To really establish a sense of urgency when the heroes are trying to accomplish something quickly, have NPCs constantly interrupt them and ask how things are going. Bonus points if they're the heroes' boss, or otherwise in some position of authority such that they can't just be blown off.

Transcript

Lando: Come in, 3PO! How's the progress with R2 hacking a fighter to get the shield access code so that we can fly right up to the Peace Moon and blow it up...
{beat, Lando thinking}
Lando: ... going?
C-3PO: Um, bad news, Lando. Artoo's been neutralised.
R2-D2: Ha ha!
C-3PO: Why is that funny?
GM: Don't say anything.
R2-D2: Right. Here I am, knocked unconscious by something I can't talk about. So I can't talk about it.
C-3PO: Are you done not talking about it?
R2-D2: No, I have to keep not talking about it!
Nien Nunb: I love the way she never talks about all that relationship stuff with me.