Astronomers advocate Earth Day to rein in satellites

Astronomers say this streak in a Hubble space telescope image was likely caused by a Starlink satellite flying just a few miles above Hubble. (MAST image via Nature Astronomy/Simon Porter)

Astronomers have issued an Earth Day call to further extend environmental awareness to the last frontier, and for companies like SpaceX and Amazon to roll back their mega-constellation plans.

Among the authors of today’s commentary in the journal Nature Astronomy is Meredith Rawls of the University of Washington.

Astronomers have expressed concern about the impact of having thousands of satellites in low Earth orbit for years, starting with SpaceX’s launch of the first operational satellites for its Starlink broadband constellation in 2019. Rawls and the other authors of the comments today emphasize that this is the case. They are only concerned about interfering with their astronomical observations, but are also concerned about the wider impact on the appreciation of the night sky.

“We need all hands on deck to tackle the rapidly changing satellite situation if we can create a future together with dark and still skies for everyone,” said Rawls, a research scientist at the Vera C. Rubin Observatory and UW’s DIRAC Institute, said in a press release.

“Rubin Observatory will be one of the hardest hit astronomy facilities by large numbers of bright satellites because of its large mirror and wide field of view — the same features that make it such a remarkable engine for discovery,” Rawls said. “I care deeply about how satellite streaks affect science, but the case for dark and still skies is much bigger than that.”

The commentary cites other threats to the space environment, ranging from in-orbit collision threats and space debris to pollution caused by missile launches. But it mainly focuses on projects, including Starlink and Amazon’s Project Kuiper, that aim to place thousands of satellites in low Earth orbit, or LEO, to provide global broadband Internet access from above.

Starlink and Project Kuiper are both headquartered in Redmond, Washington. SpaceX builds dozens of satellites a month and already offers limited internet service. This week, JSX, a Texas-based “hop-on” airline, said it would use Starlink for in-flight Wi-Fi. Project Kuiper is currently still under development.

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Many other companies – including OneWeb, Telesat and Boeing – have their own plans for broadband satellite constellations. If all those plans come true, tens of thousands of satellites could be flying through the sky within a decade. For the purposes of their commentary, the authors of the Nature Astronomy commentary assume that by 2030, 100,000 satellites will orbit around 600 kilometers (373 miles).

SpaceX and other companies have been working with astronomers on ways to minimize the impact of their satellites on night sky observations, but the authors of today’s commentary say that isn’t enough. “None of these measures can completely prevent LEO satellite constellations from harming astronomical science; launching significantly fewer satellites is the only limitation that could do this,” they write.

Among the researchers’ recommendations:

Regulatory bodies such as the Federal Communications Commission should more fully assess the impact of space projects on Earth’s space environment during the permitting process. The authors define the space environment as the area between 62 miles (or 100 kilometers, the so-called “Karman Line”) and 22,000 miles in elevation (the orbital distance for geostationary satellites). Scientists should develop metrics for a global “Space Traffic Footprint”, loosely interpreted as the burden that any intentionally launched object poses to the safety and durability of other orbiting objects and to the orbital environment itself. analogous to the “Carbon Footprint” so prominent in assessing human-induced climate change. a satellite observation hub under the center’s organizational umbrella. “Such long-term mitigation activity requires significant sustainable resources,” say they.

Some of the comment’s authors are involved in a legal challenge to FCC rulings related to SpaceX’s Starlink network, and the arguments in their amicus brief parallel the arguments in today’s comment.

The lead author of the Nature Astronomy commentary entitled “The Case for Space Environmentalism” is Andy Lawrence of the University of Edinburgh. In addition to Lawrence and Rawls, co-authors are Moriba Jah, Aaron Boley, Federico Di Vruno, Simon Garrington, Michael Kramer, Samantha Lawler, James Lowenthal, Jonathan McDowell, and Mark McCaughrean.

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