Islamic calendar lunar months begin precisely at the time of the monthly "conjunction", when the Moon is located most directly between the Earth and the Sun. The month is defined as the average duration of a revolution of the Moon around the Earth (29.53 days). By convention, months of 30 days and 29 days succeed each other, adding up over two successive months to 59 full days. This leaves only a small monthly variation of 44 minutes to account for, which adds up to a total of 24 hours (i.e., the equivalent of one full day) in 2.73 years. To settle accounts,
Pioneer 3 direct ascent trajectory, the odds of hitting the Moon were slim. However, a lunar flyby rather than impact would still be considered a successful mission. The flight plan called for the "Pioneer 3" probe to pass close to the Moon after 33.75 hours and then go into solar orbit. The Juno II lifted from LC-5 at 12:44 AM on December 6. Launch went entirely according to plan until first stage cutoff, when the engine cut off 3.7 seconds early due to a failure of the propellant depletion sensors, leaving a velocity shortfall of several hundred feet per second. The injection