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March 28, 2024

Every night, the stars in the sky compete with thousands of satellites. The number of intruders will only increase as the satellite constellation proliferates, and the company plans to launch tens of thousands of orbiters to beam internet and other communications signals back to Earth. These include SpaceX, which has already launched thousands of Starlink satellites, and Amazon, which plans to launch its Project Kuiper constellation later this year.

This is a growing problem for astronomers who study the universe from the surface of our world.

“It’s a hot topic,” says astronomer Eric Burns of Louisiana State University. “We’re dealing with so many satellites that they limit the sensitivity of ground-based telescopes.”

Many astronomers have been highly critical of the current and future impact of satellite constellations on their research. But Dr. Burns and other scientists are considering making cosmic lemonade out of orbital lemons. What if, they asked, all these jamming satellites could help advance the field of astronomy as they expand access to satellite signals from the ground?

What these astronomers see is the potential for new types of telescopes that mega-constellations can offer. In an upcoming proposal that Dr. Burns and his colleagues plan to share with private companies building satellite constellations, they hope thousands of tiny gamma-ray detectors could hitch a ride into space on satellites. Taken individually, each individual detector would be weak. But operating together in a mega-constellation of thousands of satellites, such a system would rival Swift and Fermi, two space-based gamma-ray observatories managed by NASA.

The impact will be huge. Gamma-ray bursts are hallmarks of the most cataclysmic events in the universe since the Big Bang. Digging deeper into this phenomenon could help answer some of today’s biggest questions, such as what the cores of neutron stars are made of, or how the behavior of dark energy reveals the shape of the universe.

“These questions are as important as those in astronomy,” Dr. Burns said. “We will be able to treat thousands of gamma-ray detectors as a single, extremely powerful coherent telescope looking down on the entire universe, which will be more sensitive than anything that has been done before.”

The idea is not without precedent. in 2011, Iridium Communications Partners with Scientists Carried research instruments into space. Some 30 Iridium satellites — which typically carry voice and data communications to Earth — also carry dosimeters to measure radiation in low Earth orbit. REACH plana collaboration between the U.S. Air Force and scientists.

Iridium’s more than 60 satellites carry magnetometers ampere planoperated by the Johns Hopkins University Applied Physics Laboratory, which studies how energy enters the Earth’s ionosphere from the magnetosphere.

Iridium readings are an important source of radiation data, said Alexa Halford, deputy laboratory director at NASA’s Goddard Space Flight Center. Her work reveals the connection between Earth’s magnetosphere and its atmosphere, and how the two work together to protect the ground from the intense radiation from space.

Dr Halford said the way satellite megaconstellations would interfere with telescopes on Earth’s surface required more consideration.

“Ground-ground astronomy is very important, and we need to be responsible,” she said.

On the other hand, she sees great potential for putting scientific instruments on more satellites.

“More data can give us a more complete picture,” Dr Halford said. “It’s hard for me to say no.”

SpaceX is already sharing some data with scientists, an arrangement that benefits both parties.

After a disastrous launch in February 2022, Fang Ziwei, a NOAA scientist specializing in space weather forecasting, began working with SpaceX. SpaceX watched as 38 of its 49 newly deployed Starlink satellites caught fire.

Doctor Fang’s autopsy documented how a small geomagnetic storm increases air density at altitudes in low Earth orbit. So instead of making it into orbit, the Starlink satellite hit the dense hot air and disintegrated.

“No one is doing low-Earth orbit drag very well right now because we don’t have the right satellites,” she said.

After that incident, SpaceX agreed to share a year’s worth of position and velocity data from its roughly 4,000 Starlink satellites, giving Dr. Fang and her colleagues the opportunity to study the types of orbital drag that destroy satellites. This could lead to better space weather forecasts, giving satellites more time to deal with surges in air density by ascending to safer orbital altitudes, “which ultimately benefits everyone,” Dr Fang said.

There are technical barriers to obtaining scientifically useful data from satellite constellations. Satellites in low Earth orbit move very quickly, completing a full orbital cycle in about 90 minutes. Therefore, it is not easy to combine data from many satellite constellations.

In order to get scientific equipment into orbit, there are strict constraints.Low-Earth Orbit Communications Satellites, Like SpaceX’s Starlink, Have Short Lifespans about five years, so the detector must be cheap.By contrast, the Hubble Space Telescope Cost about $16 billion In today’s dollars, but expected to last around 40 years old.

Nothing can be added at the last minute. Satellite engineers need to modify their designs to accommodate new payloads and make upgrades such as larger power and data links.

None of the companies building vast constellations of satellites has expressed a willingness to deploy gamma-ray detectors or other new sensors that could help scientists. SpaceX declined to respond when asked for comment on the idea, and OneWeb, which recently completed another smaller constellation, did not respond either. Project Kuiper, the constellation of online retailer Amazon that could launch its first satellite later this year, said it had invited Dr Burns to submit his proposal.

Increasing the number of partnerships with constellation operators is a way to benefit everyone without adding more confusion to the sky, suggests Dr Halford. “It’s not a great answer, but I think it’s the best we have,” she said.

So far, the burden of negotiating alone with a company as hesitant as SpaceX has frustrated astronomers. Dr Burns believes now may be the time for government oversight to ensure that megaconstellations do minimal harm to science.

By getting more involved, Dr Burns hopes scientists and satellite manufacturers will learn to work together. “I do think the idea of ​​having scientific instruments on the megaconstellation itself is beneficial to both parties,” he said. “If they were open about it, it would be a better solution.”



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