About a week ago, the 18th Space Control Squadron, US Air Force, relayed warning data to the European Space Agency.
The data indicated that there was a non-negligible collision risk between ESA's Aeolus satellite and Starlink44, an active SpaceX satellite, at 11:02 UTC on Monday, 2 September.
As days passed, the probability of collision continued to increase, and by Wednesday, August 28, ESA's Ops team decided to reach out to Starlink to discuss their options. Within a day, the Starlink team informed ESA that they had no plan to take action at that point. By Thursday evening, ESA's probability threshold for conducting an avoidance manoeuvre had been reached, and preparations were made to lift Aeolus 350 meter in orbit. By Sunday evening, chances of a collision had risen to 1 in 1000, and commands were sent to the Aeolus satellite, which triggered a total of 3 thruster burns on Monday morning, half an orbit before the potential collision. About half an hour after the collision prediction time, Aeolus contacted base, and normal measurement operations could continue.
What the SpaceX satellite was doing in ESA's Aeolus orbit is not clear.
ESA has taken the opportunity to point out that, given SpaceX plans to put up 20,000 of those things, handling monitoring and avoidance semi-manually, and by mail, is no longer practical.
Related Stories
SpaceX submits paperwork for 30,000 more Starlink satellites
SpaceX has asked the International Telecommunication Union to arrange spectrum for 30,000 additional Starlink satellites. SpaceX, which is already planning the world's largest low-Earth-orbit broadband constellation by far, filed paperwork in recent weeks for up to 30,000 additional Starlink satellites on top of the 12,000 already approved by the U.S. Federal Communications Commission.
The FCC, on SpaceX's behalf, submitted 20 filings to the ITU for 1,500 satellites apiece in various low Earth orbits, an ITU official confirmed Oct. 15 to SpaceNews.
[...] In its filings, SpaceX said the additional 30,000 satellites would operate in low Earth orbit at altitudes ranging from 328 kilometers to 580 kilometers.
[...] It is not guaranteed that, by submitting numerous filings, SpaceX will build and launch 30,000 more satellites. Tim Farrar, a telecom analyst critical of SpaceX, tweeted that he was doubtful the ITU will be able to review such big filings in a timely manner. He sees the 20 separate filings as a SpaceX effort to "drown the ITU in studies" while proceeding with its constellation.
Nothing a Starship can't launch.
More coverage:
Previously: FCC Authorizes SpaceX to Provide Broadband Satellite Services
SpaceX Seeks Approval for 1 Million Starlink Ground Stations, Faces Pentagon Audit
FCC Approves SpaceX Lowering Orbit of Internet SatellitesRelated: SpaceX Valued at $25 Billion... and More
SpaceX Starlink Satellite Prototypes Include Packed, Flexible Solar Arrays
SpaceX to Launch 60 Starlink Satellites at Once, and More
SpaceX Satellites Pose New Headache for Astronomers
Most of SpaceX's Starlink Internet Satellites are Already on Track
Three of SpaceX's Starlink Satellites have Failed
Near Collision Between ESA and SpaceX Satellite
(Score: 5, Informative) by bradley13 on Wednesday September 04 2019, @07:35AM (19 children)
This is an incredible website, showing all the satellites in orbit [stuffin.space]
Everyone is somebody else's weirdo.
(Score: 2, Interesting) by shrewdsheep on Wednesday September 04 2019, @08:06AM (17 children)
According to the site (very cool), Starlink satellites live on an altitude of ~ 550km whereas Aeolus is on ~330km making this incident look quite unusual. I could not identify Startlink44 there, how realtime is the site?
(Score: 2) by bradley13 on Wednesday September 04 2019, @08:55AM (1 child)
The site does get updated, but how frequently? Not sure...
Everyone is somebody else's weirdo.
(Score: 3, Informative) by All Your Lawn Are Belong To Us on Wednesday September 04 2019, @05:07PM
Orbital elements updated daily, according to the About on the webpage.
This sig for rent.
(Score: 2) by choose another one on Wednesday September 04 2019, @10:48AM (13 children)
> how realtime is the site?
Perhaps more importantly, how accurate at all is the site? If Starlinks are at 550km up and Aeolus is at 330, why boost Aeolus _up_ to avoid collision?
Things not adding up here, some of the information must be wrong.
