SpaceX signed an agreement with the National Science Foundation (NSF) to have its Starlink constellation avoid interfering with astronomical readings. The agreement covers Starlink’s radio transmissions, especially the 10.6 – 10.7 GHz radio band often used by telescopes.
NSF and SpaceX already had an agreement to have Starlink meet international radio astronomy protection standards for that band. The agreement also complied with the terms of a license that the FCC granted for launch of Starlink’s first-generation satellites.
This new agreement updates the understanding between the NSF and SpaceX for the new second-generation Starlink satellites.
These satellites are more capable and might even add the capacity for laser-based communications. As part of the deal with the NSF, SpaceX will study the laser communications’ impact on astronomical readings.
Plans for mitigating interference with ground-based astronomy include dielectric mirror film, solar array mitigations, new black paint that minimizes brightness and glints, and best practices during flight operations. The agreement also calls for the sharing of orbital data so that astronomers can plan their observations with minimal interference from the low-orbiting satellites.
SpaceX will coordinate with the NSF’s Office of Polar Programs to mitigate Starlink’s impact on radio astronomy-related operations at the NSF’s polar posts. NOIRLab will serve as a point of contact for technical communications between NSF and SpaceX.
SpaceX currently has 3,500 Starlink satellites in orbit. The new agreement between NSF and SpaceX may not affect satellites already in orbit beyond making small adjustments to their orbits using their collision avoidance systems. However, the agreement includes provisions for communications between NSF and SpaceX if interference occurs or unforeseen challenges might cause Starlink to interfere with astronomical observations.
Some skywatchers have gotten pictures of strings of the satellites as they passed overhead, indicating that they can be bright enough to be easily spotted from the ground. Like many satellites that aren’t in a geosynchronous orbit, they can show up as rapidly moving specks of light.
Starlink has occasionally been the topic of regulatory challenges on environmental grounds. Competitors questioned whether SpaceX really needs to launch that many satellites, which could clutter up low-Earth orbit.
However, these competitors do not seem to have bothered negotiating with organizations like the NSF to ensure that their satellites do not interfere with science operations. Some of them even come off as far more inconsiderate than SpaceX has been even with its plan to launch tens of thousands of Starlink satellites. The International Astronomical Union (IAU) says AST SpaceMobile’s BlueWalker 3 test satellite is one of the brightest objects in the sky, which could fake out astronomers. BlueWalker 3 has a highly reflective 693-foot communication array. A statement from the IAU expressed concern about AST SpaceMobile’s plan to launch dozens of similar satellites.
Despite the environmental concerns, Starlink provides Internet access to more than 600,000 locations and still has a long list of potential customers who are awaiting their Starlink kit. (Apparently, SpaceX can only manufacture them so fast.) SpaceX has marketed it as a way for populations who lack access to affordable, reliable high-speed Internet to get up to speed and backed that up by making a few deals with national or local government entities to provide Internet access to low-income or isolated communities.