Russia's Luna 15 crashed into the lunar surface shortly after Apollo 11 landed.
It's widely considered a failed sample return mission, but did Russia ever officially announce that sample return was indeed the objective?
The Soviet space program was famously secretive, and the accepted explanation of failed sample return only seems to be a conclusion drawn from the objectives of later Luna landers - as far as I've seen.
Does anyone know if the Soviets ever published official statements or documents about the Luna 15 plan? Can we be certain it was a sample return mission?