NASA's giant pool recreates moon for underwater spacewalks.

NASA's Neutral Buoyancy Laboratory, a facility used for International Space Station missions, is being modified to simulate lunar conditions for underwater training of future moonwalkers. The facility is adding simulated sand and boulders to the pool floor, and prototype spacesuits and lunar vehicles are being tested. The underwater training will help astronauts get used to the harsh lunar lighting and extreme shadow and light differences, as well as the sandy and steep slopes of the moon's surface. The company V2X is leading the underwater training, and expects commercial companies to follow NASA to the moon.