Genesis Two made this so much easier:

1. Go near the zone where manas spawn (Rockwell's Garden southwest, around 60;10-20).

2. Build a trap.

3. Lure all low lvl Manas away by using the Federation Tek Suit.

4. Lure the mana you want to the trap.

5. Go to the other half of the ship and kill some sheep.

7. Profit.