Core Viewpoint - The article emphasizes the importance of reusable technology in the aerospace industry, highlighting that the shift from "single-use exploration" to "scaled application" is crucial for cost reduction and efficiency in space missions [4][6]. Group 1: Key Developments in Reusable Rocket Technology - On February 7, a significant milestone was achieved when the Long March 2F rocket successfully launched a reusable experimental spacecraft into orbit, reaffirming the central role of reusable technology in the aerospace sector [3]. - The evolution of materials used in reusable rockets is described as a balance of performance, cost, and reusability, with a focus on achieving a 97% cost reduction [4][6]. Group 2: Material Selection Principles - The selection of materials for reusable rockets must meet three critical criteria: extreme environmental adaptability, durability for multiple uses, and cost-effective mass production [7][8]. - The article outlines that the materials used in reusable rockets have transitioned from single high-end materials to a mixed system tailored for specific operational scenarios [8]. Group 3: Structural Material Analysis - The core structure of reusable rockets includes the airframe, propulsion system, recovery landing system, fairing, and navigation control system, each requiring targeted material selection based on functionality [11]. - The airframe structure has shifted from a focus on lightweight materials to practical applications, with stainless steel becoming the primary choice due to its low cost, extreme environment resistance, and ease of mass production [14]. Group 4: Propulsion System Requirements - The propulsion system, which includes the engine combustion chamber and nozzle, must withstand temperatures exceeding 2000°C, necessitating materials that are heat-resistant and capable of enduring high-pressure loads [17][18]. Group 5: Recovery and Landing System - The recovery landing system is crucial for reusable rockets, requiring materials that can absorb impact loads during landing and withstand aerodynamic heating during re-entry [20][21]. Group 6: Future Trends in Material Innovation - Future developments in reusable rocket materials will focus on enhancing the performance of stainless steel and breakthroughs in low-cost composite materials, potentially increasing the number of reuse cycles from 18 to over 20 and reducing launch costs to the million-yuan level [30][31].

Core Viewpoint - The core competition in commercial aerospace has shifted from "can it go to space" to "can it go to space repeatedly at low cost," with the key to this shift lying in the materials used for reusable rockets, which are essential for both technological breakthroughs and cost reduction [3][4]. Group 1: Material Selection Principles - Reusable rockets must meet three critical criteria: extreme environmental adaptability, durability for multiple uses, and cost-effective mass production [6][7]. - The materials must withstand temperatures from -196°C to 1200°C, endure high-pressure combustion, and resist wear and tear to minimize maintenance costs after recovery [6][7]. Group 2: Structural Material Analysis - The main structure of reusable rockets includes the airframe, propulsion system, recovery landing system, fairing, and navigation control system, with each component requiring targeted material selection [9]. - The airframe has transitioned from a focus on lightweight materials to practical applications, with stainless steel becoming the mainstream choice due to its low cost and ability to withstand extreme conditions [10][14]. Group 3: Propulsion System Requirements - The propulsion system, which includes the engine combustion chamber and nozzle, must endure temperatures exceeding 2000°C, necessitating materials that are heat-resistant and capable of withstanding high-pressure loads [16][17]. Group 4: Recovery Landing System - The recovery landing system is crucial for reusable rockets, requiring materials that can absorb impact loads during landing and withstand aerodynamic heating during re-entry [20][21]. Group 5: Fairing and Navigation Control System - The fairing protects payloads and must be lightweight, insulated, and vibration-resistant, while the navigation control system components need to function reliably under extreme conditions [23][25]. Group 6: Material Mixing Trends - The trend in material selection for reusable rockets has moved towards a combination of materials tailored for specific functions, balancing cost, performance, and reliability [26][28]. - This approach avoids the high costs associated with carbon fiber and the fatigue issues of aluminum-lithium alloys while leveraging the strengths of stainless steel [28]. Group 7: Future Trends in Material Innovation - Future developments in reusable rocket materials will focus on enhancing stainless steel performance and breakthroughs in low-cost composite materials, potentially increasing the number of reuse cycles and reducing launch costs significantly [30][31].