The current United States space suit, called an extravehicular mobility unit (EMU), is pressurized with 100% oxygen at 0.29 atm (4.3 psi or 29.6 kPa) in the vacuum of space. This pressure is much lower than that on the earth or in the International Space Station, and prebreathing is required to avoid decompression sickness (DCS). Higher pressure can reduce the risk of DCS, but mobility would be sacrificed due to larger pressure differential between the inside and outside of the suit. To solve the issues regarding mobility, we employed elastic material. If high mobility is acquired, higher pressurization can be employed. Thus, we developed an elastic glove pressurized at 0.65 atm, which is the minimal pressure to avoid decompression sickness without prebreathing.
Range of motion with the nonelastic glove at 0.29 atm, which is simulated current EMU, was similar to that of the elastic glove at 0.65 atm. However, the required force evaluated by electromyography during finger flexion using elastic glove at 0.65 atm was smaller than that using the nonelastic glove at 0.29 atm. These results will encourage further development and investigation of a new extravehicular activity suit.