日本“隼鸟2号”无人探测器目前唯一仍在工作的离子发动机已发生故障。消息人士周四表示，该探测器在2020年12月将小行星“龙宫”的样本带回地球后，正执行前往新目标小行星的延伸任务。
The only working ion engine on Japan’s Hayabusa2 unmanned probe, which is on an extended mission to its new target asteroid after bringing samples from asteroid Ryugu to Earth in December 2020, has broken down, sources said Thursday.
日本宇宙航空研究开发机构（JAXA）计划采用“隼鸟2号”上另外两台故障离子发动机中仍可使用的部件继续执行任务，首次“隼鸟”探测器也曾采用过同样的技术。
The Japan Aerospace Exploration Agency, or JAXA, aims to continue the mission by employing usable parts of two other failed ion engines on Hayabusa2, the same technique as that used with the first Hayabusa spacecraft.
这家隶属于日本政府的航天机构计划最快于本月下半月重新启动此次发生故障的发动机。然而，目前尚不清楚“隼鸟2号”能否于2031年抵达其新的目标小行星“1998 KY26”，因为这取决于探测器受损和性能劣化的程度。
The government-affiliated space agency plans to restart the operation of the newly failed engine as early as in the second half of this month. It remains unclear at the moment, however, whether Hayabusa2 will be able to reach its new target, 1998 KY26, in 2031 as that depends on the degree of the probe’s deterioration.
自2014年12月发射以来，近12年已经过去，“隼鸟2号”大幅超过设计寿命，导致其多个部件和系统出现损坏及性能退化。
With nearly 12 years having passed since its December 2014 launch, Hayabusa2 has greatly exceeded its design life, resulting in damage to and deterioration of various parts and systems.
“隼鸟2号”的四台离子发动机中，A、C和D三台已严重性能下降，因此在往返“龙宫”小行星期间得到保留的B发动机，成为延伸任务中的主力。8月中旬B发动机发生故障后，JAXA曾尝试维修，但未能成功。
Of Hayabusa2’s four ion engines, A, C and D had degraded substantially, so engine B, which had been preserved during its journey to and from Ryugu, has been mainly used on the extended mission. After the B engine broke down in mid-August, JAXA unsuccessfully attempted to fix it.
离子发动机由离子源和中和器组成，两者必须同时运行，探测器才能进行导航。
The ion engine consists of an ion source and a neutralizer, and both must operate simultaneously for navigation.
检查发现，B发动机的离子源已经失灵，但其中和器仍在工作。与此同时，C和D发动机的中和器均已发生故障，但它们的离子源仍在运行。
A close examination found that the B engine’s ion source has failed while its neutralizer is functioning. Meanwhile, the neutralizers of the C and D engines have broken down, but their ion sources are functioning.
因此，JAXA决定切换电路，将B发动机的中和器与D发动机的离子源组合起来，以恢复B发动机的运行。
Therefore, JAXA decided to switch the circuit to combine the B engine’s neutralizer with the D engine’s ion source to resume the operation of the B engine.
首次“隼鸟”探测器曾采用这一方法，从而得以返回地球。当时负责“隼鸟”任务的JAXA名誉教授国中仁使用了这一超出技术规格规定的非常规方法。隼鸟2号的规格将其列为一项标准技术。
This method was used in the first Hayabusa, enabling it to return to Earth. JAXA professor emeritus Hitoshi Kuninaka, who was in charge of the Hayabusa mission at the time, used the method as a nonstandard technique outside specifications. The Hayabusa2 specs include it as a standard technique.
“我们将不言放弃，齐心协力，与不断超越极限运行的离子发动机一起，将隼鸟2号的任务进行到底。”日本宇宙航空研究开发机构（JAXA）隼鸟2号拓展任务团队负责人三桝裕也表示。
“Without giving up, we will work as one to continue Hayabusa2 operations until the very end, together with the ion engines, which keep working beyond their limits,” Yuya Mimasu, head of JAXA’s team for the Hayabusa2 extended mission, said.