We had a thread about this when China’s first space station had uncontrolled reentry (2018). When the second one came down, it was aimed at a lonely ocean spot and was less newsy. Now a “Long March” (CZ) 5B is soon to reenter uncontrolled and folks seem to be watching. It is unusual as it is a ‘first stage to orbit’ (discounting the 4 side sticks) and weighs about 20 tons. Current reentry guess can be seen here: CZ-5B Rocket Body (ID 48275) | The Aerospace Corporation and gets updated through time. Current uncertainty is 8 hours, meaning about 5.3 orbits, so uncertainty is still very large. Since about 2000, average of 37 rocket boosters drop back in per year. I don’t know what fraction are ‘aimed’ (controlled de orbiting). As they are mostly second stages, they weigh much less than 20 tons. Seems to me that upgrading CZ 5B for controlled de orbiting would be possible. Don’t know why that is not done. International law does not require it (a weak excuse), but does require compensation if the thing hits something of perceived value. Construction of the orbital station (Tianhe 3) will require two more CZ 5B shots, and presumably two more uncontrolled reentries within about 1 year. Other launches to support the orbital station use different rockets (CZ 2F and CZ 7) that ‘debris’ less. Possibly they have controlled de orbiting.
They work against aluminum eh? Actually the Al part will mostly become 'sprinkles' during re entry. The two engines have lots of steel and that is what wants to enter your house from above. Or could decorate Beijing, or anywhere else within 41.5 N-S latitude band. This web site has recent altitude history: China's Long March 5B Rocket, Seen in Weibo Post Mocking India, Now Hurtling Out of Control Altitude tracking is impressive. Y'all ought to read about Leo Labs
Item of interest seems to have ended its travels near Saudi-Oman border about 22.2 degrees N Lat. It was a nighttime reentry so one hopes for sky sparkle images. If someone was harmed, expect to hear about that within a couple of days.
Newer news says differently, a marine splash: Chinese rocket updates: Debris splashes down in Indian Ocean - ABC News (Earth's oceans are actually pretty hard to miss)
I also saw those two different locations a few hours ago. But they are not necessarily in conflict. From the displayed charts, they appear to be on the same orbital ground track. Remember that there is a very considerable distance from where incandescent ablation begins, to where the large pieces plop or spash down. We are still waiting for more detail information. Do remember that several weeks ago, Musk missed a Washington State home by about 50 feet, quite far downrange from the many meteor cluster videos: SpaceX rocket junk streaked spectacularly across the Pacific Northwest sky. Here’s the science behind the extraordinary show | The Seattle Times After fireballs streaked across sky, space-junk sleuths got busy — and hit the jackpot in Washington | The Seattle Times
Another year? Good. I completely missed this one, have got to build a better net with a longer handle.
Correcting the name, it's Tiangong-3. Tianhe-3 is a supercomputer (may no longer be the fastest one). Some media source got names mixed up and I repeated the error here.
I think this station will resemble Mir when it had 3 modules connected. Hope the resemblance ends there
Like this The large tubes are less than 5 meter diameter but I don't know how much less. To review, Tiangong-1 did the uncontrolled re entry in 2018 and TG-2 was controlled (in downgoing) later. This one is supposed to be functional for a decade or more.
Human beings manage to muck up EVERYTHING that they touch eventually. The current obsession with Internet service has resulted in one company putting what I think will eventually be near to ONE THOUSAND small satellites just to relay Internet signals.......or at least that is what they say. This doesn't seem like a really good thing to me. Is there any central agency who TELLS people doing this what orbit they can occupy to keep from running into each other ? I highly doubt it........and it seems like just a matter of time until it turns into a disaster. And all just so that the native tribes in Africa can get their daily Twitter fix.
Space is pretty big.....hence the name....but yeah...humans have to have cheap, low latency internet so that they can play all of those first person shooter games. Musk isn't the only person looking to put lotsa satellites into LEO....and the number of satellites that Starlink wants to loft is closer to 40,000.....and no....that's not a typo. I've heard of numbers as high as 42,000. Starlink currently has a regulatory OK from the FCC to operate something like 2800 satellites in various polar (birdcage) orbits, and the ITU also got some kind of say. I'm sure that the FAA is involved as well, but only for the first 300,000 feet or so, and then only in issuing and enforcing NOTAMs and keeping quadcopter operators at bay. Fun Fact: Starlink is reportedly named after the novel "The Fault in Our Stars" which I can report was only slightly better than the movie.....meaning that the movie was actually pretty good - ESPECIALLY by modern standards. Musk can give the FCC the middle finger when it comes to orbiting satellites, but somehow the FCC got the weird idea that they have regulatory grunt when it comes to the stuff emitting FROM the satellites, which may or may not be true in real life. HOWEVER (comma!) internet is a two way sorta thing and the FCC DOES have regulatory power over terrestrial ground stations, so it pays to play nice with them....ESPECIALLY if you haven't yet been forced into the Apple model of offshoring and outsourcing. One might normally be tempted to think that there should be an international body regulating these sorts of activities but....2020 informs us that this might not be the most effective approach either....and besides, the US is probably the most frequent violator of orbital littering besides maybe the Rooskies, who, literally....slimed Canada one time with radioactive debris from one of their school-bus sized intel satellites. Fun times...
Starlink is one of about 3 companies doing the 'internet from 500 km' thing. Seem to be most advanced in fleet aloft and equipment for the earth end. That sells for $500 up front and $100/month if you are in a served area. Which does not currently include Africa. I really don't think it will be twitter solution for Africa.
The bars on the birdcage DO tend to get a little further apart the further south you get - but if Elon gets all of the launches he wants then I have little doubt that he will solve the riddle for cost and coverage. His $100/month is reportedly for cash flow and to fund other spacey things once the company goes cash positive....and folks in the lower latitudes will probably get a price break. Elon wants a dynamic de-orbiting option and seems to also want to coat his birds to reduce reflectivity - because even as big as space gets 'out there' 42,000 extra twinkles is lots of them. The tech in me wonders what kind of thermal cost (benefit?) will arise in the sun/shade. So....when the soda cans are empty Starlink wants to incinerate them promptly rather than waiting for them to decay naturally or go 'bump' in the night....which seems to be a wise business strategery, since he's lifting squishier and more expensive junk into space than just internet nodes. 500 km is something like 20 years for a mostly circular orbit (swagging here) which is....close enough to worry about. We'll see. The satellites I worry the MOST about are all up a little bit higher, and they face a more imminent threat than getting holed by space litter.
