 What is Dom Blessings's relationship to Dr. Mansard?
Trella feared she was in for trouble even before Motwick's head dropped forward on his arms in a drunken stupor. Perhaps she could call one of Motwick's friends; she had no one on Ganymede she could call a real friend herself. The dark man moved in on Trella again as Kregg overtook his quarry and swung a huge fist like a sledgehammer. It smashed on Kregg's head, splashing the floor with liquor, and Kregg sank stunned to his knees. The dark man, who had grabbed Trella's arm, released her and ran for the door. He followed Trella out the door of the Golden Satellite and fell in step beside her. The transparent dome of Jupiter's View was faintly visible in the reflected night lights of the colonial city, but the lights were overwhelmed by the giant, vari-colored disc of Jupiter itself, riding high in the sky. “If Dr. Mansard succeeded in landing on Jupiter, why didn't anyone ever hear from him again?” she demanded. Trella could get a cab from here, but the Stellar Hotel wasn't far. Trella had the desk clerk call a cab to deliver the unconscious Motwick to his home. For some reason she decided against telling him that the assignment on which she had come to the Jupiter system was to gather his own father's notebooks and take them back to Earth. Motwick was an irresponsible playboy whom Trella had known briefly on Earth, and Trella was glad to dispense with his company for the remaining three weeks before the spaceship blasted off.
 Dom Blessing was Dr. Mansard's assistant.
 Dom Blessing was Dr. Mansard's assistant.  Dom Blessing was Dr. Mansard's business partner.  Dom Blessing was Dr. Mansard's employer.  Dom Blessing was Dr. Mansard's best friend.