Science Art: Mariner 10 issue of 1975, by Roy Gjerston

scientific illustration of Mariner 10 for a 10c stamp

scientific illustration of Mariner 10 for a 10c stampClick to embiggen

Roy Gjerston was an artist who designed stamps for the US Postal Service and spaceship concept art for General Dynamics. So this stamp, commemorating the Mariner 10 probe to Venus and Mercury, falls right into the sweet spot between them.