Heads-up - uncontrolled reentry of large rocket booster projected May 8-10

[treadigraph]

Blimey...

Parts of high-speed, 21-ton Chinese rocket could crash land anywhere in the world over next week

Space vessel due to make an uncontrolled re-entry shortly and is 11 tons heavier than would normally be allowed to come back down to EarthA Chinese rocket that successfully blasted off a building block for a space station is set to make an uncontrolled re-entry back to Earth, and its debris could crash into an inhabited area, according to reports.

The Long March 5B Y2 lifted off on Thursday from China’s southern Hainan island carrying the main module for China’s first permanent space station.While the module separated from the launcher to continue its journey as planned, the launch vehicle’s core section also reached orbit and is now slowly and unpredictably heading back to Earth.

Daily Telegraph (https://www.telegraph.co.uk/news/2021/05/04/parts-high-speed-21-ton-chinese-rocket-could-crash-land-anywhere/?li_source=LI&li_medium=liftigniter-rhr)

Tianhe Space Station (https://en.wikipedia.org/wiki/Tianhe_(space_station_module))

[TURIN]

The Angry Astronaut was getting all hot under the collar about this the other day.

https://youtu.be/PxDM8DOYbuM

[pasta]

could crash land anywhere in the world
I know journalists are selected for their writing skills rather than their scientific knowledge, but the author of this headline clearly didn't even read the article...

[WillowRun 6-3]

Pilot organizations circulating bulletins alerting aviators to pending imminent uncontrolled re-entry of large rocket booster:

21sab10-long-march-re-entry.pdf (ifalpa.org) (https://www.ifalpa.org/media/3634/21sab10-long-march-re-entry.pdf)

[Nick 1]

This is crazy , launching rockets in space and let booster fall random on earth ...

[NutLoose]

It would be ironic if it hit Beijing:)

[Ex FSO GRIFFO]

Not 'irony' - as much as 'KARMA'.....

That rather large rectangular building on the LHS of 'T' Square would be 'luvly'....

[jolihokistix]

Why does the USA offer to track this thing and warn us exactly when on 8th May it will come cartwheeling down?

Is it not the responsibility of the government of China to do this? Or are they just being irresponsible?

[wiggy]

Nick 1

Random re-entries have been going on since 1957 but most final stages of boosters are small enough for them/their components to not generally survive re-entry.

Problem here is this a seriously big piece of hardware and custom and practice is entry should have been controlled and targeted for a remote area.

https://spacenews.com/huge-rocket-looks-set-for-uncontrolled-reentry-following-chinese-space-station-launch/

[wiggy]

FWIW the US has had a system in place for years that tracks objects in orbit 24/7 and if relevant to the object produces reentry predictions, so why wouldn't they continue to do so?

https://en.wikipedia.org/wiki/Space_Detection_and_Tracking_System

Nobody can tell when exactly it will re-enter, certainly not at this stage there are so many variable involved in the decay process that generally it's more of case of " we're now fairly certain it'll come down in the next hour...oh looks like it's gone", or: more accurately:

"Based on 15 well-monitored IADC re-entry prediction campaigns since 1998, with well-established, observed re-entry times and locations, ESA’s predictions were found to be within ±6% of the remaining orbital lifetime for about 50% of all cases, within ±10% for about 75%, and outside ±20% for about 5% of all forecasts. The latter figure supports ESA’s a priori assumption that a reentry time window of ±20% is a good representation of agregate error sources, leading to a ±2σ = 94.4% confidence interval."

Bearing in mind these things are moving at about 5miles per second even a 1 minute error in entry time means the entry point prediction is out by 300 miles..

Maths stuff about decay in this paper. (https://conference.sdo.esoc.esa.int/proceedings/sdc6/paper/148/SDC6-paper148.pdf)

[Less Hair]

Better than nuclear battery powered radar satellite launch failures.

[TURIN]

More China bashing?

Does no one remember Skylab or Mir?

[ehwatezedoing]

No, we are just saying that China is 20 to 40 years behind with their space program :p

[wiggy]

Certainly does seem to be a case, putting it politely, of not caring a jot about modern day custom and practise/guidelines regarding disposing :bored: of items of more than ten tonnes.

[Less Hair]

Practically there are like 20 zenit upper stages waiting to reenter or similar? So just one more doesn't concern me.
Have any airborne aircraft ever been hit by satellite debris or space junk?

