The military probably.
China's Space Program Thread II
- Thread starter Blitzo
- Start date
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).
- 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.
- 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.
- 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.
- 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).
- 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.
- 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.
- 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.
Please don't do this again.
A Long March 3B/E lifted off today, delivering the Gaofen-14-02 satellite (a mapping satellite) into planned orbit. This is the tenth Long March 3B/E this year to launch. According to information, China is trying to produce at least one Long March 3A variant rocket per month. This was the 603rd Long March launched, in addition to being the 67th launch this year from China.
Below is a photo of the launch and the mission patch.
Below is a photo of the launch and the mission patch.
@nativechicken & @Jason_
If you want to continue your almost private dispute on Space X vs whatever from China especially in that tone, then I kindly advance you to take this into the private DM section!
Any more of these ultra-long back & forth posts will be deleted from now on.
If you want to continue your almost private dispute on Space X vs whatever from China especially in that tone, then I kindly advance you to take this into the private DM section!
Any more of these ultra-long back & forth posts will be deleted from now on.
by78
General
Latest powerpoint slides on Jiuzhou's Lingyun and Longyun LOX/Methane engines. A few specs have been revised upward, while the weight of LY-70 has been reduced.
LY-70 Longyun:
– Ground thrust: 745kN
– Vacuum thrust: 811.7kN
– Ground specific impulse: 293.9s
– Vacuum specific impulse: 320.2s
– Weight: ≯750kg
– Maximum swing angle: ±8°
– Variable thrust range: 40%-100%
– Number of re-starts during a single flight: ≥3 times
LY-10 Lingyun:
– Ground thrust: 100kN
– Vacuum thrust: 121kN
– Ground specific impulse: 287.4s
– Vacuum specific impulse: 332.5s
– Weight: ≯240kg
– Maximum swing angle: ±8°
– Variable thrust range: 40%-100%
– Number of re-starts during a single flight: ≥3 times
Jiuzhou plans an annual production of 150 to 200 Longyun (LY-70) Lox/Methane engines once its new plant becomes fully operational.
In other Jiuzhou related news, the company is currently assembling a prototype of a certain 140-ton LOX/Methane engine, which will undergo its first full-system ignition test in the first quarter of 2026:
The company has also formed technical partnerships with quite a few launch providers, positioning itself as a major engine provider for the space industry. Current partners include CASC, Arrowhead/Space Epoch, AstronStone, etc.:
I already posted this in the page before fwiw
Everyone has talked too much about SpaceX and Starship in the last few pages since Deino wrote his warning.
I will move all posts to a new "SpaceX and future space architecture" thread. Discussions will continue there.
Jason will also be unbanned, because he was banned after a minor post after Deino's warning post, but obviously many have continued on the discussion.
The new thread is here:
I will move all posts to a new "SpaceX and future space architecture" thread. Discussions will continue there.
Jason will also be unbanned, because he was banned after a minor post after Deino's warning post, but obviously many have continued on the discussion.
The new thread is here:
Global future space architecture thread
Moderator edit: 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...
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