we need traffic lights for satellites - Page 1
Forum section: electronics / general

author: madires
author_rank: Super Contributor
timestamp: September 03, 2019, 12:26:20 pm
content: ESA had to perform a collision avoidance manoeuvre for Aeolus because of SpaceX' Starlink:https://twitter.com/esaoperations/status/1168533241873260544SpaceX Refused To Move A Starlink Satellite At Risk Of Collision With A European Satellite:https://www.forbes.com/sites/jonathanocallaghan/2019/09/02/spacex-refused-to-move-a-starlink-satellite-at-risk-of-collision-with-a-european-satellite/#6e2c36d51f62Aeolus is a little bit longer in space than the Starlink satellite. So we can guess what will happen with tons of LEO internet satellites and SpaceX' attitude.

author: Ysjoelfir
author_rank: Frequent Contributor
timestamp: September 03, 2019, 01:30:14 pm
content: Naaaah, just build a three dimensional matrix of hyperloopses in space for every sattelite out there. Problem solved. It will only cost 1$ for a sat to travel through the loop!

author: bd139
author_rank: Super Contributor
timestamp: September 03, 2019, 02:43:09 pm
content: Raytheon have a decent solution for this in development. It's called the MOKV, the Multiple Object Kill Vehicle

author: nuclearcat
author_rank: Unknown
timestamp: September 03, 2019, 05:50:49 pm
content: As i understand they have quite weak Krypton thruster, and it can operate only some time on each turn (90min), i guess only when panels are insolated.They have single panel, again according "internet sources" approx 3kW, thruster according to publicly available data on efficiency can provide approx 150 millinewtons.Weight of satellite is approx 227kg.Current orbit according to article 320km.It means 7718.27m/s current orbital speed. Just if they raise orbit 10km they will have orbital speed 7712.51m/s, and need ~24h of continuous engine operation, taking in assumption ESA tweet "The manoeuvre took place about 1/2 an orbit before the potential collision. "I have some doubts that we can say these satellites have proper collision avoidance capabilities.Does anyone have more info?To test my theory i took this data on their orbit change maneuer.According to news orbit raise maneuver was (very approximately) from 2019/05/27 to 2019/06/14, 19 days. If we assume data above is correct, they need to run at least 56% of time such thruster.On the orbit 440km satellite will spend in shadow (keeping in mind atmosphere attenuation too) t=τ*(2θ)/(2π)m where is τ = orbital period θ = arcsin(r/(r+h)) (r is 6371 + 100) approx 39% of all time.It looks like close to true...Knowing how I am prone to make horrible mistakes in numbers and how in a hurry i wrote this assumption - maybe I wrote nonsense above

author: schmitt trigger
author_rank: Super Contributor
timestamp: September 03, 2019, 06:02:42 pm
content: Quote from: bd139 on September 03, 2019, 02:43:09 pmWhich, instead of a single object one would have to watch for, would generate thousands of fragments creating a lethal shrapnel cloud orbiting the earth.As a matter of fact the Chinese military performed such a test a few year ago, and created such an orbiting hazard.

author: magic
author_rank: Super Contributor
timestamp: September 03, 2019, 07:19:24 pm
content: Yeah, cheaper to just nuke SpaceX and let their satellites safely fall down into the atmosphere

author: SiliconWizard
author_rank: Super Contributor
timestamp: September 03, 2019, 08:04:42 pm
content: Oh, and who said it would never get crowded enough up there that we should care?

author: Red Squirrel
author_rank: Super Contributor
timestamp: September 03, 2019, 08:15:49 pm
content: Will be interesting once SpaceX does in fact launch all the sats they plan to. If they do it I'm sure another party will want to compete and do so as well. it's going to be like the 401 up there except instead of travelling at 0.01m/s you're travelling at 7000m/second.

author: madires
author_rank: Super Contributor
timestamp: September 04, 2019, 08:43:13 am
content: SpaceX satellite was on “collision course” until ESA satellite was re-routed:https://arstechnica.com/information-technology/2019/09/spacex-satellite-was-on-collision-course-until-esa-satellite-was-re-routed/SpaceX underestimated the risk of collision and then a bug in the paging system prevented them to receive the US Air Force's update about the increased collision probability. A convenient excuse?