[wiggy]

The sources I can find seem to give an empty mass for the typical zenit upper stages such as the Blok D of just over two tonnes..

OTOH the Chinese launcher seems to have delivered it's whole darned core stage into orbit, and that's being estimated as having a mass of just over twenty tonnes....hence the concern being expressed in some quarters;..

I'm just north of 41.5 degrees north so I guess I can be a bit relaxed about this...and no idea of any aircraft have ever been hit.

https://aerospace.org/reentries/cz-5b-rocket-body-id-48275

[slacktide]

Mir was intentionally de-orbited over a mostly unpopulated area using the reaction control system that was installed for that purpose. It hit reasonably close to the pre-planned and pre-announced impact point.

Skylab was intended to be re-boosted during the Skylab V mission, which was cancelled for budgetary reasons as the Shuttle was coming online soon and could do the mission cheaper. Then due to Shuttle program delays the Shuttle was not available to re-boost the station, therefore it re-entered uncontrolled. But that was not the baseline plan, it was a failure of program management and contingency planning.

Uncontrolled de-orbit was the baseline plan for the Long March 5B. And it was launched in 2021, not in 1973. What was once acceptable is now unacceptable, in rocketry and many other fields. We've upped our standards, so up yours.

[WillowRun 6-3]

Just getting this out of the way first: I opened this thread strictly based on the IFALPA (and ALPA) deeming the situation serious enough to be the subject of the warnings or advisories they issued -- no anti-China sentiment or bias motivated it.

Second, I've acquired some at least modest familiarity with academic and related literature on space debris, congestion of the space domain, and the application of conventional thinking to overall, or generalized, problems of safety of space operations. I am not completely certain of this answer, but if significantly large pieces of space debris ever had collided, upon re-entry, with a civil aircraft anywhere, such an accident would -- without question -- feature prominently in the referenced literature. I know, absence of evidence is not evidence of absence, so FWIW. (For comparison, references to the Chinese ASAT test which created thousands of pieces of debris in 2007 are almost a prerequisite in discussions, slide decks, academic papers, and much else, on space debris problems.... the inference being that if a collision of debris with an aircraft ever had occurred, logically it would have garnered similar prominence, in all likelihood.)

Last, it's clear that expertise, virtuosity in performance, and even real pioneering achievements in space technology are continuing to make news. Some would argue that latecomers to space technology do more than just "stand on the shoulders of giants" who preceded them - such latecomers sometimes bypass the attention given to safety, quality assurance, and implicit norms of responsible behavior in space. Some argue that the U.S. is at fault, because it has opposed efforts by other countries to set in place formal rules or norms, or items like a proposed Code of Conduct. Since this is one of my professional areas of study I could go on a lot more....but a prior post said it better than I could: yes Skylab tumbled out of orbit, let's see, that was before Wright Field on Mars, wasn't it?

[NWA SLF]

Just curiosity - did the SpaceX Starlink booster de-orbit burn failure make a splash here last month when eventually created a light show in the Seattle skies back in March? Incidentally, I am posting this using Starlink. Does the Chinese announcement state whether this booster de-orbit creating a possible problem was due to intentionally having no way to do a controlled de-orbit or was it like the SpaceX booster that had a plan but the plan, successful so many times, failed this time. Trying to weed out the China bashing from the oops, sorry about that, didn't mean for my engine nacelle to fall on a soccer match.

[WillowRun 6-3]

NWA SLF

According to the ALPA Safety Bulletin --

Regarding the current situation: "While the launch was successful, the booster stage of the launching Long March 5B rocket was designed for an “uncontrolled” re-entry, and therefore the exact time and location of its return is unknown." (emphasis added)

Regarding the Starlink rocket in the Seattle area: "The most recent uncontrolled re-entry of a rocket was on March 26, 2021, when part of a SpaceX Falcon9 launch re-entered at night over the Pacific Northwest. Debris, including several 200lb pressure tanks, survived re-entry and struck the ground."

Several news outlets have quoted - in both incidents - the professor who is widely regarded as the most knowledgeable and authoritative person on stuff in orbit (a Harvard astrophysics prof). I'm quoting, though, just the ALPA bulletin, inasmuch as this isn't an astrophysics forum (which I wouldn't understand anyway), and whereas the ALPA information was issued over the names of three ALPA officials with relevant subject matter areas of responsibility. (What might or might not have been stated in any publicly available English versions of announcements by PRC or its agencies, I don't know.)

