The Mercury-Redstone Launch Vehicle was an American expendable rocket that was in service with NASA in the mid-20th century. This rocket was used for the Mercury Program and was a variant of the classic Redstone missile. It was the first American rocket rated for Humans, and was a single stage rocket which was powered by an alcohol fuel that propelled the sub-orbital Mercury capsules into space. (Star Trek: Enterprise) A schematic of this rocket appeared in the opening credits of Enterprise superimposed over background images, including an image of the Spirit of St. Louis.