(Score: 3, Interesting) by Immerman on Wednesday September 04 2019, @01:39PM (12 children)
From the summary:
>What the SpaceX satellite was doing in ESA's Aeolus orbit is not clear.
That makes quite clear that the Starlink was *not* in its designated 550km orbit. Which in turn makes SpaceX's response all the more puzzling. A few possibilities spring to mind:
- SpaceX can't control the satellite, but doesn't want to just come out and admit it. Which might not be that surprising - that far below its orbit it would seem to indicate either a (possibly unreported?) orbital insertion failure, or a major malfunction, which could look really bad for maintaining their licensing.
- The satellite was deployed on some other mission they don't want to talk about - including the possibility that it's not actually a Starlink satellite, but instead a military/intelligence satellite that perhaps took advantage of the bulk launch as camouflage
- SpaceX knows exactly what they're doing, and this is a dominance play in beginning to assert themselves as an orbital power unto themselves. In essence "We're in this orbit because we want to be. What are you willing to do about it?". They are planning to put up more than 10x as many satellites as everyone else combined. Perhaps best to start establishing now that they don't intend to answer to bit players.
(Score: 2) by deimtee on Wednesday September 04 2019, @05:23PM (11 children)
Aeolus is a wind/weather research satellite. Two more possibilities:
- Aeolus found conclusive proof of global warming and the deniers are trying to take it down.
- Aeolus found conclusive proof there is no global warming and the warmists are trying to take it down.
If you cough while drinking cheap red wine it really cleans out your sinuses.
(Score: 2) by Immerman on Wednesday September 04 2019, @05:45PM (10 children)
Chuckle.
Seriously though, there is no such thing as "proof" in science, only overwhelming evidence. And that already exists for global warming - even Exon's own research concluded that decades ago. No amount of new evidence is going to sway anyone's opinion until it becomes personal. Modern research is focussed on better understanding the subtleties so that we can predict and prepare for what's coming, as well as improving short-term and seasonal weather forecasts.
Today, people's belief or disbelief in anthropogenic global warming pretty much comes down to their politics, and global disbelief appears to be concentrated primarily within a certain segment of the U.S. population - most of the rest of the world has long since accepted the scientific consensus, and is now arguing about what, if anything, should be done about it.
(Score: 2) by deimtee on Thursday September 05 2019, @03:26AM (9 children)
I know that. But Climate Change is no longer science.
I was trying to be evenhanded so as to upset both sides of the religious debate equally. :)
If you cough while drinking cheap red wine it really cleans out your sinuses.
(Score: 2) by Immerman on Thursday September 05 2019, @01:27PM (8 children)
And is thermodynamics no longer science either? You know, because the overwhelming evidence has resulted in a near-total consensus among the people who once researched it?
Climate change has become a political football, just as lead poisoning once was - but that doesn't change the science, just gets a whole lot of people who couldn't science their way out of a paper bag involved on both sides of the argument.
(Score: 2) by deimtee on Friday September 06 2019, @12:39AM (7 children)
Of course thermodynamics is science. It makes testable repeatable predictions and any situation that credibly violated those predictions would result in an investigation into what was wrong with (most likely) the experiment or (very unlikely) our understanding of thermodynamics.
When chanting crowds crucify anyone who gets the "wrong" answer while measuring the enthalpy of an oxidation reaction then Thermodynamics will be a religion too.
If you cough while drinking cheap red wine it really cleans out your sinuses.
(Score: 2) by Immerman on Friday September 06 2019, @02:14AM (6 children)
You are again conflating the science with the throngs of people who've been rallied behind flags for or against it.
The crowds are irrelevant to the science - and the science was settled long before there were any crowds.
(Score: 2) by deimtee on Friday September 06 2019, @03:34AM (5 children)
"and the science was settled"
Chanting a mantra does not actually make it true. Climate science is one of the least settled of the real sciences. It is incredibly complex and chaotic. Unbiased research would be great, but it doesn't seem likely, almost everyone involved has an agenda and any real science is lost in the noise.
If you cough while drinking cheap red wine it really cleans out your sinuses.
(Score: 2) by Immerman on Saturday September 07 2019, @12:29AM (4 children)
Depends what exactly you're talking about. That human CO2 emissions are building up in the atmosphere and causing increased heat retention is long since settled.
