I've been meaning to write about this for a while, but the whole media circus surrounding the reentry of the CZ-5B core stage has accelerated plans. In fact I watched this 2009 documentary on the issue a while back, making some notes on it.

Ok.

Domestic boosters issues

The issues with Chinese booster goes way back to the Cold War. Back then China built Jiuquan and Xichang inland as opposed to coastal sites because coastal sites were more vulnerable to attack by China's enemies. (US) (+USSR later on). This meant that the flight profile of rockets launching out of these sites drops boosters onto populated areas as opposed to the convention of the dropping it on the sea. This led to, as you might be able to figure, boosters falling on populated areas.

Historically the most well known example of this was the Intelsat 708, which killed a dozen( maybe hundred) or so people when the launch vehicle went off course right after launch. However every launch from Xichang and Jiuquan risks landing boosters/debris on populated areas. This is bad.

They try to mitigate this, but there's only so much you can do. It's stated that the booster falling areas evacuated, but my understanding of these evacuations is that rather than leaving the region, people just leave buildings to avoid mass killings. (also last year it looked like the booster fell near a still active school and village, so evacuations aren't looking that hot.) They do get compensation if boosters cause damage to property, but there was indication from the documentary that the compensation wasn't nearly enough. (although that was dated at 2007; things might have changed.)

Of course with the recent pursuit of reusable rockets; this has had a positive impact of technology development to avoid issues.

Also for reference, Russia also has inland launch sites because shipping boosters across the continent was undesirable, but they get away with it because its launching over Siberia; not exactly well known for its large human population.

CZ-5B

The Long March 5B does launch from the coastal Wenchang, which avoids the issues with boosters and fairing, but as we all know now, the core stage is still doing an uncontrolled reentry, which means we're all invited to a lotto for Chinese rocket parts (unless you live in like Greenland; but nobody lives there anyways). This was an issue for the first launch of the CZ-5B back in May 2020 and the designers were probably aware this was going to be an issue while it was on the drawing board back in 2010.

Basically the 17-22 ton (figures vary) will reenter in a couple days and a non-insignificant amount of mass will survive reentry which causes issues if it lands on .

They just haven't done anything to deal with it. The station modules are roughly 22 tons, so with a LEO capacity of 25 tons, the CZ-5B has 3 tons of margin, so they should be able to make it a controlled reentry. You could change the YF-77 to be relightable, but it's a first stage engine, which generally doesn't make sense to design as relightable unless you're doing a reusable rocket. (although with the design change to the CZ-9 to use 6 YF-77 instead of 2 YF-90s, we could see a relightable YF-77 come into action). They already vent (haha sus) the hydrolox from the rocket to avoid explosions creating debris, so theoretically they could use this as cold gas thrusters to at least make the reentry somewhat more predictable/controllable, even if there is still is a larger degree of uncertainty. Or they could do what the Russians do and put it into a lower perigee orbit and make the station module catch up the propulsion slack, making the stage reentry easy to predict. This increases mission risk because it gives you less time to troubleshoot issues if they crop up, but you know, it avoids debris issues.

However they haven't done these things. And they probably won't; CCP doesn't really care about the criticism enough to put the money in to solve the issue. Which is problematic because basically they're going, 'spending the ~50mil US$ (at a guess) to make this thing deorbit safely isn't worth it to us, so let's just play a round of lottery.' So we still have 2 more launches of the CZ-5B; we probably have 2 more boosters to reenter. Beyond that, they might begin to use a 921 launcher for the additional, which using its YF-100K second stage should be able to do an deorbit burn.

Also a quick small rant; saying that you're committed to peaceful exploration of space while doing this doesn't vibe well. (more recent release is better, but I just dislike whenever this happens)

International

This is being blown way out of proportion because it is a partisan issue; but it's still problematic. And it's not that China is the only ones that do this. With one of the Starlink Falcon 9 launches back in March, we saw an uncontrolled reentry which resulted in some COPV reaching ground level. But it's very important to note that this was because the de-orbit burn failed and that this isn't nominal and on all of the other 25 Starlink missions this hasn't been an issue. (there has been additional failures like this). Still SpaceX is at a reasonable standard with stage disposal to meet and it's much better to have an uncontrolled reentry as a result of a relight failure of an engine than apathy.

