midnight
What 's so fascinating about one valve ? '' Tom 's job on the control deck was less tiring , since his was more of a command post , which demanded decisions , as conditions arose , rather than a fixed routine that could be explained . But even so , to be asked over and over what the astral chronometer was , how he could read time on Earth , Mars , Venus , Titan , Ganymede , and all the satellites at the same time was wearing on the toughest of young spirits . Eager to forget the grueling day of questions and answers , the cadets turned their thoughts to the mysterious midnight activity that had been taking place around the spaceship concession during the last ten days . `` I just ca n't figure out what those guys are up to , '' said Roger , blowing on his hot chocolate . `` We 've watched those guys for over a week now and no one has even come near them with anything that could be smuggled . '' `` Could be a small package , '' suggested Astro , his mouth full of ham sandwich .