Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
Impressed
2001 is impressed with itself. It tells a story of big, honking, cosmic events, and it thinks those big, honking, cosmic events are pretty cool. The narrator is constantly nudging you to tell you how awesome the narrative is. The novel doesn't just say, hibernation is disorienting; it pulls out the rhetorical big guns to tell you:
Though [Bowman] had come back safely from the furthest borders of sleep, and the nearest borders of death, he had been gone only a week. (15.37)
Or it rushes to explain to you:
Space pods were not the most elegant means of transport devised by man, but they were absolutely essential for construction and maintenance work in vacuum. (22.2)
Hibernation is awesome and we really, really need those space pods. Either way, the point is that we should respect and be impressed by technology, progress, and gadgets—whether human, or alien. The tone of the book can be summed up as "Space stuff is cool."