After a gap of two months, SpaceX has returned the batches of dozens of satellites in its gambit to allow Earth high-speed Internet access.
The satellites are a new “VisorSat” variety to make them less luminous for the ground and especially for the telescopes of astronomers. But researchers say the experimental new feature of spaceflight, while useful, does not solve problems posed by the existence of Starlink itself (or other planned thousands of powerful satellite fleets, for that matter).
SpaceX, founded by Elon Musk, calls its Internet project Starlink, and can deploy tens of thousands of broadband Internet-radiating satellites in low-Earth orbit. On Friday at 1:12 p.m. ET, one of the company’s Falcon 9 rockets launched a new batch of them, along with two Earth-imaging spaceships built by BlackSky Global.
SpaceX has provided all of its agency’s 57 Starlink satellites with a new feature: sunshades or shadows.
The fissures would have to deploy after launching and blocking sunlight from reflecting off the satellites’ surfaces – glare that makes Starlink spacecraft appear as bright, moving beams in the night sky that could bomb telobs observations, remove attenuated astronomical objects, and even searching for killer can hinder asteroids.
The fissures are likely to make the satellites less bright, but that will not stop them from interfering with astronomy, says astronomer Jonathan McDowell.
“If you figure out where the fissures need to be placed, you could really cut those reflexes. And that will no longer make the satellites with the naked eye, which is good,” he told Business Insider in June. “It probably won’t make them so embarrassed that they won’t be a problem for professional astronomers.”
SpaceX did not immediately respond to a request for comment.
An illustration of the Starlink satellite. (Room X)
Astronomers fear that SpaceX’s bright satellites could shine on the stars
After SpaceX launched its first set of Starlink satellites in May 2019, many astronomers were alarmed by how bright the new objects were. In the days after the launch, people all over the world saw the train of satellites, like a line of twinkling stars.
“I felt like life as an astronomer and a lover of the night sky would never be the same,” said astronaut James Lowenthal The New York Times in November.
“When there are a lot of very bright moving objects in the air, it complicates our task enormously,” Lowenthal added. “It potentially threatens the science of astronomy itself.”
Telescopes on Earth searching for distant, dim objects could pick up these false stars and destroy astronomers’ data. A single satellite can create a continuous streak of light over long exposures of telescopes from the sky, blocking the objects that astronomers want to study.
“It only takes a few seconds for the satellite to cross the field of view of the telescope, but we take really long exposures with our cameras. So in that few seconds a whole exposure of 10 or 15 minutes is ruined,” McDowell said. .
The satellites can mainly affect telescopes that observe near the horizon near the dwarf – the kind of observations that help astronomers track asteroids flying near Earth.
SpaceX shares Starbin’s orbital data with astronomers so that they can plan their observations of the telescope on the motions of the satellites. Closing the camera briefly when the satellite is on top can store a long-exposure image.
To date, SpaceX has flown nearly 600 Starlink spacecraft to orbit – the most from any satellite operator. But Musk’s great ambitions could make it virtually impossible for astronomers to avoid the fast-moving satellites.
SpaceX already has permission to launch nearly 12,000 satellites, and last year sought additional clearance to launch a total of 42,000 satellites. And that does not take into account the plans of other providers.
“If they come all the time, it’s not helpful to know when they’re coming,” McDowell said. Even now, he added, astronomers can sometimes avoid the photobombers.
It is not yet clear how well a VisorSat works
It is unclear how effective SpaceX’s new visors will be, although the company has launched an experimental “VisorSat” to test the concept on June 3rd. SpaceX has yet to report the results of that test.
“We are still waiting for the satellite to reach its operational orbit,” said Youmei Zhou, an integration and testing engineer for SpaceX’s Crew Dragon spacecraft, during a live broadcast of the launch early Friday morning.
Launching a whole fleet of visor-equipped satellites without sharing much, or perhaps knowing, the results of the experimental space travel visitor seem like “a gusty move” to McDowell.
“I think what it reflects is that they have a lot more confidence now that they understand the sources of the problem,” he said.
The company does not expect earlier, visor-free Starlink satellites to complete its five-year lifespan, said Patricia Cooper, Vice President of SpaceX of satellite government relations, Spaceflight Now in May. This means that in a few years the brightest satellites may no longer appear in the air.
Satellite constellations present major problems that visors cannot repair
The Starlink float caught the attention of astronomers for how bright it was, but it revealed a much bigger problem: The skies could soon swim with false stars.
SpaceX is not the only company to build a massive fleet of satellites. Companies like Amazon and OneWeb have similar ambitions to establish their own fleets each year and listen in billions of dollars.
“If OneWeb goes ahead and launches its proposed constellation without mitigation, it will have a very severe impact on basic astronomy to the point that, for at least four months out of the year, it will be completely impossible to make the most observations,” McDowell said.
“You can just shut down the observation just for the summer months, because there will be so many satellites screwing up your data.”
Mitigating solar reflexes also only go so far. Astronomers are also concerned about invisible wavelengths of light that could stand to compromise other forms of astronomy.
The Federal Communications Commission, which authorizes the flight and use of Internet-radiating satellites in the US, says preventing astronomy is “not a condition” for licensing – so SpaceX strives for proprietary solutions. Sources known to Business Insider also say that Amazon’s Kuiper satellite internet project is working with astronomers to reduce the impact of these satellites.
But SpaceX and others have yet to announce potential shear reduction measures for radio waves that will emit the satellites, as well as for the infrared light they emit through heat production. Both can interfere with telescopes on Earth that observe the skies using radio or infrared.
“We are in a new phase of space use. It is a new space-industrial revolution, things are different, and astronomies will be affected,” McDowell said.
“We just need to make sure we’re part of the conversation so we can keep it up to the ‘neck pain’ level and not the ‘give up and go home’ level.”
Dave Mosher contributed reporting.
This article was originally published by Business Insider.
More from Business Insider:
.
