Unexpected solar weather is accelerating satellites' orbital decay
space.com
space.com
This is an ignorant fear article and/or an article written by someone who knows NOTHING about space launch and design.
(I used to be a military rocket scientist specializing in radiation effects on space electronics many moons ago).
Apparently not simply part of the solar cycle when new types of spacecraft (lacking typical propulsion systems) haven’t been in orbit during a high activity solar peak.
There are some points that are alarmist. “Plummet” isn’t something that seems to happen.
Theoretically, as $ per kg launch costs come down with things like reusable falcon 9, it makes it much less costly to equip medium sized LEO satellite with more fuel than it might have costed 10 or 15 years ago.
Or if you have something that needs to orbit really low and minimize drag/maximize lifespan, you could design it to be particularly aerodynamic and shaped like this:
https://en.wikipedia.org/wiki/Gravity_Field_and_Steady-State...
> 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. The last cycle, which officially ended in December 2019, was rather sleepy, with a below-average number of monthly sunspots and a prolonged minimum of barely any activity. But since 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.
> In late 2021, operators of the European Space Agency's (ESA) Swarm constellation noticed something worrying: 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.
> By coincidence (or beginner's luck), the onset of the new space revolution came during that sleepy solar cycle. These new operators are now facing their first solar maximum. But not only that. The sun's activity in the past year turned out to be much more intense than solar weather forecasters predicted, with more sunspots, more coronal mass ejections and more solar wind hitting our planet.
> "The solar activity is a lot higher than the official forecast suggested," Hugh Lewis, a professor of engineering and physical sciences at the University of Southampton in the U.K. who studies the behavior of satellites in low Earth orbit, told Space.com. "In fact, the current activity is already quite close to the peak level that was forecasted for this solar cycle, and we are still two to three years away from the solar maximum."
> Stromme confirmed those observations. "The solar cycle 25 that we are entering now is currently increasing very steeply," she said. "We do not know if this means that it will be a very tough solar cycle. It could slow down, and it could become a very weak solar cycle. But right now, it's increasing fast."
Check out the NOAA solar cycle data: https://www.swpc.noaa.gov/products/solar-cycle-progression
You are right that operators plan for variations in solar activity. But it remains to be seen how many can cope with a significantly more active cycle than predicted.
Great, and I'm sure literal rocket scientists are not space.com's target audience.
I read the article, and I didn't receive it as fear mongering at all. You might not be aware that people outside of rocket science are probably pretty ignorant of space weather and its direct affect on the Earth and its inhabitants. Putting a bit of explanation out there in a fairly easy way to understand is not a bad thing. As easy as this was to grasp, there will still be people that are confused after reading.
Really what is unexpected.
This plot of sunspot activity, and the (highly correlated) 10.7cm radio flux, indicates that the current cycle (cycle #25) is rising much faster than typical:
https://www.swpc.noaa.gov/products/solar-cycle-progression
As you can see, cycle #24, which ended in 2019, was quieter than expected (annoying to solar physicists who only see a few cycles within their whole career) -- so it's actually very interesting that Cycle #25 is starting out with a bang.
NOAA is the main US government agency tasked with monitoring/predicting solar activity for the protection of ground and space systems. The main facility is the Space Weather Prediction Center which is in Boulder, CO -- that's the data source of the above plots. The SWPC centerpiece used to be a control room with a bunch of people looking at computer monitors filled with various real-time and historical time series.
We don't know why some cycles are less intense, and the last few cycles have generally been on a downward trend (e.g., https://en.wikipedia.org/wiki/Solar_cycle#Sunspots). So again, it is indeed quite interesting to see this high activity - if it holds up.
But a prominent astrophysicist at the National Center for Atmospheric Research, Scott McIntosh, foresees the sun going gangbusters. The cycle is already off to a fast start, coinciding with the recent publication of McIntosh’s paper in Solar Physics. The study, with contributions from several of his colleagues, forecasts the nascent sunspot cycle to become one of the strongest ever recorded."
