Global future space architecture thread

[Blitzo]

Use this thread for discussion for global future space launch architectures, including SpaceX.
Chinese future efforts can also be discussed here but it is not a primary China space thread, rather it is for discussing the pros and cons of various global space launch architectures, including SpaceX.

 

[nativechicken]

The level of investments in Chinese space is insane for sure. I just they don't go overboard.

China’s level of investment in the aerospace sector does not exceed that in chips. If China felt a sense of urgency in aerospace, you would find that it would immediately start construction of the CZ-9. In the chip/AI sector, China is now in “war mode.” In the aerospace sector, China is still in “normal mode.”


Many people say the CZ-9 is just a “PPT rocket,” but in fact, China has a strict five-year milestone plan. It generally takes about five years to go from zero to a fully built heavy-lift rocket. Right now, key technologies for the heavy rocket—such as the heavy rocket engines, large-diameter propellant tanks, and many related components—have already been stockpiled (work began in 2021).

If the first flight is targeted for 2030, then concrete progress will likely be set after the Two Sessions (National People’s Congress and CPPCC) in March 2026 (specifically, in the latter half of the year). That’s when new developments will become visible.

For example, the new Long March 9 was officially initiated in the second half of 2021. The reason is that 2020 was the last year of the previous five-year plan. The new plan had to wait until after the new leadership and fiscal budgets were confirmed at the Two Sessions in March 2021, and only then would implementation information be released.

So, if 2026 is when the CZ-9 schedule is confirmed, that will be the next key observation point. There’s no need to rush.

 

[Blitzo]

So? Models are just ideas and ideas are a dime for a dozen. Your reply illustrates my criticism of this thread so clearly — a whole lot of "China should do Y because SpaceX did it", not a single answer on why idea Y is sound and not stupid.

The fact that the newest CZ-9 designs, and the many medium and heavy state and commercial new reusable launch systems from China, adopt configurations similar to Super Heavy or Falcon 9/Heavy, is a reflection that among the Chinese space industry they seem to recognize SpaceX architecture is what they want to pursue for the short and medium term.

View attachment 163359
He has never seen the early Chinese evolution diagrams from large launch vehicles to the heavy-lift launch vehicle configuration, which were published before the Heavy Falcon configuration was revealed. In the development of the Long March 9, 300 to 400 different configuration combinations were explored…

These diagrams actually include some of the intermediate designs between the CZ-5DY and the CZ-10.

The fact that they have ended up with architectures for CZ-10 and CZ-9 which are reminiscent of Falcon 9/Heavy and Super Heavy respectively, is not a glowing endorsement of their prior design thinking and ambition. If anything it is an endorsement of SpaceX.

The next-generation space station will require modules at least 6 meters in diameter and 18 meters in length. Using Starship's second stage modified for space station purposes has the problem that one entire quadrant is completely unusable, and its diameter is too large—the original second-stage tanks are too big (creating wasted volume), posing significant practical risks.
China has a design for a rigid lunar module, 6 meters in diameter and 16-18 meters long (intended for use with heavy cargo landers). Subsequent space construction—whether for space solar power demonstrations or space service stations (systems specifically for refueling and resupplying satellites)—will involve building large-scale structures (200-300 meters in diameter), requiring cargo transport capabilities of over 20 meters.
For crewed Mars missions after 2040, it will be necessary to assemble two nuclear-powered spacecraft in space, each at least 100 meters long (generally, such designs require about 100 meters of separation between the crew module and the propulsion module—this is standard practice).
Therefore, the current partially reusable version of the Long March 9 is very practical for China. If the U.S. doesn't have similar space plans, then I have nothing more to say.
So don't call me arrogant for saying that by 2035, U.S. space capabilities will be noticeably behind China's. That's because America currently has no concrete plans for these super-large space systems, while all of them are on China's Long March 9 mission manifest. If the U.S. doesn't want to start falling behind by 2035, it must begin budgeting and designing them now (don't forget, the average R&D cycle for a U.S. crewed space payload is about 8.2 years).

I've read all of your posts on this matter, and while I see where you are coming from, I think you have two underlying major blindspots.

