AST SpaceMobile’s Large Satellites to Roll and Tilt to Prevent Astronomy Interference

AST SpaceMobile is highlighting how it will ensure that its large satellites do not become a nuisance to astronomers through several changes, including rolling and tilting in space. 

Last week, the cellular satellite provider sent a letter to the FCC about its efforts to prevent the company’s BlueBird satellites from interfering with astronomy. These satellites each boast an exceptionally large 700-square-foot panel, which can reflect sunlight, turning the satellites into some of the most luminous objects in the sky, akin to a bright star.  

In the letter to the FCC, AST says it’s close to reaching a “comprehensive coordination agreement” with the US National Science Foundation for both optical astronomy and radio astronomy. “The parties are in the final stages of approving the agreement,” Texas-based AST SpaceMobile writes.

The document adds that AST has committed to taking several measures, which include “using commercially reasonable efforts to operationally roll or tilt spacecraft to avoid direct illumination of optical telescopes.” 

Another measure involves the satellites incorporating “deployable antenna elements that reduce brightness.” The company has also pledged to share its satellite location data with astronomers, giving them a way to plan their observations ahead of time. 

“AST SpaceMobile will also continue to evaluate ways to mitigate impacts on optical astronomy interests, including physical design changes, attitude maneuvering, maintaining authorized orbital elevations, and providing orbital information to astronomers,” the letter adds.   

AST SpaceMobile didn’t immediately respond to a request for comment. But in a statement, NSF said it’s “in the process of coordinating with AST SpaceMobile [and will] share more information when coordination is complete.”

So it’s unclear how AST plans to roll and tilt its satellites, and what other design changes may be in store. But the FCC made the NSF coordination a condition to granting partial approval to AST operating its satellite constellation. The startup envisions one day operating dozens of BlueBird satellites in orbit, capable of beaming internet data to phones on the ground. But astronomers have been worrying about the brightness of the company’s satellites, especially since they could proliferate and disrupt telescopic observations.  

In the meantime, AST’s first batch of BlueBird satellites were sent into Earth’s orbit in September. Over a month later, all five satellites unfolded their antenna arrays. AST is now waiting for FCC approval so that it can start testing the satellites with phones on the ground.

About Michael Kan

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