OV1-4/OV1-5

Orbiting Vehicle 1-4 (also known as OV1-4), launched 30 Mar 1966, was the fourth, and second successful, satellite in the OV1 series of the United States Air Force's Orbiting Vehicle program. OV1-4 was a long-term bioscience and materials science satellite, designed to return data relevant to long-term human presence in space. Its launch marked the first time two satellites (the other being OV1-5) were placed into orbit side by side with each other.

Orbiting Vehicle 1-5 (also known as OV1-5) was launched on 30 Mar 1966, and was the fifth satellite (and third successful satellite) in the OV1 series of the United States Air Force's Orbiting Vehicle program. OV1-5 conducted optical experiments, surveying the Earth in the infrared spectrum to see if water, land, mountains, and deserts could be distinguished by their thermal gradients. It was launched concurrently with OV1-4 in the first-ever side-by-side satellite orbital deployment.