SpaceX internet satellites knocked out after small solar storm

But last week, SpaceX witnessed a staggeringly different impact from charged particles streaking through space when 40 of their small Starlink communications satellites were knocked out a day after launch. The loss could cost the company tens of millions of dollars. Starlink will eventually be made up of tens of thousands of small satellites in low Earth orbit.

According to a SpaceX press release, 40 of the 49 Starlink satellites will re-enter or have already re-entered the atmosphere after encountering a geomagnetic storm on Feb. 4. The fleet of satellites, intended to bring low-cost Internet service to remote areas of the planet, was launched on February 3. at the Kennedy Space Center in Florida. The company said the satellites should not create debris or touch the ground during reentry, but instead would be incinerated during fiery reentry.

“This is the first time that so many spacecraft have been hit at once to our knowledge,” said Jim Spann, space weather manager for NASA’s Heliophysics Division., who studies physics related to the sun.

Spann said NASA and the National Oceanic and Atmospheric Administration (NOAA) are analyzing the exact nature of the event causing the problem, but the conditions don’t appear to be particularly special.

January 30, observed satellites the sun undergoes coronal mass ejection — an expulsion of plasma and magnetic matter. The stream was directed towards Earth and arrived around February 2, triggering aurora sightings in the northern United States, as shown above.

“It’s the solar storm we predicted. It was about right on time,” said Tamitha Skov, research scientist at Aerospace Corp. “When we saw it, we were like, ‘Oh, that’s kinda sweet.'”

Geomagnetic storms are rated on a scale of G1 to G5 by NOAA, but Skov said this storm was recorded as “only active conditions” – not even reaching the lowest G1 storm level. “We see a lot of storms like this. They literally happen once a week.

However, another solar storm lurked behind this one, and it took the scientists by surprise.

“We basically had an observation which was the line of sight, which means we’re looking from Earth towards the sun and we see the structure coming towards us,” Skov said. “But if there are other things hidden inside that structure or just behind it, it’s very difficult to pull them out or discern them.”

When SpaceX launched its satellites on February 3, the second storm was intensifying. The storm was rated G1, stronger than the first but still relatively weak.

Skov said the effects of the two successive storms, however, caused the Earth’s atmosphere to swell or puff up.

Think of Earth’s atmosphere like a bicycle tire, Skov said. When the first solar storm hit, its magnetic field drove currents that caused Earth’s upper atmosphere and particles to move in one direction. the movement continued for almost an entire day.

When the second surprise solar storm hit, however, it was angled to cause the motion of Earth’s upper atmosphere to reverse, Skov said. The friction and energy of the two opposing forces released heat in greater amounts than the models predicted – similar to the frictional heat released when trying to stop and reverse a moving bicycle tire with your hand.

“Your atmosphere is going to swell a lot when you have to spin the atmosphere around and spin it the other way“, said Skov, who also regularly posts space weather forecasts on her Youtube channel.

Spann said NASA and NOAA were still analyzing the data and working to get a full understanding of the event, but he also said there may have been some buildup since the first event that took place. helped prime the environment as the G1 storm arrived.

“It’s kind of a normal G1 storm. It wasn’t anything exotic or extreme,” Spann said. He said his colleagues were working to “understand how it all happened, to make us more efficient at predicting and providing the support that commercial entities and others may need for future launches.”

The second storm also brought auroras to a handful of areas around the world, from near the Canada-US border to Britain.

SpaceX said in its press release that the storms caused the atmosphere to warm and atmospheric density to increase at altitudes at which magnetic storm activity occurs.

“Geomagnetic storms, when energy from the sun enters the environment of the Earth’s magnetic field, changes the upper atmosphere. … The density of that changes,” said Elizabeth MacDonald, space weather physicist at NASA. When many particles enter the atmosphere, it can lead to an increase in drag.

The drag was up to 50% higher than in previous satellite launches, according to SpaceX’s press release. The Starlink team ordered the satellites to enter safe mode to minimize the effect, but the increased drag then prevented the satellites from exiting safe mode to begin maneuvers to enter the correct orbit.

MacDonald said the atmospheric conditions led to a “perfect storm” in some sense. The timing of the sun’s radiation flux and the storm’s effects on Earth’s upper atmosphere increased the drag. But she added that this is not particularly unusual, nor is the occurrence of two geomagnetic storms in close succession.

“What’s unusual is the very low altitude of the Starlink satellites,” she said.

SpaceX said the satellites were hovering a planned 130 miles above Earth (the perigee of its orbit), although Skov said it was lower than expected for a stable orbit. Particle density is also higher at lower altitudes.

Skov said that design satellites probably didn’t help reduce drag either. Satellites are incredibly small, with a relatively large solar array – a recipe for drag if the atmosphere swells. Imagine one of those plastic military toys deploying its parachute.

Starlink had not encountered such a dense atmosphere on previous launches, but previous satellite launches have occurred under very different conditions on the sun. About every 11 years, the orientation of the solar magnetic field reverses and activity goes up and down. The Starlink system came online as the sun passed through a period of low activity called solar minimum. Recently however, the sun has begun to enter a period of increased activity, heading towards solar maximum.

“Because the sun has been so quiet and all of this technology has been developed over the past few years, this is the first time we’ve used this type of technology in this new environment,” Spann said.

Space weather researchers say the sun’s activity is expected to increase, reaching solar maximum around 2025. In the past, Spann said, some of the most intense magnetic storms have occurred after the sun has reached its peak and the solar maximum has diminished – which means that Starlink engineers will have to learn to adapt the system to these conditions for many years.

“It’s something that Elon and his crew will have to pay attention to, because it’s by no means an extreme event,” Skov said, referring to SpaceX founder Elon Musk and the February 4 storm. “We’re going to see more.

In fact, in the week since Starlink’s last launch, skywatchers around the world saw several auroras as another G1 storm reached Earth:

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