Scientists warn that launching millions of satellites will threaten space research
Satellite constellations, networks of multiple satellites that can number from a few dozen to thousands, are interfering with scientific research using ground-based telescopes, but now a new study looks at how they might impact space-bound telescopes like Hubble.
The Hubble Space Telescope has captured some incredibly beautiful photos of galaxies and nebulae that have left us in awe, but it has also made incredible scientific discoveries, including measuring the rate of expansion of our universe.
But that science could be threatened if all proposed satellites are megaconstellations – clusters of thousands. Number of satellites launched by companies like SpaceX and Amazon – come to fruition.
author of the paper Published today in Nature Specifically looked at NASA’s Hubble SPHEREX – a near-infrared telescope launched last March – proposed by the European Space Agency Arkihs (Analysis of resolved remnants of galaxies collected as a major tool for HALO survey) and China’s plan xuntian telescope,
The authors calculated that should the 560,000 proposed satellites be launched into orbit in the coming decade, about 39.6 percent of the Hubble images would be affected, and 96 percent of the other three would be affected.
As satellites move across the sky, they create long streaks of light on any images taken by the telescope. They can also interfere with radio astronomy, as they “leak” electromagnetic radiation in lower frequencies.
The authors calculated that for Hubble the average number of satellites observed per exposure (which could be minutes long) would be 2.14, 5.64 for SPHEREx, 69 for ARRAKIHS, and 92 for Xuntian.
“I remember when…sometimes we would see like a satellite (one night), and it was very strange to see. Now it’s becoming more and more common, very common,” said lead author Alex Borloff, a NASA research scientist at the agency’s Ames Research Center.
“In the last two, three years, we have started to see more satellites, even in some space telescopes like Hubble. They pass in front of them because their orbits are similar.”
Curious to see how these megaconstellations might impact astronomical research using space-based telescopes, Borloff and his co-authors decided to take a guess, which resulted in their latest findings.
a growing problem
In 2019, there were approximately 2,000 satellites in orbit. Today, there are about 15,000, primarily the result of SpaceX’s Starlink satellites. But the company is not alone: ​​Amazon has just started with its Kuiper constellation (with plans for 3,200 satellites), OneWeb plans 632 satellites, and China plans to launch 14,000 satellites. These are just some of those proposed.
The boom in satellites is largely due to lower costs than a decade ago, reusable launch vehicles and smaller payloads like CubeSats, which are about the size of a bread box.
And these satellites, like Starlink’s satellites, are primarily providing and improving Internet access in remote locations around the world. So he is unlikely to go anywhere anytime soon.
Currently, ground-based observatories can pause their scientific research when they detect a satellite passing in front of their telescopes, Borloff said, but that’s a nuisance and takes more work. And while space-based telescopes may also be able to do this, that is not the case all the time.
The (projected) structure of a proposed satellite telecommunications constellation in low Earth orbit from 1958 to 2037. The satellites’ altitudes are compared to the orbits of the Hubble Space Telescope, the Xuantian Space Telescope (CSST), SPHEREx, and the proposed ARRAKIHS mission.
But Borloff said if that’s happening 96 percent of the time, as their simulations show, “then we could have a problem.”
Also, it is important to note that not all satellites will be affected. For example, the James Webb Space Telescope is in an orbit that takes it far beyond low Earth orbit. The Nancy Grace Roman Space Telescope, scheduled to launch in 2027, will be similarly unaffected.
other results
Some people may be wondering why it’s such a big deal: just retake the images or get rid of the stripes. But there is more to it than that.
“One of the problems is that some astronomical targets are things you don’t know where they are. For example, looking for a new asteroid,” Borloff said. “And asteroids are very interesting because they look like satellites. It’s just a thin line of light crossing in your image.”
So if your images have many lines, it could block out a potentially dangerous asteroid, he explained.
Astrophysicist Aaron Tohuwawohu says maybe we need to rethink where we put those space telescopes.
“We have to build space telescopes farther still,” he said Tohuwawohu. ,I mean, astronomers have always gone above and beyond. That’s why we keep things on mountains. And we thought space was above all the mess, and it turns out it depends on where in space you are.”
But according to Borloff, this may not be an option, especially for telescopes that already cost millions to billions of dollars. Launching a telescope beyond low Earth orbit would increase costs, he said. Also, some telescopes are meant to be located in low Earth orbit.
Tohuwawohu says that for some instruments, raising their orbits will impact astronomers.
“I think it will put a huge cost and responsibility on astronomers, in particular, for how and where we build our instruments and how we operate them,” he said.
Beyond their research, both astronomers are concerned about how this affects our enjoyment of the night sky.
Tohuwawohu said, “All other things being equal, let’s say we can solve the infrastructure challenges. We can’t take your eyes and your backyard to space, OK? So I’m really more concerned about the impacts on our shared cultural ownership of the night sky.”
“What it means when we look up. I think about it more often than I think about the impact it has on my research.”
Borloff says he’s also concerned about how these satellites might have other effects, such as causing confusion among birds that use the stars to navigate. Then there’s also the concern about the end of life of these satellites, where they burn up in our atmosphere and are left behind soot and vaporized metals,
Then it affects humans.
“There are also cultural problems. The positions of the sky and the stars have been used for generations.” “Unearthing the stories in humanity and carrying forward the memories of our elders,” Borlaf said.
“Space is for everyone, and it will impact everyone.,
