When the Lunar Reactor core goes haywire , Commander White must find a way to save the crew before they get literally cooked alive.

my r must not be working properly "excuse" "excuse" :) I meant learns not leans

I believe there are three problems with this logline, none are too big.

First: I don't believe Haywire is the right word to use for a reactor. "When the Lunar Reactor goes into meltdown" would be better.

Second: You should probably give us a glimpse why they can't just hop in a space ship and fly back to earth.

Third: Saying 'commander White', tells us nothing about the character, you should instead give us a character trait."An alcoholic Commander" "A by the book Commander" "A hard nosed Commander" Ideally this character trait should be part of his character growth; preferable the "before"

An alcoholic Commander--by the end of the story gives up drinking
A by the book commander-- by the end of the story leans to be creative
A hard nosed Commander-- by the end of the story leans to soften up and listen.

Anyway, I believe your logline is pretty close, these things are minor changes the would probably only change a few words.

Sounds like an interesting story idea,

Hope that helped, good luck with this!

Lunar kind of sets the location to on the moon