(S (S (BASENP (DT This)) (VP (VBZ is) (PP (JJ due) (PP (TO to) (NP (BASENP (DT the) (NN efficiencies)) (PP (IN of) (NP (BASENP (DT the) (NN spacecraft)) (S (VP (RB not) (VP (VBG having) (S (VP (TO to) (VP (VB carry) (BASENP (PRPD its) (JJ own) (NN fuel))))))))))))))) (PERIOD .))