Featured Image Source: SpaceX
SpaceX plans to fund future missions to the moon and Mars by offering Starlink internet services. SpaceX officials stated that Starlink broadband internet network will be affordable enough that areas in the world where internet is non-existent, or unreliable will benefit from their service. The company is in the process of building the Starlink constellation consisting of approximately 1,584 internet-beaming satellites in low Earth orbit, they have approval from the Federal Communications Commission (FCC) to operate as many as 12,000 satellites. Currently there are a total of 290 satellites in low Earth orbit. This year, deployments are scheduled for approximately twice a month, each Falcon 9 rocket launch deploys a batch of 60 satellites. A total of 60 satellites would be capable of supporting 40,000 Starlink broadband internet users streaming ultra-high-definition content at once. SpaceX officials said it will take about 400 satellites to establish "minor" internet coverage and 800 satellites for "moderate" or "significant operational" coverag SpaceX plans to roll-out service in parts of Northern United States and Canada before the year ends. The initial plan is to deploy the first 1,584 satellites into 72 orbital planes around earth consisting of 22 satellites each (pictured below). The Starlink constellation will be deployed into three orbital shells with operational altitudes of 340 kilometers, 550 kilometers and 1,150 kilometers.
Image Source: Wikipedia
According to online satellite tracker SatView.org, it appears SpaceX intentionally deorbited a Starlink satellite. The satellite that appears to have lowered it's altitude to burn into Earth's atmosphere is known as Starlink-46, which was deployed in May 2019. SpaceX launched the first 60 satellites of the constellation in May last year into a 450 kilometer orbit.
It is still not confirmed if SpaceX intentionally deorbited the satellite but its likely that the company tested out the satellite's controllability features at low altitudes, according to Harvard-Smithsonian Astronomer Jonathan McDowell.
Satellite tracking data shows that on February 20. Starlink-46 was in orbit at an altitude of 164 x 184 kilometers, data suggests the satellite reentered Earth's atmosphere late day. SatView.org tracking stated:
"The STARLINK-46 satellite reentered the atmosphere Feb/20/2020 at 17:43 UTC with an approximate error of +/- 95 minutes."
Starlink-46 was lowered in altitude, If the satellite did reenter, it will be the first Starlink unit to lower its altitude for reentry. It is still unknown where the satellite is, McDowell said via Twitter:
"We don't currently have a specific reentry time for Starlink 46, so we don't know *where* it reentered. It's not entirely clear whether it was deorbited over a specific location or just lowered enough that it decayed uncontrolled."
We don't currently have a specific reentry time for Starlink 46, so we don't know *where* it reentered. It's not entirely clear whether it was deorbited over a specific location or just lowered enough that it decayed uncontrolled.— Jonathan McDowell (@planet4589) February 22, 2020
SpaceX designed its satellites to have a lifespan of 1 to 5 years, they plan to intentionally deorbit old satellites so they could completely burn up into Earth's atmosphere, this feature avoids contributing to space junk. This way, they could continually upgrade the satellite constellation by deploying new satellites to replace the old ones as years go by. Each satellite is equipped by ion thrusters powered by krypton which allow each to adjust into orbit. It is probable (not confirmed) that SpaceX tested the thrusters adjusting capabilities with the Starlink-46 satellite to see if the feature is working at optimal levels.