back to article Spent Chinese rocket stage set to make an uncontrolled return to Earth

The spent booster stage responsible for placing the first module of China's next space station into orbit is set to make an uncontrolled rendezvous with Earth. The first module of Tiangong-3, "Tianhe", was launched at the end of April atop a Long March 5B rocket and is currently safely in orbit. The same, alas, cannot be said …

  1. Tom 7 Silver badge

    If you can

    keep us updated. If I find I could have watched it burn up from my garden I'll cry!

    1. Graham Cunningham

      Especially....

      ... if it actually burns up your garden?

    2. Anonymous Coward
      Anonymous Coward

      Re: If you can

      Well it's about the only way to get a reliable weather forecast (in the UK). If it burns up in our skies, it _will_ be cloudy. The only way it'll be visible is if we don't know about it.

    3. Vulch

      Re: If you can

      It's in a 41.5 degree inclination orbit so can't hit outside the range of 41.5 degrees latitude north and south. If your garden is inside that band, keep a hard hat handy.

      The station module, Tianhe, only gets about 10 degrees above the horizon from the UK.

  2. Version 1.0 Silver badge

    I wonder if the rocket designers used to work in the mobile phone design industry?

    1. hplasm
      Happy

      Re:I wonder if the rocket designers used to work in the mobile phone design industry?

      Well, if the battery files out and goes one way when the other parts spring off in another, then yes.

  3. Ken Moorhouse Silver badge

    Monte Carlo results

    If you put a bet on that being the place it landed, and it did, you would be able to afford to live there.

    1. Anonymous Coward
      Anonymous Coward

      Re: Monte Carlo results

      What, in the crater?

      :)

      1. jake Silver badge

        Re: Monte Carlo results

        Have you seen how much it costs to take the top off a mountain to build a house with a view?

  4. Anonymous Coward
    Anonymous Coward

    A request...

    Please, Mister Space Crap, could you crash land on the HQ of the telemarketers that keep calling me? I'd appreciate it if you could be as "disruptive" as possible to their current business model. Thank you.

    Signed, a grumpy person sick & fekkin tired of hearing BS about my auto/computer warranty, credit card rates, or any other of a dozen forms of shite.

    1. 2+2=5 Silver badge
      Joke

      Re: A request...

      > Please, Mister Space Crap, could you crash land on...

      ... could you crash land on that laboratory in Wuhan because the Internet is a bit short of wild conspiracy theories at the moment. Thanks.

    2. EricB123 Bronze badge

      Re: A request...

      Long ago I remember hearing about something called "satellite insurance". The idea was if some space junk slammed into your house they'd cover it. It was of course laughed at back then.

      Funny how it doesn't sound quite so outrageous now

  5. bombastic bob Silver badge
    Trollface

    The SKY is falling!

    Chicken Little was right, At least, when it comes to flaming chunks of metal being sent back. i guess Earth has a pretty good "return policy" for defective spacecraft (heh).

    RMA says "did not perform as expected"

    1. jake Silver badge

      Re: The SKY is falling!

      "RMA says "did not perform as expected""

      Actually, it is performing exactly as expected.

      Unless it has some kind of attitude adjustment (vernier thrusters) that can nudge it into a slightly less than accidental path ... Cheating Monte Carlo simulations without raising concerns can be big business.

  6. Anonymous Coward
    Anonymous Coward

    Spent Chinese rocket stage set to make an uncontrolled return to Earth

    it would be 'pretty ironic' if it crash-landed on top of its own launch pad. Or the Palace of The People's Party (or wherever they sit and stand to clap the Chairman X). That said, if it were to crash in the middle of the White House...

    1. Jellied Eel Silver badge

      Re: Spent Chinese rocket stage set to make an uncontrolled return to Earth

      Awkward if it landed on Taipei. I guess the good news is that due to space tracking, unexpected objects landing in the sensitive areas are less unexpected.

  7. Anonymous Coward
    Anonymous Coward

    Re: The sky is falling!

