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keep us updated. If I find I could have watched it burn up from my garden I'll cry!
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 …
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.
"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.
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...
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.
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 ;-)
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 ****?"
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.)
"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?
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.
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.
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.
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?
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.
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.
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!?!
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.
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.
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