Freeze-dried ice cream, also known as astronaut ice cream or space ice cream, is

ice cream Ice cream is a sweetened frozen food typically eaten as a snack or dessert. It may be made from milk or cream and is flavoured with a sweetener, either sugar or an alternative, and a spice, such as cocoa or vanilla, or with fruit such as s ...

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, 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 Atmospheric pressure, also known as barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1013.25 millibars, 7 ...

to a point where ice sublimates directly from a

solid Solid is one of the four fundamental states of matter (the others being liquid, gas, and plasma). The molecules in a solid are closely packed together and contain the least amount of kinetic energy. A solid is characterized by structural r ...

to a

gas Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or ...

. 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 de ...

. 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 A science museum is a museum devoted primarily to science. Older science museums tended to concentrate on static displays of objects related to natural history, paleontology, geology, industry and industrial machinery, etc. Modern trends in mu ...

and NASA visitor center

gift shops A gift shop or souvenir shop is a store primarily selling souvenirs, memorabilia, and other items relating to a particular topic or theme. The items sold often include coffee mugs, stuffed animals, toys, t-shirts, postcards, handmade collecti ...

, 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 Food science is the basic science and applied science of food; its scope starts at overlap with agricultural science and nutritional science and leads through the scientific aspects of food safety and food processing, informing the development o ...

, although freeze-dried ice cream was developed on request, "it wasn't that popular." Astronaut Mike Massimino 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 Skylab was the first United States space station, launched by NASA, occupied for about 24 weeks between May 1973 and February 1974. It was operated by three separate three-astronaut crews: Skylab 2, Skylab 3, and Skylab 4. Major operations i ...

space station and regular ice cream has also been eaten on the

International Space Station The International Space Station (ISS) is the largest modular space station currently in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA (United States), Roscosmos (Russia), JAXA ( ...

. Skylab had a freezer that was used for regular ice cream, and occasionally

Space Shuttle The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program nam ...

and International Space Station astronauts have also taken regular ice cream into the space station.

References

External links

History of Space Food - Retrofuture.com
{{DEFAULTSORT:Freeze-Dried Ice Cream Dried foods Human spaceflight Ice cream NASA spin-off technologies

Space use

Traditional ice cream in space

See also

References

External links