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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.

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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

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.

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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.

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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.

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.

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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.

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

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“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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Elon Musk

SpaceX to decommission Dragon spacecraft in response to Pres. Trump war of words with Elon Musk

Elon Musk says SpaceX will decommission Dragon as a result of President Trump’s threat to end his subsidies and government contracts.

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SpaceX will decommission its Dragon spacecraft in response to the intense war of words that President Trump and CEO Elon Musk have entered on various social media platforms today.

President Trump and Musk, who was once considered a right-hand man to Trump, have entered a vicious war of words on Thursday. The issues stem from Musk’s disagreement with the “Big Beautiful Bill,” which will increase the U.S. federal deficit, the Tesla and SpaceX frontman says.

How Tesla could benefit from the ‘Big Beautiful Bill’ that axes EV subsidies

The insults and threats have been brutal, as Trump has said he doesn’t know if he’ll respect Musk again, and Musk has even stated that the President would not have won the election in November if it were not for him.

President Trump then said later in the day that:

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“The easiest way to save money in our Budget, Billions and Billions of Dollars, is to terminate Elon’s Government Subsidies and Contracts. I was always surprised that Biden didn’t do it!”

Musk’s response was simple: he will decommission the SpaceX capsule responsible for transporting crew and cargo to the International Space Station (ISS): Dragon.

Dragon has completed 51 missions, 46 of which have been to the ISS. It is capable of carrying up to 7 passengers to and from Earth’s orbit. It is the only spacecraft that is capable of returning vast amounts of cargo to Earth. It is also the first private spacecraft to take humans to the ISS.

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The most notable mission Dragon completed is one of its most recent, as SpaceX brought NASA astronauts Butch Wilmore and Suni Williams back to Earth after being stranded at the ISS by a Boeing Starliner capsule.

SpaceX’s reluctance to participate in federally funded projects may put the government in a strange position. It will look to bring Boeing back in to take a majority of these projects, but there might be some reluctance based on the Starliner mishap with Wilmore and Williams.

SpaceX bails out Boeing and employees are reportedly ‘humiliated’

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SpaceX hit with mishap investigation by FAA for Starship Flight 9

Starship’s ninth test flight has the FAA requiring a mishap investigation from SpaceX.

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Credit: SpaceX

SpaceX has been hit with yet another mishap investigation by the Federal Aviation Administration (FAA) related to the company’s ninth test flight of Starship earlier this week.

The FAA said the mishap investigation is “focused only on the loss of the Starship vehicle, which did not complete its launch or reentry as planned.” The agency said the loss of the Super Heavy booster is covered by one of the FAA’s approved test induced damage exceptions requested by SpaceX.

All of Starship and Super Heavy booster debris landed within the designated hazard areas, the FAA confirmed.

SpaceX Starship Flight 9 recap: objectives & outcomes

It said it activated a Debris Response Area out of an abundance of caution as the booster “experienced its anomaly over the Gulf of America during its flyback toward Texas. The FAA subsequently determined the debris did not fall outside of the hazard area. During the event there were zero departure delays, one flight was diverted, and one airborne flight was held for 24 minutes. ”

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SpaceX has become accustomed to mishap investigations by the FAA, as they have been impacted by them on several occasions in the past, including on Flight 8. However, they are a precautionary measure and usually are resolved within a few weeks.

Flight 9 was one of SpaceX’s most eventful, as there were several discoveries during the launch. First, it was SpaceX’s first time reusing a Super Heavy booster, as the one utilized for Flight 9 was also used on Flight 7 in January.

Contact with the booster and Starship were both lost during Flight 9. SpaceX said the booster was lost “shortly after the start of landing burn when it experienced a rapid unscheduled disassembly approximately 6 minutes after launch.”

Meanwhile, Starship was set to make a splashdown in the Indian Ocean, but the vehicle was lost about 46 minutes into the flight, SpaceX said in a mission recap.

It was an improvement from the previous two flights, as both 7 and 8 resulted in the loss of Starship after just a few minutes. Flight 9 lasted considerably longer. These flights are also not intended to make it to Mars, despite what other reports might try to tell you.

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These are ways to gain information for when SpaceX eventually tries to get Starship to Mars.

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Elon Musk

SpaceX Starship gets FAA nod for ninth test flight

The FAA has given the green light for Starship’s ninth test flight.

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(Credit: SpaceX)

SpaceX has received FAA approval for the ninth test flight of the Starship rocket. The approval was delayed due to the federal agency finishing its comprehensive safety review of the eighth flight earlier this year.

The FAA said in a statement that it has determined that SpaceX has “satisfactorily addressed the causes of the mishap, and therefore, the Starship vehicle can return to flight.”

The eighth test flight occurred back on March 6. SpaceX completed a successful liftoff of Starship and the Super Heavy Booster, before the two entered stage separation a few minutes after launch.

Starship Flight 8: SpaceX nails Super Heavy booster catch but loses upper stage

The booster returned and was caught by the chopsticks on the launch pad, completing the second successful booster catch in the program’s history. However, SpaceX lost contact with Starship in the upper atmosphere.

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The ship broke up and reentered the atmosphere over Florida and the Bahamas.

The debris situation caused the FAA to initiate a mishap investigation:

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The FAA said it will verify that SpaceX implements all the corrective actions on Flight 9 that it discovered during the mishap investigation.

There is no current confirmed launch window, but the earliest it could take off from Starbase is Tuesday, May 27, at 6:30 p.m. local time.

To prevent any injuries and potentially limit any damage, the FAA has stayed in contact with various countries that could be impacted if another loss of vehicle occurs:

“The FAA is in close contact and collaboration with the United Kingdom, Turks & Caicos Islands, Bahamas, Mexico, and Cuba as the agency continues to monitor SpaceX’s compliance with all public safety and other regulatory requirements.”

The agency has also stated that the Aircraft Hazard Area (AHA) is approximately 1,600 nautical miles and extends eastward from the Starbase, Texas, launch site through the Straits of Florida, including the Bahamas and Turks & Caicos.

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For flight 8, the AHA was just 885 nautical miles.

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