author: Psi
author_rank: Super Contributor
timestamp: September 04, 2019, 09:04:59 am
content: Traffic lights wouldn't work, but i'm sure you know that.But maybe a TCAS system like planes use could work.Where the satellites can take their own action to move out of the way in opposite directions if they sense a proximity issue.It would likely have to be based on a global tracking system of all sats, rather a than radio signal/transponder system like TCAS.Depending on the orbits the collision could be a slow approach or a head on collision at km's per second with little time to detect a short range transponder before impact.And the issue of satellites with hall/plasma/ion thrusters not being able to move fast means you need lots of advanced warning.

author: timgiles
author_rank: Regular Contributor
timestamp: September 04, 2019, 09:53:08 am
content: I still find it hard to believe in a three dimensional space (spherical skin with depth of x meters or kms) the size of the earths diameter plus a tiny bit - that satellites really get that close to each other - ever! Unless they are programmed to do so (conspiracy theory time!).Am I wrong? Please help my old grey matter understand if so. I just dont see it happening. Sure, space debris, but that is many many magnitudes higher density.

author: Brumby
author_rank: Unknown
timestamp: September 04, 2019, 12:10:31 pm
content: Every orbit of every satellite is different. They will have different apogee and perigee and they will drift. The more satellites you have, the longer they are circling the Earth, the greater the chances that you will have an intersect - and destruction.The reason there hasn't been a big problem with collisions is because of the volume of space involved, but as the number of satellites increase, these odds get less.It is the same sort of problem we have had to deal with in regards to atmospheric pollution.... When it first started out, the impact on the environment was ignorable - so it was ignored. Then it got worse and now we are facing major problems. The only reason satellites have been given the attention they have is because of the cost.

author: Psi
author_rank: Super Contributor
timestamp: September 04, 2019, 01:43:50 pm
content: Also, when they say collision it's not a certainty it's a statistical probability and it's very small.When your satellite is worth 100 of millions in replacement costs even a remote chance of a collision is too high.

author: madires
author_rank: Super Contributor
timestamp: September 04, 2019, 01:49:04 pm
content: Quote from: Psi on September 04, 2019, 09:04:59 amWe already have a tracking system of all satellites and larger debris. TCAS for sats sounds neat, but I think it wouldn't be feasable. Current sats in space can't be upgraded, and we still have to track debris. What about rogue sats or ones with a broken TCAS?

author: Psi
author_rank: Super Contributor
timestamp: September 04, 2019, 02:00:18 pm
content: Quote from: madires on September 04, 2019, 01:49:04 pmIt would be for new sats, It would obviously not help older sats hitting other older sats.But any new sats could avoid any olders sats or debry using data from ground based sat tracking.Newer sats could also coordinate directly with other newer sats to avoid each other

author: SparkyFX
author_rank: Frequent Contributor
timestamp: September 04, 2019, 04:01:47 pm
content: Quote from: Psi on September 04, 2019, 09:04:59 amThe orbital mechanics require satellites to take action while on the other side of the orbit the potential collision would occur, at least that is the location where you get the biggest change of height in the shortest time with the lowest amount of fuel.You could move a satellite sideways (change its inclination), but it would cost lots of fuel for very little change.So there is no direct line of sight/communication and for proximity based systems this would be too late, as most satellite thrusters do not have a lot of thrust (provide only a small fraction of the weight of the satellite, making this a very slow process). They are built for small corrections that need to take place at the right time.As far as i understood it, TCAS in planes more or less assumes all others stay on their course on their altitude (as in a circular orbit), satellites do not necessarily have to have a circular orbit, making the calculations and detection way more complex.Video about collisions in space and collision avoidance:

author: nuclearcat
author_rank: Unknown
timestamp: September 04, 2019, 10:54:44 pm
content: Quote from: SparkyFX on September 04, 2019, 04:01:47 pmI think it is quite simple, if satellites able to get their position anyhow (GPS on orbit?). They need few points and its enough to build TLE. Send it to ground stations across the globe, and they will assist this "satellite-TCAS", same as flight dispatchers.The only difference is that the satellite is better to start the maneuver in advance. For example, Starlink is very slow to move.Dispatchers can also help to plan orbit movements.

author: klunkerbus
author_rank: Unknown
timestamp: September 04, 2019, 11:26:27 pm
content: I seem to recall that the Kessler Syndrome from the 70's suggested it was just a matter of time before LEO became a disaster zone.