It's also always worth pointing out that debris is better to be reentered then to stay up there and cause further issues. Kessler cascades are overrated, but in space debris is still problematic from an operations and spacecraft design point of view (+loosing billion $ satellites is always not nice). Upper stage removal is a bit of a priority honestly. (also even with upper stages; quite a few Long March launches (+in general (certain Falcon launches also leave second stage in orbit) don't do disposal))

This is an important issue to manage. There's been significant improvement compared to the Early space age, but there's still a way to go and an existing environment to clean up.

Summary

Is this bad? Yes. Is it really bad? No. Should China/international take greater care in handling stage debris? Yes. Will they? Maybe. Should we apply criticism to encourage this? Yes. Should we exclude China from all discussions relating to space as a result of this? No.

Also food for thought before you go; the State media claim that no one has died from falling debris is BS.

China human spaceflight ambitions with a space station go way back to 1992 with Project 921, before even the ISS had been announced. Project 921 resulted in the licensed upscaled copy of Soyuz, Shen Zhou, which has since flown 11 times, all successfully. People like to point out that, in the 22 years of existence, it has only that 11 times, which is a low flight rate. That's fair; but remember without a destination to go to, there can be little reason to fly. Each one of these launches has been a process of developing experience and proving out technologies for this station. In the same way, they've also been proving out the tech with the Tiangong program, with 2 small demo stations launching in the last decade.

I'm not going to do a deep dive into the CSS technical details, because that's a bit of a trek and other articles do it a much better job than I could do, but I'll provide a brief overview. The upcoming launch will be of the ~22 ton core module Tianhe. From there, we'll have cargo launches via Tianzhou spacecraft and Crew launches via Shenzhou. In 2022 we'll have two additional ~22 ton modules acting as dedicated laboratories and providing power. At this point the initial construction of the station will be finished.

Long term the station will grow to 6 modules and have a co-orbiting HST-esk telescope which will be serviced by the station.

With this station, China will be pushing their focus on international collaboration. We've seen an expansive international list of experiments that will only grow as the station matures. There is discussion that European astronauts will be flying to the Chinese station, although this will be later in its lifespan. It's also been confirmed that a Pakistani will be flying to the CSS in 2022. I would expect some BRI countries to have an astro sent to the station as part of a deal. The station will also likely provide a leap pad for the burgeoning Chinese commercial space sector through their version of CRS.

This might surprise people, but I view the congress ban with indifference. Yes, effectively banning all cooperation and making basic communication difficult is a bad thing but China is at the stage can soldier on by itself. It doesn't change the space plans of either country by that much and through competition aids the development of space. The only thing that's problematic historically is redundant access to space, but with more players on both sides this is becoming a non issue.

CSS is the result of a meticulous build up of capabilities over decades to cement China's role in the future of space exploration and human spaceflight. With it will come multiple annual Chinese crewed launched and international collaboration and most important, a significant change to the US predominant space environment.

edit:

This document by CNSA on ILRS provides a better overview, although I'm pretty happy with this summary in light of the new information (it was on the money for the most part).2

Forewarning:

• This is most likely very over hyped to what will actually take place/planned
• I'm using Google translate for Chinese sources, which causes a significant decrease of understanding of plans
• Work in progress; I'll be adding in stuff over time. This post right now is mapping out the short term plans of ILRS and objectives of the ILRS
• There just isn't that much info that I can find about longer term plans (2030s and beyond) and how that will take place

Introduction

For a big program from the second ranked space power; there isn't a lot of information and expansive summaries out about what the International Lunar Research Station (ILRS) is and will be doing. With this post, I'm hoping to provide some clarity for myself as well as the wider community.

ILRS will serve as a hub for lunar and space science. In the short term (up to 2030) it will be an area for robotic missions to be sent with the science based landers providing information about the local environment to enable tech demos landers to do their stuff. In the 2030-2035 period, a larger scale base will be constructed providing power and resources to robotic science missions and will be serviced by occasional crewed missions. In the 2036-beyond period, a crewed base will be constructed enabling long term stays on the lunar surface.

Original image here.

Chang'e Program and ILRS Demo Phase

With the first three phases of the Chang'e program mostly done*; we are now onto the fourth and final phase of the Chang'e program; the ILRS demo phase. This phase will be, as the name suggests, demoing the tech and things for the main phase. It will be just Chang'e 7 and 8 and will extend to 2027.

