China's Space Program News Thread

[siegecrossbow]

Shoulda, woulda, the West also said lockdown was the wrong approach to COVID and that the right approach should be democracy and transparency. How did that turn out?

Did you stop posting here for two years because b797 aka mig29 aka mig23 got banned and there was no incentive for you?

 

[Kejora]

Passivation technology" intentionally shortens the flight time in orbit, and the wreckage will eventually fall on the inaccessible "spacecraft cemetery" in the South Pacific.

That's an interesting claim, let's see if it actually crash there.

 

[Quickie]

Designing a single stage rocket that results in a 20 ton core undergoing uncontrolled re-entry on every launch is irresponsible and deserves to be called out as such. They should've designed and installed retro rockets to separate the core and initiate a controlled re-entry and brake-up over the ocean. This Atlas 5 mission animation shows how that's normally done:

The retrorocket is just to push back the first stage rocket away from the second stage. It wouldn't have changed the trajectory of the first stage rocket which you said broke up over the ocean. The LM-5 four boosters (equivalent to the first stage of the rocket) ended up in the ocean by the nature of its trajectory without any additional intervention.

You did not mention the second stage of the rocket carrying the spacecraft to orbit. Did any of the remains of the second stage come crashing back to earth?

 

[broadsword]

I think it will be like the Tiangong-1 which crashed into the Pacific Ocean.

 

[Temstar]

The retrorocket is just to push back the first stage rocket away from the second stage. It wouldn't have changed the trajectory of the first stage rocket which you said broke up over the ocean. The LM-5 four boosters (equivalent to the first stage of the rocket) ended up in the ocean by the nature of its trajectory without any additional intervention.

You did not mention the second stage of the rocket carrying the spacecraft to orbit. Did any of the remains of the second stage come crashing back to earth?

No, LM-5B core stage is separated from payload under spring power not retro-rocket. They talked about this during the live broadcast of the launch.

Either the people on the broadcast are wrong (which seems unlikely), or else if there are retro-rockets then it must be for deorbiting burn.

 

[nlalyst]

Anglos criticising China? Suprise, suprise! Never seen before! Truly an objective voice with no ulterior motives that deserves to be heard.

Just give it up and stop embarrassing yourself. The Russian space agency Roscosmos declared yesterday that Long March 5B was set for uncontrolled reentry.

 

[nlalyst]

The retrorocket is just to push back the first stage rocket away from the second stage. It wouldn't have changed the trajectory of the first stage rocket which you said broke up over the ocean. The LM-5 four boosters (equivalent to the first stage of the rocket) ended up in the ocean by the nature of its trajectory without any additional intervention.

You did not mention the second stage of the rocket carrying the spacecraft to orbit. Did any of the remains of the second stage come crashing back to earth?

There is no second stage on the LM-5B (unless you count the boosters). The problem is that the core stage reached orbit and is now tumbling in space with apparently no means to deorbit in a controlled manner. The core stage of Atlas V does not reach orbit by design.

In order to avoid rockets falling over our heads, standard practice calls for one of two things, according to McDowell.

• The rocket stage is built with a booster to steer it into a safe landing point in the water after it reenters Earth’s atmosphere, or ...
• built with a rocket stage with some kind of stabilization system and a restartable engine whereby you can slow it down and turn it 180 degrees to land in the ocean.

China’s Long March 5B was not built with either of those options. “And so it's just left in orbit the old fashioned way to reenter uncontrolled and that is very unusual nowadays,” McDowell says.

Although there are no international regulations that stipulate rockets be built with this in mind, it is a best practice by space agencies around the world.
“When they did that design, they should have stopped and thought, ‘you know, that's going to leave a big chunk of debris in orbit, we should change the design of the engine’,” McDowell says. “But they didn't. This is real negligence.”

NASA standard practice of disposing upper stages.

