Space
SpaceX shares how it’s making Starlink satellites less bright.
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.
New document from @SpaceX https://t.co/aI17WdaqrF
explaining what they have been doing to make their satellites less bright.
I applaud SpaceX for their work on this (and for making the document public), while remaining concerned to see how bright the Gen2 Starlinks end up being— Jonathan McDowell (@planet4589) July 29, 2022
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.
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
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.
- Sunlight scatters off the main body.
- 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
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.
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.
You can see how the BRDF for decreases visibility in the chart below.
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.
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.
“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
Elon Musk
Elon Musk breaks his silence on the Starlink impact to Ukraine drones
Musk says the US military and president set Starshield limits, not SpaceX, amid Ukraine complaints.
Elon Musk says the speed limit cutting out Ukraine’s military Starlink terminals is not SpaceX’s decision. In a post on X Wednesday, Musk wrote that “Starshield systems are owned and controlled by the US government. Any limits on speed or usage are decided by the US military and ultimately POTUS.” He added that Starlink is a commercial service limited to civilian or defensive activities and “cannot be used for offensive military action, as doing so would be inappropriate for a commercial company.”
He was replying to Mykhailo Fedorov, Ukraine’s former defense minister, who had thanked Musk for restoring connectivity at speeds up to 160 km/h and said removing the Starshield limit entirely is “now critical for Ukraine’s defense.”
Starshield systems are owned and controlled by the US government. Any limits on speed or usage are decided by the US military and ultimately POTUS.
Starlink is a commercial service owned and controlled by SpaceX. Usage of Starlink is limited to civilian or defensive activities and cannot be used for offensive military action, as doing so would be inappropriate for a commercial company.
— Elon Musk (@elonmusk) October 14, 2026
The complaint started Tuesday night, when Ukrainian officials said military terminals began losing service above roughly 100 mph. Presidential adviser Serhiy Beskrestnov said the defense forces got no warning and several missions were disrupted, as Teslarati reported earlier Wednesday. The 7th Rapid Reaction Corps told Reuters connections dropped for 10 to 20 seconds at speeds well below the limit, which made drones harder to control. Poland’s foreign minister, Radoslaw Sikorski, asked Musk on X whether he is “playing politics with your products again.”
That is why the Starlink and Starshield distinction matters. SpaceX introduced Starshield in 2022 as the government version of Starlink, with an initial focus on Earth observation, communications and hosted payloads. It won a Space Force contract in 2023 with a $70 million ceiling. In December 2024, the Pentagon moved Ukraine’s terminals onto Starshield, covering about 3,000 units across two contracts. Ukraine’s military connections therefore run through a service that Musk now says sits under Washington’s control.
While Musk’s post describes who holds authority, it does not infer that anyone ordered the limit, and neither SpaceX nor the US government has confirmed who set it. Ukrainian officials have pointed to the timing, which follows President Trump’s push for an energy ceasefire and Musk’s Saturday post that “Zelensky has gone too far.” The BBC noted Trump denied threatening to restrict intelligence sharing with Kyiv, and no evidence has been presented that Washington requested the cap.
The episode also revives a promise from 2025. After Poland accused him of threatening Ukraine’s access, Musk said Starlink “will never turn off its terminals” and would not be used as a bargaining chip. Poland has since supplied more than 29,000 terminals to Ukraine. Teslarati also covered Kyiv’s search for Starlink alternatives in 2025, and the latest dispute gives that search new urgency.
News
SpaceX brings four astronauts home after 8 months in space, and the return was flawless
SpaceX Crew Dragon Freedom returned four Crew-12 astronauts home after 237 days aboard the station.
Four Crew-12 members are back on Earth after 237 days at the International Space Station. SpaceX’s Crew Dragon Freedom splashed down in the Pacific Ocean about 50 miles west of Los Angeles at 11:34 a.m. ET on Thursday.
NASA astronauts Jessica Meir and Jack Hathaway, ESA astronaut Sophie Adenot, and Roscosmos cosmonaut Andrey Fedyaev landed one day after undocking from the station’s Harmony module at 8:05 a.m. ET on Wednesday. NASA confirmed the splashdown minutes later. SpaceX had flagged the 27.5 hour trip home on X while Dragon was still firing its departure burns away from the station.
The descent ran on schedule when Freedom started a nine minute deorbit burn at 10:46 a.m. ET, then hit the thicker atmosphere about 36 minutes later at nearly five miles per second. Chutes deployed at around 18,000 feet, and four main parachutes brought the capsule down to roughly 15 mph at splashdown.
SpaceX fast boats secured Dragon before the recovery ship Shannon hoisted it onto the deck with the crew still inside. Flight surgeons on board ran initial medical checks. All four crew members will be flown ashore by helicopter and then head to NASA’s Johnson Space Center in Houston for rehabilitation.
