SpaceX believes that this change will make the space environment safer, because it is easier to get rid of these satellites in Earth orbit at this new altitude when they are underfueled or cannot function properly in orbit. This update also explains why the orbit of the two test satellites of SpaceX is still lower than expected.
As early as March, the Federal Communications Commission approved the first phase of SpaceX's ambitious Starlink program. The company's long-term plan is to put nearly 12,000 satellites into orbit to extend Internet coverage to Earth. Initially, SpaceX asked the Federal Communications Commission to allow 4425 satellites to be launched into orbit between 1100 and 1325 kilometers high. However, with this new application, SpaceX requires 1584 satellites to be allowed to operate at 550 kilometres, which should have been running at 1110 kilometres.
SpaceX said moving the satellite to a lower altitude means that it can do more things with less. Initially, the company said it needed 1,600 satellites to operate at an altitude of 1,110 kilometers, but lowering their altitude meant that the company could reduce 16 satellites to achieve the same coverage effect. Lower altitudes made it easy to dispose of these satellites when they completed their missions in space. At this altitude, particles from the Earth's atmosphere bombard satellites faster, push them out of orbit and tow them to Earth and burn them up in the atmosphere.
Because the SpaceX program requires a large number of satellites to enter orbit, it is essential to ensure that these satellites reach or leave orbit in time after completing their missions. Plans like Starlink can greatly increase the number of satellites operating in space, thereby increasing the risk of space collisions. According to a recent NASA study, 99% of these satellites need to be reliably brought out of orbit within five years of launch, otherwise the risk of satellite collision will be considerable.