I noticed that the crew icons for upgrading the ships are different in the core set.

Does this mean that you can´t use them, unless they match the ship upgrade icons?

(The one depicting a death star gunner helmet, and the other depicting a rebel soldier cap).

That is correct. They need to match.

That is correct. They need to match.

Huh, weird that I didn´t notice the difference in all the previews.

But thank you for the quick reply.

That is correct. They need to match.

Are you positive about this?

I just looked at this article again: https://www.fantasyflightgames.com/en/news/2015/1/16/star-destroyers/

And the Engine techs and the crew member next to it, from the Gladiator expansion, both depicts the rebel silhouette icon.

Seems a bit weird to include Rebel only crew in an imperial expansion.

It's not a Rebel Icon, it's a symbol for Support team.

Page 13 of the RRG has a list of all the upgrade symbols.

A card is faction aligned only if the faction icon is displayed adjacent to the fleet point cost in the lower right. But, the ship must have an available upgrade for that card in its upgrade bar at the bottom, an icon that matches the icon in the card's lower left.

Right now, Only the Vic I and both Gladiator variants can upgrade to concussion missiles. No Rebel ship can - but a future expansion may allow such an upgrade. Concussion missiles are not faction aligned, although they seem so right now.

It's not a Rebel Icon, it's a symbol for Support team.

Page 13 of the RRG has a list of all the upgrade symbols.

Ah, that clears it up for me. Scrolled through the rulebook again and again to find the darned Icon explanations, and hadn´t thought to look in the reference guide.

Thank you!

Always use the RRG when you have a question. Every RRG is great resource for their games. 99% of questions can be answered by them.