[.Scott]

There has been no word at all from China.

Also, the aviation community is alerted because they are more likely to see something than others.
As far as the risk to aviation, its about the same for everyone. Airplanes may be more fragile, but they are also pretty compact - presenting a small target per passenger.

Right now, the aerospace prediction is down to a 32 hour window. Regions at higher than random chance of catching the rocket are the South Atlantic and the region around Japan include areas of China and the Pacific just east and west of Japan.

[wiggy]

slacktide


The other issue with Skylab was ( shorthand description) an unusually solar active solar cycle made the upper atmosphere more dense then had been predicted and increased the rate of orbital decay, making even the most optimistic plans for a Shuttle boost redundant.

It's that sort of known unknown thats a driver for having a de-orbit plan..

[rattman]

jolihokistix

They are but theres a margin of error, they normally give 12 hours warning of re entries or collisions.

[WillowRun 6-3]

Credit, SpacePolicyOnline (U.S. Secretary of Defense stating no plans to shoot down the rocket stage - plus good background information about this and related situations)

Austin: No Plans to Shoot Down Errant Chinese Rocket Stage – SpacePolicyOnline.com (https://spacepolicyonline.com/news/austin-no-plans-to-shoot-down-errant-chinese-rocket-stage/?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+Spacepolicyonline+%28SpacePolicyOnline+ News%29)

[wiggy]

A shoot down makes pretty zero sense anyway..the ironmongery won't just disappear, all that blowing the thing up does is risk increasing the amount of debris in Low Earth Orbit and/or increasing the size of the footprint on the Earth's surface likely to be on the receiving end of the incoming debris.

[Less Hair]

Updated reentry prediction.
https://aerospace.org/reentries/cz-5b-rocket-body-id-48275

And some tweed:
https://twitter.com/planet4589

[meleagertoo]

WillowRun 6-3

That is simply an April 1st headline.
What an utterly nonsensical concept - to 'shoot down' an object that is not airborne at all but is in free-fall!

Can there really be people so dim and naiive to even suggest or imagine such things?

[ShyTorque]

I can’t see how something like this can be “shot down” because it’s on its way down anyway. However, presumably if it were broken into smaller pieces there would be more chance of it burning up more completely on re-entry (surface area to mass ratio is increased).

[Less Hair]

Around 4:30 hours to go.

[Big Pistons Forever]

Sadly another example of the Chinese government refusal to follow established norms of responsible behavior. Responsible governments which basically include all space capable governments except for China and North Korea, allow for some extra residual fuel to allow a managed descent. China loads up the rocket so every pound of fuel is needed to get the payload to orbit and then they throw away the launch body and basically walk away from any responsibility for the resulting uncontrolledly re-entry.

They know they can get away with such irresponsible behavior because there is not the political will to hold them accountable with meaningful sanctions.

[wiggy]

Latest prediction from Space-Track..

projected re-entry at 2021-05-09 0204(UTC) +/- 60 minutes at latitude 41.6, longitude 350.7 (North Atlantic) NOTE: Getting closer to re-entry, but still not a precise time or location.

That peculiar Longitude translates as 9.7 west, in reality the plus/minus 60 min on the timing is effectively an uncertainty of a whole orbit plus a bit.

Other sources are predicting 0302 UTC with re-entry over the Pacific, but again with a big plus/minus....

We'll only know when it's happened.

[India Four Two]

BBC: China rocket debris 'disintegrates over Indian Ocean' - Chinese media
https://www.bbc.com/news/science-environment-57045058

[WillowRun 6-3]

meleagertoo

As this is R&N, even if the Secretary of Defense's answer to a reporter's question did not point out the silliness of the question itself, it's still worthy of a post to note the SecDef response. Going back to the news source, SpacePolicyOnline News reported Sec. Austin's comments as;
"At this point we don’t have a plan to shoot the rocket down. We’re hopeful it will land in a place where it won’t harm anyone. Hopefully in the ocean or someplace like that. I think this speaks to the fact that for those of us who operate in the space domain that there should be a requirement to operate in a safe and thoughtful mode and make sure that we take those kinds of things into consideration as we plan and conduct operations." (emphasis added).

