From September 12 to September 17, the ‘Target marker separation operation’ will be performed. After that, the ‘Target marker orbit observation operation’ will continue. This is an operation to observe the target marker that goes around Ryugu, and it will be done until the target marker is landed (until about September 23). This operation was rescheduled from September 5 as announced in another article.
These ‘Target marker separation operation’ and ‘Target marker orbit observation operation’ are rehearsals for the separation operation of MINERVA-II2 Rover-2 (University consortium development) scheduled for October.
Figure 1 shows an overview of the operation. The descent starts at a low speed from September 12, and the TM is separated at a surface altitude of 1km from around 0:00 to 2:00 (JST) on September 17. A total of two TMs will be separated. They will be put into the equator and polar orbits around Ryugu, respectively. After that, the spacecraft moves to a position 20km away from Ryugu, with the sun behind. From that position, the optical camera continuously observes the TM trajectory descending around Ryugu. With the sun on the back, the retroreflective film covering the surface of the TMs shines brightly and can be observed. They will be observed until around September 23.
Figure 2 shows the mounting position of the targer markers. B and A are already separated from the five target markers. This time, E and C will be separated.