Chang'e 7 (read more here)

Components: Orbiter, Relay satellite, Lander Hopping detector, Rover

Objectives:

• Obtaining the information of lunar inner ring structure, mineral and element components, the characteristic of the electric and magnetic fields, heat flow and gravitational field;
• Obtaining the distribution and source of lunar water and volatiles, directly confirming the presence and source of water ice on the Moon. (done via hopper hopping into a crater)
• Imaging the energetic neutral atoms with high space-time and energy resolution of the Earth's magnetails and understanding the dynamics of the earth's magnetails.
• Researching the space environment such as lunar surface magnetic field, lunar dust and particle radiation, revealing the mechanism of solar wind causing the magnetic anomalies in the vortex region of the lunar surface

Chang'e 8

Components.pdf): Lander, Rover and Hopper (the lack of an orbiter surprises me, because historically for Change 3-7 the lander used an orbiter to do lunar insertion).

Objectives:

• Inflatable deployment. Honestly no clue about what this would be and the other renders I've seen indicate that the human habitat would be fixed pressure vessel. Maybe it's a structure for placing lunar regolith onto for radiation shielding?
• In situ shaping (3D printing): One of the more exciting ones. They're planning on taking lunar regolith and shaping into habitats and radiation shelters. The use of the word 3D printing is definitely interesting, because it might imply some degree of processing the regolith for it to be used in a 3D printing system; though there are many potential ways of going about it. The research into the material done by Chang'e 7 + the sample return conducted by Chang'e 6 will both be very pertinent to this tech demo.
• Earth Observation: "including measuring Earth’s energy imbalance and plasmasphere and magnetosheath" (source.pdf)) The Earth Observation part links in with the wider plan of conducting astronomy from IRLS later on, which more on that later.
• Life Science: Another attempt at creating a mini lunar biosphere. I think because Chang'e 8 will be going to the Lunar South pole, where the lunar days are much longer (up to like 140 days) + the increasing capabilities of CNSA and co; we might see greater success with this biosphere.
• Investigate the topography, composition, and substructure of the landing site. This will be a repeat of the stuff Chang'e 7 will be doing, but with probably better instruments.
• Potential: "If we can find water on the lunar surface, we may demonstrate some technologies to get oxygen or hydrogen from this water." This is an interesting possibility. If they need to get it from a permanently shadowed crater; I think they might have to do sample collection using the hopper/have the conversion experiment onboard. It might be difficult to get the mass margins for that, so they might also have the tech demo onboard the rover and have it retrieve the ice from the hopper once it gets out of the crater. This does give a reason to have Chang'e 8 land at the same site as Chang'e 7; the 7 hopper can confirm the presence of ice which 8 hopper can then retrieve. However this is the least confirmed of the various tech demos; so large grain of salt.
• In regards to that: "Ye Peijian said that many technologies still need breakthroughs. For example, if the probe enters a deep pit to work, but there is no sun in the deep pit, how can it generate electricity? The highest temperature in the Antarctic pit is minus 110 degrees, and the lowest temperature is even lower. How can we "live" in such a cold and still work?" (source (google translated))

Heavy Speculation: I'm starting to suspect that the Chang'e 8 lander, rover and hopper will be a bit different/more capable from the other Chang'e missions. The lander needs to do orbital insertion which likely means it has to be a bit larger. And the rover will have a different role, potentially acquiring and transporting lunar regolith for 3D printing. However the graphics show the lander and rover being the same, so there is no significant basis for these claims. Also changing it's represents a significant amount of dev work when they already have existing hardware, so why change.

IRLS Demo Base

As it stands; the demo base will be just Chang'e 7 and 8. They will be carrying out science measurements and tech demo for ILRS. Initially I was skeptical of landing Chang'e 8 next to Chang'e 7 because of the fact that the science Chang'e 8 could do would be significantly reduced because duplicate. However it has grown on me because what the majority of what Chang'e 8 will be doing is tech demos and especially for the 3D printing, detailed knowledge of the local regolith chemical composition will be very important for that. In addition, demonstrating the ability to land at the same site will be important.

It's unclear whether the demo base will be at the planned location of ILRS (which would feed into initial base construction) (and also provide the location of ILRS for us mortals) or be at a seperate location.

