(QT (DQL ``) (QTC (S (PP (IN Within) (NP (BASENP (NN 24) (NNS hours)) (PP (IN of) (BASENP (DT the) (NN collision))))) (COMMA ,) (S (BASENP (DT the) (NNP U.S.) (NN space) (NN tracking) (NN system)) (VP (VBD had) (VP (VBN identified) (NP (BASENP (NN 600) (NNS pieces)) (PP (IN of) (BASENP (NN debris)))))))) (PERIOD .)) (DQR ''))