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SpaceX is trying to make its satellites less of a nuisance to astronauts by testing ways to prevent Starlink from showing up in space photos. The company recently lowered the altitude of its Internet satellites to reduce their brightness as seen from Earth.
In a a letter at the Federal Communications Commission (FCC), SpaceX revealed that it has begun operating its 300 satellites in low-orbital space as part of the company’s efforts to reduce Starlink’s impact on spaceflight. The company claims that the new method has been successful, resulting in a nearly 60% reduction in the amount of solar radiation seen in images taken by the Vera Rubin Observatory, a telescope in Chile.
Low Earth orbit is increasingly occupied by satellites, many of which belong to SpaceX. There are currently 6,912 Starlink satellites in orbit, which are approximately 342 miles (550 kilometers) above Earth. These orbiting satellites add unwanted noise to the night sky by reflecting sunlight, appearing as streaks in images taken by ground-based observatories. Starlink’s first satellites were very bright, making them visible to the eye and filling the telescope’s lenses pointing in their direction.
In December 2022, the FCC approved SpaceX to launch up to 7,500. next-generation Starlink satelliteswhich are bigger and brighter than their predecessors. The first-generation Starlinks weighed about 573 pounds (260 kilograms), but later versions are heavier at 2,755 pounds (1,250 kg) and are therefore estimated to be significantly lighter than the OG satellites.
SpaceX is partnering with the National Science Foundation (NSF) to reduce the impact of next-generation satellites on space exploration. The company recently lowered the height of its Starlinks display to 217 miles (350 km) above Earth, which reduces their ability to capture and reflect sunlight.
“SpaceX’s analysis also shows that the maximum brightness from the nadir is only slightly increased when operating at a distance of 350 km (217 miles), due to the high eclipse and angular rate,” the company wrote in its letter. In other words, SpaceX says that the light of the satellites, as seen below, does not increase much on the ground because they spend most of the time in the shadow of the Earth and move quickly through space.
NSF agrees that this approach can help. Ground motions “can be beneficial for astronomical and astronomical applications where satellites move faster in the telescope’s focal plane and are less focused, reducing pixel brightness,” an NSF spokesperson told Gizmodo in an email. “At low altitudes, satellites are also blocked by the Earth so they don’t get sunlight for much of the night, not looking down.” This causes the satellites to be smaller than 7th magnitude – the distance visible to the naked eye – for much of the night, the spokesman explained.
There have been previous attempts to limit Starlink’s astronomical observations. SpaceX has been working with the International Astronomical Union, and the Center for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference, to find the main source of the satellites’ illumination and create mitigation measures. As a result, the company has changed the direction of the satellites and their solar arrays, installing visors to reduce their glare.
Recent changes in satellite navigation are still under review as they may have some complications. “There is a trade-off, low-level satellites can be bright at dusk and affect science that requires observation of dusk, such as the study of near-Earth objects,” added the NSF. The foundation will continue to work with SpaceX next year to determine whether the reduction is working as intended.
Not only is SpaceX launching satellites into orbit, but the amount of space debris orbiting the Earth could cloud our view of space unless more companies commit to reducing their space interference.
