Iron Sky: Invasion

You'll find dozens of these ships throughout your Invasion campaign. They are the ones pulling large asteroids towards Earth. Intercepting these medium sized sluggish spacecraft will earn you some respect and salvage and prevent you from losing large amounts of respect should they reach the Earth's atmosphere.

Finding them

The best time to target these is in between missions by pressing to bring up your map, move the reticule over the red markers and see if you can find a 'Brunnhilde' and an 'Asteroid' in the list to the left, if so press to fast travel to them.

Taking them out

Brunnhildes are almost always protected by about 4-6 Walkyr (fighters) and a more powerful Wotan war-ship. Take out the Walkyr with your lasers as they rush at you then concentrate on the Wotan using missiles, keep pressing if your shield gets too low to transfer energy to it.

After these are dead you want to keep pressing to find the Brunnhilde cannon, taking out this cannon first really makes things easier. Once the cannon is out you can gain some extra salvage by targeting the engines on the asteroid and the Brunnhilde before taking the Brunnhilde out itself. There are three engines on the rear of the Brunnhilde that always give you one salvage each, but if you destroy the main ship before the engines you only get one salvage total. Make sure to finish off both the Brunnhilde and the Asteroid before leaving.

If you can't find any more Brunnhildes just complete a story mission and then use the map to find one again, they appear quite often during the whole campaign. Once you have destroyed 10 ships (which does not necessarily include the asteroid or the Brunhilde's escort) the achievement will unlock.