SPACE TECHNOLOGY
'It's the 4-letter term for the viewing assembly seen <a href="http://www.j-archive.com/media/2005-06-09_DJ_25a.jpg" target="_blank">here</a> of the <a href="http://www.j-archive.com/media/2005-06-09_DJ_25.jpg" target="_blank">Mars rover</a>; a ship might have more than one'
mast