If further factual information about where the rocket body re-entered and impacted, this update (from the same online source, noted in the space law and policy community as to reliability and accuracy of the site's proprietor):
"U.S. Space Command reports that the LM-5B rocket stage reentered over the Arabian Peninsula at approximately 10:15 pm EDT May 8. 'It is unknown if the debris impacted land or water.' Separately, NASA Administrator Bill Nelson criticized China for 'failing to meet responsible standards regarding their space debris.' Reports are that debris fell near the Maldives. China’s Xinhua reported a slightly different time (May 9 10:24 am Beijing Time, or May 8 10:24 pm EDT) and said the 'vast majority' of the rocket disintegrated and the rest of the debris fell in the sea in an area centered at 2.65 degrees North, 72.47 degrees East." (internal quotations in original; links converted to ordinary type)

The apparent sole holder of both expertise and authoritativeness, in the English-speaking world anyway, is a gentleman who also happens to be an astrophysics prof at Harvard. His site on Twtr social media platform is @planet4589. (I've met this gent several times in connection with professional and academic projects of mutual interest, and ladies and gentlemen, Prof. McD. is the real deal, for both expertise and authoritativeness on these sorts of subjects - however lacking this combination may be elsewhere.)

Big Pistons Forever

The contrary assertion, relative to the criticisms your post offers, is that it is the United States which has earned the title of Big Hypocrite insofar as norms of behavior are concerned. If you want more elaboration, look for the Twtr thread of the gent from SWF, Secure World Foundation (with a PhD and title like Policy Administration Director). I don't subscribe to the overall criticism, or any of its primary or logical elements - but it's where the discussion typically winds up.

As long as I've gone pedantic, for current diplomatic content on developing norms of responsible behavior in space check out the website where official comments (positions) by various countries, including United States, on the subject are posted (it's a U.N. deal, originated by the U.K., and currently in progress - if you don't have a seat at the negotiating table you might be surprised to find someone else wound up as the main course on the menu while you're only the soup, or maybe the parsley only).
Report of the Secretary-General on reducing space threats through norms, rules and principles of responsible behaviors (2021) – UNODA (https://www.un.org/disarmament/topics/outerspace-sg-report-outer-space-2021/)

[Big Pistons Forever]

It is not rocket science........well I guess it is :O; but this issue is entirely about a policy decision on the part of the Chinese government not to engineer a planned entry. You can roll out a bunch of "whataboutisms" , but that does not change the facts. The current norm for space capable nations is to design a controlled re-entry system for all space debris that could survive re-entry. China did not do that and should therefore be called out for it.

[etudiant]

If there is such a 'norm', it is nowhere articulated afaik.
It is simply that no one has sent up anything large enough to be noticed. The ISS presumably will get deorbited eventually under some control, but neither Skylab nor Mir had anything but orbital decay.

[WillowRun 6-3]

etudiant

But there are several sets of rules close to norms, though dealing with orbital debris (and not in the form of an international convention or treaty). These are what people who work with international law refer to as "soft law". Attorneys, also diplomats and other governmental types, and of course a full complement of academics, non-lawyers as well as lawyers (a regrettable portion of this last subset having little if anything in the "actually representing a client" experience category).

There's a set of Debris Mitigation Guidelines. These were formulated and put into circulation by the IADC, Inter-Agency Space Debris Coordination Committee, an "international forum of governmental bodies for the coordination of activities related to the issues of man-made and natural debris in space." This was done under the auspices of UNOOSA, the U.N. Office of Outer Space Activities, and the multi-country U.N. forum COPUOS (Committee on Peaceful Uses of Outer Space). Relatedly COPUOS has issued "Guidelines for the Long-term Sustainability of Outer Space Activities."

Whether the concept of ultimate, maximum rocket fuel dedication for payload, paired with deliberate ignorance of risks of uncontrolled re-entry, is specifically rejected in any of these or other sets of guidelines (or proposed guidelines), I don't recall. This isn't quite the same problem area as orbital debris.

There's like a "cottage industry" in space law and policy focused upon debris, active debris removal, debris mitigation, and so on (lots of academic conferences, papers, research budgets). If I were a betting poster, I'd wager that one would be hard-pressed to find more than a sliver of this group which does not decry this act by China - not counting China's own space cadres, certainly.

