China's Space Program Thread II

[SCE2Aux]

They're also planning two CZ-10 pads, right? Makes sense for a dual launch Lunar Orbit Rendezvous architecture. At the moment they've got one pad showing really good progress on construction, but no info on even ground preparation for the second pad.

So for me it it raises the following questions:
- Are they comfortable with using the single pad for both Mengzhou and Lanyue launches, and are happy with either the pad turnaround time, or Lanyue's ability to loiter in lunar orbit?
- Or alternatively is a 2029/30 landing contingent on that second pad?

 

[enroger]

Elon Musk commenting on Landspace rocket

https://twitter.com/i/web/status/1981399997699805613

Wow Musk really loves stainless steel. Is stainless steel really advantageous though? Not in terms of strength to mass ratio, but in terms of cost and ease of construction sure

 

[jli88]

Posting AI Slop

Benefits of Stainless Steel for Orbital (Reusable) Launch Vehicles​

1. Superior Temperature Resistance​

• Stainless steel can withstand very high temperatures (up to ~1100°C) without losing strength.
• This makes it ideal for atmospheric reentry, where external skin temperatures can exceed 1000°C.
• In some designs, it can serve as both structure and partial thermal protection, reducing or eliminating heat shield mass in less critical areas.

Why it matters for reusability:

• Reduces the need for fragile heat tiles or ablative coatings.
• Minimizes refurbishment between flights.

---

2. High Strength Across a Wide Temperature Range​

• Unlike aluminum (which becomes brittle at cryogenic temps) or composites (which degrade with heat), stainless steel remains strong and ductile from cryogenic fuel temps (~−180°C) to reentry temps (~1000°C).
• Perfect for cryogenic propellant tanks (e.g., liquid methane and oxygen).

Why it matters:

• The same tank structure can survive fueling, launch, reentry, and landing.
• Fewer material transitions → simpler, lighter, more reliable design.

---

3. Structural Toughness and Crack Resistance​

• Stainless steel has excellent fracture toughness — it resists crack propagation from stress, fatigue, or micrometeoroid impacts.
• This is crucial for multiple flight cycles and pressurized tanks under dynamic loads.

Why it matters:

• Allows for higher safety margins in reusable vehicles.
• Lower risk of catastrophic failure due to fatigue over many reuses.

---

4. Simplified Thermal Protection System (TPS) Integration​

• Because of its high emissivity and heat capacity, stainless steel can be used bare or with minimal TPS.
• It can act as a radiative cooling surface during reentry, shedding heat effectively.

Why it matters:

• Less TPS mass and complexity = lower maintenance and faster turnaround.
• Ideal for hot regions like flaps or leading edges.

---

5. Low Cost and Ease of Manufacture​

• Readily available industrial-grade steels (like 301, 304L, or 30X series) are inexpensive compared to aerospace-grade aluminum or carbon composites.
• Weldable and formable with standard industrial techniques — no autoclaves, complex curing, or expensive tooling.

Why it matters:

• Huge cost savings for large structures (e.g., Starship’s 9 m diameter tanks).
• Easier to repair or replace sections after flight.

---

6. Excellent Compatibility with Cryogenic Propellants​

• Handles liquid oxygen and liquid methane well — no embrittlement or leakage problems.
• Good for long-duration storage (important for orbital refueling or interplanetary missions).

Why it matters:

• Reliable tank integrity through many thermal cycles.

---

7. High Reflectivity and Radiative Properties​

• Polished stainless steel reflects sunlight and radiates heat efficiently.
• This helps regulate tank and vehicle temperature in orbit, reducing boil-off of cryogenic propellants.

Why it matters:

• Better thermal control in vacuum and during long-duration missions.

---

8. Reusability and Rapid Refurbishment​

• Durable under multiple launch/reentry cycles with minimal degradation.
• Damage (from heat, micrometeoroids, or impacts) can often be welded or patched on-site, unlike composites.

Why it matters:

• Supports airplane-like reuse — faster turnaround and lower cost per flight.

