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SpaceX shares how it's making Starlink satellite less bright. SpaceX shares how it's making Starlink satellite less bright.

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SpaceX shares how it’s making Starlink satellites less bright.

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SpaceX shared how it’s making its Starlink satellites less bright. The space exploration company published a document titled, Brightness Mitigation Best Practices for Satellite Operators that outlines how it’s working with the astronomy community to reduce light pollution.

SpaceX has been criticized for the brightness of its Starlink satellites by astronomers. Elon Musk and the team at SpaceX not only listened to the criticism but are actively responding to it by collaborating with the astronomy community to solve the issue.

SpaceX Is Making Starlink satellites Invisible to the naked eye.

SpaceX noted that through the collaboration, it has identified and mitigated the key causes of satellite brightness. The company is working on making the satellites invisible to the naked eye when they are at their standard operational altitude.

If satellites are illuminated by the sun at night, they can be visible to observers from the earth. However, the visibility of any satellite depends on the materials used for its surfaces.

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Since satellites don’t emit their own light, the brightness results from natural sunlight scattering off of the satellites’ surfaces and reflecting down to earth. The light can scatter in two different ways: specular or diffuse.

SpaceX is focusing on specular scatter

Credit: SpaceX

SpaceX is investing in specular surfaces. Specular light is reflected at a single angle just like a mirror. Diffuse light reflects from many angles. The image above shows the difference between how specular light scatters and diffuse light scatters.

SpaceX noted that not all materials are highly reflective and some can be absorptive or make the light that is reflected much less bright.

SpaceX’s satellites are visible from the ground in two ways.

  1. Sunlight scatters off the main body.
  2. Sunlight scatters from the solar arrays.

To solve this, SpaceX adopted mitigations for both problems for its current, first-generation satellites.

Sun Visors and RF-Transparent mirror films

starlink
Credit: SpaceX

Sun Visors 

For the first-gen satellites, SpaceX developed sun visors that block sunlight from hitting the bottom side of the chassis (body of the satellite.) They were made from materials that engineers developed to be invisible to radio frequencies.

However, the sun visors blocked the laser links that SpaceX uses to expand coverage to remote regions of the world. Additionally, the visors generated significant drag on the satellites. So, SpaceX determined that the sun visors weren’t a long-term solution.

RF- transparent mirror films.

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SpaceX developed RF-transparent mirror films as an alternative to the sun visors. The film scatters most of the sunlight away from the Earth. SpaceX said that it has been improving its mirror films to scatter less light back to the earth.

It plans to deploy a new and improved version of the film on its next-generation satellites.

Inter-cell backing material

Another change that SpaceX made to its first-gen satellites involved the inter-cell backing material. The material was initially white but SpaceX changed it to a dark red that reduces the arrays’ brightness.

The downside is that the darkening of the material increases the temperature of the solar array which reduces performance. However, SpaceX will adopt many designs such as this one to reduce the brightness of the satellites.

Dielectric Mirror Film for Starlink satellites.

SpaceX noted that its second-gen satellite will add more capacity to the Starlink network; connecting more people in more places.

The second-gen satellites will use the following three advanced brightness techniques and I will dive into one of them: Dielectric Mirror film.

SpaceX will cover the bottom of the satellites with a second-gen dielectric mirror film. This version reduces the observed brightness ten times better than the first-gen film by using a Bi-Directional Reflectance Distribution Function (BRDF) metric.

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You can see how the BRDF for decreases visibility in the chart below.

SpaceX shares how it's making Starlink satellite less bright.

Credit: SpaceX

 

Through extensive research and iteration, SpaceX maximized the film’s specular scatter. The core of the film is a Bragg mirror that includes many thin layers of plastic that have a variety of refractive indices which create interference patterns internally to reflect the light.

It also allows radio waves to pass through with no issues. Protective layers of titanium dioxide and silicon dioxide were added to protect the film in thin, pure layers that don’t affect the film itself. Below is a comparison between the first-gen and second-gen mirrors.

