星舰StarShip原型版本快速迭代,测试结果也越来越好。StarShip SN10首次实现了着陆,其起飞、降落、姿态控制、着陆的完整过程,看上去都还不错。
StarShip SN10着陆后起火、火焰熄灭,随后爆炸。Elon Musk在Twitter解释,主要原因可能是:SN10着陆时引擎推力偏低,10米每秒的着陆速度导致着陆腿撑和尾部裙边损坏。从头部燃料箱吸入部分氦气,导致引擎推力下降。SN11正在修复上述问题。(“SN10 engine was low on thrust due (probably) to partial helium ingestion from fuel header tank. Impact of 10m/s crushed legs & part of skirt. Multiple fixes in work for SN11.”)
网友问到,StarShip是不是可以考虑省掉着陆点火反推,加大(加多)星舰舰翼,把降落速度从75米每秒降至50米每秒,然后用大网接住。Elon Musk回答,内部讨论过这个方案。用大网或弹跳城堡😆接住星舰。此方案虽不太体面,但可行。不过着陆反推系统仅占星舰总质量的5%,故(大网接住方案)并非gamechanger(“Yeah, we talked about that internally. Could just have it land on a big net or bouncy castle. Lacks dignity, but would work. But, optimized landing propellant is only ~5% of dry mass, so it’s not a gamechanger.”)—老实讲,Musk的回复因为极简,感觉话语之间逻辑关联不强。另,用大网接住,直觉上更安全😏。
星舰StarShip后续的测试应该会加快。据称,SpaceX计划今年7月1日前后,用超级重型火箭把星舰SN20送入轨道(SpaceX aiming for Starship+SuperHeavy to ORBIT by July 1st of this year, performed with Starship SN20 on top of Super Heavy BN3.)。可以想象,7月1日之前的迭代测试将会是紧锣密鼓。