A Hard Upper Torso Assembly, or HUT, is a central component of several

space suit A space suit (or spacesuit) is an environmental suit used for protection from the harsh environment of outer space, mainly from its vacuum as a highly specialized pressure suit, but also its temperature extremes, as well as radiation and ...

s, notably

Roscosmos The State Corporation for Space Activities "Roscosmos", commonly known simply as Roscosmos (), is a State corporation (Russia), state corporation of the Russian Federation responsible for space science, space flights, List of space agencies, c ...

' Orlan and

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

Extravehicular Mobility Unit The Extravehicular Mobility Unit (EMU) is an independent spacesuit that provides environmental protection, mobility, life support, and communications for astronauts performing extravehicular activity (EVA) in Geocentric orbit, Earth orbit. Introd ...

(EMU). The

fiberglass Fiberglass (American English) or fibreglass (English in the Commonwealth of Nations, Commonwealth English) is a common type of fibre-reinforced plastic, fiber-reinforced plastic using glass fiber. The fibers may be randomly arranged, flattened i ...

HUT forms a rigid enclosure about the upper body of the occupant, providing pressure containment for this part of the body. The HUT incorporates structural attachment points for the arms, Lower Torso Assembly (LTA), helmet, chest-mounted Display and Controls Module (DCM), and Primary Life Support Subsystem (PLSS) backpack. The original HUT design for the EMU, first used in 1980, included bellowed shoulder bearings, which allowed for variation in the angle of the shoulder bearings. This allowed for one configuration to ease donning of the suit, and a different configuration to allow maximum mobility during EVA. However, the limited life of the bellows prompted a redesign in 1990 to a fixed shoulder bearing angle and position, referred to as the Planar HUT, resulting in reduced mobility and more difficult donning and doffing. Because of the high cost of manufacturing, only three sizes of HUTs are produced for the EMU. This has the effect of limiting the number of people who can be properly fit for the suit. The three HUT sizes are supposed to accommodate occupants from the 5th to the 95th

percentile In statistics, a ''k''-th percentile, also known as percentile score or centile, is a score (e.g., a data point) a given percentage ''k'' of all scores in its frequency distribution exists ("exclusive" definition) or a score a given percentage ...

. The HUT also includes an In-Suit Drink Bag, with a plastic tube extending into the helmet, to allow the astronaut to stay hydrated.

References

{{space suit Space suit components