1) you are focusing too much on Starship (second stage), whereas you should be focusing on the success of Super Heavy (first stage). As I've written previously it is within US and SpaceX capabilities to quite feasibly and reasonably easily develop a conventional second stage for Super Heavy. Such a design, with the increasingly credible reusable capability of Super Heavy (first stage) and their production of Super Heavy boosters and Raptor engines, would enable a launch capability that is magnitudes greater than what exists for humanity at this stage -- but especially for in-earth orbital reasons.

- The caveat for 1), is fortunately for the PRC, the fact that the US and SpaceX have not elected to develop a conventional second stage for Super Heavy is a political/organizational unforced error from the US, because that gives the PRC a little bit of breathing room in terms of catching up in terms of total launch to orbit mass if they can muster up sufficient launches from their upcoming disparate state and commercial launchers until CZ-9 enters maturity.
However make no mistake, both Super Heavy and Starship are technologically very impressive, and the only reason the PRC can still be in the competition is because an unforced error from the US/SpaceX. If a conventional second stage for Super Heavy was pursued instead, it would be almost game over.
Heck, even if SpaceX wasn't even trying to develop Starship and was only testing Super Heavy and their second stage was just an empty ballast, then what they've achieved thus far with Super Heavy alone is also many years ahead of where the PRC is.


2) you are focusing too much on longer term space exploration and construction. I understand this desire, after all that is the goal of long term humanity. However, we need to remember that in the short to medium term the issue is one of geostrategic competition on earth, where space and orbital domains are a primary domain of competition/capability. Total throw weight to orbit, as well as single unitary payload mass to orbit, will be important enablers of strategic military purposes -- and it doesn't even need to be for space to terrestrial weapons -- counter satellite orbital payloads, orbital networking, orbital sensors (both low earth orbit and geostationary earth orbit), procured en masse may prove devastating to current ways of ISR, AEW&C, sea surveillance, etc. And all of those domains can be greatly enabled by consistent launch of a super heavy class rocket platform, like a Super Heavy with a conventional second stage (and/or additional upper stage bus for say, GEO payloads).

- The caveat for 2), is that even if a Super Heavy + conventional 2nd stage existed, the rest of the US space industry has yet to catch up with the ability to make use of that kind of cumulative launch capacity. Developing, and mass producing space payloads has yet to match their launch capacity, and that is part of the reason why SpaceX Falcon 9 launches are so consistently Starlink, which while useful, is not as useful as other payloads might be.
However, this mismatch of "US space industry payload development/production" with "SpaceX launch capacity to orbit" is again, just an unforced error on behalf of the US, which gives the PRC a bit of breathing room to catch up. The mere fact that SpaceX with Falcon 9 has enabled such launch capacities, and the fact that Super Heavy can present the option of it as well (and is only held back due to Starship rather than pursuing a more conventional 2nd stage), should not be comforting to PRC strategic planners or the PRC space industry.


In short, the technological achievement and actual provision of launch capacity of Falcon 9, Super Heavy (and also Starship to an extent, as silly as it is), cannot be denied and needs to be recognized.
The only reason that the US has not been able to leverage Falcon 9 to large scale strategic leads, is due to mismatch of the rest of their higher end space payload industry... and the fact that Super Heavy is not an imminent risk to potential PRC strategic space presence is due to a continued silly obsession with Starship as a second stage rather than a conventional second stage.


If in the near future the US is able to:
A) force SpaceX to develop a conventional second stage for Super Heavy, and/or
B) have its high end space payload industry develop sufficient payload types/quantity to match with their launch capacity for earth orbital purposes...

... then the PRC would be in a much more perilous position than now (which is one where they still have a bit of time to catch up if they play cards right).

But as it stands, the PRC space launch and space payload industry is essentially competing against time for A) and B).

 

[gelgoog]

The CZ-10 is already doing stage hold down testing. It will likely be in service next year.
It will still take time to get it reusable. But it is a more than adequate stopgap. Each CZ-10 module has higher thrust and Isp than the equivalent Falcon module.

The CZ-10 should be a much more economic and more capable replacement for CZ-5.

Anyway it is not like SpaceX invented modular rockets. That would have been Vladimir Chelomei with the Universal Rocket family.

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The US EELVs were already modular. The CZ-5 architecture seems to have been Ariane-5 and Energia inspired. And now the CZ-10 architecture is Falcon inspired.
CZ-10 probably takes more man hours to build than Falcon, but salaries are cheaper in China than the US anyway.