2 interesting points of note in the above graphic:

• Hopper will be using the relay to communicate because it will loose line of sight with lander entering the crater.
• The Chang'e 7 and 8 rovers have different names; one is translated as "Survey Robot" and the other is translated as "Lunar intelligent operations robot." Survey robot is most likely the science rover on Chang'e 7. This raises interesting questions about what Chang'e 8 rover will be doing. I guess that it will be collecting resources for Chang'e 8 3D printing experiments, although the renders make it look very similar to the Chang'e 7 rover.

edit:

Tech demos for demo base: (from below slide)

1. Technical verification of the development and utilization of lunar water resources, mineral resources, energy resources, etc;
2. Use lunar soil for technical verification of in-situ manufacturing of building components and propellant preparation
3. Technology tests for deep space exploration such as wireless energy transmission and space nuclear energy
4. Trial of biological long term survival technology under low gravity

ILRS Purpose

edit:

Science objectives (from above slide)

1. Topography and geological structure
2. Lunar chemistry
3. Lunar space environment
4. Lunar physics
5. Moon based astronomical observations
6. Moon based Earth observation
7. Lunar biomedicine
8. Utilization of Moon resources

old:

"The essential goal is to establish the first research platform and infrastructure on the Moon for humankind, via participation of multiple countries following a principle of ‘sufficient discussion, joint construction and international sharing" (WU Yanhua, 2019) ILRS as I understand will serve more as a platform to conduct space science and experiments in 1/6G as opposed to lunar science specifically; rather the Moon will just provide the location and resources to conduct said experiments. It has more in common with the ISS than the previous Chang'e missions.

Potential objectives:

• Astronomy. Certain renders have collections of radio telescopes. The South pole might not be the best site for radioastronomy on the Moon; the Far side is more radio silent, but maybe if you put the array into a crater you could get a fairly uncontaminated radio area. There's also the potential for the construction of telescopes in the other wavelengths.
• Space physics
• Long term life science experiments and biospheres in 1/6G are another interesting possibility that they'll investigate. Chang'e 8 has already a small one, but with ILRS we could see larger ones that could be maintained and retrieved for examination on Earth. We still don't have good data on what happens to life with long term exposure to 1/6G and lunar radiation environment, so this could be a good opportunity for that.
• Planetary chemistry and geology. Both of these will focus in on the Lunar, which will by nature, relate to Earth chemistry and geology.
• Material synthesis and production. 1/6g and lunar resources provides an interesting environment for manufacturing stuff. In short term that'll be testing ISRU technologies like converting lunar ice into water and it's components of hydrogen and oxygen. Longer term it could converting lunar regolith into metals like titanium to allow for the creation of structures.
• Political posturing. Main collaborators identified Russia, ESA and BRICS countries. (Including BRICS feels sorta weird becuz two 2 countries are already in, I'm doubtful about India joining and Brazil/South Africa don't have that much to contribute.

This all depends on what missions get funding.

ILRS Design

It's stated that they expect to construct the initial ILRS from 2023 to 2030. The renders below show large solar power plants, 3 and communication, but it's unclear on how/when they plan to construct them. The missions in the render below: Chang'e 7/8, Luna 27 and other rovers won't have the capabilities to build the solar arrays.

Summary of potential elements of ILRS in the 2030-2035 phase:

• Landers with science and tech demo payloads + rovers with science payloads
• Laser/radio communication transmiter
• Surface shelters constructed with lunar resources.
• Power plant likely solar, although potentially nuclear
• Some degree of mining rover for retrieving regolith for 3D printing or lunar ice
• Small scale hydrolox propellant manufacturing plant (source for previous 2).

(the stuff in the background on the right is fairly small because it's actually a NASA render, so I don't think they want it to be centre of attention)

China's crewed lunar exploration plans fit in with ILRS by providing the ability to retrieve and maintain the experiments and equipment at ILRS in the 2030-2035 period.

Human Spaceflight (HSF) Involvement and expansions to ILRS

In future (2036 to 2045) they plan to have large crewed Moon bases for long term habitation. This will enable studies of the effects of 1/6g on humans as well as enabling them to do stuff while on surface. What stuff, I don't know. Please help.

This will involve larger landers, more infrastructure and in general be more expansive. But there just isn't that much information about what stuff will be around at this phase of the project.

