According to Kaleidoscope what makes a good death?

It looks like you are referring to the short story "Kaleidoscope" in the collection.
According to "Kaleidoscope," a good death is a meaningful death and a testament to a life lived without regrets.
In the story, Hollis (the lead character) engages in deep self-contemplation after the rocket he shared with 7 other astronauts explodes. The destruction of the spacecraft propels the men into space.
It is very evident that none of the men will survive such a catastrophe. The story centers on how the men handle the inevitability of death. The names of the astronauts are Hollis, Woode, Stimson, the Captain, Stone, Lespere, Applegate, and Barkley.
Because they did not have time to connect their force units, the astronauts float away in different directions. Each experiences feelings of helplessness, anger, fear, and disbelief as death approaches. Two of the men begin screaming in panic, and Hollis kills one of them. He rationalizes that he is sparing his fellow astronaut from further misery.
The most interesting conversation occurs between Hollis and Lespere. During their exchange, Lespere maintains that he is going to "rest easy" until death claims him; he will not become "mean" like Hollis. Lespere tries to comfort Hollis, but the latter is inconsolable. Hollis does not want to die, and the thought of his previous behavior distresses him. In the end, Hollis acknowledges that his placid manner had always been a facade; however, he had never felt it socially acceptable to admit this.
In the last moments of his life, Hollis wonders how he can do "good" by himself.

And I? thought Hollis. What can I do? Is there anything I can do now to make up for a terrible and empty life? If only I could do one good thing to make up for the meanness I collected all these years and didn’t even know was in me! But there’s no one here but myself, and how can you do good all alone?

In the end, Hollis consoles himself that his dead ashes will enrich the earth, thus contributing something of value to the world. So, according to the story, a good death is a meaningful one, a benefit to others, and a testament to a life well lived.