Why Chinese Rocket Body Cross Over America Frequently?

[gloriousldpc]

I'm quite confused about this, it seems Chinese rocket body enters atmosphere above our country frequently, the trajectory should be accurate and calculated in advance right|? , do they do this on purpose or just their rocket body is out of control?

below is their CZ-7 rocket



This is the picture that the People's Republic of China CZ-2D Rocket Body, a March Long 5B style of rocket, reentered the Earth's atmosphere over Texas this year

 

[Unclear Engineer]

When anybody launches a rocket into Earth orbit, it will have an orbit that crosses all of the parts of the Earth that are at lesser latitudes than the launch site. (Unless the rocket changes course and shifts the plane of its orbit once it gets to orbital velocity, which is now done faily often.) Think of the orbit as a ring around Earth that is tilted to some angle away from the equitorail plane. Then imagine the Earth rotating every 24 hours as the satelite travels around the orbit ring.

So, typically, Chinese orbits cross the U.S., U.S. orbits cross China, Russian orbits cross the U.S. and China, etc.

The important thing is where unusually large satellites eventually come down. Smaller or less dense satellites just break appart and burn up to nothing on the way down, so they do not create any hazard on Earth's surface. But, large satellites and some big rockets that go into orbit with them can make re-entry debris that hits the Earth's surface and could harm people.

That is why most recent launches make plans ahead of time for the way the re-entries of large things will be handled. Most really big booster rockets that end-up in orbits after they separate from their satellite payloads are now designed to have engine restart capability so that they can be fired to initiate re-entry when they will land in remote areas - often the South Pacific Ocean in an area that has become known as the 'space graveyard". But, so far, China has not bothered to do that, perhaps because they don't have the technology in-hand to restart their large rocket motors.

The newest trend is to actully have the big boosters come back and land gently for reuse. SpaceX pioneered that process with its Falcon 9 booster, which can land on barges places in the ocean. And SpaceX is working on its Super Heavy booster to come dierctly back to its launch pad after launching its Starship. China has also announced that it is working on reuseable booster recovery technology.

Now, for the satellites that may stay in orbit for decades, the current approach is to provide propellant sufficient to make those satellites deorbit and re-enter the atmosphere on command. That allows them to be directed to the remote points on Earth' surface, as well as getting them out of orbit so that they don't contribute to the clutter of "space junk" in orbit.

 

[gloriousldpc]

When anybody launches a rocket into Earth orbit, it will have an orbit that crosses all of the parts of the Earth that are at lesser latitudes than the launch site. (Unless the rocket changes course and shifts the plane of its orbit once it gets to orbital velocity, which is now done faily often.) Think of the orbit as a ring around Earth that is tilted to some angle away from the equitorail plane. Then imagine the Earth rotating every 24 hours as the satelite travels around the orbit ring.

So, typically, Chinese orbits cross the U.S., U.S. orbits cross China, Russian orbits cross the U.S. and China, etc.

The important thing is where unusually large satellites eventually come down. Smaller or less dense satellites just break appart and burn up to nothing on the way down, so they do not create any hazard on Earth's surface. But, large satellites and some big rockets that go into orbit with them can make re-entry debris that hits the Earth's surface and could harm people.

That is why most recent launches make plans ahead of time for the way the re-entries of large things will be handled. Most really big booster rockets that end-up in orbits after they separate from their satellite payloads are now designed to have engine restart capability so that they can be fired to initiate re-entry when they will land in remote areas - often the South Pacific Ocean in an area that has become known as the 'space graveyard". But, so far, China has not bothered to do that, perhaps because they don't have the technology in-hand to restart their large rocket motors.

The newest trend is to actully have the big boosters come back and land gently for reuse. SpaceX pioneered that process with its Falcon 9 booster, which can land on barges places in the ocean. And SpaceX is working on its Super Heavy booster to come dierctly back to its launch pad after launching its Starship. China has also announced that it is working on reuseable booster recovery technology.

Now, for the satellites that may stay in orbit for decades, the current approach is to provide propellant sufficient to make those satellites deorbit and re-enter the atmosphere on command. That allows them to be directed to the remote points on Earth' surface, as well as getting them out of orbit so that they don't contribute to the clutter of "space junk" in orbit.

thank you for the awesome post, yes, i have read about chinese reuseable booster recovery technology, but i don't think they can copy Space X, i even doubt if they acquire this tech from Elon?