sentences:  The first two surface samples were scheduled to start in late October 2018, but the rovers showed a scenery of large and small boulders and no regolith to sample, so the mission team decided to postpone sampling to 2019 and evaluate several options.The first surface sampling was completed on 22 February and obtained a substantial amount of regolith, so the second surface sampling was postponed and was eventually cancelled to decrease risk to the mission.The second and final sample was of excavated material dislodged by a kinetic impactor shot from a distance (SCI impactor).