I guess i found some tricks and also bugs, so i hope author will read this.
Dedicated to all of those, who can't beat nebula part with ions.
Start with resource collectors, build about 20 (you will need them). Then gather from local asteroids, with harvesting module.
build squadrons of fighters, than destroy them -> salvage. Price is buggy, 600 for one interceptor. So you will have 3000 from for 450 (don't remember exact price)
Get yourself a captain, build corvettes and frigates. You will need marine frigate to capture one or two ion frigates in nebula.
If you will capture those ions in nebula, you'll have to destroy them, in other case you won't be able to go further, sadly.
Then jump with carrier close to turanic carrier, build marines to capture it. You can also capture ions, but, here is the third bug: even if those ions will be yours, they will fire on your own carrier :) so try to put them behind enemy carrier, so they will fire through turanic carrier, and constantly move them in that spot again. If you will be able to capture enemy carrier, it's almost game over for your opponent. After this you can build and salvage pulsar fighters (1250 build cost and 5000 salvage price)
You'll get research module, and all of upgrades will be potentially yours. After this step, strategy is fully yours.
You will have to get rid of this carrier, otherwise the core will not appear.
You can even destroy keepers from cutscene, but the bug number six will crush you: every texture becomes totally black, excluding hangars and lights.
Remember to look into upgrades when solar shield is on.
I guess those are most important things to beat that mission..