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 04, 2019, 11:31:11 pm
content: Quote from: timgiles on September 04, 2019, 09:53:08 amAviation safety used to depend on exactly that reasoning. Then flying became more popular and people started dying.

author: m98
author_rank: Frequent Contributor
timestamp: September 04, 2019, 11:48:22 pm
content: There really should be some kind of space traffic control a commercial satellite operator should have to stay in touch with to coordinate maneuvering.

author: coppercone2
author_rank: Super Contributor
timestamp: September 04, 2019, 11:58:24 pm
content: lol, pay protection money for your satellite.

author: Red Squirrel
author_rank: Super Contributor
timestamp: September 05, 2019, 01:49:53 am
content: Is a satellite considered a vehicle, wonder if you can get car insurance for one."Sir, can you clarify your speed before the collision? Are you still on the accident scene? We're going to need to send an adjuster. "Quote from: m98 on September 04, 2019, 11:48:22 pmThis is probably the best bet, I think they already do track space objects including junk, so it could be the thing of predicting collisions way ahead of time, calculating the most efficient maneuver, and time, and then sending the info to the operator. Kinda like a "btw your satellite will collide with xyz on this date, to correct, follow this maneuver".

author: coppercone2
author_rank: Super Contributor
timestamp: September 05, 2019, 02:22:54 am
content: are they gonna have to pay NORAD for all the extra shit they put up there? should there be a rule against American companies using foreign nation to launch satellites under their control? should a space control cabal be formed?

author: windsmurf
author_rank: Frequent Contributor
timestamp: September 06, 2019, 07:05:46 am
content: Quote from: Red Squirrel on September 05, 2019, 01:49:53 amhttp://www.parabolicarc.com/2019/08/01/satellite-insurance-rates-increasing-after-failures-of-vega-worldview-4/https://en.wikipedia.org/wiki/Satellite_insurance

author: lilstevie
author_rank: Contributor
timestamp: September 06, 2019, 07:24:56 am
content: Quote from: Red Squirrel on September 05, 2019, 01:49:53 amThe problem is there's a margin of error in the calculations, like with everything the real world is far from perfect, without mapping the exact amount of gravity and resistance from the upper layers of the atmosphere for every mm^2, we won't know exactly where the satellite will end up on its track. That's why this story, and collision tracking in general talks in probability of a collision. The collision was in no way guaranteed, it was just too much of a risk to chance it.

author: Gyro
author_rank: Super Contributor
timestamp: September 06, 2019, 08:49:45 am
content: Quote from: coppercone2 on September 05, 2019, 02:22:54 amESA should certainly charge them for the fuel used and reduction in operational life of Aeolus.

author: coppercone2
author_rank: Super Contributor
timestamp: September 07, 2019, 02:48:42 am
content: are satellite related lawsuits precedented?I mean, for stuff that happens in space, not dishnet related scammers as usual/illegal tv, or patent crap. I mean like collisions, occupation of orbital path, interferencehttps://www.space.com/20173-china-space-junk-crash-lawsuit.htmlhttp://www.thespacereview.com/article/3392/1can this lead to lesser nations becoming some kind of satellite launch havens since they will reject litigation? Kind of like Caymen islands, Panama, Switzerland, Ireland being tech/financial hubsMany states have adopted national space legislation, including Argentina, Australia, Austria, Belgium, Brazil, Canada, Chile, China, France, Germany, Japan, Kazakhstan, the Netherlands, Norway, the Republic of Korea, Russia, South Africa, Spain, Sweden, Ukraine, the United Kingdom, and the United States.4 Several are detailed below, in order to demonstrate the common approach to absolute versus fault-based liability and state liability versus corporate liability.Is north korea a Chinese satellite haven?I don't think it would take too much to build a launch pad some where? I feel like south/middle america can make bank if they just decide to have lax space laws and are in dire straits already. Their not exactly horrible places to live for space engineers.Ecuador,Colombia, Brazil,Sao Tome & Principe,Gabon, Republic of the Congo, Democratic Republic of the Congo, Uganda, Kenya, Somalia,Maldives,IndonesiaandKiribati. All equatorial .Somalia, Kenya, Congo and Uganga would probably be destabilized by the CIA if they tried it. No idea what Gabon or Sao Tome or Kiribati are. shady Nigerian satilite launch site possible? can this fix africa?

author: Lord of nothing
author_rank: Super Contributor
timestamp: September 11, 2019, 11:30:41 am
content: A Group in Denmark when I right rember build a Space Rocket with parts from the conventional Market.Why not collect Money and troll the Ami by wrap some Sticky Alu foil around there Keyhole Sat.