    Or maybe the rocket stage is coming down in a controlled manner. They just want plausible deniability when it comes down on Mar-a-Lago or Washington DC.

    1. jake Silver badge

      Re: The sky is falling!

      Why would they land it on commie sympathizer Trump's ugly shack?

      1. Stoneshop Silver badge

        Re: The sky is falling!

        Because of their sense of aesthetics. And Trump has been spent like any rocket stage except those from SpaceX (and quite a few of those too)

  8. Persona Silver badge

    Not uncommon

    To put it in context the Falcon 9 second stage is 3.66m diameter, 12.5km long and weighs about 4 tons, so the Chinese booster is a lot bigger but not massively so. While most are controlled a lot of Falcon 9 second stages have come down unguided and it's very likely that some bits (pressure vessels and engine core etc.) hit the ground or much more probably the sea. I don't believe any F9 S2 debris has ever been reported.

    1. Mishak Silver badge

      Well, not that many

      https://spaceflight101.com/falcon-9-jcsat-16/spacex-rocket-parts-rain-down-over-indonesia/

      https://www.theverge.com/2021/4/2/22364582/spacex-rocket-debris-falls-farm-washington

      They do plan to bring them all back in a controlled way so this doesn't happen, but things don't always go to plan.

      Still, congratulations to SpaceX for making most satellite launches very, very boring ;-)

    2. thames Silver badge

      Re: Not uncommon

      Yes, well you'll notice that McDowell's statement was qualified as "above 10 tonnes". Europe was intentionally dumping spent 8 ton rockets into the general area of Canada and Greenland, including roughly a ton of highly toxic hydrazine into the atmosphere as recently as 4 years ago, and may still be doing it for all I know. Protests from Canada to Europe were met with a "do I look like I give a ****?"

    3. Mark Exclamation

      Re: Not uncommon

      Holy crap! "...3.66m diameter, 12.5km long and weighs about 4 tons.." What's it made of? Tissue paper?

    4. Anonymous Coward
      Anonymous Coward

      Re: Not uncommon

      "12.5km long"

      Long and skinny.

      1. ThatOne Silver badge
        Coat

        Re: Not uncommon

        At 3.55 m diameter and 12.5 km long it would be best described as a hollow wire.

        Impressive feat to get such a thing to orbit without it bending out of shape, but even more impressive is getting it to stand upright on the launching pad! (And avoiding commercial aircraft from crashing into it while it stands there.)

        1. jake Silver badge

          Re: Not uncommon

          "(And avoiding commercial aircraft from crashing into it while it stands there.)"

          I think you'll find that launch pads are no-fly zones.

    5. Stoneshop Silver badge
      Boffin

      Re: Not uncommon

      To put it in context the Falcon 9 second stage is 3.66m diameter, 12.5km long

      That would be one way to get its payload reach planned altitude, but I have my doubts that it's an effective one.

      1. John Brown (no body) Silver badge

        Re: Not uncommon

        An early prototype of a space elevator?

  9. Neil Barnes Silver badge

    On the other hand...

    Better it comes down than stays in a low orbit indefinitely, cluttering up near earth space...

    Though on the gripping hand it would be better that it came down under some sort of control.

    1. Mishak Silver badge

      The advatage of low orbits...

      Nothing stays there that long without a re-boost.

    2. Pascal Monett Silver badge

      Yeah, it would be better. But, if it really had to come down on Mar-a-lago, well, I'd understand.

  10. Jim Mitchell

    "Far less kinetic energy is involved in this instance – "worst case," he said, "is like a small plane crash.""

    Is less reassuring than perhaps the author thinks. Small plane crashes usually kill at least one person, sometimes more.

    1. A. Coatsworth
      Mushroom

      The person killed in those cases is almost invariably inside the falling object... That is not the case here, as far as we can tell.

      Although, given the CCP's way to do things and their utter disregard for human life, we will never know for sure

  11. aregross

    "which features a core stage and four strapped-on liquid fuelled boosters."

    Waitwut? Liquid fueled 'booster'? I thought boosters used solid fuel. What kind of "strapped-on" booster uses liquid fuel? How would that work?

