Satellites are Sinking Faster Toward Earth. Scientists Blame Solar Wind (space.com) 30
"In late 2021, operators of the European Space Agency's Swarm constellation noticed something worrying," reports Space.com. "The satellites, which measure the magnetic field around Earth, started sinking toward the atmosphere at an unusually fast rate — up to 10 times faster than before.
"The change coincided with the onset of the new solar cycle, and experts think it might be the beginning of some difficult years for spacecraft orbiting our planet." "In the last five, six years, the satellites were sinking about two and a half kilometers [1.5 miles] a year," Anja Stromme, ESA's Swarm mission manager, told Space.com. "But since December last year, they have been virtually diving. The sink rate between December and April has been 20 kilometers [12 miles] per year."
Satellites orbiting close to Earth always face the drag of the residual atmosphere, which gradually slows the spacecraft and eventually makes them fall back to the planet. (They usually don't survive this so-called re-entry and burn up in the atmosphere.) This atmospheric drag forces the International Space Station's controllers to perform regular "reboost" maneuvers to maintain the station's orbit of 250 miles (400 km) above Earth. This drag also helps clean up the near-Earth environment from space junk.
Scientists know that the intensity of this drag depends on solar activity — the amount of solar wind spewed by the sun, which varies depending on the 11-year solar cycle.... [S]ince last fall, the star has been waking up, spewing more and more solar wind and generating sunspots, solar flares and coronal mass ejections at a growing rate. And the Earth's upper atmosphere has felt the effects. "There is a lot of complex physics that we still don't fully understand going on in the upper layers of the atmosphere where it interacts with the solar wind," Stromme said. "We know that this interaction causes an upwelling of the atmosphere. That means that the denser air shifts upwards to higher altitudes."
Denser air means higher drag for the satellites. Even though this density is still incredibly low 250 miles above Earth, the increase caused by the upwelling atmosphere is enough to virtually send some of the low-orbiting satellites plummeting. "It's almost like running with the wind against you," Stromme said. "It's harder, it's drag — so it slows the satellites down, and when they slow down, they sink...." The lower the orbit of the satellites when the solar storm hits, the higher the risk of the spacecraft not being able to recover, leaving operators helplessly watching as the craft fall to their demise in the atmosphere....
All spacecraft around the 250-mile altitude are bound to have problems, Stromme said. That includes the International Space Station, which will have to perform more frequent reboost maneuvers to keep afloat, but also the hundreds of cubesats and small satellites that have populated low Earth orbit in the past decade.... "Many of these [new satellites] don't have propulsion systems," Stromme said. "They don't have ways to get up. That basically means that they will have a shorter lifetime in orbit. They will reenter sooner than they would during the solar minimum."
Thanks to long-time Slashdot reader schwit1 for sharing the article!
"The change coincided with the onset of the new solar cycle, and experts think it might be the beginning of some difficult years for spacecraft orbiting our planet." "In the last five, six years, the satellites were sinking about two and a half kilometers [1.5 miles] a year," Anja Stromme, ESA's Swarm mission manager, told Space.com. "But since December last year, they have been virtually diving. The sink rate between December and April has been 20 kilometers [12 miles] per year."
Satellites orbiting close to Earth always face the drag of the residual atmosphere, which gradually slows the spacecraft and eventually makes them fall back to the planet. (They usually don't survive this so-called re-entry and burn up in the atmosphere.) This atmospheric drag forces the International Space Station's controllers to perform regular "reboost" maneuvers to maintain the station's orbit of 250 miles (400 km) above Earth. This drag also helps clean up the near-Earth environment from space junk.
Scientists know that the intensity of this drag depends on solar activity — the amount of solar wind spewed by the sun, which varies depending on the 11-year solar cycle.... [S]ince last fall, the star has been waking up, spewing more and more solar wind and generating sunspots, solar flares and coronal mass ejections at a growing rate. And the Earth's upper atmosphere has felt the effects. "There is a lot of complex physics that we still don't fully understand going on in the upper layers of the atmosphere where it interacts with the solar wind," Stromme said. "We know that this interaction causes an upwelling of the atmosphere. That means that the denser air shifts upwards to higher altitudes."