Credit: SpaceX

 

SpaceX plans to offer the dielectric mirror film as a product

SpaceX plans to offer the dielectric mirror film as a product on the Starlink website. The reason is that SpaceX can not reduce the effect of satellites on space exploration by itself.

The film will be offered at cost and all operators will be able to use it to reduce the effect of their own constellations.

SpaceX will continue to work with the astronomy community

SpaceX emphasized that not only is the astronomy community’s work important but that it would continue to work with them to reduce the effects of all satellite operations.

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“SpaceX is committed to connecting as many people as possible through Starlink, improving the lives of millions of people here on Earth.”

“As a space exploration company, SpaceX is a strong supporter of astronomy and the scientific community.”

You can read the full document here.

I’d love to hear from you! If you have any comments, or concerns, see a typo, you can email me at johnna@teslarati.com. You can also reach me on Twitter @JohnnaCrider1

Johnna Crider is a Baton Rouge writer covering Tesla, Elon Musk, EVs, and clean energy & supports Tesla's mission. Johnna also interviewed Elon Musk and you can listen here

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NASA taps SpaceX for more astronaut missions as Boeing Starliner remains grounded

NASA just gave SpaceX a $946 million contract for three more astronaut missions through 2030.

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NASA has awarded SpaceX a $946 million contract modification covering three more astronaut missions to the International Space Station, according to an announcement the agency published Friday. The award adds Crew-15, Crew-16, and Crew-17 to SpaceX’s existing Commercial Crew Transportation Capability contract, bringing the agreement’s total value to $5.92 billion across 17 flights.

SpaceX confirmed the award on X, writing that it was excited for Falcon 9 and Dragon to launch NASA’s Crew-15, 16, and 17 missions to the Space Station from Florida. The new missions cover ground, launch, in orbit, and return operations, along with cargo transport and a lifeboat capability while docked at the station, and the period of performance runs through 2030.

The award follows a notice of intent NASA issued in May, when the agency first signaled it would purchase up to six additional post certification missions from SpaceX. Teslarati covered that filing at the time, noting NASA cited technical issues and schedule delays encountered by Boeing as a driving factor. Friday’s contract modification locks in three of those six missions, with the remaining three left open for NASA to award later, potentially to Boeing if Starliner clears certification.

Boeing’s CST-100 Starliner has still not flown an operational crew rotation mission for NASA. The spacecraft’s most recent crewed test flight in 2024 ended without the astronauts returning aboard Starliner, and the company has spent the time since working through thruster problems. SpaceX President Gwynne Shotwell said this week that SpaceX is not retiring Crew Dragon today, for sure, while stopping short of committing to fly it past 2030.

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Crew-12 is currently docked at the space station, and NASA has said Crew-13 is targeting a launch in the coming weeks. The newly awarded Crew-15 through Crew-17 missions extend SpaceX’s role as NASA’s primary way of getting astronauts to and from orbit well into the back half of the decade, regardless of what happens with Starliner or Starship in the meantime.

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SpaceX’s next Starship launch is about to attempt its biggest leap yet

SpaceX targets September 22 for Starship Flight 14, its first attempt to reach real orbit.

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SpaceX has set September 22 as the target date for Starship’s 14th test flight, and this one carries a different goal than any of the 13 that came before it. Every previous Starship mission has intentionally flown a suborbital arc, reentering the atmosphere within the same hour it launched. Flight 14 is designed to send the craft into a genuine orbit around Earth for the first time.

The launch window opens at 7:15 a.m. Central time at Starbase in South Texas and runs for 75 minutes, pending regulatory approval, according to SpaceX’s mission description published Tuesday. If the flight goes as planned, Starship will circle the planet roughly six times at an altitude near 275 kilometers over about ten hours before a deorbit burn sends it toward a splashdown in the Pacific Ocean west of Chile, a departure from the Indian Ocean recoveries used on the last several flights.

