A Maximum Absorbency Garment (MAG) is an adult-sized diaper with extra absorption material that NASA astronauts wear during liftoff, landing, and extra-vehicular activity (EVA) to absorb urine and feces.^[1][2][3][4] It is worn by both male and female astronauts.^[2] Astronauts can urinate into the MAG, and usually wait to defecate when they return to the spacecraft.^[5] However, the MAG is rarely used for this purpose, since the astronauts use the facilities of the station before EVA and also time the consumption of the in-suit water.^[2] Nonetheless, the garment provides peace of mind for the astronauts.^[2]

The MAG was developed because astronauts cannot remove their space suits during long operations, such as spacewalks that usually last for several hours.^[6][7] Generally, three MAGs were given during space shuttle missions, one for launch, reentry, and an extra for spacewalking or for a second reentry attempt.^[5][8] Astronauts drink about 2 L (2.1 US qt) of salty water before reentry since less fluid is retained in zero G.^[9] Without the extra fluids, the astronauts might faint in Earth's gravity, further highlighting the potential necessity of the MAGs.^[9] It is worn underneath the Liquid Cooling and Ventilation Garment (LCVG).^[7]

During the Apollo era, astronauts used urine and fecal containment systems worn under spandex trunks.^[10][5] The fecal containment device (FCD) was a bag attached directly to the body with an adhesive seal,^[11] and the urine collection device (UCD) had a condom-like sheath attached to a tube and pouch.^[8][10] Women joined the astronaut corps in 1978 and required devices with similar functions.^[11] However, the early attempts to design feminized versions of the male devices were unsuccessful.^[11] In the 1980s, NASA designed space diapers which were called Disposable Absorption Containment Trunks (DACTs).^[5] These addressed the women's needs since it was comfortable, manageable, and resistant to leaks.^[11] These diapers were first used in 1983, during the first Challenger mission.^[5]

Disposable underwear, first introduced in the 1960s as baby's diapers then in 1980 for adult incontinence, appealed to NASA as a more practical option.^[11] In 1988, the Maximum Absorbency Garment replaced the DACT for female astronauts.^[12] NASA created the name Maximum Absorbency Garment to avoid using trade names.^[11] Male astronauts then adopted the MAG as well.^[11] In the 1990s, NASA ordered 3,200 of the diapers of the brand name Absorbencies, manufactured by a company that has folded.^[8] In 2007, about a third of the supply remained.^[8]

The MAGs are pulled up like shorts.^[5] A powdery chemical absorbent called sodium polyacrylate is incorporated into the fabric of the garment.^{[5][8][13][9]} Sodium polyacrylate can absorb around 300 times its weight in distilled water.^[5][13] Assuming the astronaut urinates, the diaper would only need to be changed every eight to ten hours.^[5] The MAG can hold a maximum of 2 L (2.1 US qt) of urine, blood, and/or feces.^[1][14] The MAG absorbs the liquid and pulls it away from the skin.^[5]

These garments gained attention in February 2007, when astronaut Lisa Nowak drove 1,450 km (901 mi) to attack Air Force officer Colleen Shipman out of jealousy for her former lover.^[5][8][15] It was stated in a police report that Nowak said she used the diapers to avoid pit stops during her journey.^[15] However, Nowak denied these claims and testified that she did not wear these diapers during her trip.^[15]

• Extravehicular Mobility Unit