The ALSEP experiments left on the Moon by Apollo 12 were connected to a Central Station, which contained a transmitter, receiver, timer, data processor, and equipment for power distribution and control of the experiments. The equipment was powered by SNAP-27, a radioisotope thermoelectric generator (RTG) developed by the Atomic Energy Commission. Containing plutonium, the RTG flown on Apollo 12 was the first use of atomic energy on a crewed NASA spacecraft—some NASA and military satellites had previously used similar systems. The plutonium core was brought from Earth in a cask attached to an LM landing leg, a container designed to survive re-entry in the event of an aborted mission, something NASA considered unlikely. The cask would survive re-entry on Apollo 13, sinking in the Tonga Trench of the Pacific Ocean, apparently without radioactive leakage. The Apollo 12 ALSEP experiments were activated from Earth on November 19, 1969. The LAD returned only a small amount of useful data due to the failure of its power supply soon after activation. The LSM was deactivated on June 14, 1974, as was the other LSM deployed on the Moon, from Apollo 15. All powered ALSEP experiments that remained active were deactivated on September 30, 1977, principally because of budgetary constraints. Mission highlights Launch With President Richard Nixon in attendance, the first time a current U.S. president had witnessed a crewed space launch, as well as Vice President Spiro Agnew, Apollo 12 launched as planned at 11:22:00 on November 14, 1969 (16:22:00 UT) from Kennedy Space Center. This was at the start of a launch window of three hours and four minutes to reach the Moon with optimal lighting conditions at the planned landing point. There were completely overcast rainy skies, and the vehicle encountered winds of during ascent, the strongest of any Apollo mission. There was a NASA rule against launching into a cumulonimbus cloud; this had been waived and it was later determined that the launch vehicle never entered such a cloud. Had the mission been postponed, it could have been launched on November 16 with landing at a backup site where there would be no Surveyor, but since time pressure to achieve a lunar landing had been removed by Apollo 11's success, NASA might have waited until December for the next opportunity to go to the Surveyor crater. Lightning struck the Saturn V 36.5 seconds after lift-off, triggered by the vehicle itself.