Starlink satellite trains – are they the future of the night sky?

Nearly 15 years later, seeing the northern lights is a bit like a drug, says photographer Ronn Murray.

“Once you taste it… you always try to see it again because you get that kind of spiritual high.”

Subscribe to The Post Most newsletter to receive the most important and interesting articles from The Washington Post.

The lakes near Delta Junction, Alaska, were not yet frozen when it was dark enough to see a magical halation above the night sky and another phenomenon Murray knew instantly – a moving train of lights.

Guide and co-owner of Aurora Chasers, an Alaska-based tour group, Murray had seen the satellite list a few days earlier. He recognized it from other people’s accounts, but had never seen it himself. The stars literally aligned and the night sky opened on a 150 mile drive from Fairbanks. The footage shows what looks like stars following each other amidst the emerald glow of the aurora borealis.

“At first we were a little baffled, and then we realized, ‘Wait, it has to be Starlink,'” he said. “Then my wife launched her star tracker app and showed that’s what we saw.”

The sight, as mesmerizing as it is surprising, has astronomers wondering if there is any way to dim the lights on these satellites, or are we doomed to a mega-constellation in the future?

Murray captured 46 objects launched on August 31 by SpaceX clumped together, reflecting the sun back to observers on Earth. These satellites are part of the growing Starlink constellation, which aims to bring broadband to the world, much like GPS delivers location data to mobile phones around the world.

But unlike GPS, this task requires tens of thousands of satellites for the service to work without coverage drops. In three years, Elon Musk’s SpaceX aerospace company went from 60 satellites to launching more than 3,500 Starlinks. According to data from the non-profit organization CelesTrak, almost half of all active satellites come from SpaceX. A recent approval from the Federal Communications Commission approved the launch of 7,500 more satellites and nods to the company’s plan to launch 30,000 orbiting internet boxes – a feat it could achieve by 2050 at this rate.

Why are Starlink satellite trains visible?

Most satellites are visible. Time is everything.

The most famous satellite, our moon, is visible as it crosses our sky. We can see the surface of the moon because half of it is directed at our sun at all times. It’s easier to see the moon at night when we’re in the shadow of the sun.

These principles also apply to smaller orbital bodies. If you measure it right, you can see the International Space Station at night. You can see it passing before the full moon.

The Starlink satellites are also pretty clear on what they’ve been working on with the astronomy community since they started launching satellites.

The most pronounced factor in the creation of Starlink trains has to do with physics:

The satellite travels along the launch vehicle into Low Earth Orbit (LEO).

The satellite is launched into space where, unless aborted, it will orbit the Earth.

As the Starlink satellite orbits, it deploys its solar panels and lays flat in a low-drag position to resist the pull of gravity back to Earth.

When ready, it will point its panels directly “up” and its antennas directly down toward the Earth to transmit data to customers.

SpaceX isn’t just launching one satellite. Each launch contains 50 to 60 satellites; On December 28, SpaceX put 54 into orbit.

Moving at the same altitude and speed, these satellites initially revolve around the globe clumped together. This is what is perceived on land as a “train”. When the time is right, each satellite uses its ion engine to ascend to a higher altitude and operational orbit.

How does the theory work in practice?

Jonathan McDowell, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics, tracked orbital data from each Starlink launch. He observed that batches of satellites would rise into operational orbits in groups, using what is known as aircraft drift to cover different parts of the globe in one launch.

Rising into operational orbit in phases may improve global coverage, but it means the non-trivial part of these satellites’ lives is parked where they are more visible. McDowell notes, “Instead of one month from launch to launch, it takes three months from launch in some cases because they’ve been in this intermediate orbit for a while.”

SpaceX wants to shorten Starlink trains

To some extent, it is in the interest of the company to limit the visibility of their constellations. Seeing them at night is a byproduct of them not reaching operational orbit. No matter how long they are parked or sailing beyond the heights of the ISS and Tiangong, they are far from providing internet to customers and making money for SpaceX.

The satellites we rely on for GPS have experienced similar infrastructure issues. Decades of failed launches and federal budget cuts passed until the constellation of 24 GPS satellites we rely on today was completed in 1994. Early applications required the use of synchronization with the availability of enough satellites to triangulate positions. There are now several GPS-like constellations that offer 16 feet (4.9 meters) accuracy to users around the world.

SpaceX’s Gabit is all about achieving this with a planned constellation of 30,000 satellites. While this mega-constellation sounds like a lot, OneWeb and Amazon’s Project Kuiper are vying for similar fleets. According to some estimates, the number of connected satellites could exceed 100,000 by 2030.

How will this affect terrestrial astronomy?

The visibility of these satellites affects critical scientific work from our planet. As SpaceX works to limit its visibility, astronomers are concerned about the bigger picture. A study simulating the impact of 65,000 proposed satellites published in the Astronomical Journal found that 1 in 5 observations of the night sky will be interspersed with passing satellites. The level of interference depends on whether operators are able to reduce the brightness enough for astronomers.

SpaceX’s operating altitude, less reflective materials, and angle toward the sun all contribute to how much science data is obscured. One of the authors of the study, Meredith Rawls of the University of Washington, is quoted in SpaceX FCC documents that these mitigation efforts are “voluntary, insufficient, and in the case of Starlink Gen2, untested.” SpaceX did not respond to a request for comment on this report.

Astronomer Patrick Seitzer of the University of Michigan said there are other problems beyond what we can see, as the satellites will also emit heat. Even if “there is no shadow,” he said, “they will always be visible.”

The last problem is that mega-constellations interfere with radio communication. These satellites use high-frequency bands to transmit data to customers. This is the main reason why the FCC is the compliance agency approving the launch of the next batch of Starlink devices. Unlike light interference, obstacles are hard to locate, University of Virginia radio astronomer Harvey Liszt told radio astronomer, so the responsibility is being dispersed among the many companies now vying for the skies.

Currently, Starlink communication remains within the allocated frequency bands, but the radio waves are becoming congested. In the past, astronomers could avoid the noise of commercial radio bands by moving to remote locations such as the Atacama Mountains in Chile or the desert in New Mexico. However, since satellite companies communicate between higher frequency bands, there is not a treble high enough to avoid broadcasting them. Scientists have to adapt.

Broadcasting in remote regions is also a market target for SpaceX. Its company website lists marine, aviation, and RV applications.

Ashley VanderLey of the National Science Foundation’s Radio Astronomy Facilities said NSF was able to coordinate with SpaceX for its constellation, and that generally companies in the United States showed a good faith effort to work with astronomers to resolve the issues.

For Murray, the Starlink constellation could give his company a competitive advantage. Some tours may take them 200 miles from their home base in Fairbanks, where there is no cellular service. Without that, it’s hard to keep track of where the cloudless view might be for his customers.

“It’s not the northern lights we’re chasing – it’s clear skies,” Murray said. “We’re like storm chasers, but we’re trying to get out of the storm.”

The Starlink-based internet would allow Murray to locate the open sky. Whether the observation above is clear from satellites will depend on space management from Earth.

related content

The hot future of the world is etched in the crippled kidneys of Nepalese workers

The tough guys in the House of Representatives who are blocking McCarthy are not listening to Trump

In her own words: Pelosi is stepping back after decades in power

Leave a Reply

Your email address will not be published. Required fields are marked *