Trade-offs / Drawbacks​

Factor	Challenge
Density	Heavier than aluminum or composites → lower payload fraction.
Forming complexity	Harder to machine and shape, but offset by easier welding.
Surface oxidation	Needs protective coatings/polish for aesthetics and corrosion resistance.

---

Example: SpaceX Starship​

• Switched from carbon composite to 301 stainless steel.
• Benefits:
  • Survives reentry heating with minimal TPS.
  • Tanks handle cryogenic methane/oxygen.
  • Easier, faster, cheaper to build and repair.
  • High reflectivity reduces propellant boil-off in orbit.
• SpaceX found that the mass penalty was offset by lower cost, higher durability, and better thermal performance for reuse.

 

[enroger]

Posting AI Slop​

​

Benefits of Stainless Steel for Orbital (Reusable) Launch Vehicles​

1. Superior Temperature Resistance​

• Stainless steel can withstand very high temperatures (up to ~1100°C) without losing strength.
• This makes it ideal for atmospheric reentry, where external skin temperatures can exceed 1000°C.
• In some designs, it can serve as both structure and partial thermal protection, reducing or eliminating heat shield mass in less critical areas.

Why it matters for reusability:

• Reduces the need for fragile heat tiles or ablative coatings.
• Minimizes refurbishment between flights.

---

2. High Strength Across a Wide Temperature Range​

• Unlike aluminum (which becomes brittle at cryogenic temps) or composites (which degrade with heat), stainless steel remains strong and ductile from cryogenic fuel temps (~−180°C) to reentry temps (~1000°C).
• Perfect for cryogenic propellant tanks (e.g., liquid methane and oxygen).

Why it matters:

• The same tank structure can survive fueling, launch, reentry, and landing.
• Fewer material transitions → simpler, lighter, more reliable design.

---

3. Structural Toughness and Crack Resistance​

• Stainless steel has excellent fracture toughness — it resists crack propagation from stress, fatigue, or micrometeoroid impacts.
• This is crucial for multiple flight cycles and pressurized tanks under dynamic loads.

Why it matters:

• Allows for higher safety margins in reusable vehicles.
• Lower risk of catastrophic failure due to fatigue over many reuses.

---

4. Simplified Thermal Protection System (TPS) Integration​

• Because of its high emissivity and heat capacity, stainless steel can be used bare or with minimal TPS.
• It can act as a radiative cooling surface during reentry, shedding heat effectively.

Why it matters:

• Less TPS mass and complexity = lower maintenance and faster turnaround.
• Ideal for hot regions like flaps or leading edges.

---

5. Low Cost and Ease of Manufacture​

• Readily available industrial-grade steels (like 301, 304L, or 30X series) are inexpensive compared to aerospace-grade aluminum or carbon composites.
• Weldable and formable with standard industrial techniques — no autoclaves, complex curing, or expensive tooling.

Why it matters:

• Huge cost savings for large structures (e.g., Starship’s 9 m diameter tanks).
• Easier to repair or replace sections after flight.

---

6. Excellent Compatibility with Cryogenic Propellants​

• Handles liquid oxygen and liquid methane well — no embrittlement or leakage problems.
• Good for long-duration storage (important for orbital refueling or interplanetary missions).

Why it matters:

• Reliable tank integrity through many thermal cycles.

---

7. High Reflectivity and Radiative Properties​

• Polished stainless steel reflects sunlight and radiates heat efficiently.
• This helps regulate tank and vehicle temperature in orbit, reducing boil-off of cryogenic propellants.

Why it matters:

• Better thermal control in vacuum and during long-duration missions.

---

8. Reusability and Rapid Refurbishment​

• Durable under multiple launch/reentry cycles with minimal degradation.
• Damage (from heat, micrometeoroids, or impacts) can often be welded or patched on-site, unlike composites.

Why it matters:

• Supports airplane-like reuse — faster turnaround and lower cost per flight.

