Union Suits - YesterYear 
Astronaut Underwear 

Mercury 7 Astronauts in Union Suits
and Homemade Garments - Survival Training

 America's first astronauts: Walter M. Schirra Jr. , Donald K. "Deke" Slayton, John H. Glenn Jr., Scott Carpenter, Alan B. Shepard Jr.  (middle), Virgil I. "Gus" Grissom and L. Gordon Cooper. Image credit: NASA 

Astronauts Made Outer Clothing Out of Parachutes 

The selected seven astronauts go through survival training in the Nevada desert. The astronauts were left there for four days in just their union suits and boots with a mock-up of a Mercury spacecraft, a parachute and a survival scenario. Image credit: NASA.

The Mercury Program was the beginning of United States’ manned, exploration of space. The seven men chosen to be the first astronauts came from many different backgrounds, but soon would become heroes of their country and the world. The men went through a meticulous selection process and a very vigorous and fast paced training program. All of the astronauts, except for one, flew in the Mercury missions and returned to Earth safely. These men were the first test subjects for flights to the Moon, and in the future, Mars and beyond.

On Monday April 27, 1959, the seven astronauts began their training. In 1960, the astronauts spent four days in desert survival training. This was incorporated into their training program because of the remote possibility they could land in Africa. This training was completed at Stead Air Force Base near Reno, Nevada. During this training, they were left in only their long underwear to learn how to “protect themselves from the sun, how to utilize the limited water supply, and to build clothing and shelter from their parachutes” 

To this day, astronauts wear a type of Union Suit under their space suits.

Thanks to Rich of Buffalo, NY, Union Suit Fan, for this topic contribution!