Narrator: Twelve hours and thirty minutes have passed since the discovery of the time-traveling VDA node. . .
Petey: We've got three ships pumping power into this wormgate, and it's nowhere near opening. In 90 minutes, we'll still be trying to spin this thing up, and that VDA node will become quite the little paradox.
Kevyn: So why wait?
Kevyn: Why bother sending it at all?
Petey: Because if we don't send it, then it won't go back in time and demonstrate to us that the wormgate allows for upstream time-travel.
Kevyn: Hah. That's a load o' Loxie-plops. We already know. It already happened.
Petey: Kevyn, I'm thousands of times smarter than you are. How is it that you're not able to explain this to me so I'll understand it?
Kevyn: It's a paradox. Most smart people hate paradoxes. They defy our understanding of the rules. For as smart as you are you still adhere to the rules of a causal universe. That model is now broken.

We don't need to send it again, because it already happened once, in the future, and that future is now part of our causal past. Cause and effect are preserved, but not in the way you've been expecting.
Kevyn: Allow me to demonstrate.
SFX: B L A M
Kevyn: VDA node 42 is now damaged beyond our ability to repair it. The time-traveling VDA node 42 is still here, undamaged.
Kevyn: Face it, Petey. We're trying to change the past, so that this event in the galactic core never happened. That event is what's making time travel possible in the first place.

Without paradoxical causality, we can't succeed.
Petey: Okay, confession time. When you fired, I was genuinely frightened for the first time in this whole affair.
Kevyn: You call that a confession? Here's a real confession:
Kevyn: So was I.

But hey, now we know it works, right?