Every night the stars in the sky compete with thousands of satellites. The number of invaders is only increasing as constellations of satellites proliferate, and companies plan to launch tens of thousands of orbiters to send Internet and other communications signals back to Earth. Among them are SpaceX, which has already launched thousands of Starlink satellites, and Amazon, which plans to launch its Project Kuiper constellation later this year.
For astronomers who study the universe from the surface of our world, this is a growing problem.
“It’s a hot topic,” said Eric Burns, an astronomer at Louisiana State University. “We are dealing with such a large number of satellites that they limit the sensitivity of ground-based telescopes.”
Many astronomers have strongly criticized the current and future effects of satellite constellations on their studies. But dr. Burns and other scientists are thinking of making cosmic lemonade from orbital lemons. What if, they ask, all those interfering satellites could contribute to the advancement of astronomy while expanding ground-based access to satellite signals?
What these astronomers see is the potential for a new type of telescope that megaconstellations could provide. In an upcoming proposal that Dr. Burns and his colleagues want to share with private companies building satellite constellations, they hope thousands of tiny gamma-ray detectors can lift off into space with the satellites. On its own, any individual detector would be weak. But operating together in a mega-constellation of many thousands of satellites, the power of such a system could rival Swift and Fermi, two space gamma-ray observatories operated by NASA.
The impact would be significant. Gamma-ray bursts are the hallmark of the most catastrophic events in the universe since the Big Bang. In-depth research into the phenomena could help answer some of today’s biggest questions, such as what forms the nuclei of neutron stars or how the behavior of dark energy might reveal the shape of the universe.
“These are about as important questions as can be asked in astronomy,” said Dr. Burns. “We will be able to treat the thousands of gamma-ray detectors as a single, extremely powerful coherent telescope that scans the entire universe, which would be more sensitive than ever before.”
The idea is not without precedent. In 2011, Iridium Communications partnered with scientists to transport research instruments into space. About 30 Iridium satellites — which typically transmit voice and data communications to Earth — also contain dosimeters that measure radiation in low Earth orbit as part of the REACH program, a collaboration between the US Air Force and scientists.
And all of Iridium’s more than 60 satellites have magnetometers for the AMPERE program, led by the Johns Hopkins Applied Physics Laboratory, that studies how energy enters Earth’s ionosphere from the magnetosphere.
Alexa Halford, an associate lab chief at NASA’s Goddard Space Flight Center, says the Iridium measurements are an important source of radiation data. Her work reveals the connection between Earth’s magnetosphere and its atmosphere and how the two work together to protect the ground from downpours of strong radiation from space.
Dr. Halford said more attention was needed to the ways mega-satellite constellations interfere with Earth-surface telescopes.
“Astronomy on the ground is incredibly important and we must take responsibility,” she said.
On the other hand, she sees great potential in placing scientific instruments on more satellites.
“More data can give us a more complete picture,” said Dr. Halford. “I would find it hard to say no.”
SpaceX is already sharing some data with scientists in an arrangement that could benefit both parties.
Tzu-Wei Fang, a scientist at the National Oceanic and Atmospheric Administration who specializes in forecasting space weather, began collaborating with SpaceX after a disastrous launch in February 2022. SpaceX watched as 38 of its 49 newly deployed Starlink satellites in went up in flames.
Dr. Fang’s post-mortem documented how a small geomagnetic storm had increased the density of the air at the altitudes where low Earth orbits occur. So instead of sailing into orbit, the Starlink satellites slammed into dense, hot air and broke apart.
“Nobody can tow very well in low Earth orbit right now because we don’t have the right satellites,” she said.
After that incident, SpaceX agreed to share the position and velocity data for its roughly 4,000 Starlink satellites for a year, allowing Dr. Fang and her colleagues got a chance to study the type of orbital drag that destroyed the satellites. That could potentially lead to better weather forecasts in space, giving satellites more time to respond to an increase in air density by ascending to a safer orbit altitude, “which will ultimately benefit everyone,” said Dr. Fang.
Obtaining scientifically useful data from satellite constellations poses technical hurdles. Satellites in low Earth orbit move very fast, completing a full orbital circuit in about 90 minutes. Combining data from a constellation of many satellites is therefore not easy.
And to drive scientific equipment into orbit, there are strict restrictions. Communications satellites in low Earth orbit, such as SpaceX’s Starlink, have a short lifespan of about five years, so the detectors shouldn’t be expensive. In contrast, the Hubble Space Telescope cost about $16 billion in today’s dollars, but is expected to last about 40 years.
Any additions could not be made at the last minute. Satellite engineers would need to modify their designs to accommodate the new payloads with upgrades such as larger power sources and data links.
None of the companies building huge satellite constellations have said they are willing to deploy gamma-ray detectors or other new sensors that would help scientists. When asked to comment on the idea, SpaceX declined to answer, and OneWeb, which recently completed another smaller constellation, never responded. Project Kuiper, the constellation of online retailer Amazon that may launch its first satellites later this year, said Dr. Burns to submit his proposal.
Dr. Halford suggested that increasing the number of partnerships with the constellation operators was a way to help everyone without further polluting the air. “That’s not a great answer, but I think it’s the best we’ve got,” she said.
Until now, the burden of individual negotiations with reluctant companies like SpaceX has frustrated astronomers. Dr. Burns thinks it may be time for government oversight to ensure science is harmed as little as possible by megaconstellations.
With increased participation, Dr. Burns that scientists and satellite makers can learn to work together. “I think this idea of science instruments on the mega-constellations themselves would be a mutual benefit,” he said. “If they’re open to it, it’s an even better solution.”