Trade-offs / Drawbacks​

Factor	Challenge
Density	Heavier than aluminum or composites → lower payload fraction.
Forming complexity	Harder to machine and shape, but offset by easier welding.
Surface oxidation	Needs protective coatings/polish for aesthetics and corrosion resistance.

---

Example: SpaceX Starship​

• Switched from carbon composite to 301 stainless steel.
• Benefits:
  • Survives reentry heating with minimal TPS.
  • Tanks handle cryogenic methane/oxygen.
  • Easier, faster, cheaper to build and repair.
  • High reflectivity reduces propellant boil-off in orbit.
• SpaceX found that the mass penalty was offset by lower cost, higher durability, and better thermal performance for reuse.

Yes, stainless steel has better thermal performance, but it doesn't necessarily apply to the first stage since the first stage does not need to endure re-entry, at most it gets to a lateral velocity of arround 1.5~2km/s and then boost back.

Maybe steel tankage can offset some of it's mass disadvantage though

 

[iewgnem]

Posting AI Slop​

​

Benefits of Stainless Steel for Orbital (Reusable) Launch Vehicles​

1. Superior Temperature Resistance​

• Stainless steel can withstand very high temperatures (up to ~1100°C) without losing strength.
• This makes it ideal for atmospheric reentry, where external skin temperatures can exceed 1000°C.
• In some designs, it can serve as both structure and partial thermal protection, reducing or eliminating heat shield mass in less critical areas.

Why it matters for reusability:

• Reduces the need for fragile heat tiles or ablative coatings.
• Minimizes refurbishment between flights.

---

2. High Strength Across a Wide Temperature Range​

• Unlike aluminum (which becomes brittle at cryogenic temps) or composites (which degrade with heat), stainless steel remains strong and ductile from cryogenic fuel temps (~−180°C) to reentry temps (~1000°C).
• Perfect for cryogenic propellant tanks (e.g., liquid methane and oxygen).

Why it matters:

• The same tank structure can survive fueling, launch, reentry, and landing.
• Fewer material transitions → simpler, lighter, more reliable design.

---

3. Structural Toughness and Crack Resistance​

• Stainless steel has excellent fracture toughness — it resists crack propagation from stress, fatigue, or micrometeoroid impacts.
• This is crucial for multiple flight cycles and pressurized tanks under dynamic loads.

Why it matters:

• Allows for higher safety margins in reusable vehicles.
• Lower risk of catastrophic failure due to fatigue over many reuses.

---

4. Simplified Thermal Protection System (TPS) Integration​

• Because of its high emissivity and heat capacity, stainless steel can be used bare or with minimal TPS.
• It can act as a radiative cooling surface during reentry, shedding heat effectively.

Why it matters:

• Less TPS mass and complexity = lower maintenance and faster turnaround.
• Ideal for hot regions like flaps or leading edges.

---

5. Low Cost and Ease of Manufacture​

• Readily available industrial-grade steels (like 301, 304L, or 30X series) are inexpensive compared to aerospace-grade aluminum or carbon composites.
• Weldable and formable with standard industrial techniques — no autoclaves, complex curing, or expensive tooling.

Why it matters:

• Huge cost savings for large structures (e.g., Starship’s 9 m diameter tanks).
• Easier to repair or replace sections after flight.

---

6. Excellent Compatibility with Cryogenic Propellants​

• Handles liquid oxygen and liquid methane well — no embrittlement or leakage problems.
• Good for long-duration storage (important for orbital refueling or interplanetary missions).

Why it matters:

• Reliable tank integrity through many thermal cycles.

---

7. High Reflectivity and Radiative Properties​

• Polished stainless steel reflects sunlight and radiates heat efficiently.
• This helps regulate tank and vehicle temperature in orbit, reducing boil-off of cryogenic propellants.

Why it matters:

• Better thermal control in vacuum and during long-duration missions.

---

8. Reusability and Rapid Refurbishment​

• Durable under multiple launch/reentry cycles with minimal degradation.
• Damage (from heat, micrometeoroids, or impacts) can often be welded or patched on-site, unlike composites.

