A new study highlights the need for better space weather observations and forecasts for the emerging commercial spacecraft industry. | Bot To News

NOAA, satellite industry leaders identify solutions after a geomagnetic storm caused the total loss of 38 Starlink satellites in February

November 15, 2022: Flares from the sun’s surface are common, occurring on average 2-3 times a day during the most active period of the 11-year sunspot cycle. Most of these eruptions are not directed towards Earth. Those that are directed at Earth can create disturbances in Earth’s magnetic field or geomagnetic storms. These storms produce impressive Northern Lights, but can also cause significant disruption to critical infrastructure.

Home of the nation’s official civilian space weather forecasters, NOAA’s Space Weather Prediction Center (SWPC) issues real-time warnings and alerts to help customers mitigate impacts to the power grid, satellites , airlines, telecommunication networks, navigation systems (including GPS) and pipelines. The biggest concern for many customers is extreme geomagnetic storms, or G5 on the NOAA space weather scales. Fortunately, G5 storms are not common events, occurring only 2-3 times on average during an 11-year solar cycle.

Due to a rapidly growing commercial space industry, SWPC scientists are learning more about customer needs and paying more attention to minor geomagnetic storms that have traditionally had little effect on our lives and infrastructure on Earth and in space. . In early February, 38 of the 49 Starlink satellites that SpaceX launched into very low Earth orbit burned up as a result of a prolonged period of minor geomagnetic storms.

A new study in space weather, a journal published by the American Geophysical Union, provides an analysis of the space weather conditions that led to the loss of the Starlink satellite. Scientists at NOAA’s Center for Space Weather Prediction and the University of Colorado at Boulder’s Cooperative Institute for Research in Environmental Sciences (CIRES) worked closely with SpaceX Starlink to co-author this study. They used observations from the Starlink satellites and NOAA forecasts and numerical simulations to demonstrate the disturbance in the upper atmosphere and the improved satellite drag conditions during the February event. This study confirms SpaceX’s preliminary analysis: the high-drag conditions of the satellite reduced the stability of the satellite and made the orbit-raising process impossible. In response, the satellites rapidly left their orbit, eventually burning up during re-entry into Earth’s atmosphere.

NOAA’s GOES-16 satellite captured a series of M-class solar flares on February 1, 2022. These flares on the sun caused minor geomagnetic storms that destroyed 38 SpaceX Starlink satellites launched on February 3, 2022. (NOAA)

SWPC meteorologists predicted minor to moderate geomagnetic storms and issued watch, warning and alert products beginning January 30 and continuing through February 5. described in the study, but has since prioritized the importance of this service after the satellite loss event.

With the commercial satellite industry establishing large constellations of small satellites and CubeSats (launching over 1000 satellites per year) in low Earth orbit, there is an increasing need for customer information on atmospheric density as it can have large impacts. in lower orbit, as seen. with the loss of the Starlink satellite. The study recommends accurate forecasts of these events prior to the onset of solar and geomagnetic storms, and identifies that it is “crucial for SWPC to establish appropriate alerts and warnings based on neutral density predictions to provide guidance to users to prevent satellite losses due to drag.” and to assist in collision avoidance calculations.” To provide adequate space weather forecasts and warnings for this expanding industry, SWPC needs new observations and data to improve space weather forecast models.

The study identifies additional space weather forecast enhancement services and research areas that are critical to supporting the low-Earth orbit spacecraft industry, including:

  • Better predictions of the arrival time of the coronal mass ejection and the magnitude and duration of geomagnetic activity. In addition, establishing the uncertainties and variability of the interactions between the solar wind and the nearby Earth should be prioritized to provide probability forecasts of responses on Earth.

  • Computationally efficient data assimilation techniques to utilize the large volume of orbiting neutral density observations will allow SWPC to improve nowcasts of the neutral atmosphere and produce better forecasts.

  • Improved processes in the satellite industry to incorporate space weather information and neutral density models that better capture space weather responses into satellite design and operations.

The study also notes that insufficient measurements between the sun and Earth, limitations in SWPC modeling tools, and knowledge gaps in space physics lead to prediction errors about the timing and intensity of geomagnetic storms.

The study found that SWPC’s physics-based numerical model, called WAM-IPE, captured the enhanced neutral density environment responsible for the Starlink satellite stall event, outperforming the empirical model used by the Starlink team for their analyses. In collaboration with Starlink and others in this growing industry, SWPC will incorporate design changes to the WAM-IPE to make the model more useful to both industry and government interests in low and very low Earth orbit. In addition, SWPC is developing a ND product with a comprehensive, satellite-focused web page for the spacecraft industry to access model results and forecasts. These improvements will take place in mid-2023.

“This study demonstrates the benefits that can be derived from collaborative work between government and industry,” said Tzu-Wei Fang, Ph.D., lead author of the study and a space scientist with NOAA’s Space Weather Prediction Center. “The free exchange of model and satellite data and the close interaction between SWPC and the Starlink team have allowed us to identify the quantitative impact of space weather events on these satellites, helping us quickly prioritize our tasks to improve our models. and space weather designs. operational products that will best meet the needs of modern space commerce.”

In addition, the Starlink team has implemented system upgrades to ensure that future low insertion missions can accommodate satellite drag given the anticipated increase in solar and geomagnetic activity as we approach the Solar Cycle 25 maximum, according to the study. . SpaceX has successfully accomplished more than 60 satellite launches since November 2019, specifically to implement the Starlink system. The previous launches have taken place during a period of calm space weather conditions compared to what was observed in early February.

This event renews the need for an improved space weather observing and forecasting system that not only focuses on capturing massive coronal mass ejections, such as that associated with the Carrington event, but also on the minor to moderate space weather events that they have been occurring much more frequently. In recent months. These minor to moderate events, similar in magnitude to the Starlink loss event, will increase as we move further into Solar Cycle 25. It is important to improve space weather forecasting capabilities and services ahead of solar maximum in 2024-2025.

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