Hi again

I managed to do seige and some other dreadlords campaigns thanks to the advice I got at an earlier date on this forum

Im am getting to know some of the tech branches but Im still new and aside from building influence starbases , how can I get my ships to travel further out from my base quicker and without going out of range? I tried for higher sensors and that never did it, looking at the tech tree I reckon maybe if I upgrade engines tech and upgrade ships engines after this I may be able to go m further out from base? but the tech mentions nothing of this so im thinking its another branch I should be skilling - could someone tell me which ?

Thanks
David