author: madires
author_rank: Super Contributor
timestamp: May 28, 2020, 02:09:43 pm
content: Bankrupt OneWeb seeks license for 48,000 satellites, even more than SpaceX:https://arstechnica.com/tech-policy/2020/05/spacex-and-oneweb-seek-licenses-to-launch-78000-broadband-satellites/

author: nuclearcat
author_rank: Unknown
timestamp: May 28, 2020, 08:11:53 pm
content: I think all of them should pay "insurance", provide specs and keep up to date current info about satellites to some international authority, in case they declare themself "not profitable" as many startups do, and then just disappear.At least someone should be able to manage their crap on orbit, to avoid collisions and making huge amount of debris."Oh sorry our"solar roadways"tons of satellites for better internet idea didnt worked", and whole humanity watch flying junk that will close access to space for several generations.

author: coppercone2
author_rank: Super Contributor
timestamp: May 30, 2020, 03:22:15 am
content: That would be 8 times more satellites then are currently in space. That is alot of liabilities.

author: rgarito
author_rank: Regular Contributor
timestamp: May 30, 2020, 08:40:31 am
content: Perhaps the same person who thought we'd never outgrow 640K of RAM?

author: Syntax Error
author_rank: Frequent Contributor
timestamp: May 30, 2020, 09:42:43 am
content: Problem with satellites is they are not meant to come down. Even LEO satellites remain as hazardous waste for decades. There must be a rule to deorbit (burn up) a satellite after it's mission has expired. Graveyard orbits are just a way of moving space junk somewhere/some when else. Oceanic states may protest that the Pacific is not a dumping ground for space waste.A thought about Starlink, would a major earth bound CME leave hundreds of dead satellites in orbit? They are rad-hard?A concept solution? Space harpoon skewers 'orbital debris'https://www.bbc.co.uk/news/science-environment-47252304

author: madires
author_rank: Super Contributor
timestamp: July 31, 2020, 12:58:54 pm
content: FCC approves Amazon’s internet-from-space Kuiper constellation of 3,236 satellites:https://www.theverge.com/2020/7/30/21348768/fcc-amazon-kuiper-satellite-constellation-approval

author: cdev
author_rank: Super Contributor
timestamp: July 31, 2020, 03:18:57 pm
content: Those satellites are ruining astrophotography and increase the risk that an unobserved meteor could collide with Earth but Elon Musk couldn't care less.At the very least he could have simply painted them black.Quote from: madires on September 03, 2019, 12:26:20 pm

author: cdev
author_rank: Super Contributor
timestamp: July 31, 2020, 03:26:52 pm
content: If brought in the courts of any specific country, especially the US, I suspect they will bepreempted, if they aren't already.Meaning preempted by some international treaty or another. In case you hadn't noticed there is an international gold rush going on to grab up all rights that arent already grabbed by somebody, this is so corporations can claim the continuation of that policy, whatever it is, is their "property". "After all they are the job creators". /sarcasm.Quote from: coppercone2 on September 07, 2019, 02:48:42 amSeehttp://apps.agi.com/SatelliteViewer/for an idea of how much debris we need to track now.Re picture: ALL YOUR SPACE ARE BELONG TO US!"

author: Lord of nothing
author_rank: Super Contributor
timestamp: July 31, 2020, 07:11:57 pm
content: Why does it remember me at many Bond Movies? That Guys with the Satellites was never the good one.

author: wraper
author_rank: Unknown
timestamp: July 31, 2020, 07:39:01 pm
content: Quote from: madires on September 03, 2019, 12:26:20 pmThis is an outdated claim which is not true. There was miscommunication.https://www.theverge.com/2019/9/3/20847243/spacex-starlink-satellite-european-space-agency-aeolus-conjunction-space-debrisQuoteAlso that was not a standard Starlink orbit. It happened during deorbiting testing.

author: wraper
author_rank: Unknown
timestamp: July 31, 2020, 07:45:32 pm
content: Quote from: Syntax Error on May 30, 2020, 09:42:43 amThey are exactly meant to come down. Even if they fail to do so, they will deorbit due to atmospheric drag (yes there still are a little bit of air particles) in a few years unlike satellites at higher orbits which will stay there basically forever.Quote from: cdev on July 31, 2020, 03:18:57 pmWith current technology available, you would have observed meteor colliding with Earth. Result would be exactly the same.

author: Lord of nothing
author_rank: Super Contributor
timestamp: July 31, 2020, 08:51:21 pm
content: Quotewell I would say such company must be forced to pay, hire a Insurance Company who kicks in to remove it when the Company not exist any more.

