It was on an English TV in 1977 in this program: http://www.crowdedskies.com/tony_dodd_alternative3.htm
From what William Cooper said, there would have been a joint American-Russian mission.
(And possibly helped by alien beings see "ALIENS MEET SOME GOVERNMENT PEOPLE" video).
W. Cooper stated that after this mission ,they knew mars "could support life", then the year after ,the project of establishing a colony (on the ground or in a station) began later.
You might see in the document "TRAVEL IN THE TIME AND THE GALAXY" a station with an American flag close to mars, this "was in 1976".