sentences:  It operated over the altitude range between 30 m–25 km.When the spacecraft was closer to the surface than 30 m during the sampling operation, the Laser Range Finders (LRF-S1, LRF-S3) were used to measure the distance and the attitude (orientation) of the spacecraft relative to the terrain.The LRF-S2 monitored the sampling horn to trigger the sampling projectile.