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.
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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.
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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.
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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
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Just hours after Starship Flight 13 achieved a successful soft splashdown of its upper stage in the Indian Ocean on July 24, Elon Musk announced an ambitious next step for the company’s next launch of the rocket.
“Unless we discover problems after mission data review, SpaceX will attempt to catch the ship with the tower on [the] next flight,” the SpaceX CEO posted on X on Friday.
That “next flight” is expected to be Flight 14. The plan involves returning the Starship upper stage, commonly called the “ship,” to the Starbase launch tower in Texas and catching it mid-air using the same mechanical “chopsticks” arms that have already proven themselves with the Super Heavy booster.
Unless we discover problems after mission data review, SpaceX will attempt to catch the ship with the tower on next flight
— Elon Musk (@elonmusk) July 25, 2026
A successful catch would mark the first time an orbital-class upper stage has been recovered this way, advancing SpaceX’s goal of full and rapid reusability for the entire vehicle.
SpaceX has already demonstrated the tower-catch technique multiple times with Super Heavy. The first successful catch came on Flight 5 in October 2024, when Booster 12 was plucked from the sky by the Mechazilla arms. Subsequent flights, including those involving Boosters 14 and 15, repeated the feat. Several of those recovered boosters were later inspected, refurbished, and flown again, proving the system’s viability for quick turnaround.
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Traditional reusable rockets, such as SpaceX’s own Falcon 9 or Blue Origin’s New Shepard, land on legs either on land or droneships. Rocket Lab has recovered its small Electron first stages by helicopter, but those are far lighter vehicles.
SpaceX Starship just nailed something it’s never done before
The China Academy of Launch Vehicle Technology (CALT), a subsidiary of the China Aerospace Science and Technology Corp. (CASC), completed a catch of its booster on July 10. They are the only entity besides SpaceX to attempt and complete the feat.
Flight 13 provided encouraging data. The ship executed a controlled reentry, flipped, and soft-landed intact in the ocean after deploying Starlink satellites, offering the first clear post-splashdown views of an undamaged heat shield. The Super Heavy booster, meanwhile, experienced a harder splashdown in the Gulf of Mexico.
Musk has previously stressed that ship catches would only follow multiple successful soft ocean landings to minimize risk of debris over land.
If Flight 14 succeeds, SpaceX would take a major stride toward routine, rapid reuse of both stages—critical for lowering launch costs and supporting ambitious plans for lunar and Mars missions. For now, teams are reviewing the Flight 13 data. Should everything check out, the next Starship flight could deliver one of the most spectacular recoveries in aerospace history.
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Elon Musk
SpaceX Starship just nailed something it’s never done before
SpaceX’s Starship flew successfully Friday, landing both stages and deploying its first Starlink V3 satellites.
Starship’s thirteenth test flight delivered exactly what SpaceX needed with a clean liftoff, two successful stage recoveries, and the first real payload the vehicle has ever carried to space. Booster 20 and Ship 40 lifted off at 5:51 p.m. CT from Starbase, and by the time the mission wrapped roughly an hour later, both halves of the rocket had done exactly what they were supposed to do.
Booster 20 separated from Ship 40 a few minutes into the flight and stuck a controlled splashdown in the Gulf of Mexico about six minutes after liftoff. That is a meaningful turnaround from Flight 12 in May, when the booster lost several engines during its boostback burn before a hard water landing attempt.
Starship as seen from Starlink satellites pic.twitter.com/e2hvfmnewh
— Elon Musk (@elonmusk) July 25, 2026
Starship 40’s performance was arguably the bigger win. The vehicle deployed the first 20 operational Starlink V3 satellites Starship has ever carried, then flew a suborbital arc to a landing in the Indian Ocean that SpaceX commentator Dan Huot called the company’s softest splashdown yet. “This is a dream scenario for this team that’s trying to get this heat shield data,” Huot said on the live broadcast, according to Space.com’s live coverage. “I’m a little over the moon right now. Wow. Lucky number 13.”
Unlike the mass simulators SpaceX flew on Flight 12, these were production Starlink V3 satellites, meant to extend solar arrays and antennas and attempt to link with the broader constellation before reentering minutes later. Getting real hardware through a full deploy sequence on only the second flight of the V3 generation keeps Starship on schedule for the payload work NASA is counting on for future Artemis lunar landings.
What an awesome launch, really seems like everything went super well and it was all incredibly smooth.
SpaceX is awesome. Very interested to see how the market will respond on Monday pic.twitter.com/KSHmyBfV55
— TESLARATI (@Teslarati) July 25, 2026
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— TESLARATI (@Teslarati) July 25, 2026
The flight also arrives at a moment when SpaceX needed a win. SPCX has traded below its $135 IPO price since mid-July, as Teslarati reported when the mission slipped to Friday, and short interest has climbed to roughly a third of the tradable float. A clean flight will not fix a balance sheet, but it does answer the one question SpaceX absolutely needed answered this week: whether the fixes made after the July 16 abort would hold up under real flight conditions. They did, on both stages, on the first try after the redesign.
SpaceX has not set a target date for Flight 14, though the company has said it wants to push toward an orbital attempt on the next mission. After Friday, that goal looks a lot more within reach.
Elon Musk
Elon Musk handed Grok something no other AI company can get their hands on
Elon Musk says SpaceX will feed engineering data into Grok’s next model, avoiding restricted material.
Elon Musk said Tuesday that SpaceX will feed its internal engineering data into the next major training run for Grok, the AI model now folded into SpaceX following February’s merger. In a post on X, Musk wrote that SpaceX’s “massive corpus of world-class engineering data,” excluding anything restricted under U.S. arms export law, will be added during supplemental training of what he called the “2T run,” a reference to a roughly two trillion parameter model that would nearly double the parameters behind the latest Grok 4.5 that’s rolling out.
SpaceX’s massive corpus of world-class engineering data (excluding material blocked by ITAR) will be added during supplemental training of the 2T run.
This will dramatically improve Grok’s engineering capabilities. https://t.co/BbQEViFByn
— Elon Musk (@elonmusk) July 21, 2026
The excluded material that Musk is referring to would fall under the International Traffic in Arms Regulations (ITAR), which restricts export of technical data tied to defense and space hardware. That likely rules out propulsion specifics for Merlin and Raptor engines along with guidance and control details for SpaceX’s launch vehicles, but leaves manufacturing knowledge, materials science, and Starlink hardware design on the table.
The announcement extends a pattern that has been building since SpaceX’s Nasdaq debut in June, when the company went public with Grok and xAI’s Colossus supercomputer folded into the pitch to investors.
Days after that listing, SpaceX closed its $60 billion all stock acquisition of coding startup Cursor, giving xAI both enterprise software distribution and a stream of real world developer data to train on. Grok 4.5 launched July 8 running partly on that Cursor training data, with Musk describing it as roughly comparable to Anthropic’s Opus 4.7 but faster and cheaper to run.
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Feeding SpaceX’s own engineering data into the next AI model follows the same logic Musk has applied across xAI’s sister companies. Tesla supplies real world driving data and manufacturing expertise, X supplies conversational data, and now SpaceX supplies aerospace engineering data built up since 2002.
Musk did not give a release date for the upcoming AI model, referred to elsewhere as Grok 4.6. He has said the two trillion parameter run is in its final training phase and expected to wrap this week.
SpaceX wants to catch Starship for launch 14, Elon Musk says
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