Definition: In this task, you are given a news article. Your task is to classify the article to one out of the four topics 'World', 'Sports', 'Business', 'Sci/Tech' if the article's main topic is relevant to the world, sports, business, and science/technology, correspondingly. If you are not sure about the topic, choose the closest option. Note that URLs in the text have been replaced with [Link].
Input: Astronauts Float Outside for a Spacewalk CAPE CANAVERAL, Fla. - Leaving the orbiting outpost unmanned, the international space station's two astronauts floated outside on a spacewalk Friday to plug in new antennas and replace a worn-out piece of cooling equipment...

World