7:15 AM | *The latest on the SpaceX Starlink satellite internet constellation following the impact of a geomagnetic storm in early February*
Paul Dorian
Still photograph of the latest deployment of Starlink satellites taken by amateur astronomer, Szabolcs Nagy, in London, England on Friday, February 25th. Courtesy spaceweather.com
Overview
In early February, nearly 40 Starlink satellites fell out of the sky as the result of a minor geomagnetic storm which followed a coronal mass ejection from the sun. The Starlink constellation is designed by SpaceX - the world’s leading provider of launch services - to provide high-speed, low latency internet connectivity to people all over the globe, including in underserved and remote regions. Last Friday, February 25th, SpaceX launched a new batch of Starlink satellites to replace those lost in early February and these went successfully into low-orbit. In the very near future, there are two more scheduled launches of Starlink satellites including one set for later this week, March 3rd and another planned for next Tuesday, March 8th – both from the Kennedy Space Flight Center in Florida.
Space weather information surrounding the launch of Starlink satellites early in February 2022 that were impacted by a geomagnetic storm (Courtesy spaceweather.com)
Discussion
In an effort to provide high-speed, low-latency broadband internet connectivity around the world, SpaceX - the American aerospace company founded by Elon Musk in 2002 - has deployed numerous satellites into extremely low-orbit altitudes relative to industry standards. These satellites are deployed into altitudes of <350 kilometers and then boosted to an operational altitude of about 550 kilometers to start their mission. The reasoning behind the low-orbit deployment and operation of these satellites is the reduced natural orbit decay relative to those that are higher up in the atmosphere. This approach is not without complexity or other challenges as was evidenced by the February 3rd launch of 49 Starlink satellites into low orbit from the Kennedy Space Center in Florida.
According to Dr. Tony Phillips of spaceweather.com, two days before the early February launch, a coronal mass ejection (CME) hit the Earth’s magnetic field. It was by no means a major space event, but it did result in some G1-class geomagnetic storms. It was one of these minor storms that impacted many of the just-deployed Starlink satellites on Friday, February 4th. In fact, 38 of these satellites prematurely deorbited because of the increased drag from the geomagnetic storms. According to SpaceX, onboard GPS devices detected atmospheric drag of up to 50% higher than during previous launches resulting in the de-orbiting of these 38 satellites. SpaceX says that the deorbiting satellites “pose zero collision risk with other satellites and by design demise upon atmospheric reentry—meaning no orbital debris is created and no satellite parts hit the ground.”
Orbital lifetime for a satellite with a mass-to-area ratio of 40 kg/m2 at various starting altitudes and average solar cycle. Plot and data courtesy SpaceX
The replacement Starlink satellites that were launched on Friday, February 25th were captured in a video by an amateur astronomer in London, England some 12 hours into the mission (video courtesy YouTube, spaceweather.com). The amateur astronomer, Szabolcs Nagy, photographed the train of satellites using a telescope and camera from his back yard and inserted an artist’s rendition of a Starlink satellite into the animation. Starlink satellites can be very bright to those on the ground since sunlight reflects off of the broad solar panels which have a reflecting area of more than 30 square meters. In fact, some astronomers have likened the brightness of the Starlink satellites to (undesirable) light pollution and SpaceX has installed “sunblocking visors” to try to mitigate the problem and there is onboard software that can be used to tilt the solar arrays in an effort to reduce glinting.
The first launch of Starlink satellites took place in 2019 and these advanced satellites enable video calls, online gaming, streaming, and other high data rate activities that historically have not been possible with the more conventional satellite internet. According to SpaceX, users can expect to see download speeds between 100 Mb/s and 200 Mb/s and latency (i.e., time spent for the signal to travel from point A to point B) as low as 20 milliseconds in most locations. The Starlink satellite launch schedule shows two more in the very near future including one set for this Thursday, March 3rd, and another planned for next Tuesday, March 8th – both of which will be from the Kennedy Space Flight Center in Florida. One final note, just yesterday, the Pentagon’s Space Development Agency announced its own plans for a next-generation low-latency, high-volume data satellite internet system for the military that will consist of 126 satellites.
Meteorologist Paul Dorian
Arcfield
arcfieldweather.com