author: wraper
author_rank: Unknown
timestamp: July 31, 2020, 09:06:44 pm
content: Quote from: Lord of nothing on July 31, 2020, 08:51:21 pm

author: Lord of nothing
author_rank: Super Contributor
timestamp: July 31, 2020, 09:16:36 pm
content: Why should the Public aka Tax Payer pay a Company to remove the Sat from an old one?Well here in my Country a Company who own a Property who is contaminated with Toxic Material must remove then thats why some place in a (former) Business Park is emty and the City was forced to remove the remains because the just Dumped Chemicals behind the Factory in a Trench.

author: wraper
author_rank: Unknown
timestamp: July 31, 2020, 09:23:56 pm
content: Quote from: Lord of nothing on July 31, 2020, 09:16:36 pmDo you have completely no clue about space or what? Satellite will deorbit by itself in a time of a few years if it fails and cannot deorbit proactively. Nobody in sane mind will fly to collect garbage from space with current technology available. Unless there is a huge leap in propulsion like from electron tubes to modern CPUs, it won't be viable. FYI Geostationary satellites move to graveyard orbit at the and of their lifetime.https://spaceplace.nasa.gov/spacecraft-graveyard/en/

author: cdev
author_rank: Super Contributor
timestamp: July 31, 2020, 09:38:18 pm
content: Lots of LEO satellites are still up there that have been orbiting Earth for a very long time. So I dont think it's so cut and dry.Quote from: wraper on July 31, 2020, 09:23:56 pm

author: wraper
author_rank: Unknown
timestamp: July 31, 2020, 09:44:25 pm
content: Quote from: cdev on July 31, 2020, 09:38:18 pmLEO has a quite broad orbit altitude range. Starlink satellites are on the lower part of LEO where atmospheric drag is significant.

author: Lord of nothing
author_rank: Super Contributor
timestamp: July 31, 2020, 09:48:55 pm
content: QuoteWhich Upcomming Space Company want to wait "a few years" until there is space for them?Here in Europe we saw it with the Scooter. A Company shut down at Friday and declare bankruptcy and the City had to remove on there own cost all useless Scooter.Lets say Space X when out of Business or sell there Sat (on the Paper) and that Company went down who feel capable of that junk?QuoteThats why we must force them to think about that FIRST and than permit them to launch a huge amount of Sat who will be up forQuote.Maybe its the "European way" of think about sub stability.

author: wraper
author_rank: Unknown
timestamp: July 31, 2020, 10:02:32 pm
content: Quote from: Lord of nothing on July 31, 2020, 09:48:55 pmLOL?There is no "space" of deorbiting sattelite new company needs to wait for. Nor that "exact spot" will be given to any other company to begin with. Not to say that decaying satellite gradually lowers it's orbit.I started doubting your sanity. It's not like any satellite is obstructing anyone. There is a lot of free space. The concern it that satellites on different orbits may collide in some circumstances and as they travel at extremely high speed create a lot of widespread debris clouds which then may hit other satellites.My suggestion is go read some stuff about what the space is, how things work there and don't embarrass yourself further.

author: madires
author_rank: Super Contributor
timestamp: August 01, 2020, 11:34:01 am
content: Launch windows will have to become tighter and the operational part be will be harder too, especially if some satellites aren't there where they should be according to the database.

author: rdl
author_rank: Super Contributor
timestamp: August 01, 2020, 07:00:50 pm
content: There's only going to be about one satellite for every five thousand square kilometers or so.

author: madires
author_rank: Super Contributor
timestamp: October 27, 2020, 01:53:59 pm
content: About 3% of Starlink satellites have failed so far:https://phys.org/news/2020-10-starlink-satellites.html

author: sandalcandal
author_rank: Unknown
timestamp: October 27, 2020, 02:54:20 pm
content: Quote from: madires on October 27, 2020, 01:53:59 pmI was interested in getting actual numbers but couldn't find anything.Cited (hobbyist?) reports here:https://planet4589.org/space/jsr/back/The only thing I found was"As of Oct 7 , 775 Starlinks have been launched and 728 remain in orbit.", 47 lost out of 775 which is a 6% loss at most compared to 8% in the phys.org article and doesn't mention 3% failures to respond.This also contradicts the phys.org article's statement "To date, the company has launched over 800 satellites..." maybe if you include non-starlink satellites?another 120 have been launched between the quote from Jonathan's Space Report No. 784 and the phys.org article.Also 39 of the no longer in orbit were deorbited prototype systems:Quote from: Jonathan's Space Report No. 784

