Applications are now open for The Ember Cast Fall 2017 ProtoGuide Experience. This experience is the capstone Ember offering, designed to catalyze a student into a trajectory of cross cultural and missions leadership. It's meant for the emerging global student leader - someone already interested in world cultures and global potential. I don't know of any other missions agency or church or nonprofit that built an experience like this, specific for high school students, from the ground up.
More info here. 2017 application here. Thanks for passing it on to someone you think might fit.