    And does that mean the main core engine is solid fueled? Isn't that kinda bass-ackwards?

    1. Stoneshop Silver badge

      What kind of "strapped-on" booster uses liquid fuel? How would that work?

      Just like any other small-to-medium single-stage liquid-fuel rocket. And with liquid fuel boosters you can adjust thrust in flight, which you will likely want for a heavy lifter.

      It's not at all unlike any multi-engine rocket stage, only put together from a couple of existing rockets and a couple of zipties.

      And does that mean the main core engine is solid fueled?

      Definitely not.

    2. Francis Boyle

      There are indeed good reasons to make your boosters solid-fuelled mostly related to avoiding unnecessary complexity but they're hardly definitive. Boosters are essentially extra first stages* so there's no special concerns here. Of course, when you've got as many engines burning as you have on a first stage Soyuz you might appreciate the simplicity of a solid-fuel engine. The Russian obviously didn't as the Soyuz is all liquid fuelled.)

      *Interestingly Wikipedia is still insisting that all first stages are boosters. I don't think that's correct but I don't like my chances of getting a change to stick.

      1. Anonymous Coward
        Anonymous Coward

        It's all a bit grey these days...

        At the start, the first stage really was just a booster used to get the subsequent stages (sometimes as many as four) moving - lots of fuel, lots of thrust and lots of weight (hence the staging to drop off unneeded mass once the tanks are empty).

        This rocket is a bit different, as the core stage lights at launch and runs all the way to orbit; the side boosters are effectively the "first stage".

        There is also the possibility of SSO (Single Stage to Orbit), but I'm not aware of anyone putting one together that's commercially viable (yet).

        Falcon 9, Starship and SLS all use the more "traditional" two stage (+boosters for SLS) configuration.

      2. Anonymous Coward
        Pirate

        Interestingly Wikipedia is still insisting that all first stages are boosters

        Interestingly, NASA are still insisting on calling, for instance, the S-1C, a booster. But, well, what would they know.

  12. aregross

    OK, so I found this: https://spaceflightnow.com/wp-content/uploads/2016/11/lm5_schematic.jpg

    From: https://spaceflightnow.com/2016/11/03/china-launches-long-march-5-one-of-the-worlds-most-powerful-rockets/

    Center engine is Liquid hydrogen and LOX (if I'm reading this correctly)

    It must not be very powerful if they need liquid fueled boosters to get it up.

    Is the red square the stuff that's falling on my head ~May10th?

    1. Anonymous Coward
      Anonymous Coward

      My, what a big strap on you have there...

      And it's got a lot of powerful thrust to go along with it? I wonder if they have anything to mitigate the reentry burn? *Runs away*

    2. Jellied Eel Silver badge

      It must not be very powerful if they need liquid fueled boosters to get it up.

      It's more powerful than the Falcon Heavy. Neat thing about the LM-5 is it can mix & match core and boosters. Most of the heavy rockets work that way.

      1. rg287

        It's more powerful than the Falcon Heavy.

        By what measure? LM-5 is roughly equivalent to Delta-IV Heavy, and is generally ranked third in the world.

        In terms of LEO:

        * FH: 64,000kg

        * DIVH: 28,790kg

        * LM5: 25,000kg

        GTO:

        * FH: 26,700kg

        * LM5: 14,500kg

        * DIVH: 14,220kg

        Mars Transfer Orbit:

        * FH: 16,800kg

        * DIVH: 8,000kg

        * LM5: 6,000kg

        Falcon Heavy is by far the most powerful rocket in the world, unless you have a very specific or niche deep space mission which calls for a higher impulse (usually Hydrogen) upper/third stage. FH can still send 3 tonnes to Pluto though.

        The main caveat is that Falcon Heavy's cores are a slender and delicate 3.66m in diameter, rather than the chunkier 5m diameters for Delta and Long March. Consequently the payload is more likely to be volume-constrained than mass-constrained and some payloads may need the volume on offer from Atlas or Delta even if that means compromising on mass.