Why it matters:

• Supports airplane-like reuse — faster turnaround and lower cost per flight.

Trade-offs / Drawbacks​

Factor	Challenge
Density	Heavier than aluminum or composites → lower payload fraction.
Forming complexity	Harder to machine and shape, but offset by easier welding.
Surface oxidation	Needs protective coatings/polish for aesthetics and corrosion resistance.

---

Example: SpaceX Starship​

• Switched from carbon composite to 301 stainless steel.
• Benefits:
  • Survives reentry heating with minimal TPS.
  • Tanks handle cryogenic methane/oxygen.
  • Easier, faster, cheaper to build and repair.
  • High reflectivity reduces propellant boil-off in orbit.
• SpaceX found that the mass penalty was offset by lower cost, higher durability, and better thermal performance for reuse.

You can get AI to write slop about benifit of anything, here's a list of benifit of using wood for rocket body:

Potential Benefits of a Wooden Rocket Body​

1. Cost and Availability

• Low Raw Material Cost: Wood is significantly cheaper to source than aerospace-grade aluminum, titanium, or carbon fiber composites.
• Minimal Processing Energy: Transforming raw wood into a usable form requires far less energy than smelting aluminum or manufacturing carbon fiber, which translates to lower cost and a smaller initial carbon footprint.

2. Manufacturability and Repairability

• Ease of Fabrication: Wood can be worked with simple tools and skills. It can be cut, carved, sanded, and shaped without the need for advanced CNC machines, autoclaves, or specialized welding expertise.
• Simple Joining Methods: It can be effectively joined using adhesives, screws, or traditional woodworking joints, which are less complex than precision welding or composite bonding.
• On-Site Repairs: In a hypothetical scenario (like a pioneer-style space program), damage could potentially be repaired in the field with basic materials.

3. Thermal and Insulative Properties

• Natural Heat Resistance: Wood is an excellent insulator. It does not conduct heat well, which could be a benefit in protecting internal components from the heat generated by the sun or aerodynamic friction during the early phases of flight.
• Charring Ablation: When exposed to high heat, wood chars. This charred layer can act as a primitive ablative heat shield, protecting the inner layers of wood by slowly burning away and carrying heat with it. This is the same principle used on the capsules of the Mercury, Gemini, and Apollo programs (though with advanced materials).

4. Mechanical and Structural Properties

• High Specific Strength: When considering strength-to-weight ratio (specific strength), some woods like spruce, birch, or advanced composites like plywood can be competitive with certain metals. This is why wood was used in early aircraft and is still used in high-performance gliders.
• Good Vibration Damping: Wood naturally absorbs and dampens vibrations better than many metals. This could be beneficial in reducing the transmission of violent engine vibrations to more sensitive payloads and avionics.
• Fatigue Resistance: Wood can handle a high number of stress cycles without failing from fatigue, a common issue in metal airframes.

5. Sustainability

• Renewable Resource: Wood is a renewable material, especially if sourced from sustainably managed forests. This is a stark contrast to the energy-intensive mining and processing of metals.

When it comes down to it, the only actual advantage of steel is low cost, both material and handling, making it great for expendable vehicles, which is ironic considering it's being advertised as good for reuse.
Steel for first stage doesn't incur a lot of penalty, especially for boosters that separate early.
Steel for upper stage comes at a staggering payload loss.

 

[iewgnem]

Wow Musk really loves stainless steel. Is stainless steel really advantageous though? Not in terms of strength to mass ratio, but in terms of cost and ease of construction sure

Elon wants to love stainless steel and wants validation, but between two iterations of Starship being unable to make orbit, and NASA now talking about cancelling Starship contract for Artemis 3 because I'm guessing their internal data on future payload looks even worse, Elon might not love stainless steel anymore, not as much has his ego want to.

It's one thing to forget Falcon Heavy exist with Starship, it's another to come up with something else to make people forget Starship exist.

