LEOs Seen Starting to Blind Radioastronomy Observations

Radioastronomy isn't yet blind in the Ku band, but it's becoming increasingly inaccessible to radioastronomers due to increased satellite downlink traffic there, said Square Kilometer Array (SKA) Observatory Mission Assurance Head Tim Stevenson Thursday on a Satellite Industry Association webinar. Geostationary Ku-band traffic is transitory and “relatively benign,” but OneWeb and SpaceX low earth orbit (LEO) constellations are vastly noisier, he said. Other bands, like V, will surely face similar problems as LEO satellite traffic there grows, he said. Radioastronomy has some ITU protections, but it also uses bands well outside those protected zones, he said. Rather than counting on ITU or national regulations, the SKA and radioastronomy community "want[s] to work with you," Stevenson said. "We know you need to service customers." SKA Spectrum Manager Federico Di Vruno said the scale of the problem makes some mitigation steps that have been used in the past unworkable. He said the aim is to find a way to lower the power flux density over SKA's radio quiet zones in Australia and South Africa. The two SKA telescopes are to be built by 2028.