The Chinese private sector has rockets like ZQ-3 which if they work properly can replace the smaller legacy rockets. If that does not work out there are the new expendables CZ-7, 8, 12.

 

[enroger]

Fwiw, I don't think cargo bay design is a show stopper, even if starship's current cargo bay/door design is not optimal they can always redesign it.

I'm more concerned about the mass efficiency of the concept, with the extra thermal protection tiles, stainless steel construction, fins and actuators, leftover fuels for suicide burn...etc, just what real payload capacity is left. If they can really achieve just a 50% trade off in payload capacity is very much a open question at this point.

 

[latenlazy]

Fwiw, I don't think cargo bay design is a show stopper, even if starship's current cargo bay/door design is not optimal they can always redesign it.

I'm more concerned about the mass efficiency of the concept, with the extra thermal protection tiles, stainless steel construction, fins and actuators, leftover fuels for suicide burn...etc, just what real payload capacity is left. If they can really achieve just a 50% trade off in payload capacity is very much a open question at this point.

Keep in mind also that just because they’re able to land the thing doesn’t mean that it’s returning in a reusable state, or in the case of providing for a manned mission that it’s a safe reentry vehicle for humans. One of the main problems with popular perceptions of Starship vs engineering reality is that just because you have high testing cadence doesn’t mean you’re actually moving fast in your development. You can do a lot of testing and actually be making slow progress for your critical milestones. The frequency of Starship test launches isn’t in of itself a sure mark of rapid progress.

 

[nativechicken]

The fact that they have ended up with architectures for CZ-10 and CZ-9 which are reminiscent of Falcon 9/Heavy and Super Heavy respectively, is not a glowing endorsement of their prior design thinking and ambition. If anything it is an endorsement of SpaceX.