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Accepted disposal strategies for upper stages include:
1. reentry within 25 years. Risk of human casualty must be less than 1:10000. Because of their small size (just 10% of LM-5B core), the danger the Centaur uppers stages present is far smaller.

2.
- storage orbit between 2000km and 19700km
- storage orbit between 20700km and 35300km
- storage orbit above 36100km

3. Direct retrieval: retrieve the structure and remove it from orbit as soon as practical after completion of mission.

 

[nlalyst]

No worries, I have put you in my ignore list long time ago. I only realized your BS after seeing responses by other members. And I only made the reply not because there is a value to reason with you but rather I enjoy punching the bag.

LOL. This is already the third time you pop up to remind me that you are ignoring me.

How about you finally get over me and move on?

 

[Dante80]

In other news, every single major operations in the construction of the CSS through to late 2022:
(from Chinese social media - I'm not sure of its original source but it looks legit)

View attachment 71627

Managed to find where that diagram came from. It's in the launch mission booklet for the Core Module launch by CASC. Attaching the whole below.

 

[Dante80]

Based on this infographic and NET dates published on Twitter, here is a - guesstimated - timeline of upcoming CSS operations:

May 20 - launch of Tianzhou 2 on CZ-7
May 22 (NET) - docking of Tianzhou 2 with aft port of Tianhe
June 10 - launch of Shenzhou 12 on CZ-2F/G
June 11 (NET) - docking of Shenzhou 12 with forward port of Tianhe
August (NET) - undocking of Tianzhou 2 from aft port of Tianhe for rendezvous testing
September (NET) - undocking from forward port & landing of Shenzhou 12
September (NET) - docking of Tianzhou 2 with forward port of Tianhe for propellant transfer testing
September (NET) - launch of Tianzhou 3 on CZ-7
September (NET) - docking of Tianzhou 3 with aft port of Tianhe
October (NET) - launch of Shenzhou 13 on CZ-2F/G
October (NET) - docking of Shenzhou 13 with axial (nadir?) port of Tianhe
October (NET) - robotic arm relocation testing of Tianzhou 2 (to side port?)
October (NET) - undocking of Tianzhou 2 from forward (side?) port of Tianhe for EOM & reentry
March (NET) - undocking from axial port & landing of Shenzhou 13
March (NET) - undocking of Tianzhou 3 from aft port & docking at forward port of Tianhe
March/April (NET) - launch of Tianzhou 4 on CZ-7
March/April (NET) - docking of Tianzhou 4 with aft port of Tianhe
May (NET) - launch of Shenzhou 14 on CZ-2F/G
May (NET) - docking of Shenzhou 14 with axial (nadir?) port of Tianhe
May (NET) - undocking of Tianzhou 3 from forward port of Tianhe for EOM & reentry
May/June (NET) - launch of Wentian on CZ-5B
May/June (NET) - docking of Wentian at forward port of Tianhe

After this it gets a bit murky as Tianzhou 5 operations seem to overlap with Tianzhou 4 but there is no free docking port? But maybe TZ-4 will undock before TZ-5 arrives as it was scheduled (according to Twitter) to fly only in Oct. 2022?

July? (NET) - undocking of Tianzhou 4 from aft port of Tianhe for EOM & reentry
July? (NET) - launch of Tianzhou 5 on CZ-7
July? (NET) - docking of Tianzhou 5 with aft port of Tianhe
July? (NET) - robotic relocation of Wentian from forward to port on Tianhe
August/September (NET) - Mengtian launch on CZ-5B
August/September (NET) - docking of Mengtian at forward port of Tianhe
September? (NET) - robotic relocation of Mentian from forward to starboard on Tianhe
November (NET) - launch of Shenzhou 15 on CZ-2F/G
November (NET) - docking of Shenzhou 15 with forward port of Tianhe
November (NET) - undocking from axial (nadir?) port & landing of Shenzhou 14
December? (NET) - undocking of Tianzhou 5 from aft port of Tianhe for EOM & reentry