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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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SpaceX aces Starship test flight 10 with successful payload deployment

The mission began at 6:30 p.m. local time in Starbase, Texas, when the launch of Starship initiated. After about eight minutes, stage separation was completed, and the Super Heavy Booster headed back down to Earth for a planned splashdown in the Indian Ocean:

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Credit: SpaceX

SpaceX aced its tenth Starship test flight on Tuesday night after multiple delays pushed the mission back to this evening. Originally scheduled for Sunday night, SpaceX had two delays push the flight back to Tuesday, which ultimately provided ideal conditions for a launch attempt.

The tenth test flight of Starship had several objectives, including a successful splashdown of the booster in the Gulf of America, the deployment of eight Starlink simulation modules from the PEZ dispenser, and a splashdown of the ship in the Indian Ocean.

SpaceX Starship Flight 10: What to expect

SpaceX successfully achieved all three of these objectives, making it one of the most successful test flights in the Starship program. There was no attempt to catch the booster this evening, as the company had been transparent about it ahead of the launch.

The mission began at 6:30 p.m. local time in Starbase, Texas, when the launch of Starship initiated. After about eight minutes, stage separation was completed, and the Super Heavy Booster headed back down to Earth for a planned splashdown in the Indian Ocean:

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Starship was then the main focus of the rest of the broadcast as it completed its ascent burn and coasted through space, providing viewers with spectacular views as the mission headed toward new territory, including the deployment of Starlink simulators. This would be the first time SpaceX would attempt a payload deployment.

The deployment works like a PEZ dispenser, as the simulators were stacked on top of one another and would exit through a small slit one at a time.

This occurred roughly 20 minutes into the mission:

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An hour and six minutes into the flight, Starship reached its final destination, which was the Indian Ocean. A successful splashdown would bring closure to Starship’s tenth test flight, marking the fifth time a test flight in the program’s history did not end with vehicle loss.

It was also the first of four test flights this year that will end with Starship being recovered.

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SpaceX is expected to launch Starship again in approximately eight weeks, pending the collection of data and other key metrics from this flight.

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WATCH: SpaceX attempts Starship’s tenth test flight after two delays

This evening, SpaceX has already stated that conditions appear to be approximately 45 percent favorable for launch. This is ten percent less than last night, when the mission was eventually scrapped around 7 p.m. local time.

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Credit: SpaceX

SpaceX is set to launch Starship tonight, provided the weather cooperates and everything with the ship goes smoothly.

This is SpaceX’s third attempt to launch Starship for its tenth test flight, with Sunday’s and Monday’s attempts both being scrapped due to a leak and unfavorable weather conditions on the respective days.

This evening, SpaceX has already stated that conditions appear to be approximately 45 percent favorable for launch. This is ten percent less than last night, when the mission was eventually scrapped around 7 p.m. local time.

SpaceX Starship Flight 10: What to expect

Propellant load of the upper stage and Super Heavy booster is already underway, and the launch is expected to occur at 6:30 p.m. in Starbase, Texas.

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You can watch the tenth test flight of Starship below via SpaceX:

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SpaceX calls off Starship 10 flight attempt once again

SpaceX is calling off a potential launch of Starship this evening, marking the second consecutive night the tenth test flight of the massive rocket will be delayed.

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Credit: SpaceX

SpaceX is calling off a potential launch of Starship this evening, marking the second consecutive night the tenth test flight of the massive rocket will be delayed.

Originally planning to launch on Sunday at 6:30 p.m. local time in Starbase, Texas, SpaceX was forced to delay the tenth launch of Starship due to a hardware issue.

“Ground side liquid oxygen leak needs to be fixed. Aiming for another launch attempt tomorrow,” CEO Elon Musk posted on the social media platform X.

Starship Flight 10 rescheduled as SpaceX targets Monday launch

The launch was then pushed to Monday night, and the launch window was set to start at the same time as Sunday. However, SpaceX would push it back to 6:44 p.m. due to some weather issues.

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Eventually, Starship seemed like it was trending toward a launch, but weather continued to persist in the area, with thunder, rain, and lightning all threatening in the area.

At around 7:03 p.m., SpaceX decided to stand down once again, confirming weather was the culprit of yet another delay:

SpaceX will likely try again on Tuesday night, but the company has not yet confirmed if it will open another launch window.

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