Affiche Apollo 15 Command Service Module above the Moon

Apollo 15 was the first of the Apollo "J" missions capable of a longer stay time on the moon and greater surface mobility. There were four primary objectives falling in the general categories of lunar surface science, lunar orbital science and engineering-operational. The mission objectives were to explore the Hadley-Apennine region, set up and activate lunar surface scientific experiments, make engineering evaluations of new Apollo equipment, and conduct lunar orbital experiments and photographic tasks. Exploration and geological investigations at the Hadley-Apennine landing site were enhanced by the addition of the Lunar Roving Vehicle, or LRV. Setup of the Apollo Lunar Surface Experiments Package, or ALSEP, was the third in a trio of operating ALSEPs (on Apollos 12, 14 and 15). Orbital science experiments were concentrated in any array of instruments and cameras in the scientific instrument module, or SIM, bay. Engineering and operational objectives included evaluation of modifications to the lunar module, or LM, made for carrying a heavier payload and for a lunar stay time of almost three days. Changes to the Apollo spacesuit and to the portable life support system, or PLSS, were evaluated, and performance of the Lunar Roving Vehicle and the other new J-mission equipment that went with it -- lunar communications relay unit, or LCRU, and the ground-controlled television assembly, or GCTA. Another major mission objective involved the launching of a Particles and Fields, or P&F, subsatellite into lunar orbit by the command and service module, or CSM, shortly before beginning the return-to-Earth portion of the mission. The subsatellite was designed to investigate the moon's mass and gravitational variations, particle composition of space near the moon and the interaction of the moon's magnetic field with that of Earth.