This to me is one of the most important images from the Apollo missions, and its something most people outside space circles don't know about, and may not get the significance of. It shows Pete Conrad standing next to Surveyor 3, an unmanned spacecraft that landed on the Moon in 1967, and in the background can be seen the Apollo 12 lunar module he arrived in in late 1969. One of the objectives of this mission was to demonstrate high accuracy landing - and they managed to put the LM down a short walk from this probe. They recovered material samples from it to study how it had held up after 2 years on the surface. What this meant was that, in 1969, NASA had the capability to do lunar surface rendezvous missions - i.e. sending multiple payloads to the same site - up to and including other lunar modules. An unmanned LM that removed its ascent engine and propellant could deliver an extra 3 tonnes of cargo - a manned mission landing near to it later would then have that available for a much longer duration mission. NASA indeed began planning this, with 14 day surface time, but the budget was cut before even the first lunar landing. So this demonstration undermines claims that Apollo was a dead end. It wasn't - the decision to not continue after it was purely political.