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First of all this is not the first, but second stage (because rocket has a parallel layout and second stage engine starts at same time with the first, it can be

First of all this is not the first, but second stage (because rocket has a parallel layout and second stage engine starts at same time with the first, it can be called "core" stage, but not "first"). First stage are the boosters on the sides. For example, Soyuz also has same layout (plus an upper stage, LM5 also has it, just not for LEO launches), and it's core is never called "first stage". Also, this isn't a sign of anything going wrong. Upper stages very commonly enter orbit and sometimes stay there for long. It happened to SpaceX Falcon 9 too, it's just their rockets are smaller.

JshWright 6y ago
No, this is unusual because it is a first stage booster (it is lit on the ground, making it "first" stage in most people's common usage of the term (in reality, there's no hard and fast definition)). It is definitely not the "second stage" (the second stage of the Long March 5 is the CZ-5-HO). This would be like the center booster of a Delta IV Heavy making it to orbit. Second stages pretty much invariably make it to orbit. To say "it happened" to SpaceX makes it sound like something went wrong... it's just how rockets work. The central booster of a Long March 5 making it to orbit is unusual (though it has happened before).
- anovikov 6y ago
  Just because this is launch of a very heavy payload onto a low earth orbit. So there is no upper stage as there is no need for it. Center core of Delta IV Heavy can't make it to orbit in any normal circumstances.
  - deleted 6y ago
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  - JshWright 6y ago
    I haven't done the math, but I would be surprised if a Delta IV-H couldn't fly a similar profile, resulting in the first stage being in a low orbit. DIVH and LM5 have similar LEO payload capacities, and the mass of everything above the first stage (dry second stage, propellant, and payload) is ~90t for both. So, quick napkin math looks like it works (obviously there are a lot of other complexities I'm ignoring here, for the sake of simplicity).
    - anovikov 6y ago
      It can get to orbit technically of course! For that matter, just simply a single Delta core almost can do it, falling just short of LEO. All i wanted to say is that there are no possible payloads for this scenario (payload will be so small, a much smaller and cheaper vehicle could deliver it). It's not an operational configuration of DIVH because it makes no sense.
Denvercoder9 6y ago
> it's just their rockets are smaller. That's actually what's important here. We don't really care much about re-entry of things that burn up. We care if a giant hunk of metal lands on Earth. The Long March core stage is about ~7 times as massive as the Falcon 9 second stage.
NikolaeVarius 6y ago
The 2nd stage is smaller AND efforts are made to de-orbit in a controlled manner.

JshWright 6y ago

No, this is unusual because it is a first stage booster (it is lit on the ground, making it "first" stage in most people's common usage of the term (in reality, there's no hard and fast definition)). It is definitely not the "second stage" (the second stage of the Long March 5 is the CZ-5-HO). This would be like the center booster of a Delta IV Heavy making it to orbit. Second stages pretty much invariably make it to orbit. To say "it happened" to SpaceX makes it sound like something went wrong... it's just how rockets work. The central booster of a Long March 5 making it to orbit is unusual (though it has happened before).

anovikov 6y ago
Just because this is launch of a very heavy payload onto a low earth orbit. So there is no upper stage as there is no need for it. Center core of Delta IV Heavy can't make it to orbit in any normal circumstances.
- deleted 6y ago
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- JshWright 6y ago
  I haven't done the math, but I would be surprised if a Delta IV-H couldn't fly a similar profile, resulting in the first stage being in a low orbit. DIVH and LM5 have similar LEO payload capacities, and the mass of everything above the first stage (dry second stage, propellant, and payload) is ~90t for both. So, quick napkin math looks like it works (obviously there are a lot of other complexities I'm ignoring here, for the sake of simplicity).
  - anovikov 6y ago
    It can get to orbit technically of course! For that matter, just simply a single Delta core almost can do it, falling just short of LEO. All i wanted to say is that there are no possible payloads for this scenario (payload will be so small, a much smaller and cheaper vehicle could deliver it). It's not an operational configuration of DIVH because it makes no sense.

Denvercoder9 6y ago

> it's just their rockets are smaller. That's actually what's important here. We don't really care much about re-entry of things that burn up. We care if a giant hunk of metal lands on Earth. The Long March core stage is about ~7 times as massive as the Falcon 9 second stage.

NikolaeVarius 6y ago

The 2nd stage is smaller AND efforts are made to de-orbit in a controlled manner.