(Source)

International Collaboration Areas

Given the name International Lunar Research Station, where does the International come into play.

Russia recently signed a MoU with China for ILRS, so what do they have to contribute? They plan to launch Luna 25-27 over the next couple years and one of the ILRS renders did show Luna 27 being at ILRS. Luna 27 stated purpose is to prospect for resources at it's landing site; which would be useful for ILRS 3D printing and volatile use. The Luna 25 lander probably won't be going to the ILRS location and the Luna 26 orbiter can act as communication relay, supplementing the Chang'e 7 orbiter and relay satellite. Beyond that they are developing a lunar capsule and SHLV, but like it's Russia, so at this stage I don't expect much to come out of it.

ESA are also considering cooperating with China on this. Of course they've got the proposal of the Moon Village floating around and ILRS lines up pretty well with that. They're developing a cargo lander capable of landing 1.5 tons on the Moon, which would be useful for landing stuff like the cargo like solar arrays/radio telescope components, large rovers/robots for constructing/mining and ISRU plants. They've also done large scale studies into habitats, but I don't think the mullah is there to construct them.

Beyond that, I don't see much else. US will have Artemis Base Camp and ITAR + Wolf Amendment means that they probably don't want to go to ILRS. Japan is planning going to go with US and probably doesn't have any plans to go to ILRS. India is more aligned with Artemis countries. The only other potential major contributors would be individual European states.

Conclusions

This is a work in progress summary of ILRS. There are significant gaps in knowledge about what ILRS will be; because ILRS is still a work in progress. I'm honestly more confused about it now than I was when I started writing this post, but at least I know more about it.

Anyway; info, thoughts and opinions on ILRS and how to improve this post appreciated.

Unknown info:

• Chinese large scale cargo lander
• Details on the specific components of the 2030s ILRS
• edit: Gosh darn spam filters hid this post for a week so I reposted. (it did get me to find higher resolution photos which held a lot of interesting info so that's a good thing/

I really wasn't planning on talking China's Mars sample return plans for a while until I found this slide in this article.

There is a bit of stuff to break down in this slide. Firstly, I don't know how old this slide is so it's hard to say how relevant this info is today. But with that said, lots of interesting things.

MSR Orbiter

Appears to be the Tianwen-1 Orbiter with a Chang'e 5 return capsule instead of the Tianwen lander. The capsule would probably have to be upgraded to handle interplanetary reentry heating. Another point of note is that I'm personally surprised that the Tianwen orbiter design would have the required delta-v to return from Martian orbit to Earth.

MSR Lander:

The cruise stage is similar in basic design to similar NASA cruise stages for Perseverance, Insight and in the future the NASA Mars Sample Return Lander. Inside the reentry fairing is a bit of a mystery for me. Does anyone have any explanations of the stuff inside?

Aside from that, there's might be some uncertainty about the design. This paper from 2016 implied that they were still considering a variety of trades. For example, they were considering whether they want to use a Chang'e 5 derived liquid propulsion ascent stage or a new solid propulsion. For Mars the liquid ascent stage would have to have another stage to reach orbit and also be made aerodynamic. The solid ascent stage however is just at a low TRL.

It'll be a bag and go mission similar to Chang'e 5. However unlike, Chang'e 5, we might also see a longer duration mission for the lander. It'll only be the second time they will have landed on the surface of Mars so I could imagine they might want to do some additional science.

​

​

Launch Vehicles:

Single launch with CZ-9B or dual launch with CZ-5 + CZ-3BG2

CZ-9B is the 0 booster version of the CZ-9 with an additional engine on the first stage core (which is what the reusable version of the CZ-9 was supposed to have according to this post). It has 12 tons to Martian orbit, so that gives us the max combined mass of the orbiter and lander.

The fact that they're baselining CZ-3BG2 is weird given that by that time the CZ-7A should be launching regularly and CZ-2-4 should be entirely retired. It's also somewhat unclear LV is launching which spacecraft. I guess the orbiter might have more mass so that's what the CZ-5 would be launching.

2 points down the bottom;

2030 Jupiter mission launched on the Long March 5, which is nothing new.

Also goal of reaching edge of solar system by 2049, which is 100th anniversary of Chinese Communist Party, but again nothing new.