 

[enroger]

Elon wants to love stainless steel and wants validation, but between two iterations of Starship being unable to make orbit, and NASA now talking about cancelling Starship contract for Artemis 3 because I'm guessing their internal data on future payload looks even worse, Elon might not love stainless steel anymore, not as much has his ego want to.

It's one thing to forget Falcon Heavy exist with Starship, it's another to come up with something else to make people forget Starship exist.

Starship most likely is able to make orbit, payload mass though.... I'm just extremely curious to the mass breakdown of starship. Though if company like Landspace is going for full stainless steel construction as well then it may not be that bad after all.

 

[TheRathalos]

They're also planning two CZ-10 pads, right? Makes sense for a dual launch Lunar Orbit Rendezvous architecture. At the moment they've got one pad showing really good progress on construction, but no info on even ground preparation for the second pad.

So for me it it raises the following questions:
- Are they comfortable with using the single pad for both Mengzhou and Lanyue launches, and are happy with either the pad turnaround time, or Lanyue's ability to loiter in lunar orbit?
- Or alternatively is a 2029/30 landing contingent on that second pad?

2 CZ-10/10A pads may eventually happen but it's unsure, one of the model of the long term vision of WSLC/HCSLC has another pad next to CZ-10's LC-301, but it seems to be for the CZ-9. Nearer term renders still show only one launch pad.





What is certain is that there will be 2 CZ-10/10A mobile launcher (only one is in Wenchang currently) to enable simultaneous preparation of 2 CZ-10/10A in the two CZ-10/10A VAB, which is necessary for both lunar missions and to have the backup for Tiangong missions.

Generally speaking the launch pad proper is less of a bottleneck than the assembly building/infrastructure and mobile launcher platforms themselves, since the launcher spend much more time in/on the laters than the former, e.g., WSLC is currently building a second CZ-7 & CZ-5 assembly building with their mobile launcher platforms (the later were completed this spring), they're going to increase the launch rate of both launcher famillies while still using the same launch pad.

The two CZ-10 of a lunar landing are going to launch at least 2 weeks apart, because of the lunar transfer windows, 2 weeks seems a doable time for a pad turnaround, even for a superheavy launcher.

There is also the question of the CZ-10B, which is a commercial derivative of the CZ-10A, it may either use the same launch infrastructure or method (like CZ-8 in WSLC vs CZ-7) but it could also use brand new infrastructures (like the CZ-8 in HICAL/HCSLC)

My speculation:

The current infrastructure of 2 CZ-10 VAB with one LC-301 launch pad is enough for the rest of the decade, and is enough to support the first lunar landing, the Shenzhou-Mengzhou transition period and the first demonstration launches of the CZ-10B.

Another launch pad, with its associated VABs may eventually be built to support increased Lunar launch cadence, the post-2030 mengzhou only period, the operational commercial use of CZ-10B and the replacement of CZ-7 to launch Tianzhou (Post-2032), but it will only be in the next decade

 

[iewgnem]

Starship most likely is able to make orbit, payload mass though.... I'm just extremely curious to the mass breakdown of starship. Though if company like Landspace is going for full stainless steel construction as well then it may not be that bad after all.

Landspace is the only Chinese launch startup using stainless steel, investors might care about your pitch deck, but the rocket equation doesn't. Steel is cheap to buy and work, it's not bad material for low performance expendable launchers, say if you plan on blowing up 11 Starship stacks without going bankrupt. Falcon 9 is made out of aluminum btw.

Starship making orbit with small payload is one thing, might even be enough to launch a few Starlinks to satasify Elon's ego, the problem is Artemis architecture with Starship requires refuel, and the number of refuels explode non-linearly as your payload shrinks, and I suspect NASA has a much better picture of performance of future Starship versions than Elon is letting out.

 

[Daniel707]

Xiong'an City saw its first locally made satellite roll off the production line on Wednesday, marking a breakthrough in the intelligent manufacturing of its aerospace information industry.

https://twitter.com/i/web/status/1980919554797601077