author: madires
author_rank: Super Contributor
timestamp: January 18, 2021, 11:22:00 am
content: Good news:OneWeb reduces constellation plans from 47,884 to 6,372 satellites:https://www.oneweb.world/media-center/oneweb-streamlines-constellationBad news:Darkened SpaceX Satellites Can Still Disrupt Astronomy, New Research Suggests:https://gizmodo.com/darkened-spacex-satellites-can-still-disrupt-astronomy-1846066403

author: Gyro
author_rank: Super Contributor
timestamp: January 18, 2021, 12:20:39 pm
content: Richard Branson has just sent up another 10 small low orbit satellites from a Boeing 747.https://www.bbc.co.uk/news/science-environment-55699262

author: madires
author_rank: Super Contributor
timestamp: April 12, 2021, 09:28:10 am
content: Direct competition?OneWeb, SpaceX satellites dodged a potential collision in orbit:https://www.theverge.com/2021/4/9/22374262/oneweb-spacex-satellites-dodged-potential-collision-orbit-space-force

author: GlennSprigg
author_rank: Super Contributor
timestamp: April 16, 2021, 11:47:40 am
content: Maybe my 'mind' is too simplistic and/ornaive, but I can't help thinking that all we need is better communication between Countries, andwork more together towards commongoals/needsin space now. I would 'like' to think that GONE are the Cold-War days of secretive developmentsand deployments, and to a certain degree it is happening now between certain Countries & Companies!I remember reading a book by the very knowledgeable & talentedCarl Sagan, (who has sadly passed), who wrote a book called 'Contact'.It was a work offiction, but I'm sure it was his dream about how he would love something like this to really come to fruition!! For the un-initiated, it is about some remote Alien lifeforms finally actually making contact with us... Containing complex instructions about how to 1stinterpret their information/data, and then instructions about how to 'build' a massively complex machine, to travel back to them!!!Theupshotof it all, was that it was so huge, complex & expensive technological project, that literally the whole World had to get togetherto fabricate all the components, and to actually build it!! I'm sure he desired 'us' all working together some day!!

author: madires
author_rank: Super Contributor
timestamp: August 21, 2021, 09:40:24 am
content: SpaceX Starlink satellites responsible for over half of close encounters in orbit, scientist says:https://www.space.com/spacex-starlink-satellite-collision-alerts-on-the-rise(includes autoplay video)

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 21, 2021, 05:39:25 pm
content: And this is just the beginning...

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 21, 2021, 05:45:36 pm
content: Quote from: GlennSprigg on April 16, 2021, 11:47:40 amThis sounds nice, but what exactly would be those common goals and who is going to define them? Who is going to make sure they'll be good for people and the future of humankind? At this point, it looks like a lot of what we have done has been pretty disastrous on a large scale, and those disastrous decisions are usually the ones that are the most well shared among countries. In other words, if there's something we seem to easily agree on worldwide, it's doing a lot of shit. This doesn't bode well.Quote from: GlennSprigg on April 16, 2021, 11:47:40 amOh really. It doesn't appear to be the case. The current situation is a lot worse than during the cold war IMHO, and the world a lot more unstable.

author: james_s
author_rank: Super Contributor
timestamp: August 21, 2021, 09:04:22 pm
content: Quote from: timgiles on September 04, 2019, 09:53:08 amIt's one of those things where if you tried to aim a satellite so it would collide with another it would probably never happen, but chance collisions do happen. It's similar with aircraft, the sky is really big, airplanes are relatively thin, yet aircraft still collide now and then.

author: ejeffrey
author_rank: Super Contributor
timestamp: August 21, 2021, 10:21:23 pm
content: Also just like aircraft certain orbits are much more popular than others, such a sun synchronous polar orbits and geostationary equitorial orbits.Also the threshold for corrective action is extremely conservative. The vast majority of events would not result in a collision without correction but they move anyway.

author: rdl
author_rank: Super Contributor
timestamp: August 22, 2021, 07:41:56 pm
content: Starlink satellites are in a fairly regularly spaced network. They are widely spread over a range of inclinations. They are at low enough altitudes that they will naturally de-orbit in a matter of years due to atmospheric drag. Seems like the biggest danger is running into one on the way up to somewhere else.