The full impacts of that, where exactly is the tipping point to a runaway transition to a hothouse-Earth, and whether there are as-yet-undiscovered negative feedback loops that will eventually mitigate our influence before we reach that point all remain to be seen. But at present none of the negative feedback loops that have been identified appear to be up to the task, and the positive feedback loops keep looking worse.
So basically, at present we're faced with two choices: mitigate our influence in order to maintain the Earth in the relatively stable interglacial period that civilization arose in, or jump off the cliff and hope that something we haven't yet discovered will slow the process before catastrophic climate change decimates the global ecosystem, and us along with it.
(Score: 2) by deimtee on Saturday September 07 2019, @04:50AM (3 children)
Definitely
Only about half as fast as they should be due to measured emissions.
Not settled at all. The IR window CO2 blocks is not that wide and adding extra CO2 doesn't really do very much over what is already there.
The biosphere is strongly CO2 limited. At 200 ppm plants are right on the edge of starving. At 400 they are growing like they are having a good year in terms of water/fertilizer/sunlight. Higher CO2 also reduces a plant's need for water. At about 600ppm we are likely to get significant de-desertification. Would you like to see the Sahara being a verdant land again?
I strongly support the use of nuclear/solar/wind power and I think we should be shutting down coal as fast as we can, but because of pollution and ecological damage, not the CO2 bogeyman.
The problem with climate science is that lying about CO2 is being used by too many people with a political agenda and sufficient political power to make life uncomfortable for dissidents.
You cannot be for or against science without being irrational. It's like marching around with a sign that says "Repeal the Law of Gravity". The illusion suffered by both sides that you can change facts by political action is one of the more damaging things about the CO2 industry, because of the effort and resources it wastes.
Did you know that limestone deposition by shellfish removes 0.01% of all the carbon in the biosphere each year? Doesn't sound like much but if it wasn't for volcanoes and oil seeps life would have gone extinct about 10,000 years after molluscs developed shells.
Almost the whole biosphere is limited by CO2. What we release is a temporary blip that it will gear up and eat in a very few years. If we are lucky we will end up with a greener planet with more life on it. If we are unlucky we will end up back at the current baseline with all the extra carbon sequestered.
If you really want to make a difference to CO2 levels? Advocate for spraying 100,000 tons of iron compounds across the middle of the Pacific ocean each year. Maybe chuck some in the Atlantic as well. Trivial expense in terms of the CO2 industry and would massively increase the amount of life in the middle of the oceans. You get CO2 absorption and better fisheries. ("Save the whales!"). Middle of the ocean deserts are some of the few ecologies not limited by CO2, they are limited by the amount of iron - the main source is meteorite dust. I'm in favour of this mitigation because of the beneficial effects and because it will smooth out the 'hump' in the CO2 graph. Abrupt transitions are disruptive and slowing things down can be a good thing. Little bit conflicted because I would also like to see the 'Fertile Crescent' be fertile again but you can't have everything.
If you cough while drinking cheap red wine it really cleans out your sinuses.
(Score: 2) by quietus on Sunday September 08 2019, @11:57AM (1 child)
Strong statements require strong proof: care to donate some references to plant physiology articles?
(Score: 2) by deimtee on Sunday September 08 2019, @05:47PM
From Greenpeace co-founder Dr. Patrick Moore:
https://fcpp.org/2016/06/07/the-positive-impact-of-human-co₂-emissions-on-the-survival-of-life-on-earth/ [fcpp.org]
If you cough while drinking cheap red wine it really cleans out your sinuses.
(Score: 2) by Immerman on Tuesday September 10 2019, @02:01AM
>Only about half as fast as they should be due to measured emissions.
Right we're pumping water into a pool at 10 gallons/minute, and the pool is filling at 5 gallons/minute. Doesn't matter how complicated any hidden plumbing is, it's a pretty safe bet that the pool wouldn't be filling without our contribution. Also, we have a pretty good idea where the extra CO2 is going - ocean acidification, etc. It's not like the atmosphere is an isolated system.
> The IR window CO2 blocks is not that wide and adding extra CO2 doesn't really do very much over what is already there.
IR isn't blocked, it's scattered - the same way blue light is scattered by the atmosphere so that the sky looks blue while the sun looks yellow, rather than black and white as they look from orbit. And every time a photon scatters off a CO2 molecule it's a 50/50 chance whether it's re-emitted towards space, or back towards Earth. And one of the features of scattering is that the more scatting substance you put in a solution (like the atmosphere), the more slowly scattered light escapes. 100% of the IR will always escape eventually, the question is how many times an average photon worth of energy ends up back on the surface before it finally makes it out of the atmosphere.
