Freeze-dried ice cream, also known as astronaut ice cream or space ice cream, is
ice cream that has had most of the water removed from it by a
freeze-drying
Freeze drying, also known as lyophilization or cryodesiccation, is a low temperature dehydration process that involves freezing the product and lowering pressure, removing the ice by sublimation. This is in contrast to dehydration by most conve ...
process, is sealed in a pouch, and requires no refrigeration. Compared to regular ice cream, it can be kept at room temperature without melting, is dry and more brittle and rigid, but still soft when bitten into. It was developed by
Whirlpool Corporation under contract to
NASA for the
Apollo missions
The Apollo program was a United States human spaceflight program carried out from 1961 to 1972 by the National Aeronautics and Space Administration (NASA), which landed the first astronauts on the Moon. The program used the Saturn IB and Saturn ...
.
[ The license is now not held by Action Products International, Inc.] However, it was never used on any Apollo mission.
Freeze-dried foods were developed so that foods could be sent on long-duration spaceflights, as to the Moon, and to reduce the weight of the water and oxygen normally found in food as well as to not melting and spilling liquid in
zero-gravity
Weightlessness is the complete or near-complete absence of the sensation of weight. It is also termed zero gravity, zero G-force, or zero-G.
Weight is a measurement of the force on an object at rest in a relatively strong gravitational fi ...
, which would be problematic.
Freeze drying
Freeze drying, also known as lyophilization or cryodesiccation, is a low temperature dehydration process that involves freezing the product and lowering pressure, removing the ice by sublimation. This is in contrast to dehydration by most conve ...
(or lyophilization) removes water from the ice cream by lowering the
air pressure to a point where ice sublimates directly from a
solid to a
gas. The ice cream is first placed in a
vacuum chamber
A vacuum chamber is a rigid enclosure from which air and other gases are removed by a vacuum pump. This results in a low-pressure environment within the chamber, commonly referred to as a vacuum. A vacuum environment allows researchers to condu ...
and frozen until any remaining water
crystallizes
Crystallization is the process by which solid forms, where the atoms or molecules are highly organized into a structure known as a crystal. Some ways by which crystals form are precipitating from a solution, freezing, or more rarely deposi ...
. The air pressure is then lowered below
water's triple point, creating a partial vacuum, forcing air out of the chamber; next heat is applied,
sublimating the ice; finally a freezing coil traps and turn the vaporized water into ice. This process continues for hours, resulting in a freeze-dried ice cream slice.
Freeze-dried ice cream is sold by mail order and is common in
science museums and NASA visitor center
gift shops, sometimes accompanied by other freeze-dried foods.
Space use
Freeze-dried foods were initially developed for the Mercury missions. Despite use of images of space-walking astronauts in space suits on product packaging, freeze-dried ice cream was not included on any mission in which space suits were used. The only evidence for freeze-dried ice cream ever having flown in space is the menu for the Apollo 7 mission, on which is it listed for one of the meals. However when the only surviving member of Apollo 7 was asked, he did not remember it being served on the flight.
According to one NASA
food scientist, although freeze-dried ice cream was developed on request, "it wasn't that popular." Astronaut
Mike Massimino
Michael James Massimino (born August 19, 1962) is an American professor of mechanical engineering at Columbia University and a former NASA astronaut. He is the senior advisor of space programs at the Intrepid Sea, Air & Space Museum.
Early li ...
expressed dislike of freeze-dried ice cream, calling it "disgusting" and "more closely related to a building material than a food".
Traditional ice cream in space
During the 1970s, astronauts ate regular ice cream on the
Skylab space station and regular ice cream has also been eaten on the
International Space Station.
Skylab had a freezer that was used for regular ice cream, and occasionally
Space Shuttle and International Space Station astronauts have also taken regular ice cream into the space station.
See also
*
Camping food
*
List of dried foods
*
Space food
*
Freeze-drying
Freeze drying, also known as lyophilization or cryodesiccation, is a low temperature dehydration process that involves freezing the product and lowering pressure, removing the ice by sublimation. This is in contrast to dehydration by most conve ...
References
External links
History of Space Food - Retrofuture.com
{{DEFAULTSORT:Freeze-Dried Ice Cream
Dried foods
Human spaceflight
Ice cream
NASA spin-off technologies