(S (S (BASENP (DT The) (NNP Planetary) (NNP Society)) (VP (VBZ is) (VP (VBG planning) (PP (IN on) (S (VP (VP (VBG launching) (BASENP (DT a) (JJ solar) (NN sail))) (PP (ADVP (RB possibly)) (PP (IN by) (BASENP (NNP June) (NN 21)))))))))) (PERIOD .))