Splashdown of Dragon confirmed! https://t.co/P2o7A3Gytf
— SpaceX (@SpaceX) October 8, 2026
Crew-12 launched on February 13 from Space Launch Complex 40 at Cape Canaveral, a flight that also marked the first Falcon 9 booster landing at SpaceX’s new LZ-40 pad. Over the mission, the crew completed 3,792 orbits, covered nearly 101 million miles, and carried out four spacewalks to maintain and upgrade the station.
Meir now has 440 cumulative days in space, which places her in NASA’s top 10. This was the first spaceflight for Hathaway and for Adenot, a French Air Force colonel and former helicopter pilot. Fedyaev, who spent 186 days in orbit on Crew-6 in 2023, has now flown two long duration Dragon missions.
The return closes out a busy stretch of Dragon traffic. Crew-13 arrived on October 1 aboard Crew Dragon Grace, which docked just 7 hours and 55 minutes after liftoff, the fastest launch to docking of any U.S. spacecraft in ISS history. Commander Jessica Watkins, pilot Luke Delaney, Canadian Space Agency astronaut Joshua Kutryk, and cosmonaut Sergey Teteryatnikov remain aboard alongside the three person Soyuz MS-29 crew.
With Crew-12 gone, the port is clear for CRS-35, a cargo Dragon carrying the final pair of ISS Roll-Out Solar Arrays. NASA is holding a post-splashdown teleconference at 1:15 p.m. ET covering both the crew’s return and the upcoming cargo launch.
Elon Musk
Elon Musk shuts down talk of TSMC taking over Terafab
Musk says Tesla and SpaceX will build and run Terafab, with TSMC limited to renting.
Elon Musk has drawn a firm line around who will be in charge of Terafab, the giant chip factory Tesla and SpaceX are planning in Texas.
Musk replied to a post on X arguing that Taiwan Semiconductor Manufacturing Company (TSMC) would most likely end up owning and operating the plant. “No, we will build and run the fab. Let there be ZERO doubt about that,” Musk wrote. “Maybe TSMC subleases part of the Terafab if they want, but nothing more than that.”
In plain terms, a sublease means TSMC could rent a section of the complex to make chips, similar to a tenant renting one floor of an office tower. The building, the equipment decisions and the daily operation would stay with Tesla and SpaceX.
@herbertong @thejefflutz No, we will build and run the fab. Let there be ZERO doubt about that.
Maybe TSMC subleases part of the Terafab if they want, but nothing more than that.
— Elon Musk (@elonmusk) October 7, 2026
The comment shuts down speculation that started last week. On October 2, tech journalist Tim Culpan reported that TSMC was exploring ways to help run Terafab’s factories. Musk responded the next day that it was “just discussions, but something may come of it,” as Teslarati reported at the time. That left room for a scenario where the world’s largest contract chipmaker took the wheel. Musk’s latest post closes that door.
Some background helps explain why this matters. Tesla designs its own AI chips today but pays outside companies like TSMC and Samsung to manufacture them. Musk unveiled Terafab in March as a joint project between Tesla, SpaceX and xAI, arguing that existing suppliers cannot expand fast enough to meet his companies’ future demand. The goal is to produce enough chips each year to supply one terawatt of computing power, roughly 50 times what the entire global AI chip industry produces now.
Those chips are meant for Tesla’s Optimus humanoid robots, the Cybercab and Full Self-Driving computers, along with chips for SpaceX’s planned data centers in orbit. Owning the factory means Musk’s companies would not have to compete with every other chip customer for time on someone else’s production lines.
Intel is still part of the picture. The company signed on in April to help design, build and package chips for the project, and CEO Lip-Bu Tan told Bloomberg this week that Intel will keep working on Terafab despite the TSMC chatter.
The project moved from concept to construction planning over the summer. In August, SpaceX confirmed the Grimes County site about an hour from Houston, sent the county a $10 million payment under its tax abatement deal and said civil work would begin shortly. The first phase carries a $16.8 billion price tag, and total spending across all phases could reach as much as $119 billion.
TSMC chairman C.C. Wei has said a new fab typically takes two to three years to build and another one to two years to reach full output. Tesla and SpaceX have never run one, which is why TSMC’s expertise drew so much attention. Musk’s answer suggests he would rather learn that process in house than hand control of a project this central to Tesla’s robotics and autonomy plans to an outside company.
Terafab Texas will be the largest and most valuable building on Earth by far.
And it will be stunningly beautiful. https://t.co/4NweOqTL7y
— Elon Musk (@elonmusk) August 6, 2026
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