(S (S (BASENP (PRP It)) (VP (MD will) (VP (VP (VP (VB stay) (PP (IN in) (BASENP (DT this) (NN orbit)))) (PP (IN for) (BASENP (NN two) (NNS years)))) (CC and) (VP (VP (VB conduct) (BASENP (JJ various) (NNS experiments))) (S (VP (TO to) (VP (VB gain) (NP (BASENP (DT a) (JJR better) (NN understanding)) (PP (IN of) (BASENP (DT the) (NNP Moon))))))))))) (PERIOD .))