The CBC (Common Booster Core) architecture has been discussed within China's aerospace community for a long time, long before the Heavy Falcon appeared. Russia's Angara model, with its A3/A5/A7 configurations, has always been very attractive to China. This is the origin of the two competing proposals for the CZ-10: one was a 3-CBC design, the other a 5-CBC design. The CZ-10 is a three-stage rocket architecture, which makes it a completely different matter from the two-stage Heavy Falcon.
The same goes for the CZ-9. China has always been very interested in the Soviet N1 rocket. Before the Falcon 9, China's CZ-5 was the rocket with the most engines on its first stage in the world (10 engines), and the initial CZ-5DY design featured 16 engines on its first stage (2x6 + 4). In the images I provided, there is a design for a 6-meter diameter first stage with 7 engines, which shows that the 7-engine concept existed long before the Falcon 9 v1.1 even flew. The heavy rocket described in this material is actually an early version of the CZ-9 from 2011, showing two design paths for how the CZ-5 could evolve into the CZ-9. Back then, the Falcon 9 with its nine-engine rectangular layout had not even had its maiden flight.
The CZ-10 simply adopted a 5-meter diameter body and chose a 3-CBC layout. As for the stages above the first, they have little to do with the Heavy Falcon.
The CZ-9 has always been a three-stage rocket (this concept existed before 2010), initially conceived as a smaller version of the Saturn V. In the two versions of the CZ-9 from 2011, one was not made public. The publicly disclosed 2011 version of the CZ-9 was essentially a choice between a modified Energia and a modified Ares V design, both of which were two-stage designs (the modified Energia involved converting Energia's one-and-a-half-stage design to a two-and-a-half-stage design, while the modified Ares V involved changing from twin boosters to four boosters). The problem was that neither of these versions had high-orbit flight capability. This is why, by the 2015 review, they reverted to the modified Saturn V design, which is the Saturn V's clustered booster configuration.
During the in-depth development of the CZ-9 in 2015, a "Three Transformations" requirement was proposed (standardization, commonality, and modularization), leading to the concept of the CZ-9B (essentially a "stick" version of the Saturn V). With the proposal of CZ-9B, China's aerospace community suddenly discovered a problem: the CZ-9's core stage thrust was insufficient. This is the true origin of what, between 2017 and 2020, ordinary people perceived as competition between the CZ-10 and the CZ-9. At that time, the payload capacity of the modularized CZ-9B was in the same class as the CZ-10, and it was intended to compete for the CZ-10's cargo missions. It was then discovered that the CZ-9B's structural mass was optimized for the maximum launch configuration, making its first-stage thrust severely insufficient.
This is the real reason why the CZ-9's design was adjusted in 2021.
The 2021 version of the CZ-9 is actually a combination of the Saturn V's three-stage configuration, the N1's multi-engine design, and the Starship's first-stage reuse (in the eyes of China's aerospace community, Starship's first stage is a continuation of the N1, just with the concept of VTVL reusable first stage introduced). The overall parameters of the 2021 CZ-9 are the same as the 2015 version. It wasn't until the second half of 2022 that an improved methane-fueled version of the CZ-9 was proposed, with the launch mass increased to 4,400 tons due to reasons like changing the second-stage engine (different specific impulse).
This is the true story of the CZ-9's evolution. The CZ-9 and Starship are now two different things (a three-stage rocket vs. a two-stage rocket, and the CZ-9's first-stage diameter is directly that of the Saturn V). A fully reusable version of the CZ-9B is still not yet on the charts (the CZ-9's second stage could certainly be configured as a large spaceplane with propellant tanks).
Most critically, the CZ-9 actually retains the potential for an improved Saturn V-style clustered booster configuration.
Besides SpaceX fans, no serious researcher would equate the CZ-9 and CZ-10 with Starship and Heavy Falcon. Design借鉴 and reference is a normal path. Aside from its VTVL capability, is the 3-CBC concept even SpaceX's own? The Falcon 9's initial reusable recovery plan was actually similar to the K1. It was just discovered that the K1 path had too many uncertainties. This is also the real reason why the Falcon 9 was eventually scaled up. If you adopt VTVL, the payload capacity of a traditional medium-lift rocket becomes too small, so the first stage was enlarged. China's CZ-10 had a three-stage rocket requirement, and it was found that a 3.8-meter diameter body was still not enough, which led to the emergence of 4-meter and 5-meter configurations.
For China's aerospace sector, SpaceX's only real breakthrough in the practical field of rocket launch is VTVL (in China's eyes, VTVL technology is actually in the same class as Chang'e-3—the main difference is the engine thrust size). So, it's not a matter of "copying." Reusable rockets are the industry's consensus direction, and China actually has its own plans for reusable rockets (a plan that began in 2010). One was the X-37 (a small spaceplane/re-entry vehicle), another was the BS-1 (a rocketplane for first-stage reuse). China planned to achieve these two missions by 2020, and there was also a K1-like project (mainly an advanced technology reserve for emergency return). The VTVL front that Falcon 9 opened was truly unexpected. China didn't have a suitable engine (just like the rest of the world), so it spent some time on both the new engine and new rocket body. That's why it's only now truly entering the race.
If you are willing to actually discuss aerospace, rather than using the logic of "they look similar, so it must be a copy," I am willing to engage. If superficial similarity (like not being able to distinguish between a three-stage and a two-stage rocket) is your basis for comparison, then frankly, there's no need to discuss.
This is just the typical arrogance of Westerners, just like when they insisted the J-10 must be a copy of the Lavi (without understanding the different operating principles caused by the differences in canards and airfoil profiles). Or saying the J-31/J-35 copied the F-35 (unable to tell the difference between twin-engine and single-engine designs). And then forcing a foreign parentage on Chinese designs. In any case, there are plenty of Chinese people who genuinely believe this (back on the CD forum, countless self-proclaimed aviation experts also insisted the J-10 originated from the Lavi and had absolutely nothing to do with the J-9. Does anyone believe those people now?). And then there was the AESA radar on the Type 052 destroyer, which was initially thought to be a PESA, with a firm refusal to believe it could be an AESA.
At this stage, I can only say, let everyone be happy for now. If you want to believe the CZ-9/CZ-10 are copies, so be it. When the actual hardware is revealed, the real international experts in this field will speak up for China. The structural difference between a three-stage and a two-stage rocket is similar to the difference between the J-35 (twin-engine) and the F-35 (single-engine). Fundamentally, they are two different things with two different philosophies.

 

[gelgoog]

The Russian rockets typically have one extra stage because their launch sites are far from the equator. You need a third stage in an equatorial launched rocket if you want to do TLI for lunar missions. Or for other deep space missions.