Denser air means higher drag for the satellites. Even though this density is still incredibly low 250 miles above Earth, the increase caused by the upwelling atmosphere is enough to virtually send some of the low-orbiting satellites plummeting. "It's almost like running with the wind against you," Stromme said. "It's harder, it's drag — so it slows the satellites down, and when they slow down, they sink...." The lower the orbit of the satellites when the solar storm hits, the higher the risk of the spacecraft not being able to recover, leaving operators helplessly watching as the craft fall to their demise in the atmosphere....
All spacecraft around the 250-mile altitude are bound to have problems, Stromme said. That includes the International Space Station, which will have to perform more frequent reboost maneuvers to keep afloat, but also the hundreds of cubesats and small satellites that have populated low Earth orbit in the past decade.... "Many of these [new satellites] don't have propulsion systems," Stromme said. "They don't have ways to get up. That basically means that they will have a shorter lifetime in orbit. They will reenter sooner than they would during the solar minimum."
Thanks to long-time Slashdot reader schwit1 for sharing the article!
Re: (Score:3, Interesting)
Racism? Check. Right wing groundnut? Check. Failure to observe the heat waves in the N. Hemisphere? Check.
How does one keep all that insanity in check? Okay...you don't own guns, do you?
Re: (Score:2)
I wouldn't mind those heat waves one bit if they were all like this one. [youtube.com]
Hm (Score:2, Interesting)
So, is this good for space junk?
Re: (Score:2)
So, is this good for space junk?
That was going to be my question as well. If this does affect the junk then it's a good thing. Our trash will (slowly) be cleaned up.
Re: (Score:2)
Good news for space junk? (Score:3)
Re: (Score:3)
That logic... is like saying that drought is good because it eliminates weeds. It also eliminates the expensive working satellites which mations have spent billions of dollars to put in orbit.
Re: Good news for space junk? (Score:1)
Re: (Score:2)
Re: (Score:2)
The working satellites have working thrusters to keep them in place and that was planned when they were made. Just because operators got lucky so far doesn't mean they will get lucky in future, and their luck of using less station-keeping (or orbit-keeping) fuel than planned may now be at an end.
The junk has no thrusters and needs to be got rid of, so the end result will be satellites (run by competent operators) will orbit as intended while junk is removed.
It would be very handy if some countries (ahem,
Re: (Score:2)
Those thrusters cannot normally be refilled, and provide very limited delta V indeed. They'll be turning from working satellites to space junk quite quickly with this increased drag.
Re: (Score:2)
Not solar wind (Score:5, Funny)
but solar or wind:
A solar panel and a wind turbine are taking about music
Wind turbine: So what are you into?
Solar panel: Whatever's hot, but usually I prefer light stuff, how about you?
Wind turbine: I'm a huge metal fan
Re: (Score:2)
Actually, it's cool jazz that gets the electrons dancing in a solar panel. Heat hurts efficiency quite significantly.
Re:Not solar wind (Score:4, Funny)
Re:Not solar wind (Score:4, Funny)
Solar panel: so what turns you on?
Wind turbine: blow me.
Kindergarten teacher singing... (Score:2)
..."Clean up, clean up, everybody clean up!"
Re: (Score:2)
No, no, they really didn't. No scientist promised you an ice age. Don't invent history, the real stuff is bad enough.
Re: (Score:2)
Re:Wrong cause (Score:4, Informative)
Read your own link, Einstein: Some press reports in the 1970s speculated about continued cooling; these did not accurately reflect the scientific literature of the time
scientists != journalists
Re:Wrong cause (Score:4, Funny)
I was hoping to get a Flat Earther's opinion on the topic.