As for the scattering band - the IR band CO2 scatters is separate from, and very roughly the same size as, the scattering band for water, which is the only other IR-scattering gas present in significant quantities in the atmosphere. Methane is the next most common, and there's ~200x more CO2 in the atmosphere than methane.
There's ~50x as much water in the atmosophere as CO2. Water undeniably does most of the work: it averages somewhere around 2 to 2.5% (25,000ppm) of the atmosphere. It varies wildly from about 0 to 4%, but is self-regulating in the sense that the warming from increasing the average amount of water in the air by 1%, is never enough to let the air hold a full 1% more water. So the humidity percentage increases, and with it the chance of the water leaving the air as rain or snow.
CO2 in comparison is tiny, now a bit over 400ppm, but that still makes it at least (400ppm/25,400ppm) = 1.6% of the total amount of greenhouse gasses. Not much, how big a difference can it really make? A reasonable guess would be 1.6% of all the greenhouse warming, so how much is that? Well, we can look at the moon for comparison, it's the same distance from the sun as us, but has no atmosphere. The average temperature of the moon at the equator is about -58C [58], as compared to the Earth's average temperature of about 15C. So greenhouse gasses are currently keeping the planet about 73C warmer than "normal" for our orbit. And probably much more - the Moon is quite dark colored and absorbs about 31% more solar energy than the Earth, plus I chose a nice warm place near the equator.
So, there's at least 73C of current greenhouse-gas warming that's keeping our planet from being a frozen ball of ice. Even if we assume that CO2 is no more potent a greenhouse gas than water, 1.6% of 73C is about 1.2C of extra warmth laid directly at its feet.
And CO2 has a crucial difference to water - it doesn't increase humidity. But any warming it does still increases the maximum amount of water the air can hold, and with it how much water needs to be in the air to have the same equilibrium humidity percentage.
How strong is that effect? Well, at around 15C the maximum water content of air changes by about 7% per degree C. So, if CO2 causes 1.2C of heating on its own, then the air will have to carry (7%/C*1.2C=) 8.4% more water to maintain the same humidity So that ~1.6% of the total greenhouse gas of CO2 is potentially responsible for the presence of an extra 8.4% of the water in the atmosphere, for a combined 10% of the total greenhouse warming - or 7.3C of the total estimated warming. And the effect gets more dramatic at higher temperatures - get closer to 20C, and the amount of water required to maintain the same percentage humidity is increasing by 9% per degree C.
(Score: 3, Informative) by nitehawk214 on Wednesday September 04 2019, @02:28PM
It must not be very realtime, as it doesn't include the latest data on the ISS.
http://stuffin.space/?intldes=1998-067A&search=iss [stuffin.space]
Shows 429 x 417
https://www.heavens-above.com/PassSummary.aspx?satid=25544&lat=0&lng=0&loc=Unspecified&alt=0&tz=UCT [heavens-above.com]
Shows 410 x 420, and lists today as the Epoch
This is probably even more accurate, but I have no idea how to read it.
https://spaceflight.nasa.gov/realdata/sightings/SSapplications/Post/JavaSSOP/orbit/ISS/SVPOST.html [nasa.gov]
"Don't you ever miss the days when you used to be nostalgic?" -Loiosh
(Score: 2) by All Your Lawn Are Belong To Us on Wednesday September 04 2019, @05:06PM
If one is Old School, you can also get Orbitron [stoff.pl] and then grab your own TLE elements [celestrak.com] and go. Though it doesn't look as cool as that website does.
And for the question above, the "About" pages of the website says the orbital elements are updated daily.
This sig for rent.
(Score: 4, Informative) by takyon on Wednesday September 04 2019, @07:45AM (9 children)
SpaceX reportedly refused to move Starlink satellite, provoking odd space agency tweets [updated] [teslarati.com]
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 4, Troll) by quietus on Wednesday September 04 2019, @09:42AM (8 children)
There must be amateurs working at ESA then. Logic dictates that ESA engineers (a) should have used any means of communication -- mail, phone, fax, carrier pigeon -- feasible to get a response from SpaceX, and (b) would have strongly insisted that SpaceX move their el cheapo comms satellite out of any orbit height less than dozens of kilometers away from their own half-billion dollar satellite.
