performed the transposition, docking and extracting maneuver to dock with the LM and separate the combined craft from the S-IVB, which was then sent on an attempt to reach solar orbit. The stage fired its engines to leave the vicinity of the spacecraft, a change from Apollo 11, where the SM's Service Propulsion System (SPS) engine was used to distance it from the S-IVB. As there were concerns the LM might have been damaged by the lightning strikes, Conrad and Bean entered it on the first day of flight to check its status, earlier than planned. They found no issues. At 30:52.44.36, the only necessary midcourse correction during the translunar coast was made, placing the craft on a hybrid, non-free-return trajectory. Previous crewed missions to lunar orbit had taken a free-return trajectory, allowing an easy return to Earth if the craft's engines did not fire to enter lunar orbit. Apollo 12 was the first crewed spacecraft to take a hybrid free-return trajectory, that would require another burn to return to Earth, but one that could be executed by the LM's Descent Propulsion System (DPS) if the SPS failed. The use of a hybrid trajectory allowed more flexibility in mission planning. It for example allowed Apollo 12 to launch in daylight and reach the planned landing spot on schedule. Use of a hybrid trajectory meant that Apollo 12 took 8 hours longer to go from trans-lunar injection to lunar orbit. Lunar orbit and Moon landing Apollo 12 entered a lunar orbit of with an SPS burn of 352.25 seconds at mission time 83:25:26.36. On the first lunar orbit, there was a television transmission that resulted in good-quality video of the lunar surface. On the third lunar orbit, there was another burn to circularize the craft's orbit to , and on the next revolution, preparations began for the lunar landing. The CSM and LM undocked at 107:54:02.3; a half hour later there was a burn by the CSM to separate them. The 14.4 second burn by some of the CSM's thrusters meant that the two craft would be apart when the LM began the burn to move to a lower orbit in preparation for landing on the Moon. The LM's Descent Propulsion System began a 29-second burn at 109:23:39.9 to move the craft to the lower orbit, from which the 717-second powered descent to the lunar surface began at 110:20:38.1. Conrad had