Achieving low cost, high frequency, and rapid-response launche remains the core objective of space transportation development. Since the mid-20th century, the United States pioneered reusable launch vehicle (RLV) development. Government agencies like NASA and the U.S. Air Force led numerous flight test programs and engineering initiatives, progressing through multiple phases: early exploration, the Space Shuttle era, spaceplane concepts, and second-generation RLV development. Breakthroughs in key reusable technologies were ultimately achieved by commercial entities, notably SpaceX. This evolution exhibits multiple iterative cycles and parallel development paths. Systematically analyzing the U.S. RLV development route, including key projects and technical strategies, offers valuable insights for China's reusable launch vehicle advancement, supporting the planning and execution of major national projects.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |