spacewalk

宇宙飛行士達が予定より早く国際宇宙ステーションの修復作業を終えたそうです。

NASA Astronauts End Spacewalk Early After 5 Hours

Two American astronauts conducted an urgent repair outside the International Space Station Saturday during a spacewalk that lasted five hours and 28 minutes.

The astronauts ran about an hour and a half ahead of what NASA expected to be their timeline.

Rich Mastracchio and Mike Hopkins, Expedition 38 Flight Engineers, began working at 7:01 am EST Saturday morning to replace a degraded ammonia pump module associated with one of the station's two cooling loops that keeps internal and external equipment cool, NASA said.

http://abcnews.go.com/Technology/nasa-astronauts-end-spacewalk-early-chilly-temperature-space/story?id=21297386
この記事に出てくる”spacewalk”を『Wisdom英和辞典（第三版）』（三省堂）で調べると「宇宙遊泳」という意味でした。今回任務にあたって宇宙飛行士達は何度か宇宙遊泳を経験していると書かれていました。人類の歴史で宇宙を歩いたことがある人は何人ぐらいいるのでしょうか。（Ume）