 Why are Quezy and Bob pressed for time?
And if The Interplanetary Hauling & Moving Co., hadn't been about to go on the rocks (chiefly due to the activities of Saylor & Saylor, a rival firm) neither Bob nor Queazy would have thought of sending an answering ethergram to Burnside stating that they would fill the order. Now that he and Queazy had found the asteroid, they were desperate to get it to its destination, for fear that the Saylor brothers might get wind of what was going on, and try to beat them out of their profits. Now they scuffed along the smooth-plane topside of the asteroid, the magnets in their shoes keeping them from stepping off into space. He and Queazy caught up with her on the side of the asteroid they hadn't yet examined.
 They need to fulfill Burnside's requests quickly in order to make a profit.
 They don't want their competitors getting to the asteroid before them and missing out on the profit.  The Saylor Brothers have been chasing them, and they know they're on their way to the same asteroid.  They need to fulfill Burnside's requests quickly in order to make a profit.  Hauling asteroids is dangerous work, and the quicker they get it done the better.