitter).
Problematic radio frequencies
Beyond the light pollution it causes, the launch of satellites like BlueWalker 3 into orbit could also affect radio astronomy. To operate, AST SpaceMobile technology uses a very powerful radio signal that can bias measurements of scientific devices.
“These orbiting transmitters, which are not subject to the same radio quiet zone restrictions as terrestrial cellular networks, have the potential to have a serious impact on radio astronomy research, as well as geodesy studies and space physics experiments. “specified the International Commission. Astronomical Union (IAU) in a press release published in November 2022.
A necessary “rest”
At the moment, there is no regulation that regulates the launch of the new generation of satellites into orbit in terms of light pollution or the disturbances in terms of radio astronomy that they could cause.
But the dispatch of BlueWalker 3 should be an opportunity to seriously reflect on this question, according to Piero Benvenuti, director of the IAU center dedicated to the preservation of the “dark and calm sky against interference from satellite constellations.”
Especially since the phenomenon will not stop with BlueWalker 3. Starting in 2024, AST SpaceMobile plans to launch a series of even larger satellites, called BlueBird.
Source: BFM TV
