Then the intake valve closes, and an exhaust valve opens.

然后进阀关闭，打开 排阀。

The exhaust valve leads to a condenser, which cools the steam back into water.

排阀通向冷凝器，冷凝器 蒸汽冷却并返回中。

Last step, exhaust valve opens, piston travels up, it forces that spent burnt gases out your exhaust pipe, out into the atmosphere.

最后一步，排阀打开，活塞向上移动，它迫使燃烧过的体从排管向下进。

The U.S. space agency says it encountered an issue with a panel on the mobile launcher that controls the core stage vent valve.

美国航天局表示，移动发射装置上控制核心级排阀的面板出现了问题。