 Why is Crownwall the representative from Earth sent to Vega?
The sight of an Earthman on Vega III, where it was impossible for an outlander to be, brought angry crowds to surround John Crownwall as he strode toward the palace of Viceroy Tronn Ffallk, ruler of Sector XII of the Universal Holy Empire of Sunda. If they carried out the threats of their present attitude, Earth would have to send Marshall to replace him. "Just tell him that a man has arrived from Earth to talk to him. Behind him stood a heavy and pompous appearing Vegan in lordly trappings. "It was only decided yesterday, back on Earth, that I would be the one to make the trip here. What I meant was that I expected someone from Earth to break through our blockade and come here. "If you wanted someone from Earth to come here to see you, why did you put the cordon around Earth? While these creatures could by no means be classed among the intelligent races, there was a general expectation, which we reported to the Sunda, that they would some day come to be numbered among the Servants of the Emperor. It had been manned by a dozen adventurous people, captained by Crownwall, and had headed out on its ion drive until it was safely clear of the warping influence of planetary masses. They had headed for that planet confidently and unsuspectingly, using the ion drive. Although far within the dangerous influence of a planetary mass, they had again activated the distorter drive, and they had beaten the odds. On the distorter drive, they had returned to Earth as swiftly as they had departed.
 He was a reasonable option given his prior leadership experience on missions
 He was the only one who was willing to undergo the time travel procedure  He was the only one without connections on Earth, making it easier for him to take time away  He was the default choice once the humans determined that Marshall was not fit for the job  He was a reasonable option given his prior leadership experience on missions