As I get closer to finishing building the Saturn V’s structural components and beginning the finishing, it’s time to think some more about Apollo 15’s details.

Apollo 15, 16, and 17 included a space walk for the Command Module Pilot during the trip back from the moon. (This wasn’t just to give the CMP one of the cool things on the mission, a sort of consolation prize for minding the store while his buddies cavorted on the moon. There was some film to retrieve from some additional cameras in the SM. Remember, 1970, no digital cameras with wires to remote memory.) To assist the CMP on the journey from the CM to the SM, a set of rails and foot holds was added.

The rails on the CM leading from the hatch to the SM are covered by the BPC (boost protective cover, in place until the launch escape system is jettisoned), so those are not visible during launch. The rails along the top and sides of the SIM bay (Scientific Instrument Module), though, are visible on the pad and during launch.

Questions, then: how big, how long, how many, and just where?