Also: did SpaceX really state that they're putting up a swarm of thousands of satellites but (a) without testing their incidence response system, (b) without monitoring where their, and other, satellites are flying, (c) without a working collision probability estimation system, (d) without the possibility to move their satellite into a different orbit, (e) without the automated possibility to bring down (safely) a satellite which has lost communication with base, and (f) without permanent coordination with all other space agencies & companies?
(Score: 2) by c0lo on Wednesday September 04 2019, @11:37AM
Yes. Because it's Musk, Elon Musk, and that's enough of a reason.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford
(Score: 4, Insightful) by The Shire on Wednesday September 04 2019, @02:09PM (5 children)
If you've ever worked in any sort of support role, no matter how critical, you'll know that this is exactly the sort of issue that can and does crop up all the time. Their incident response system did work initially. I'm sure a response ticket was generated, the entities involved discussed it, and both agreed no action was needed so the ticket was closed. The later request from ESA under that same ticket probably fell through because the system had already closed or deprioritized it with a "no action needed" status. This is where the bug likely lies and it's something that can happen in any complex system. I'm sure it didn't help that this occurred during a US holiday as well.
I do fault ESA for not using additional channels to contact the Starlink team however. Hell, they could have DM'd Musk himself.
It's worth pointing out that (b) SpaceX does know where their satellites are, (c) they have a working collision probability system same as ESA and the USAF (even this high risk assessment put the two satellites as passing 2km away from each other), (d) they do have the capability to move starlink satellites when necessary, (e) starlink satellites and really any satellite in that low orbit will come down fairly quickly without constant control - and there is tremendous debris up there which active satellites are always maneuvering around anyway, and (f) there is a coordination system with other agencies as was demonstrated by the initial contact with ESA.
Starlink is new, this is the first set of satellites put in place. If you think all such endeavors don't have growing pains like this then you've never worked in the tech sector. This comm bug will be fixed, the whole process reanalyzed and made better and they will move forward.
Now, if you're really looking for something to get angry about take a look at when China tested a satellite destroying satellite. They didn't announce the test, and the debris from the test posed an enormous hazard for everything in that orbit. And of course just last year they lost control of their entire mini space station, the Tiangong-1, and had to just sit there and hope it didn't hit anything before finally deorbiting. That's how you demonstrate incompetence.
(Score: 2) by quietus on Wednesday September 04 2019, @04:01PM (4 children)
I've got no beef with either SpaceX or ESA.
I do have quite a bit of experience with working in a support role, at L3. Something like this would immediately be signaled as a prio-1, and followed very closely, until estimated collision time, and then a bit after. If that didn't happen, that's a clear lack of professionalism. That's simply not a matter of a bug in a ticketing system -- which, given SpaceX' history, should have been cleared out long time by now.
Not being on the ball in space can easily cost your company at least tens of millions of dollars (or half a billion in Aeolus case) in direct damages, not to mention the damage in reputation. In such circumstances, you do not take a holiday as a company.
If Starlink is new, you'd expect even more due diligence and extensive testing.
If SpaceX knows where their satellites are, and have a working collision probability system, they should have contacted ESA themselves once their system indicated the threshold level of 1 in 10,000 was breached, let alone the threshold of 1 in 1000.
Orbits, or orbit bands, are not haphazard things you can choose to your liking: once Starlink44 came within range of Aeolus' orbit, they should have fired its thrusters and move it back to its designated place. That Starlink44 is moving at all into any other active satellite's orbit is a very, very, very, very bad sign in itself. That SpaceX didn't take such action is quite simply not believable.
There is clearly no coordination system: if there was, both companies would have followed up each other (in)actions. SpaceX clearly didn't do that, or they would have mentioned those further communications. In that respect, also note the remark in ESA's description where they mention that SpaceX reacted within a day. That's not a compliment: that's hard criticism.
(Score: 2) by The Shire on Wednesday September 04 2019, @06:25PM (3 children)
I think you overestimate the accuracy with which ANY company knows their satellite position to be especially in high drag LE orbits like Starlink occupies. In all cases they have an approximate spherical area where they believe it to be. Even so, when the probability of the two satellites positions had an overlap possibility of 1 in 50,000 they discussed the situation and both companies decided no action was necessary. So it's not like they aren't watching and communicating with each other. And it wasn't until much later that the AF systems came up with an update that placed the satellites within 2km of each other that ESA opted to make a maneuver.
