This is Apollo 17, the SM segment was opened and exposed for cameras and instruments to survey the moon surface while the LM crew was on the moons surface. Later during the trans earth phase of the flight the Command Module Pilot did an EVA to retive the film and other data. You can just make out the hand rails along both sides be of the open section. I think still holds the record for the furthest out space EVA.
darthgarlic
Im pretty sure its Apollo 13. The rest of the CMs didn’t have that [panel blown off](http://www.spaceflightinsider.com/space-flight-history/spaceflight-heritage-apollo-13/).
adamswasprez
This is Apollo 17, the SM segment was opened and exposed for cameras and instruments to survey the moon surface while the LM crew was on the moons surface. Later during the trans earth phase of the flight the Command Module Pilot did an EVA to retive the film and other data. You can just make out the hand rails along both sides be of the open section. I think still holds the record for the furthest out space EVA.