Day: June 7, 2007

It wasn’t officially a field trip to the Boston Museum of Science until we had hit the gift shop and loaded up on space ice cream. Although to be honest, I don’t remember actually liking the taste very much.

Freeze-dried ice cream, also known as astronaut ice cream[1] or space ice cream is a brick of dehydrated ice cream that is always ready to eat, with no need for refrigeration. It was developed by Whirlpool Corporation under contract to NASA for the Apollo missions.[2]

Apollo 7 in 1968 was the only NASA mission on which space ice cream flew in outer space.[3] According to a NASA food scientist, although it was developed on request, “It wasn’t that popular.”[4] Skylab had a refrigerator that was used for real ice cream.[5], and occasionally shuttle and International Space Station astronauts have enjoyed real ice cream.[6]

Freeze drying (or lyophilization) removes water from the ice cream by lowering the air pressure to a point where ice shifts from a solid to a gas. The ice cream is placed in a vacuum chamber and frozen until the water crystallizes. The air pressure is lowered, creating a partial vacuum, forcing air out of the chamber; next heat is applied, vaporizing the ice; finally a freezing coil traps the vaporized water. This process continues for hours, resulting in a freeze-dried ice cream slice.

(via the Wikipedia Knowledge Dump)