What you need is a Flight deck Lvl 3 with each deck at 1. why a level 1? Because if you upgraded to level 2 it'll take longer to farm. Level 2 deck shortest mission is 10 minutes where level 1 is 3 minutes.
STEPS:
1. Launch Assignment 3
2. Send 3 Agents on the 3 minute mission on the Flight Deck
3. When they're done, click on the "Complete & Resend" button. You've Collected 990 Silver
4. Head to Viper Fight and Clear it for 450 Silver & 120 ISO-8
5. Collect mini boss roulette prize. Hopefully you'll get whatever you need! Mainly CP
6. Re-Launch Assignment 3 and repeat steps 3-6
Each run will give you +130 exp to yourself and Heroes. You'll also gain about 1440 (1940 Roulette) Silver & 120 (620) ISO-8 a run. If you're lucky, you'll get 5/3/1 Command Points. Doing this about an hour nets you about 35k.
Below I have a map of the fight and seat arrangements to better prepare you for the fight!
