Returning to the United States, Calle's early career included designing magazine covers for The Saturday Evening Post as well as for a series of science fiction publications.

[4] Together with his son Chris, Calle returned to the subject of space exploration with a pair of stamps issued in 1994 in honor of the 25th anniversary of the Apollo 11 mission and the first human Moon landing.

[1] Calle produced dozens of postage stamp designs, featuring such individuals as Douglas MacArthur and Robert Frost.

He also produced Western-themed artworks that have been shown at the National Cowboy & Western Heritage Museum, as well as a 1981 stamp honoring Frederic Remington.

[4] After doctors discovered that his melanoma had metastasized, he was placed on intravenous Ipilimumab, an experimental treatment being tested by Bristol-Myers Squibb that is meant to improve the response by the immune system to fight cancer.