And the idea that no one knows why Starlink "was in the ESA's Aeolus orbit" is misleading. It never was. The assigned orbits simply brought the two in close (2km is considered close for a satellite) proximity. Had the ESA done nothing it would still have been a 1 in 10,000 shot that everyones position data was off enough that they would collide. ESA is the only one who says it was a 1 in 1000 chance. The AF only put it at slightly above 1 in 10,000.
Starlink can do better, and you can bet they will after this. But honestly, there was never any real danger.
(Score: 2) by quietus on Wednesday September 04 2019, @07:22PM (2 children)
What you are saying is that NASA can track 20,000 pieces of space debris the size of a softball and 500,000 pieces the size of a marble, can manoeuvre their satellites away from these, but has not really an idea where their satellites are at any moment to about, what, hundreds of meters?
Further, linky to the Air Force probability data, please.
(Score: 2) by The Shire on Wednesday September 04 2019, @09:37PM (1 child)
What I'm saying is that when NASA says they're tracking 20,000 pieces of debris they really mean they have a good ballpark idea of where it is, like within a few kilometers. This is why collisions are reported in terms of probability rather than being definitive. They only know the position of a satellite is somewhere within a given area - not exactly, nor do they have a high precision idea of its speed. Why would ESA move their satellite a 1/4 mile if they knew precisely where and how fast everything was.
(Score: 2) by quietus on Thursday September 05 2019, @10:46AM
Within a few kilometers, eh?
GPS and Galileo satellites transmit satellite orbit data as a set of 16 quasi-Keplerian parameters, known as the ephemeris. Two further parameters are used, both of which are considered constant: the Earth rotation rate, and the Earth's gravitational constant. Long story short, Keplerian motion/orbit is determined by solving Kepler's equation, a calculation which is solved iteratively, resulting in millimetric accuracy.
Satellites depart from pure Keplerian motion due to a combination of nonuniformity of the Earth's gravitational field, the gravitational fields of the Sun and Moon, solar radiation pressurre, and other effects. These are approximated by the remaining ephemeris parameters: the mean motion correction (resolution 10E-13 rad/s), rates of change of the inclination and longitude of the ascending node (both also with a resolution of 10E-13 rad/s), and six harmonic correction terms, 4 of which have a resolution of 10E-9 rad/s, and 2 of which have a resolution of 0.03125m.
Source: Principles of GNSS, inertial, and multisensor integrated navigation systems, second edition, Paul D. Groves, published by artech house (2013). Pages 330-339.
I notice you didn't provide the 'AF' data.
(Score: 2, Insightful) by nitehawk214 on Wednesday September 04 2019, @02:30PM
The ESA are the amateurs because the single point of failure at SpaceX turned his pager off or slept through the alarm?
"Don't you ever miss the days when you used to be nostalgic?" -Loiosh
(Score: 2) by black6host on Wednesday September 04 2019, @08:16AM (2 children)
I wonder what would have happened if avoidance steps had not been taken. I read both articles but didn't see mention of that. Would a collision have occurred?
Would have been a bummer if they moved the sat up 350 meters only to put it in the path of another Muskellite :)
(Score: 0) by Anonymous Coward on Wednesday September 04 2019, @08:41AM
The chance of collision for this case is roughly 1:1700, so it's not that likely to happen. However it's already much higher then the threshold (1:10000) to take avoidance action.
(Score: 1, Troll) by The Shire on Wednesday September 04 2019, @06:29PM
The Air Force estimated they could have come as close as 2km to each other. That's too close when you're operating a satellite but there was never any real danger of a collision. They were frankly in separate and distinct orbits that happen to put the satellites in proximity.
(Score: 3, Funny) by deimtee on Wednesday September 04 2019, @09:03AM (4 children)
Collision risk was 1 in 1700
If burning that much fuel shortened the satellite's life by more than 1/1700th then moving it was the wrong choice.
If you cough while drinking cheap red wine it really cleans out your sinuses.
(Score: 4, Interesting) by pe1rxq on Wednesday September 04 2019, @09:13AM
lifetime is the wrong measure. The amount of useful science data is more interesting for a satellite as this. The longer it is up their there will be more useful data, but the data gathered earlier in its lifetime is in general more valuable.