[Ascend Charlie]

"It won't land back in China, so it will not be our problem. And if it does, it will be because those aggressive countries interfered with our grand plans, in order to cause harm to our great nation of China. There WILL be consequences..."

[averow]

Someday, at some point I reckon there will eventuallly be a bad outcome if China keeps launching "dumb" (unsteered, unplanned for safe landing) boosters into space. . Then we will have a mess on our hands. I wonder if there is a collective noun for deliberately pretending there isn't a lurking problem with a huge potential for disaster!

[etudiant]

Thank you, WillowRun 6-3.
You've posted by far the best summary of the state of play for space hazard rules that I've ever seen. Clearly China pushed the tentative envelope with this launch, but 'soft law' has no teeth.
I think there are two more sections to be launched for the Chinese station. It will be interesting to see whether their boosters will likewise decay randomly, or whether China will make some effort to control their demise.

[DaveReidUK]

The Chinese have been launching rockets without worrying about where they land for the last couple of millenia. :O

Old habits die hard.

[WillowRun 6-3]

etudiant

You're very welcome! -- and I appreciate the kind words.

Past several years, concerns over orbital debris have multiplied greatly, perhaps exponentially. In the almost seven years during which I've been working toward an advanced degree in pertinent legal subject matters, "Debris" with a purposeful capital-D has been always in the top three issues in space law and policy. (If it's an interest of yours, PM me if you want cites to sources and so on.)

And just to keep the pot boiling, there are some indications that the China rocket was on a trajectory after launch which took it unusually close to the ISS. Different "mavens" on orbital dynamics and parameters, launch sequences and procedures, and tracking of space objects were tossing the issue of deliberateness or intent around earlier today. Former NASA Administrator Bridenstine remarked on this today, in a webinar on issues in national security (U.S.) space. What the various, several mathematical factors prove, infer, suggest or otherwise prompt as further questions, I'm not commenting (as it's way outside my subject matter lanes).

[wiggy]

there are some indications that the China rocket was on a trajectory after launch which took it unusually close to the ISS. Different "mavens" on orbital dynamics and parameters, launch sequences and procedures, and tracking of space objects were tossing the issue of deliberateness or intent around earlier today. Former NASA Administrator Bridenstine remarked on this today, in a webinar on issues in national security (U.S.) space. What the various, several mathematical factors prove, infer, suggest or otherwise prompt as further questions, I'm not commenting (as it's way outside my subject matter lanes).

From what I've heard/read the closest approach is being quoted at just over 280km but not the orientation of that approach and without knowing that it's hard to grasp how much of a threat there really was. There is as you point out plenty of debate about whether this was deliberate or not - FWIW I gather the launch date/time was set by the Chinese several weeks back and there was also a short pre-launch hold to complicate matters, so it could all be down to chance or simply a lack of care in the planning.

What doesn't seem to be beyond doubt is that none of the ISS partners were given any warnings or a heads up about any possible conflict.

[ORAC]

https://www.nasaspaceflight.com/2023/12/china-roundup-121723/


Chinese massive Chang Zheng 5 (CZ-5) rocket flew once again.

Liftoff of the Yaogan 41 mission took place on Friday, Dec. 15, at 13:41 UTC from Wenchang, the usual launch site for the CZ-5. The payload was described as a remote sensing satellite, which would operate in a high orbit. It was tracked in a standard geostationary transfer orbit after launch.

The fairing of the rocket seems to be extended compared to previous missions, which indicates a large payload inside. The mass could be in the range of 10,000 kilograms or more, given the capability of the rocket which is the most powerful in China’s current fleet.

Chang Zheng 5 is a heavy-lift rocket, used only for missions where China requires its performance to deploy heavy payloads or reach high-energy trajectories. It stands 57 meters toll, with a liftoff thrust of 10,565 kilonewtons. It can place up to 32,000 kilograms of payload into LEO, and up to 14,000 kilograms into GTO.

The official purpose of the Yaogan 41 is stated as “Land Surveying, survey of crops, environment control, meteorology alert, and general disaster prevention and mitigation” which is most likely a placeholder for its true mission.

[ORAC]

What goes up…
https://x.com/aj_fi/status/1739684413644972475?s=61&t=rmEeUn68HhlFHGKbTPQr_A