Countermeasure Suits for Spaceflight

In the past decade, there has been a renewed effort to develop countermeasure suits for spaceflight, largely through the Gravity Loading Countermeasure Skinsuit, or “Skinsuit”. Upcoming missions to the moon and Mars, will require unprecedented lengths of time in reduced gravity and necessitate further consideration of countermeasures to address physiological adaptations to reduced gravity during missions of several months or years. While countermeasures for bone and muscle loss currently exist on the International Space Station (ISS) in the form of exercise machines, these do not completely eliminate the debilitating effects of microgravity, and they are too large and massive for long-duration missions to Mars due to expected vehicle physical space constraints. Wearable countermeasures could address this problem by providing alternative or supplementary countermeasures. The Pingvin suit, developed in the 1970s, is a wearable countermeasure suit that aims to reduce muscle and bone loss in cosmonauts. However, it is often ineffective due to discomfort and the resulting inconsistency in wearing protocols. The Skinsuit is a more recent development in wearable countermeasure technology. This skin-tight garment provides an axial load on the skeleton to simulate the skeletal loading provided by gravity, with goals to reduce spinal elongation and bone loss, among other proposed advantages. The Skinsuit has evolved through multiple design revisions to ensure comfort, mobility, and feasibility for extended periods of wear. The function of the suit has also been tested through ground experiments, partial gravity analogs, parabolic flights, and ISS missions. This paper provides a comprehensive review of the Skinsuit and briefly highlights the Russian Pingvin Suit, the Dynasuit, the Torso Compression Harness, and the Variable Vector Countermeasure Suit.