So if it gets damaged before it has finished its main mission it is a big loss as it might mean all data is less useful. After the main mission has finished your way of thinking starts makin more sense.
(Score: 0) by Anonymous Coward on Wednesday September 04 2019, @09:18AM
Most satellite fuel goes to counteracting atmospheric drag, which takes the form of raising the satellite altitude, which is what this maneuver did. And many satellites wear out or become obsolete before they run out of fuel. So this probably doesn't have any effect on the satellite lifespan at all.
(Score: 4, Insightful) by Immerman on Wednesday September 04 2019, @01:53PM (1 child)
That's an extremely selfish and short-sighted perspective.
It's not only the satellites involved in the initial collision that are at risk - there's also everything else that comes anywhere near the band between their orbits that would get filled with debris from a collision.
(Score: 2) by deimtee on Wednesday September 04 2019, @05:15PM
Not really. It's the sort of calculation insurance assessors do. If the (cost of mitigation) is greater than (probability of event * cost of event) then you are better off taking the risk.
They are both in low circular orbits, 320km. It's extremely unlikely for any debris from a collision to have a higher perigree than the current orbit, and without active station-keeping atmospheric drag would de-orbit most of it. But you're right, a limited Kessler Syndrome should be considered as part of (cost of event).
If you cough while drinking cheap red wine it really cleans out your sinuses.
(Score: -1, Spam) by Anonymous Coward on Wednesday September 04 2019, @10:06AM (2 children)
How does this affect anyone at all? Why is this news?
I'll be censored to -1 for asking this important question because you people know I'm right and this doesn't matter. Rather than answer my question, you'll bury my post. It's shameful.
It's not like there was actually a collision. This doesn't matter and you people know I'm right.
Imported from Slashdot
(Score: 2) by tangomargarine on Wednesday September 04 2019, @08:06PM (1 child)
If we get enough satellite collisions to cause Kessler Syndrome [wikipedia.org] you can be damn sure it'll impact you. So much for GPS, for one thing. and various other things [bbc.com]
Whining like this is really just inviting people to do so. If you don't like the article, don't read it.
"Is that really true?" "I just spent the last hour telling you to think for yourself! Didn't you hear anything I said?"
(Score: 3, Insightful) by deimtee on Thursday September 05 2019, @01:49AM
Almost any collision reduces kinetic energy. You will never get a collision that raises perigee. You might get a few pieces with a higher apogee, but in that case their orbit will be more eliptical and they will de-orbit even faster.
Kessler Syndrome requires you start high and the debris works its way down. Even if these two collided it would be at 320km, the chance of any piece getting out to 36,000km is zero.
If you cough while drinking cheap red wine it really cleans out your sinuses.
(Score: -1, Troll) by Anonymous Coward on Wednesday September 04 2019, @01:22PM (2 children)
ESA sounds like a spoiled child, this sort of manoeuvre happens all the time, what's the fuss?
The gentleman's agreement appears to be for the two controllers to talk and decide what is the best plan and then do it.
That fixes the problem of each thinking the other was going to move and also both moving into a new collision course.
In this case, SpaceX did not participate in the discussion, except for an initial exchange before the collision seemed sufficiently possible.
X says this was due to a bug in their automatic call the controller, notification system.
Perhaps until they get a lot more automatic operational experience it would be wise to monitor the constellation with actual live folks present, 24-7?
ESA could have been more clear why they called X on this, but a poor message delivery does not make the message wrong.
(Score: 2, Interesting) by takyon on Wednesday September 04 2019, @01:50PM (1 child)
ESA made it news. Maybe to throw shade at SpaceX or broadband constellations in general. There may be a hidden push to restrict these 1k+ satellite constellations, and astronomers are going to be the loudest opponents.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by quietus on Wednesday September 04 2019, @04:14PM
What?
You don't see a problem with satellite A moving into orbit of another active satellite B, and the company behind satellite A going 'duh -- our guy had a problem with his pager, dude'?
(Score: 0, Offtopic) by Runaway1956 on Wednesday September 04 2019, @02:07PM
One of them got lost, and ended up in the "New World" - that's history. Now, we've got Euros bumbling around way up above the sky? There's no telling what they'll stumble onto up there. We need to keep an eye on them. The conquistadors never did find that fountain of youth, did they? It's likely up there in the heavens somewhere, and the Euros are looking for it!
“I have become friends with many school shooters” - Tampon Tim Walz