[0] https://www.washingtonpost.com/weather/2020/12/19/solar-cycl...
(Feb. 26, 2022) "“We have finalized our forecast of SC25’s amplitude,” says McIntosh. “It will be just above the historical average with a monthly smoothed sunspot number of 190 ± 20.”
"“Above average” may not sound exciting, but this is in fact a sharp departure from NOAA’s official forecast of a weak solar cycle"
[0] https://spaceweatherarchive.com/2022/02/25/the-termination-e...
Space tugs as a service: https://spacenews.com/space-tugs-as-a-service-in-orbit-servi...
Increased solar flare EMP risk during the next years ain't a picnic either. Yo this all sucks. Bummer vibes. But don't shoot the messenger.
The song: https://youtube.com/watch?v=mE5ir7bJnDI
Some competition: http://acswa.us/about/members.html
Does the global warming models take this into effect? This seems like an unfathomable amount of energy.
This turned out not to be the case...that was pretty much known by the early 2000s.
Other irradiance variations, due to orbital variations called Milankovich cycles, happening in the 10,000's of year range, do appear to influence climate. Of course, the extremes we're seeing now are not on the 10,000-year time scale.
You always have unknown unknown but is this sort of expected as the sun is not yours. The solar wind model is the problem?
Plummet gets the clicks though, so to the website, it is appropriate.
It could also be argued it's a sense of perspective. Something that falls at the rate of 2km per year suddenly in a matter of months starts to fall at a rate of 20km per year could seem like plummeting when you're the one tasked with keeping it alive or the person that paid for it to be there for 10 years to see it suddenly shortened to 2 years. It's a stretch, but we all love hyperbole
To me at least, plummet signals it's a matter of seconds or, perhaps from great altitude, minutes until it hits the bottom. So to me, and that's knowing a thing or two about space, this title is just clickbait and not a good description of the phenomenon observed even for a techy public like HN.
This article wasn't written for HN. It was written for the general audience that peruses Space.com. Because someone found it interesting and posted to HN is pretty much the only reason it is on HN. Space.com didn't submit it in hopes of gaining attention by a hypercritical audience.
Yes, I agree it is click bait. I'm just playing devil's advocate to some of your weaker arguments.
Yes, and landing is not one of those situations. To describe a plane as "plummeting" requires that it crash (or recover and stay airborne) rather than landing.
Or in other words, Aachen's claim that "we also don't say that airplanes plummet when landing" was correct in every particular.
https://en.wikipedia.org/wiki/Orbital_decay#/media/File:Alti...
We certainly do know a fair amount about the sun's "climate": https://en.wikipedia.org/wiki/Solar_cycle
The sun has an 11-year solar cycle where each cycle has a period of low and high sunspot activity and currently we are just starting Cycle 25 with a corresponding uptick of solar flare activity.
Well, the falling is rather expected, it's just the rate of it is faster, than we hoped for.
Maybe in a couple of years, once at max, the rate will start decreasing, but for some cubesats this may be terminal by then.
Thread about that:
https://news.ycombinator.com/item?id=30267587 (488 comments)
If they got unlucky they might have spiked a space in which another satellite could have orbited (no pun intended).
But really, that's neither here nor there, the point of the comment is that a combination of an unexpected solar storm and the operations procedures followed for dealing with them lead to a possibly unnecessary loss of satellites. Just because they have more doesn't mean they're happy about losing out on millions of dollars of hardware.
Same as Tesla crashes versus speed versus manufacturing cost, versus everything, tradeoffs. Are they justified or not?
You park things in low earth orbit so that they don't stay up forever and indeed come down in reasonably small human-scale timeframes. Usually on the time scale of decades, sometimes more, sometimes less.
If you designed a satellite to stay up for 10 years, it'll suddenly only be able to stay up a year, that's the scale of these things.
