Blue Sky on Mars
The cover of the album features an image by Viking 1, the first spacecraft to land on Mars; the album's liner notes include additional imagery of the planet's landscape as taken by the spacecraft on July 20, 1976. The text on the cover was done by fantastic artist Roger Dean, best known for his work on album covers for bands such as Yes. The album's title comes from the tour in the film "Total Recall".
Luna 23
"Luna 23" was the first modified lunar sample return spacecraft, designed to return a deep core sample of the Moon's surface (hence the change in index from Ye-8-5 to Ye-8-5M). While "Luna 16" and "Luna 20" had returned samples from a depth of 0.3 meters, the new spacecraft was designed to dig to 2.5 meters. After a midcourse correction on 31 October, "Luna 23" entered orbit around the Moon on 2 November 1974. Parameters were 104 × 94 kilometers at 138° inclination. Following several more changes to the orbit, the spacecraft descended to the lunar surface on 6 November and landed in the southernmost portion of Mare Crisium. Landing coordinates were 13° north latitude and 62° east longitude. During landing in "unfavorable" terrain, the lander's drilling device was evidently damaged, preventing fulfillment of the primary mission, the return of lunar soil to Earth. Scientists devised a makeshift plan to conduct a limited science exploration program with the stationary lander. Controllers maintained contact with the spacecraft until 9 November 1974.