        Falcon's payload fairings are wider than the core stage, so you can have slightly wider payloads (internal diameter is ~4.2m) but you're still constrained by the payload adaptor which has to mount to the top of that 3.66m core. The only way FH could actually put 60 tonnes into LEO is if it were launching a tank full of water or some chunks of metal stock for orbital manufacturing. It's really a side-effect of building a rocket for putting heavy satellites into GEO. The enormous LEO capability isn't that useful as most satellites simply aren't that dense. See this graphic (admittedly from ULA, but using verifiable numbers)..

        This is why they want StarShip for launching StarLink satellites - even packing F9 to the brim, they're leaving payload mass on the table. They could deploy more satellites per-launch if there were more volume.

        1. Jellied Eel Silver badge

          Carlsberg

          Falcon Heavy is by far the most powerful rocket in the world, unless you have a very specific or niche deep space mission which calls for a higher impulse (usually Hydrogen) upper/third stage. FH can still send 3 tonnes to Pluto though.

          Aye, but there's the rub. It's launched a stripped-down 1200kg Roadster and a couple of other small satellites, and the heaviest load to geo was an Arabsat at around 6500kg. On paper, the expendable Falcon Heavy can lift more to geo, but hasn't.

          It's really a side-effect of building a rocket for putting heavy satellites into GEO. The enormous LEO capability isn't that useful as most satellites simply aren't that dense.

          Yup. So a variation on 'build it and they will come'. So the solution is to obviously build an even bigger rocket.

          This is why they want StarShip for launching StarLink satellites - even packing F9 to the brim, they're leaving payload mass on the table. They could deploy more satellites per-launch if there were more volume.

          Sure, but the highest flight of Starship's only been 10km. None of the nosecones to date can deploy anything. And the economics are interesting, ie Starlink being spun off as a seperate entity to absorb US broadband subsidies, but the financials and ownership are typically opaque. I'm also dubious whether there'd really be any benefit using Starship given you're looking for global coverage, so want satellites deployed along multiple orbits.

          But so it goes. Might be another attempt to launch SN15 later today. I also watched a Starlink launch as I was curious to see how those were deployed. Wasn't exactly very dramatic as they just exited the bus in a clump, then hang around for a bit till their ion thrusters move them where they're needed.

          1. rg287

            Re: Carlsberg

            Falcon Heavy was designed in a time when F9 could only lift a fraction of it's current capacity. FH ended up being semi-obsoleted by improvements to its own stable-mate, which is why it's not launching very often.

            Yup. So a variation on 'build it and they will come'. So the solution is to obviously build an even bigger rocket.

            Yes. And they did come - but FH was partially obsoleted by the cheaper, more performant Block 5. F9 is not and cannot obsolete StarShip. It's at the natural end of it's development cycle - it can already loft more mass than is useful for the payload volume. The solution is a bigger rocket - one with a larger diameter which isn't volume-constrained. One with a more favourable mass-volume ratio.

            I'm also dubious whether there'd really be any benefit using Starship given you're looking for global coverage, so want satellites deployed along multiple orbits.

            I suspect they might have thought of that. Each orbital shell needs far more than the 60 satellites they can launch on a single F9. Starship leads to being able to repopulate a shell in fewer launches rather than sending many launches to the same orbits as they are currently doing, for a similar per-launch price, which means much lower costs per-kg and per-satellite.

            Sure, but the highest flight of Starship's only been 10km. None of the nosecones to date can deploy anything.

            Are you seriously offering that up as a criticism of a prototype? Why would they install deployable nose-cones on sub-orbital prototypes? NASA's Enterprise Orbiter didn't have a bunch of hardware on it for going to space - because it's job was to deploy from the 747 carrier and do glide tests. I guess that means the whole concept of the Space Shuttle never went anywhere - because the Enterprise chassis couldn't deploy satellites!?!

            1. jake Silver badge

              Re: Carlsberg

              "it can already loft more mass than is useful for the payload volume"

              One word: Water.

