Astronomers are searching for solutions to the man-made “constellations” of satellites from SpaceX’s Starlink and Amazon’s Project Kuiper that they say are interfering with their work. Scientific American reports:
Finally, in August — after more than a year of complaints from the scientific community and damage-control efforts from SpaceX — the National Science Foundation and the American Astronomical Society released a report on the situation. It drew from discussions among more than 250 experts at the virtual Satellite Constellations 1 (SATCON1) workshop earlier this summer to provide recommendations for both astronomers and satellite constellation operators in order to minimize further disruptions…
SpaceX’s initial efforts at mitigating the spacecraft’s impact involved launching a prototype Starlink satellite known as DarkSat earlier this year that features a black antireflective coating. Recent ground-based observations of DarkSat in orbit found it half as bright as a standard Starlink satellite — a great improvement, according to experts, but still far from what astronomers say is needed… While the dimming techniques tested by DarkSat are far from a sufficient solution, SpaceX has continued to develop other ways to further reduce spacecraft brightness. The company’s second attempt at a darkened satellite, VisorSat, uses a black sunshade to reduce light reflection. The first spacecraft with this design was launched on June 3. Astronomers are hoping to observe VisorSat and compare it with DarkSat once observatories reopen, following the COVID-19 shutdown. Even before any detailed observations of VisorSat have been made, SpaceX seems to have doubled down on the new model. All the satellites in the two Starlink batches launched in mid-June and early August were VisorSats, with each carrying its own sunshade.
Astronomers are not yet sure whether darkening methods such as DarkSat and VisorSat are the solution. Of the SATCON1 report’s 10 recommendations, only one asks satellite operators to use darkening techniques. The others suggest deploying satellites in orbits below 600 kilometers to minimize their nighttime glare, controlling their orientations in space to reflect less sunlight, developing ways to remove their trails from astronomical observations and making their orbital information available so astronomers can point telescopes away from them. By some mix of approaches from this menu of options, it is hoped, the problem can be managed. Even so, the advent of satellite megaconstellations may have made further degradation of astronomers’ view of the night sky inevitable.
It’s a problem that’s only going to accelerate, argues one astronomer at the University of Washington — adding that it’s also a question of precedent. “It’s a question of what kind of sky you want your grandkids to have.”
of this story at Slashdot.
Source:: Slashdot