In my previous update, I described how Hayabusa2 automatically halted its first target marker drop attempt when it was just 50 meters above the surface. A recently translated JAXA press briefing says the abort happened after Hayabusa2's LIDAR suddenly reported the spacecraft was much higher than it should be.

The sensitivity of Hayabusa2's LIDAR must be adjusted on a case-by-case basis for a wide variety of conditions around Ryugu. The spacecraft can automatically do this on the fly, but on 16 May, some "noise data" got factored into the adjustment and knocked the LIDAR out of calibration. Upon noticing an altitude discrepancy, Hayabusa2 immediately backed itself away from the surface.

I'm not entirely sure what "noise data" means, but Ryugu is very dark, which messes with the LIDAR and caused a similar glitch last year. In any case, JAXA says they "found [an] adjustment method that could reliably prevent noise mixing. This will be adopted from now on." With this fix in hand, Hayabusa2 descended to Ryugu on 30 May for a second try, and this time, it was successful!