SpaceX has received approval from the Federal Communications Commission to halve the orbital level of more than 1,500 planned broadband satellites to reduce space debris and improve latency.
SpaceX's satellite project, Starlink, aims to provide high-latency and low-latency broadband worldwide. Commenting on the new FCC approval, SpaceX said, "Starlink production is in full swing and the first group of satellites has arrived at the launch site for clearance."
SpaceX received FCC approval last year for launching 4,425 Earth orbiting satellites at various altitudes ranging from 1
As part of its Plan to Prevent Space Debris, SpaceX later asked for permission to operate 1,584 km of these satellites at an altitude of 550 km instead of the previous one. The FCC approved the motion in a ruling on Friday, but pointed out that SpaceX still needs to submit a detailed debt relief plan for the rest of the satellites.
"Given the atmospheric drag at this lower elevation, this shift will greatly enhance the site's safety by ensuring that orbital debris can quickly re-enter the atmosphere and die off," SpaceX said in its November 2011 amendment to the license ,
At the lower altitude, "the orbital debris will rapidly reentry and sink atmospheric, even in the unlikely event that a spacecraft fails in orbit." (SpaceX develops its satellites so that they are completely burned to atmospheric during atmospheric reentry prevent physical damage from falling objects.)
Satellites orbiting at 1,150 km will take "hundreds of years to get into the Earth's atmosphere," but a SpaceX satellite will take less than five years (even under the least favorable assumptions) when it starts at an altitude of 550 km, "the company said.
The lower altitude will give broadband users an advantage, SpaceX said. "Being so close to Earth, SpaceX would also reduce the latency of its communication signals to as much as 15 milliseconds, at which time it would almost go unnoticed by almost all users," the company said. (According to SpaceX, the latency at a height of 1,150 km is 25ms to 35ms.)
Low Altitude Compromise
However, using a lower altitude has disadvantages.
"The Same Atmospheric Load Helps" To clean the orbit of debris, satellites also have to work harder to stay in orbit, "wrote SpaceX." When in the air, the satellite must be able to overcome more atmospheric drag , In addition, satellites operating at low altitude see less of the earth and need more satellites to service a particular area. "
SpaceX said it had done tests that show it does. It can do this Solving Problems SpaceX said it intends to "work at this altitude", also because of feedback from its experimental satellites, who have extensively tested SpaceX's capabilities to work in the lower 500km range, so SpaceX has learned "Reducing the downsides of operating a lower altitude and still the known and significant benefits."
SpaceX also plans to reduce the number of satellites in the low-orbit constellation from 4,425 to 4,409. The planned circulation levels of the remaining 4,409 satellites were not changed. As part of its FCC approval, SpaceX will have to launch at least half of these satellites by March 29, 2024 and the remainder by March 29, 2027.
The FCC stated that SpaceX's planned debris mitigation plan for the 1584 satellites that are subject to the US aviation satellite is met with altitude change. SpaceX, however, has to come up with a more detailed plan for the rest of the satellites.
"Although we find that the orbital facility orbit reduction plan is sufficient for the space stations proposed by SpaceX, SpaceX has no new information on the schedules for reducing the orbit of debris for the other satellites in their proposed system," said the FCC. "SpaceX has only partially met the condition for its approvals, which requires SpaceX to submit an updated plan to reduce debris orbit before commissioning the service."
The new altitude of 550 km is not the lowest that SpaceX wants to use for its broadband service. SpaceX received a separate license in November 2018 for the deployment of 7,518 broadband satellites at altitudes of 335 km to 346 km. These lower satellites are designed to increase capacity and reduce latency in heavily populated areas. Overall, SpaceX has been approved by the FCC for the launch of nearly 12,000 broadband satellites.