author: antenna
author_rank: Frequent Contributor
timestamp: August 22, 2021, 08:34:03 pm
content: I've been using Starlink internet since January and it has been absolutely amazing. I went from 25kb tether as an only option to downloading several GB in minutes. I hope people keep their satellites out of Starlink's way, because I really like my internet! Someone needs to build a satellite with enough maneuver fuel and a big dust pan to fly around and scoop up the trash like dish network, direct tv and hughesnet, the old satcoms used by pirates, broken noaa imaging sats etc and toss it all in the pacific lol. Get rid of the junk, know your altitude, and maybe we wouldn't need traffic lights in space. Stop and go takes thrust. You cannot sustain that kind of solution.

author: james_s
author_rank: Super Contributor
timestamp: August 23, 2021, 05:41:40 am
content: The problem with trying to scoop up the junk is that it tends to be moving at thousands of miles per hour with random trajectories and if you do have a collision you end up with a whole bunch more debris flying at high speed in random directions.

author: madires
author_rank: Super Contributor
timestamp: August 23, 2021, 01:30:56 pm
content: Yep, a single collision event can cause an avalanche, especially when happening in a popular orbit. Another point often ignored is that satellites don't have a precise track they follow. They wobble around and need corrections from time to time. We're talking about a few 100 meters. The next point is about launch windows for rockets. With much more LEO satellites swirling around launches become complex as your rocket needs to avoid whatever is orbiting our planet. It's a 3D space with many objects moving around with different speeds in different orbits.

author: nuclearcat
author_rank: Unknown
timestamp: August 23, 2021, 11:33:26 pm
content: Stupid idea (because i didnt thought a lot about it), what is we deploy one big amount of substance like polyurethane foam that will expand after "cleaner satellite" reach orbit, as it expand, it take large space and work as trap. All objects will be stuck inside it and it wont go pieces, similar what sand and water does to bullets.Plus attached to the metal mesh net and some kind of engine that can deorbit it, when it gets full or too unstable (too many impacts).

author: m98
author_rank: Frequent Contributor
timestamp: August 24, 2021, 01:23:52 am
content: Quote from: nuclearcat on August 23, 2021, 11:33:26 pmSpace is big. Imagine trying to stop global traffic violations by deploying two police officers to the Gobi desert.

author: nuclearcat
author_rank: Unknown
timestamp: August 24, 2021, 03:50:54 am
content: Quote from: m98 on August 24, 2021, 01:23:52 amSince it have thruster it can be directed on collision path with debris, to adsorb them. Its big in size, but mass is low, so it wont require lot of fuel.

author: wraper
author_rank: Unknown
timestamp: August 24, 2021, 10:16:36 am
content: Quote from: nuclearcat on August 23, 2021, 11:33:26 pmYou will need a lot of very durable foam to capture something that travels at ~30000 km/h velocity. And as that foam need to stay in orbit as well, up to ~60000 km/h equivalent of hitting stationary object. And then it needs to be able to deorbit itself, otherwise you only create more junk in orbit.QuoteYou cannot simply steer it. Changing direction even slightly takes a huge amount of energy.

author: nuclearcat
author_rank: Unknown
timestamp: August 24, 2021, 02:05:41 pm
content: Quote from: wraper on August 24, 2021, 10:16:36 amMight be possible, if this foam are in cells, and foam itself is non-newtonian. But sure its not easy.And not only durable, most likely on impact all this will begin to spin, i.e. it will be difficult to compensate for the kinetic energy from the impact and stabilize such "cleaner satellite" (and it needs to be stabilized, so RF links and solar panels can work properly).Some minor manoeuvres can be done, but for sure you need to launch such satellites on specific orbits, targeting largest or most problematic debris.My idea is not original or new:https://www.forbes.com/sites/jamiecartereurope/2020/06/16/well-clean-up-space-junk-using-sticky-foam-spiderwebs-in-orbit-says-russian-space-start-up/

author: iMo
author_rank: Super Contributor
timestamp: August 24, 2021, 02:57:23 pm
content: Small debris could be swept out with a strong laser gun.Something like 10MWatt continuous laser beam would do the job, imho..

author: wraper
author_rank: Unknown
timestamp: August 24, 2021, 03:15:13 pm
content: Quote from: nuclearcat on August 24, 2021, 02:05:41 pmThat is quite different from what you proposed.

