Passage: Gangale originally chose late 1975 as the epoch of the calendar in recognition of the American Viking program as the first fully successful (American) soft landing mission to Mars (the earlier 1971 Soviet Mars 3 Landing having delivered only 15 seconds of data from the planet's surface). In 2002 he adopted the Telescopic Epoch, first suggested by Peter Kokh in 1999 and adopted by Shaun Moss in 2001 for his Utopian Calendar, which is in 1609 in recognition of Johannes Kepler's use of Tycho Brahe's observations of Mars to elucidate the laws of planetary motion, and also Galileo Galilei's first observations of Mars with a telescope.  Selection of the Telescopic Epoch thus unified the structures of the Darian and Utopian calendars, their remaining differences being nomenclatural. It also avoids the problem of the many telescopic observations of Mars over the past 400 years being relegated to negative dates.

Question: What year did Gangale chose at first to recognize the American Viking program?
1975