Introduction
The Advanced Exploration Systems (AES) Logistics Reduction Project is helping NASA get ready for long duration exploration missions, e.g. Moon and Mars. Because these trips will be lengthy, supplies must be minimized and recycling must be maximized. As part of that effort, an Advanced Clothing System (ACS) is being developed to directly reduce the mass and volume of clothing needed for the journey. Currently on the International Space Station (ISS), there is no washing machine, so clothes must last as long as possible without getting too smelly or uncomfortable to wear. Antimicrobial treatments or fabrics can help clothes last longer. Just using lighter weight fabrics, such as some modern performance sportswear, is another strategy to help reduce mass and volume.

Results
The textile industry has made significant progress with new fiber blends and garment finishing. The ACS team has leveraged state-of-the-art technology from private industry to make advancements in the ISS crew wardrobe. The initial focus has been exercise clothing and routine wear tops since so many of those are used. A ground-based experiment was conducted to evaluate current light weight commercial off-the-shelf (COTS) exercise clothing and antimicrobial treatments for length of wear. The best performers were selected for an experiment called Intravehicular Activity (IVA) Clothing Study conducted with six crewmembers on ISS during Increments 39 through 41. The results of these studies recommended the new, longer-wear garments for the catalog of approved ISS crew clothing.
Benefit
Longer wear clothing will reduce launch mass and volume, and thus costs, for ISS and future exploration missions. Since clothing can be worn longer before being thrown away, this will also delay the need to develop a space washing machine, likely until planetary surface missions. The ACS study results clearly indicate that Merino wool, modacrylic, and polyester articles of clothing can be worn for longer periods of time than currently used cotton clothing. Therefore, clothes made of these fibers are logistically more suitable than the current crew clothing.
Source: NASA