During 1970-1972, a possible fourth “new” docking mission with Skylab was considered. This new mission would not be just another Apollo docking, instead it was a radically different idea.

In 1969, NASA Administrator Thomas O. Paine saw an opportunity for a paradigm shift in Soviet-American space relations. Given the United States’ clear lead in the race to the moon, he believed an offer of cooperation would not jeopardize the US luna...