Why did the spanish and portuguese launch voyages of exploration?

It is thanks to Amerigo Vespucci and Christopher Columbus that the land was discovered, and so spurred other countires such as Spain and Portugal into what now is called the Age of Discovery. Not be outdone by the other, both of these countries wished to seize control of the raw materials and land available for their own. What they did not expect was the wide trade off of contact with the Native Americans. This includes plants, animals, diseases, and even slaves.

Portuguese began exploring , charting and sailing in open atlantic ocean , by nautical instruments , in the 1410's , 80 years before spain even wet its feet with salt water . Spain finally made its voyage 

It's lithogenous i believe of course i looked it up.