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| we need traffic lights for satellites |
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| sandalcandal:
--- Quote from: madires on October 27, 2020, 01:53:59 pm ---About 3% of Starlink satellites have failed so far: https://phys.org/news/2020-10-starlink-satellites.html --- End quote --- I 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 [2020], 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 --- Starlink retirements -------------------- SpaceX is retiring the V0.9 constellation of 60 prototype satellites launched in May 2019. As of Oct 7, 39 of the 60 satellites have reentered. This is a new kind of reentry: it's not a normal impulsive deorbit and not a normal orbital decay, but something inbetween. The Starlink satellites are, apparently, retired by continuously lowering their orbit with electric propulsion. Reentry occurs in a way similar to uncontrolled reentry - eventually the satellite is low enough and the ambient density is high enough that the vehicle heats, breaks up and is destroyed. The crucial point here is that the *location* of the breakup on the Earth is unpredictable and uncontrolled, in contrast to an impulsive deorbit where the rapid elliptical-orbit descent from a relatively high apogee means that reentry location is determined relatively precisely by the orbital parameters. These Starlink retirements should perhaps be termed `propulsion-assisted orbital decay' - they are more like normal uncontrolled orbital decay but speeded up by the thrusters. --- End quote --- |
| madires:
Good news: OneWeb reduces constellation plans from 47,884 to 6,372 satellites: https://www.oneweb.world/media-center/oneweb-streamlines-constellation Bad news: Darkened SpaceX Satellites Can Still Disrupt Astronomy, New Research Suggests: https://gizmodo.com/darkened-spacex-satellites-can-still-disrupt-astronomy-1846066403 |
| Gyro:
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 |
| madires:
Direct competition? ;D 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 |
| GlennSprigg:
Maybe my 'mind' is too simplistic and/or naive, but I can't help thinking that all we need is better communication between Countries, and work more together towards common goals/needs in space now. I would 'like' to think that GONE are the Cold-War days of secretive developments and deployments, and to a certain degree it is happening now between certain Countries & Companies! :-+ I remember reading a book by the very knowledgeable & talented Carl Sagan, (who has sadly passed), who wrote a book called 'Contact'. It was a work of fiction, 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 1st interpret their information/data, and then instructions about how to 'build' a massively complex machine, to travel back to them!!! ;D The upshot of it all, was that it was so huge, complex & expensive technological project, that literally the whole World had to get together to fabricate all the components, and to actually build it!! I'm sure he desired 'us' all working together some day!! 8) |
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