SpaceX launchedsatellites faster than any other company or agency in history over the last month, as part of Elon Musk's plan to blanket Earth in high-speed internet.- The launches hurtled 175 Starlink internet satellites into space, along with five satellites from other companies.
- The latest satellites have visors to block the sun, which should make them less visible in the night sky.
- But the visors won't solve all the problems the satellites could pose for astronomers.
In the weeks after SpaceX brought two NASA astronauts home from the space station, the company has rocketed satellites into Earth's orbit faster than history has ever seen.
On Thursday morning, the company's
The initiative eventually aims to send tens of thousands of broadband satellites into orbit, blanketing Earth in high-speed internet. Already, it has launched 650 satellites, 175 of which went up in the last month alone.
That means
Thursday's launch sent the 12th batch of Starlink satellites into orbit since launches began last year, so the three recent batches mark a significant acceleration. Musk previously suggested that the company would send up batches of Starlink satellites every two weeks throughout 2020, for a total of 1,400 by the end of the year, but the plan is progressing slower than that.
Still, the company already began private beta testing of the internet service this year.
After launching at least 500 more satellites, SpaceX plans to boot up Starlink more fully, then build toward a floating internet backbone that would offer most of the planet ultra-high-speed web access.
"For the system to be economically viable, it's really on the order of 1,000 satellites," Musk said in May 2019. All in all, SpaceX has sought government permission to put a total of 42,000 satellites into orbit to form a "megaconstellation" around Earth.
The two launches in August also carried five passenger satellites as part of a rideshare service that SpaceX now offers.
Astronomers say SpaceX's bright satellites outshine the stars
Many astronomers fears that the Starlink satellites will interfere with telescopes on Earth. So starting last month, SpaceX began fitting each new satellite with an experimental feature: visors that should block the sun from reflecting off the satellites' antennae.
Previously, that reflected light made the Starlink spacecraft appear as bright, moving trails in the night sky, photobombing astronomers' telescope observations and blotting out the stars.
"If there are lots and lots of bright moving objects in the sky, it tremendously complicates our job," astronomer James Lowenthal told The New York Times in November. "It potentially threatens the
Astronomers realized the nature of this threat after SpaceX launched its first Starlink batch in May 2019. In the days after that, people across the world spotted the train of satellites, like a line of twinkling stars.
"I felt as if life as an astronomer and a lover of the night sky would never be the same," Lowenthal said.
A satellite megaconstellation could cause telescopes on Earth that look for distant, dim objects to pick up these false stars, ruining astronomers' data. Even a single satellite can leave a continuous streak of light across a telescope's long-exposure images, blotting out the objects researchers want to study.
The satellites especially affect telescopes that watch areas of the sky close to the horizon near dawn — observations that help astronomers track asteroids flying close to Earth.
It's still unclear how effective Starlink's new visors will be. Even if they do work, the visors won't fully solve the problem, according to astronomer Jonathan McDowell.
"That will make the satellites no longer naked-eye objects, which is good," he told Business Insider in June. "It won't probably make them so faint that they won't be a problem for professional astronomers."
Starlink is not the only budding satellite constellation
SpaceX isn't the only company building a constellation of internet satellites. Companies like Amazon and OneWeb have similar aspirations to establish their own fleets.
"If OneWeb goes ahead and launches its proposed constellation without mitigation, that is going to have very severe impacts on ground-based astronomy to the point that, for at least four months out of the year, it's going to be pretty impossible to do most observations," McDowell said. "You might as well just shut the observatory down for the summer months" — when the high-altitude satellites will be visible all night — "because there's going to be so many satellites screwing up your data."
Astronomers also worry about the ways the satellites broadcast radio waves and emit infrared light, since both of those can interfere with telescopes on Earth, too.
In June, more than 250 scientists, engineers, and satellite operators convened at a satellite-constellation workshop to tackle some of these problems. Their resulting report, published in August, recommends keeping satellites as dark as possible, deploying them at lower altitudes, and tracking their positions so that telescopes can avoid them.
Or, the group suggested, companies could just not launch these satellites at all, since the plans indicate a grim future for astronomy.
"Nighttime images without the passage of a sun-illuminated satellite will no longer be the norm," the report's authors wrote. "If the 100,000 or more [low-Earth orbit] sats proposed by many companies and many governments are deployed, no combination of mitigations can fully avoid the impacts."
Dave Mosher contributed reporting.