But an alternative is orbital rendezvous and tugs.

 

[Blitzo]

The CBC (Common Booster Core) architecture has been discussed within China's aerospace community for a long time, long before the Heavy Falcon appeared. Russia's Angara model, with its A3/A5/A7 configurations, has always been very attractive to China. This is the origin of the two competing proposals for the CZ-10: one was a 3-CBC design, the other a 5-CBC design. The CZ-10 is a three-stage rocket architecture, which makes it a completely different matter from the two-stage Heavy Falcon.
The same goes for the CZ-9. China has always been very interested in the Soviet N1 rocket. Before the Falcon 9, China's CZ-5 was the rocket with the most engines on its first stage in the world (10 engines), and the initial CZ-5DY design featured 16 engines on its first stage (2x6 + 4). In the images I provided, there is a design for a 6-meter diameter first stage with 7 engines, which shows that the 7-engine concept existed long before the Falcon 9 v1.1 even flew. The heavy rocket described in this material is actually an early version of the CZ-9 from 2011, showing two design paths for how the CZ-5 could evolve into the CZ-9. Back then, the Falcon 9 with its nine-engine rectangular layout had not even had its maiden flight.
The CZ-10 simply adopted a 5-meter diameter body and chose a 3-CBC layout. As for the stages above the first, they have little to do with the Heavy Falcon.
The CZ-9 has always been a three-stage rocket (this concept existed before 2010), initially conceived as a smaller version of the Saturn V. In the two versions of the CZ-9 from 2011, one was not made public. The publicly disclosed 2011 version of the CZ-9 was essentially a choice between a modified Energia and a modified Ares V design, both of which were two-stage designs (the modified Energia involved converting Energia's one-and-a-half-stage design to a two-and-a-half-stage design, while the modified Ares V involved changing from twin boosters to four boosters). The problem was that neither of these versions had high-orbit flight capability. This is why, by the 2015 review, they reverted to the modified Saturn V design, which is the Saturn V's clustered booster configuration.
During the in-depth development of the CZ-9 in 2015, a "Three Transformations" requirement was proposed (standardization, commonality, and modularization), leading to the concept of the CZ-9B (essentially a "stick" version of the Saturn V). With the proposal of CZ-9B, China's aerospace community suddenly discovered a problem: the CZ-9's core stage thrust was insufficient. This is the true origin of what, between 2017 and 2020, ordinary people perceived as competition between the CZ-10 and the CZ-9. At that time, the payload capacity of the modularized CZ-9B was in the same class as the CZ-10, and it was intended to compete for the CZ-10's cargo missions. It was then discovered that the CZ-9B's structural mass was optimized for the maximum launch configuration, making its first-stage thrust severely insufficient.
This is the real reason why the CZ-9's design was adjusted in 2021.
The 2021 version of the CZ-9 is actually a combination of the Saturn V's three-stage configuration, the N1's multi-engine design, and the Starship's first-stage reuse (in the eyes of China's aerospace community, Starship's first stage is a continuation of the N1, just with the concept of VTVL reusable first stage introduced). The overall parameters of the 2021 CZ-9 are the same as the 2015 version. It wasn't until the second half of 2022 that an improved methane-fueled version of the CZ-9 was proposed, with the launch mass increased to 4,400 tons due to reasons like changing the second-stage engine (different specific impulse).
This is the true story of the CZ-9's evolution. The CZ-9 and Starship are now two different things (a three-stage rocket vs. a two-stage rocket, and the CZ-9's first-stage diameter is directly that of the Saturn V). A fully reusable version of the CZ-9B is still not yet on the charts (the CZ-9's second stage could certainly be configured as a large spaceplane with propellant tanks).
Most critically, the CZ-9 actually retains the potential for an improved Saturn V-style clustered booster configuration.
Besides SpaceX fans, no serious researcher would equate the CZ-9 and CZ-10 with Starship and Heavy Falcon. Design借鉴 and reference is a normal path. Aside from its VTVL capability, is the 3-CBC concept even SpaceX's own? The Falcon 9's initial reusable recovery plan was actually similar to the K1. It was just discovered that the K1 path had too many uncertainties. This is also the real reason why the Falcon 9 was eventually scaled up. If you adopt VTVL, the payload capacity of a traditional medium-lift rocket becomes too small, so the first stage was enlarged. China's CZ-10 had a three-stage rocket requirement, and it was found that a 3.8-meter diameter body was still not enough, which led to the emergence of 4-meter and 5-meter configurations.

