There are 3 types of alien spacecraft:
- Scouts are small shuttles, usually manned with 3-4 Greens.
- Frigates are the medium sized ships, and are usually quite well armed, featuring 8-10 Vipers and Hornets (note: or is it primes? I am not too sure myself! Also check the quantities)
- Battleships never actually land, and require extensive research to even board. They have a very fixed layout, and are manned by 12-16 aliens of all types.