Tokyo, Oct. 1 (Jiji Press)–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, it was learned Thursday. 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. 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. 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. 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. The ion engine consists of an ion source and a neutralizer, and both must operate simultaneously for navigation. 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. 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. 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. “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. END [Copyright The Jiji Press, Ltd.]