              A couple more words: Make up the mass in water ... it can be fit in almost anywhere. Build a large stash in LEO. It's kind of a handy commodity.

    3. Stoneshop Silver badge

      Is the red square the stuff that's falling on my head ~May10th?

      I doubt the Russians would not have noticed that by now and not just think "Черт возьми, another pothole", and would be lofting Tian An Men Square spacewards in retaliation, or at least be preparing such an action.

      Also, the Long March 5's capabilities may be impressive, but a quick calculation leads me to think it'd still fall a bit short of managing such a feat.

  13. Sleep deprived
    Happy

    China dumping a rocket on Earth

    Bah! A one-time limited event. It's not like it were a global pandemic.

    1. Anonymous Coward
      Anonymous Coward

      Re: China dumping a rocket on Earth

      They're building a space station though, there might be another 5, plus supply missions.

      1. Stoneshop Silver badge

        They're building a space station though

        So the next mission will be carrying the bamboo scaffolding.

    2. Anonymous Coward
      Anonymous Coward

      Re: China dumping a rocket on Earth ... [not] a global pandemic

      I must say, I find the idea of a pandemic of used rocket boosters raining down on the Earth a most intriguing notion.

  14. Anonymous Coward
    Mushroom

    All well and good until one country treats the incoming crap as a weapon then pushes the BIG red button in retaliation,, you would think they have done enough damage to the world over the last couple of years what with the CHina-bug and all that !

  15. Winkypop Silver badge
    Alert

    Used rocket booster for sale

    Free delivery, bring a large net.

    1. Anonymous Coward
      Anonymous Coward

      Re: Used rocket booster for sale

      As a Prime member can I get next day delivery? It's a gift so please deliver to:

      The Mar-a-Lago Club

      Palm Beach, Florida, 33480

      Thanks.

  16. Anonymous Coward
    Anonymous Coward

    China appears to do things a little differently.

    Well, yes, and not only in this area !

    1. x 7

      Re: China appears to do things a little differently.

      That's because they don't give a shit about anyone else

      1. Anonymous Coward
        Anonymous Coward

        Re: China appears to do things a little differently.

        As opposed to us, who don't give a shit about anyone else either...

        1. jake Silver badge

          Re: China appears to do things a little differently.

          Who is "us", Kemosabe?

  17. x 7

    Hidden launch of a second payload

    I read a novel years ago (name and author forgotten) in which incidents like this were used as a cover by the Chinese for placing a secondary military payload into orbit. Easy way to place a satellite-killer, or a nuke into orbit with no-one realising

    1. Stoneshop Silver badge

      Re: Hidden launch of a second payload

      Today's observation capabilities would make that as good as impossible, I'd think. And anything that is disguised as a spent rocket stage or fuel tank is going to drop out of LEO sooner or later, while keeping it in orbit would require propulsion, giving its disguise away. Though they could put such a weapon in one of the modules of the Tianhe (and not let any foreign astronauts into that module ever), and cut it loose to deploy it when the time is ripe.

      Just remote observation is easier; everyone and their dog are slinging stuff up, and everyone knows that the bigger ones from the bigger players tend to have capabilities that only their military has access to.

      1. x 7

        Re: Hidden launch of a second payload

        You misunderstand the scenario in the tale.

        After release of the first satellite the booster continued to boost to a higher orbit, releasing the second military payload before tumbling back. The second payload isn't disguised as the rocket stage - that's just a diversion.

        In both these recent episodes with the Long March 5, the problem has been with the booster continuing to burn after payload release - potentially allowing that second payload release

    2. jake Silver badge

      Re: Hidden launch of a second payload

      "Easy way to place a satellite-killer, or a nuke into orbit with no-one realising"

      Except for little things like ground-based radar watching from every country on earth with the capability.

POST COMMENT House rules

Not a member of The Register? Create a new account here.

  • Enter your comment

  • Add an icon

Anonymous cowards cannot choose their icon

Other stories you might like

Biting the hand that feeds IT © 1998–2022