Core Insights - The article discusses the structure and components of launch vehicles, emphasizing the importance of multi-stage rockets for meeting orbital insertion demands [4][5] - It highlights the trend towards reusable, low-cost, and environmentally friendly technologies in the aerospace industry, with a focus on liquid oxygen-methane engines as the next core technology [6][7] Group 1: Rocket Structure and Systems - Launch vehicles consist of multiple systems including structural, propulsion, guidance, control, and safety systems, typically featuring 2 to 4 stages [4] - Key performance indicators include payload capacity, orbital accuracy, reliability, and launch costs, with various domestic and international models catering to different orbital needs [4] Group 2: Propulsion Systems - The propulsion system is critical for cost and performance, with solid engines being simpler and having shorter launch cycles, while liquid engines offer higher thrust and better controllability [5] - Liquid engines are categorized into three types: liquid oxygen/liquid hydrogen, liquid oxygen/kerosene, and liquid oxygen/methane, with the latter gaining traction for its cooling performance and cost-effectiveness [5][7] Group 3: Industry Trends - The industry is moving towards reusable technologies, significantly reducing launch costs, and transitioning to non-toxic propellants [6][7] - Liquid oxygen-methane engines are being rapidly developed both domestically and internationally, with notable advancements in various projects [7]