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
News
SpaceX adjusts Starship Flight 13 test launch target date once again
SpaceX has updated its target for the thirteenth integrated flight test of Starship, aiming for as early as Thursday, July 23. The 90-minute launch window opens at 5:45 p.m. CT from the company’s Starbase facility in South Texas.
The target flight was initially rescheduled for today, but SpaceX pushed it back again.
This latest adjustment follows an aborted attempt earlier in the week and reflects the iterative, rapid-development approach that has defined the Starship program. With the vehicle already stacked and ground teams making final preparations, the mission represents another step toward proving the full reusability of the world’s most powerful rocket system.
Now targeting to launch Starship’s thirteenth flight test as early as Thursday, July 23 → https://t.co/Rp7VwBzpWx pic.twitter.com/Y0YNzfc5zk
— SpaceX (@SpaceX) July 19, 2026
The original launch attempt on July 16 was scrubbed at T-0 when several Raptor engines on the Super Heavy booster failed to ignite properly. The automatic abort system triggered just as the engines began their startup sequence, preventing liftoff.
SpaceX CEO Elon Musk confirmed that some engines did not start as expected, prompting the decision to replace two Raptors on Booster 20 to ensure reliability. The issue occurred despite a successful full-duration static fire earlier, highlighting the complexities of coordinating 33 engines under flight conditions.
This cautious approach underscores SpaceX’s commitment to safety amid an aggressive test cadence.
Flight 13 builds directly on the lessons from Flight 12 in May 2026. The Super Heavy booster’s primary goals include a successful liftoff, ascent, stage separation, boostback burn, and controlled splashdown in the Gulf of America.
Hardware and software modifications address the off-nominal flip and boostback burn problems from the prior flight, where propellant slosh and engine relight issues led to an uncontrolled impact.
For the Starship upper stage, objectives include deploying 20 operational Starlink V3 satellites, the first real payload of this type, performing a single Raptor engine relight in space, and executing a controlled entry, descent, and splashdown in the Indian Ocean. Propulsion upgrades aim to improve engine-out capability after one vacuum Raptor was lost on Flight 12.
Additional test elements focus on heat shield performance. Six satellites carry cameras to image the tiles during flight, while white-painted tiles and upgraded attachments on flaps and the aft skirt will gather data for future reusability.
The FAA completed its mishap investigation into Flight 12 earlier this month, clearing the regulatory path.
This suborbital mission, the second with V3 vehicles, advances Starship toward operational missions, including potential crewed flights and support for NASA’s Artemis program. Success would mark significant progress in rapid reusability and satellite deployment from the massive system.
News
Elon Musk debunks $52 billion SpaceX-NVIDIA GPU deal
Elon Musk dismissed reports claiming SpaceX had placed a massive order for NVIDIA GPUs worth $52 billion. The denial came hours after Taiwanese media, citing unnamed industry sources, reported that SpaceX planned to acquire approximately 13,000 AI server racks, equating to roughly 1 million GB300 GPUs, from Foxconn.
Each rack was estimated at around $4 million, with deliveries potentially starting in late 2025.
The story suggested this would mark SpaceX’s first major foray into Foxconn-manufactured NVIDIA hardware, breaking from suppliers like Supermicro and Dell. Musk responded bluntly on X:
This is fake news
— Elon Musk (@elonmusk) July 20, 2026
Despite the denial, the rumored scale aligns with SpaceX’s explosive growth in AI infrastructure. NVIDIA’s GB300 (successor to the GB200 NVL) racks deliver unprecedented performance for large-scale training and inference. A $52 billion commitment would dwarf most corporate AI budgets and provide the compute muscle needed for frontier models.
SpaceX already operates gigawatt-scale terrestrial clusters like Colossus in Memphis, Tennessee, and has monetized them aggressively through leasing deals.
SpaceX’s newest Starmind will make earth data centers obsolete
Major customers include Anthropic (paying ~$1.25 billion monthly for 220,000+ GPUs), Google (~$920 million monthly for 110,000 GPUs), and Reflection AI. These arrangements are projected to generate tens of billions in annual revenue, far outpacing traditional SpaceX businesses.
Such an investment would fuel internal AI efforts, particularly Grok models under the integrated SpaceXAI division, while supporting ambitious orbital data center plans. SpaceX envisions launching thousands of AI-optimized satellites powered by solar energy and cooled in space, bypassing terrestrial power and land constraints.
This “Starmind” constellation could position the company as a leader in space-based computing.
SpaceX as an Emerging AI Powerhouse
Once primarily known for reusable rockets and Starlink satellite internet, SpaceX has transformed into a multifaceted AI player.
The 2026 acquisition of xAI integrated Grok development directly into the company. Starlink’s low-latency global network complements massive compute clusters, enabling efficient data flow for training and serving AI models.
Musk has long argued that AI scaling demands solutions beyond Earth, citing things like real estate and electricity limits on the ground.
While the Foxconn deal may not be in the cards, SpaceX’s trajectory is continuing on the path of blending aerospace engineering with hyperscale AI to dominate both launches and intelligence infrastructure.
Elon Musk
SpaceX announces new Starship 13 test flight target date
SpaceX has announced a new target date for the thirteenth test flight of Starship: Monday, July 20, with the launch window opening at 6:45 p.m ET/5:45 p.m. CT.
This is the first rescheduling attempt of Starship’s 13th test flight. It was set to launch last night, but SpaceX scrubbed the launch attempt.
🚨 SpaceX is now looking at Monday, July 20th at 6:45 p.m ET/5:45 p.m. CT for the 13th test flight of Starship pic.twitter.com/7s8aMJV5Ge
— TESLARATI (@Teslarati) July 17, 2026
CEO Elon Musk revealed that some of the engines on Starship did not start, which automatically triggers a launch abort. Two of the Raptor engines will be removed and replaced.
To be confident of a good flight, 2 Raptors will be removed & replaced. Most probable launch timing is early next week.
— Elon Musk (@elonmusk) July 17, 2026
SpaceX officially announced the new launch window this morning.
Starship’s 13th test launch comes with a few new objectives, but SpaceX does not plan to attempt a catch of the booster, which it has done several times in the past.
For Starship’s Upper Stage, there are some adjustments to ensure engine reusability that will be assessed during the ascent, and 20 operational Starlink V3 satellites are also set to make their way into space. SpaceX also plans to attempt an in-space relight of a single Raptor engine, which is a critical demonstration for future orbital deorbit, refueling, and deep space maneuvers.
Ultimately, it will splash down in the Indian Ocean.
The continuous tests help SpaceX advance the Starship program toward eventual full reusability, operational Starlink V3 deployment, and future missions, which include NASA’s Artemis program.