A Warrior's Rest

(from ebookjapan):
A young man, the only crew member of a spaceship, the Seventh Noble, sends a video letter to his mother in space, about 475 billion kilometers from Earth. His father, a crew member of the sixth Noble, was in an accident and is still missing. The young man, enduring loneliness and plunging through the darkness, wonders why on earth he is doing this... In addition to the title story, "A Warrior's Rest," this collection contains seven other masterpieces of SF.