Title: SpaceX Tackles Starlink's Impact on Telescope Images with Lower Orbit Tests
SpaceX is taking strides to minimize the impact of its Starlink satellites on astronomers' work by testing various methods. Recently, the company lowered the altitude of a batch of its internet satellites to decrease their brightness as observed from Earth. This adjustment led to a nearly 60% decrease in the number of illuminated satellites appearing in images captured by the Vera Rubin Observatory, located in Chile.
In a letter to the Federal Communications Commission (FCC), SpaceX shared that it started operating 300 of its satellites at a lower orbital altitude as part of its initiative to reduce Starlink's impact on optical astronomy. The company reported success with this method, as evidenced by the significant decrease in satellite brightness in agricultural images.
The increasing litter of satellites in low Earth orbit is a cause for concern, with a majority belonging to SpaceX. Currently, there are 6,912 Starlink satellites orbiting at an altitude of 342 miles (550 kilometers) above Earth's surface. These orbiting satellites generate unwanted noise in astronomical observations as they reflect sunlight, appearing as streaks in images captured by ground-based observatories.
The FCC granted SpaceX approval to launch up to 7,500 next-generation Starlink satellites, which are larger and brighter than their predecessors. These new satellites are estimated to be a full magnitude brighter than the original Starlink satellites, weighing about 2,755 pounds (1,250 kg).
SpaceX is collaborating with the National Science Foundation (NSF) to lessen the impact of its next-generation satellites on optical astronomy. To achieve this, SpaceX has lowered the altitude of its demo Starlinks to 217 miles (350 km) above Earth's surface, which reduces their ability to catch and reflect sunlight.
The NSF agrees that this strategy could be beneficial. By reducing the orbital altitude, satellites will move faster across the sky, reducing overall brightness per pixel. Additionally, satellites will remain out of sunlight for longer portions of the night, allowing them to remain dimmer than the 7th magnitude threshold for visibility to the naked eye on most nights.
SpaceX and the NSF have been implementing various strategies to reduce Starlink's impact on astronomical observations. This includes lowering satellite orbits, applying anti-reflective coatings, adjusting satellite orientations, developing radio frequency interference (RFI) mitigation techniques, coordinating with the astronomical community, and designing future telescopes to work alongside low Earth orbit satellites.
While these strategies aim to minimize the impact of Starlink satellites, the scale of the constellation remains a concern for the scientific community. SpaceX is actively working to address these concerns and keep the astronomy community engaged in its efforts.
In the future, SpaceX and the NSF plan to further lower the altitude of Starlink satellites to reduce their brightness, potentially allowing them to remain below the 7th magnitude threshold for nighttime visibility. Embracing advanced technology and science, SpaceX is also exploring the use of anti-reflective coatings and adjusting satellite orientations to mitigate their impact on astronomical observations.
