Man I wish I'd seen this last month.
The biggest issue is there's just too much of the dialogue. The lines should be kept short; say as much with as little as possible.
"As some of you have worked out, we're not home yet. We're only halfway there. Mother has intercepted a transmission."
"What kind of transmission?"
"Unknown."
That's it.
Build some anticipation, then drop Ripley's "mother's translated part of the transmission. It looks like a warning."
Ramp up intensity, build to crescendo, drop a slow build scare at the end.
