MYKOLAIV, Ukraine — Valeriy sucked in his breath as a colleague fastened the layers of his thick bomb suit, yanking the Velcro across his abdomen even tighter. On went red gloves over Valeriy’s hands, then taped pads over the gloves. A bubble helmet was the last step, completing an ensemble that made him look like an astronaut. Except that his plastic visor had several cracks — from where shrapnel hit it.