author: sandalcandal
author_rank: Unknown
timestamp: August 24, 2021, 03:43:57 pm
content: Quote from: imo on August 24, 2021, 02:57:23 pmI was actually involved in a project using lasers to perturb space debris out of orbit during undergrad.https://www.flightglobal.com/eos-to-build-system-to-clear-up-space-debris-/55033.articleProject seems to still be alive and going (same supervisor too)https://www.universetoday.com/150896/ground-based-lasers-could-push-space-debris-off-collision-course-orbits/Edit: I'll add it was definitely a real serious project with real hardware and money being implemented. However, the laser pushing function seemed like a side benefit to the "primary" utility which was the star guide star function for Astronomy AO, most of the systems being used were interchangeable so the laser pushing concept was a major idea being explored.

author: iMo
author_rank: Super Contributor
timestamp: August 24, 2021, 07:32:47 pm
content: Quote from: sandalcandal on August 24, 2021, 03:43:57 pmThat would certainly work provided you have got a pretty powerful laser handy.Today's best military lasers are around 100kW max. That is not enough for working with LEO debris, imho.

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 24, 2021, 07:40:48 pm
content: Let's send all our trash into orbit and then play with lasers. The 21st century is going to be a lot of fun!

author: sandalcandal
author_rank: Unknown
timestamp: August 25, 2021, 07:28:16 am
content: Quote from: imo on August 24, 2021, 07:32:47 pmCan't remember the exact figures but the laser power was much lower than that I think. I recall the idea isn't to obliterate the debris but get the (presumably small) debris to deorbit through ablation/differential heating by shooting them as they are approaching (from appearing at the horizon till overhead-ish) to give negative acceleration. I was just doing some system engineering for some of the support infrastructure so I didn't do any numbers on how efficient the system was likely to be. They still seem to be going if that's any indication of being feasible still or just milking funding. The main commercial partner for the project, EOS, is a defence contractor.Edit: Found a conference paper from the same research group on the project herehttps://openresearch-repository.anu.edu.au/bitstream/1885/196466/2/01_Lingham_Adaptive_optics_tracking_and_2018.pdfLooks like the planned operational power of the manoeuvring laser was 10kW.

author: iMo
author_rank: Super Contributor
timestamp: August 25, 2021, 10:26:56 am
content: You have to build a space station equipped with powerful CW lasers, flying above the main debris belt, shooting at the debris from above to force them down to de-orbit and burn in atmosphere.All systems have been designed in detail in Pres. Reagan's "SDI program" (1983) already..https://en.wikipedia.org/wiki/Strategic_Defense_Initiative

author: madires
author_rank: Super Contributor
timestamp: December 28, 2021, 02:47:56 pm
content: China Says SpaceX Satellites Nearly Collided With Its Space Station (https://science.slashdot.org/story/21/12/28/0150255/china-says-spacex-satellites-nearly-collided-with-its-space-station)

author: wraper
author_rank: Unknown
timestamp: December 28, 2021, 02:55:19 pm
content: Quote from: madires on December 28, 2021, 02:47:56 pmAnd frankly Chinese can go fuck themselves with those accusations.https://en.wikipedia.org/wiki/2007_Chinese_anti-satellite_missile_testQuote

author: richnormand
author_rank: Unknown
timestamp: December 28, 2021, 10:18:22 pm
content: Not to forget they don't care where the booster rockets come back down to crash... until I guess when it will fall on someone.https://www.space.com/chinese-rocket-booster-long-march-5b-space-junk-crash

author: SiliconWizard
author_rank: Super Contributor
timestamp: December 29, 2021, 01:53:55 am
content: Quote from: wraper on December 28, 2021, 02:55:19 pmSure, it shows their ass is not clean, but in the end, it shows that orbital space contamination and congestion are quickly becoming a problem. And it also likely to create possibly severe international tensions.

author: cdev
author_rank: Super Contributor
timestamp: January 13, 2022, 03:03:42 am
content: IF THIS TEXT IS BLUE YOU ARE DRIVING TOO FAST

author: madires
author_rank: Super Contributor
timestamp: March 01, 2022, 02:25:22 pm
content: Next LEO constellation (roughly 1k satellites planned):- National Defense Space Architecture (NDSA), Systems, Technologies, and Emerging Capabilities (STEC):https://deftech.nc.gov/blog/2021/02/05/national-defense-space-architecture-ndsa-systems-technologies-and-emerging- Space Development Agency Makes Awards for 126 Satellites to Build Tranche 1 Transport Layer:https://www.defense.gov/News/Releases/Release/Article/2948229/space-development-agency-makes-awards-for-126-satellites-to-build-tranche-1-tra/