I never said that CZ-10 and CZ-9 are copies of Falcon 9 and Super Heavy; what I said was that their architectures were similar, as a way of pointing out that Falcon 9 and Super Heavy are endorsements for SpaceX.

Obviously CBC is something that has been done by others before SpaceX, but that wasn't what I was getting at.

For China's aerospace sector, SpaceX's only real breakthrough in the practical field of rocket launch is VTVL (in China's eyes, VTVL technology is actually in the same class as Chang'e-3—the main difference is the engine thrust size). So, it's not a matter of "copying." Reusable rockets are the industry's consensus direction, and China actually has its own plans for reusable rockets (a plan that began in 2010). One was the X-37 (a small spaceplane/re-entry vehicle), another was the BS-1 (a rocketplane for first-stage reuse). China planned to achieve these two missions by 2020, and there was also a K1-like project (mainly an advanced technology reserve for emergency return). The VTVL front that Falcon 9 opened was truly unexpected. China didn't have a suitable engine (just like the rest of the world), so it spent some time on both the new engine and new rocket body. That's why it's only now truly entering the race.
If you are willing to actually discuss aerospace, rather than using the logic of "they look similar, so it must be a copy," I am willing to engage. If superficial similarity (like not being able to distinguish between a three-stage and a two-stage rocket) is your basis for comparison, then frankly, there's no need to discuss.
This is just the typical arrogance of Westerners, just like when they insisted the J-10 must be a copy of the Lavi (without understanding the different operating principles caused by the differences in canards and airfoil profiles). Or saying the J-31/J-35 copied the F-35 (unable to tell the difference between twin-engine and single-engine designs). And then forcing a foreign parentage on Chinese designs. In any case, there are plenty of Chinese people who genuinely believe this (back on the CD forum, countless self-proclaimed aviation experts also insisted the J-10 originated from the Lavi and had absolutely nothing to do with the J-9. Does anyone believe those people now?). And then there was the AESA radar on the Type 052 destroyer, which was initially thought to be a PESA, with a firm refusal to believe it could be an AESA.
At this stage, I can only say, let everyone be happy for now. If you want to believe the CZ-9/CZ-10 are copies, so be it. When the actual hardware is revealed, the real international experts in this field will speak up for China. The structural difference between a three-stage and a two-stage rocket is similar to the difference between the J-35 (twin-engine) and the F-35 (single-engine). Fundamentally, they are two different things with two different philosophies.

I recommend you re-read my prior post in full -- nowhere did I use the word "copy".
I remarked upon the fact that CZ-10 and CZ-9 utilized architectures/configurations similar to that of Falcon 9/Heavy and Super Heavy, to endorse that the configurations SpaceX settled on have turned out to be sensible, because multiple people have argued that SpaceX were insensible.

I also recommend reading the rest of what I wrote in that post, because you seem to have only honed in on the initial part of the reply and misinterpreted it into something entirely unrelated (i.e.: you think I was accusing CZ-10 and CZ-9 of "copying" SpaceX, which is not the case), whereas the rest of my post was actually addressing the blindspots in your assessment of the overall US-PRC space competition.


Also, can you put in some paragraph breaks next time please?

 

[ENTED64]

What is this about CZ-9 being delayed? I thought they were targeting early 2030s has that scheduled been delayed? I tried to search for it in the old space thread but I can't find any info about it and you can't search "CZ-9" due to search limitations.

The CZ-10 is already doing stage hold down testing. It will likely be in service next year.
It will still take time to get it reusable. But it is a more than adequate stopgap. Each CZ-10 module has higher thrust and Isp than the equivalent Falcon module.

As for CZ-10, I thought they were targeting 2027 so it seems they are ahead here. They do seem to be significantly behind in the super heavy lift race to the Starship though given that apparently the reusable version of CZ-9 is targeting 2040 or later? Unlike the development of Falcon 9 and Falcon Heavy equivalents seemingly going pretty well, the super heavy situation does seem to be much worse for China, I'm not sure why they're so much further behind.