China's Space Program News Thread


longmarch

Junior Member
Registered Member
You cant compare the two situations. Back in the day, russia was a great space power, not so much now. But regarding china, i have already replied to that.
Not so much
Can't even give a straight no as an answer, because US still use Russian engines.
US relies on Russia, not because how great Russia is (not saying Russia is not great) but because how badly US has been managed. Don't be so cocky.
 

longmarch

Junior Member
Registered Member
Not anymore. What's important is what is happening today. Russia is no longer needed as the US have decided to get back into the Space.
Wow, you are saying US needed Russia because US didn't want to be present in space, while NASA was still there. I didn't know that. Then what did they needed Russia for.
Sure, today is more important. But never get too much ahead of yourself.
 

Quickie

Major
When will it land?

It will take at least one more day to circularize the orbit. After that, they will probably take as much time as possible to find the perfect landing place while ensuring there's enough time to complete the rest of the sample and return mission before nightfall on the landing site in about 14 days.
 
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discspinner

Junior Member
Registered Member
The lunar orbit entry burn completed at 8:58 PM Beijing. It will make 3 full orbits before the next de-orbiting burn. Each orbit lasts 8 hours. It isn't clear when the landing attempt will be. But it will be after 1300 UTC 11/29.
 

SinoSoldier

Colonel
I still do not understand the possible reasoning behind developing two completely different models of super-heavy launch vehicles when one could simply scale down a CZ-9 or scale up a 921 for respective crewed and cargo missions. There is only a 5-year difference between the projected flights of the 921 and CZ-9 - going by the 2020 predictions of course - which makes it tough to justify having different engineering teams tackling two divergent projects.

It is likely that either key technologies of the CZ-9 are at a developmental bottleneck or that CNSA is still subconsciously thinking of axing the entire project for financial, technological, or strategic reasons, hence the go-ahead with the much-safer but less-capable 921 LV.
 

Andy1974

New Member
Registered Member
I still do not understand the possible reasoning behind developing two completely different models of super-heavy launch vehicles when one could simply scale down a CZ-9 or scale up a 921 for respective crewed and cargo missions. There is only a 5-year difference between the projected flights of the 921 and CZ-9 - going by the 2020 predictions of course - which makes it tough to justify having different engineering teams tackling two divergent projects.

It is likely that either key technologies of the CZ-9 are at a developmental bottleneck or that CNSA is still subconsciously thinking of axing the entire project for financial, technological, or strategic reasons, hence the go-ahead with the much-safer but less-capable 921 LV.
A benefit is having a larger pool of experienced engineers that can be employed by the private space vehicle startups we are seeing.
 

taxiya

Colonel
Registered Member
I still do not understand the possible (1) reasoning behind developing two completely different models of super-heavy launch vehicles when one could simply scale down a CZ-9 or scale up a 921 for respective crewed and cargo missions. There is only a 5-year difference between the projected flights of the 921 and CZ-9 - going by the 2020 predictions of course - which makes it tough to justify having different engineering teams tackling two divergent projects.

It is likely that either key technologies of the CZ-9 are at a developmental bottleneck or that CNSA is still subconsciously thinking of (2) axing the entire project for financial, technological, or strategic reasons, hence the go-ahead with the much-safer but less-capable 921 LV.
1. It is not about cost or speed or technical maturity of either one. It is determined that a crew rated rocket has much higher safety margin than a pure cargo launcher. Therefor, developing a two-in-one will be too wasteful for the cargo purpose, and too high technical challenge for the crew transport purpose (if scaled up). The bottom line is that China does not want its crew to travel in a much larger cargo rocket.

The TLI payload of 25t is exactly just enough for the crew module and service module to the moon, no more. You can launch 25t carge to the moon as well, that is fine, but the 25t marking for the crew combo clearly demonstrated the Chinese thought, a dedicated crew carrier.

A scale-down cargo carrier does not do the job that China want, TLI of at least 50t is the minimum in the plan. You may think 25+25=50 that can do a job of 30, but in reality 25+25=0 because the smallest single piece is 30.

The two teams are different. One team is experienced with CZ-5 derived tech for 921. The team on CZ-9 has nothing in common with the other team, totally new engine, new tank, new fuselage.

2. That line of thought is based on the assumption that the two are in a relation of "either or", but that was never ever the the case. It was always a "one plus one combo" from the beginning.

By now it is not only CNSA committed to CZ-9, but the state consul as well, it is not totally up to CNSA to change their mind.

And most importantly, 921 does NOT have an official designation yet, CZ-9 has got it more than a year ago. That clearly says a lot.
长征九号重型运载火箭研制取得阶段性成果 2019.jpg
This publication has stated the projected work load of CZ-9, around 2030 4 to 5 launches, 2030-2035 10 launches, more frequently after 2050. If as you wanted, replacing CZ-9 with 921 would demand cutting cargo designed for CZ-9 in half, meaning redesign everything, doubling or tripling the launch frequency etc. That will certainly mess up all related space plans from 2030 to 2050 and beyond.

And last but most importantly, it does not matter what we think is better, it is what China want in reality matters.
 
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taxiya

Colonel
Registered Member
The projected landing of Chang'e 5 is around 23:00 December 1st Beijing time, according to this forum
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The owner of this thread is doing some serious calculation based on published time of events. The time can shift as nothing can be exactly predicted. One of the variables is the estimated circular orbital altitude which affects the interval of the orbiting which affect the time of decent etc.
 

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