The mission also marks the first attempt to put a working batch of Starlink V3 satellites into actual service. Flight 13 carried 20 of the new satellites in July, but because that mission never left a suborbital trajectory, the payload reentered along with the ship instead of separating into orbit.

SpaceX tells the FCC that Starship Flight 14 is going to orbit

Each V3 satellite is rated for roughly one terabit per second of downlink capacity, so a successful deployment on Flight 14 would be SpaceX’s largest single jump in network bandwidth since Starlink began flying on Falcon 9.

Flight 13 still did the heavier lifting on the technical side. That July mission flew a deliberately more stressful reentry profile to test Starship’s heat shield, and the ship survived its softest splashdown yet, intact enough for drone inspections shortly after landing. Elon Musk said the flight delivered “all the heat shield data we needed and then some,” a result Teslarati covered in detail when he later said SpaceX had solved the vehicle’s biggest reusability challenge. Flight 14 is where SpaceX starts spending that confidence on an actual orbital insertion rather than another controlled fall back to Earth.

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One thing Flight 14 will not attempt is a tower catch of the ship. Musk floated the idea right after Flight 13, but walked the timeline back in August, saying a catch attempt was more likely “in a few months.” The Super Heavy booster will still aim for its own recovery, targeting an offshore landing point in the Gulf of America, the same approach used on recent flights.

September 22 is SpaceX’s own target, not a locked date. Starship’s schedule has slipped before over hardware readiness and FAA sign off, and the company has said as much in its own mission notes. But the plan itself represents the clearest marker yet that Starship is moving from a suborbital test program into something meant to carry paying payloads and, eventually, people.

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SpaceX tells the FCC that Starship Flight 14 is going to orbit

SpaceX filed with the FCC for Starship Flight 14, its first true orbital launch attempt.

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SpaceX has asked the Federal Communications Commission for permission to fly Starlink terminals during Starship’s fourteenth flight test, and the filing lays out a genuine trip to orbit, something the program has never attempted.

Every Starship flight so far, including Flight 13’s successful splashdown in the Indian Ocean on July 24, has flown a suborbital arc that ends with the ship reentering the atmosphere within the same hour it launches. The FCC paperwork describes a mission profile built around an actual orbital insertion instead.

The payload is the other half of the story. Flight 13 carried 20 production Starlink V3 satellites, but because that mission never reached orbit, the satellites reentered along with the ship rather than joining the constellation, something Teslarati covered in detail after SpaceX released footage shot from one of those satellites as it drifted away from Starship in space. Flight 14 is designed to close that gap. If the orbital insertion holds, the roughly 20 V3 satellites onboard would separate into an operational orbit and could eventually go into service, each one rated for about 1 terabit per second of downlink capacity by SpaceX’s own account.

SpaceX announces new Starbase for ‘thousands of Starship launches annually’

Elon Musk first flagged the orbital attempt during SpaceX’s August 4 earnings call, the company’s first as a public entity following its June IPO under the ticker SPCX. He also floated catching the ship with the Starbase tower on the same flight, an idea he walked back on August 20, saying the catch attempt would more likely come “in a few months,” as Teslarati reported at the time. Flight 14 will instead target a splashdown for the ship in the Indian Ocean, the same recovery method used since Flight 12.

Hardware has been catching up to the ambition. Booster 21 completed a full 33-engine static fire on August 28, and Ship 41 finished its own six-engine test the week before. An airspace briefing circulated to pilots on August 20 listed September 15 as the target date, later than the end of August window Musk mentioned on the earnings call, though SpaceX has not confirmed a launch date publicly and Starship schedules routinely slip while hardware and FAA paperwork line up.

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The FCC filing itself does not guarantee a launch date. It covers communications authority, and not flight readiness, considering SpaceX still needs Ship 41 fully stacked and cleared by the FAA before Flight 14 can fly. But the filing is a real marker of intent and it puts a specific regulatory process behind what had so far only been Musk’s word on the earnings call.

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