<http://schema.org/alternativeHeadline>
"Missions to explore seas on Saturn's moon Titan, the interior of Mars and land on a comet are the main candidates for a 2016 launch."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/earth-matters/space/stories/nasa-shortlists-3-ambitious-planetary-missions-for-2016-launch>