航天安全专家质疑维珍太空船系统

Safety procedures at Virgin Galactic, whose spacecraft crashed on a test flight last week, had too few safeguards to prevent a potential catastrophe, one of the world’s leading space safety experts has said.

维珍银河(Virgin Galactic)太空飞船上周在飞行测试中坠毁后，一位世界一流的太空安全专家表示，该公司安全程序的保障措施太少，不足以防止潜在的灾难。

Tommaso Sgobba, a former head of flight safety for the European Space Agency, said industry best practice calls for operators to build in “two-failure tolerance”, or sufficient safeguards to survive two separate, unrelated failures – two human errors, two mechanical errors or one of each. He believes that SpaceShipTwo’s systems fell short of that standard.

欧洲航天局(European Space Agency)前飞行安全负责人托马索•斯戈巴(Tommaso Sgobba)表示，行业最佳实践要求运营商内置“双重容错”，即建立足以抵御两个不相关故障的保障措施，这两个故障可能都是人为故障，也可能都是机械故障，亦或是人为及机械故障各一个。他认为“太空船2号”(SpaceShipTwo)达不到这个标准。

According to investigators, Virgin Galactic’s SpaceShipTwo disintegrated after a pilot wrongly unlocked the “feathering” mechanism – which slows the craft during its descent – too early. The mechanism then activated even though the separate lever to deploy it was not pulled. The craft’s co-pilot died in the subsequent crash.

据调查，维珍太空船2号是在一位飞行员太早解锁“顺桨”装置（用于太空船降落时减速）后解体的。随后这个装置被启动，即便用于展开顺桨的另一个手柄并未被拉起。太空船随后坠毁，副驾驶死于此次事故。

The feathering mechanism – which is vital to slow the aircraft but potentially deadly when it is accelerating – was typical of the safety systems that need to withstand human errors and mechanical failures, analysts said.

顺桨装置对飞船减速至关重要，但在飞船加速时启动它可能是致命的。分析人士指出，顺桨装置需要承受人为失误和机械故障，形成一个典型的安全系统。

Mr Sgobba said SpaceShipTwo’s systems, which required two levers to be moved before the wings went in to a “feathered” configuration, appeared to be designed to be “one-failure tolerant” – to stay safe in the event of a single pilot error or mechanical failure. But the system had not worked that way. The design would not be acceptable in other safety critical-industries, such as aeroplane manufacture, he added.

斯戈巴表示，太空船2号要求在机翼进入顺桨姿势前拉动两个手柄，但其系统貌似被设计成“单重容错”，即只能在一次飞行员失误或一次机械故障的情况下保持安全。但系统并未如此发挥作用。他补充说，这种设计是不会为其他安全关键的行业（比如飞机制造）所接受的。

Loren Thompson, an adviser to US aerospace companies, said other safety-critical US businesses, including suppliers to Nasa, required at least the “two-fault tolerance” Mr Sgobba described. He said it was a “significant concern” that some private space operators applied less stringent standards.

美国航空航天企业的顾问劳伦•汤普森(Loren Thompson)表示，美国其他安全关键企业，包括美国国家航空航天局(Nasa)的供应商在内，至少都需要达到斯戈巴所讲的“双重容错”。他说部分私人航天运营商采用较宽松标准是个“令人担忧的重大问题”。

Virgin Galactic, which is part of Sir Richard Branson’s Virgin Group, said the locking mechanism for the feathers represented two separate safeguards. There was a “procedural” safeguard, as the lock was meant to stay in place until after the most dangerous, early part of the flight, and a “mechanical” safeguard, in the form of the lock itself.

维珍银河公司隶属于理查德•布兰森爵士(Sir Richard Branson)的维珍集团(Virgin Group)，该公司表示顺桨装置的锁定机构代表了两个不同的保障措施。一个是“程序性”保障，锁定机构应保持不动，直到飞船度过最危险的早期飞行阶段之后，另一个是“机械式”保障，即该机构本身。

Mr Sgobba said procedural rules could be seen as a safeguard in some circumstances, but “they are considered the least desirable”.

斯戈巴表示，在某些情况下程序规则可以被看作保障措施，但“它们被认为是最不可取的”。