Apollo 15 launches, initiating J-series extended scientific exploration missions

On July 26, 1971, Apollo 15 launched from Kennedy Space Center's Launch Complex 39A, inaugurating the 'J-series' phase of the Apollo lunar exploration program. Previous Apollo missions (G and H series) focused on demonstrating safe landing procedures and conducting short, constrained EVAs. In contrast, J-series missions prioritized intensive scientific research, carrying heavier payloads, advanced orbital science instrumentation, and hardware designed for extended stays on the lunar surface.

The Apollo 15 crew consisted of Commander David Scott, Command Module Pilot Alfred Worden, and Lunar Module Pilot James Irwin. To support the enhanced mission parameters, NASA made significant modifications to both the Saturn V vehicle (SA-510) and the spacecraft. Lunar Module Falcon was upgraded with larger fuel tanks and an extended engine nozzle to support three full days on the surface and heavier payloads. Most notably, Apollo 15 carried the first Boeing-built Lunar Roving Vehicle (LRV), an electric mobility vehicle capable of carrying two astronauts and hundreds of pounds of rocks across miles of terrain.

In orbit, Command Module Endeavour featured a newly designed Scientific Instrument Module (SIM) bay in the Service Module, which contained panoramic cameras, a gamma-ray spectrometer, a laser altimeter, and a subsatellite deployed into lunar orbit. Apollo 15 represented the full maturation of Apollo into an advanced scientific exploration program, transitioning astronauts from passive explorers to highly trained field geologists working in the Hadley-Apennine region.