Again it's an exponential thing, a seemingly small scale change in the slow part makes the fast part come quite a lot sooner.
However unless the author happens to know a lot about orbital mechanics (or they've played Kerbal Space Program) they probably just picked an expressive word for the sake of a compelling article rather than something that would give a better picture to the layperson.
It isn't the journalist but the nitpicking commentors who are clueless. The headline accurately enough conveys what is happening and the article articulates it well. Orbital mechanics isn't intuitive enough for there to be perfect fit words given human experience, human timescales, "plummet" is fine.
I genuinely think a decent number of people are going to envision a situation where satellites suddenly plunging out of orbit like they would in some big budget disaster movie. You are well within your right to tell them they are thinking of the word "plummeting" incorrectly but you are fighting an uphill battle. Technical and dictionary correctness has its place but to convey information properly people must consider the vernacular.
Satellites are falling relatively very fast compared to usual and some of them have or soon will burn up in atmosphere as a result, it’s a headline, not a half sentence expected to grant a degree in astrodynamics.
You are correct, one of the meanings of plummet is a rapid descent. These satellites are rapidly descending. You are correct.
Again, though, word choice matters. Can you see where other commenters and I are coming from?
Because we're now 5+ comments deep arguing semantics. You know the facts, I know the facts, we all know the facts, what do we disagree on?
[EDIT] On reflection, this is even goofier than I thought at first, since the choice of lead for those applications is precisely because it's little affected by wind, and even fares better than most things against moving water, while this is entirely about something falling faster because of its interaction with air.
Plummet:
1. to fall perpendicularly
2. to drop sharply and abruptly
fall or drop straight down at high speed.
It will also add orbital perturbations/frozen orbits if you use Real Solar System: https://github.com/mockingbirdnest/Principia/blob/master/ast...
That said, to my knowledge there isn't yet a mod that adds high-altitude drag.
So if it lasts a week, the lifetime will be reduced by 10 weeks? Still a lot but something you can cope with.
We’re ramping up to a maximum which should happen in a few years but activity has been above predictions. We don’t understand the Sun dynamics all that well, but what’s happening now is a little weird beyond expectations and might be something that continues for years.
(pet peeve, sorry)
It's clickbait. I appreciate people pointing out clickbait. I think a lot of others do as well; it's why they read the comments on an article before the look at the article.
Had the story been titled "Solar Weather Causes Unexpected Satellite Orbit Decay" or some other non-clickbait thing I'd have read it without looking at comments first. I'm actually interested in solar weather due to its impact on radio. Too bad publishers don't understand that clickbait titles are a serious turn off. Apparently everything must be TMZ.
But also, people just kind of suck at it.
https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...
(I suppose this is what you meant by "mutually exclusive interests".)
In this case, the discussion of the word plummet is halfway topical: it's about understanding the severity and going more into detail of what's actually happening, putting it in context. The equivalent discussion would happen regardless of word choice.
Too many writers—including of headlines—are so sloppy with language that it's misleading, or even incorrect.
Perhaps when GPT-4 or whatever takes over those jobs, it will be better at it. Provided we don't train it on anything written after 2000 or so, when all headlines became tabloid headlines and margins got tight enough that no-one had time for careful editing anymore.
* "Destruction of the Warship Maine was the work of an Enemy. $50,000 Reward~" https://sophia.smith.edu/fys169-f19/wp-content/uploads/sites...
* There's also the fake propaganda Ben Franklin pushed so that the 1776 revolution would have the moral high ground. (Ben Franklin fabricated the "Scalping" of USA's early citizens to fake a war-crime, to make the British look more monstrous). https://founders.archives.gov/documents/Franklin/01-37-02-01...
I'm not sure if there ever was non-clickbait headlines. In fact, the further back in history you go, the more clickbait, and even fully fake, information seems to exist.
When the warning signs are ignored because they don't fit the political propaganda, then sure...it's "unexpected"