Reddit reviews Rogue Trader RPG: Core Rulebook

"A Rogue Trader is a combination of freelance explorer, conquistador and merchant" - Lexicanum.

"Rogue Traders are like the conquistadors and explorers of the Age of Sail - they go into the unknown to find new worlds for the Imperium, and hopefully get rich doing so" - 1d4chan

"Your ship will take you to new worlds and uncharted reaches of the void, where you will encounter rivals, pirates, aliens, and possibly even creatures of the warp." - The description from the Rogue Trader RPG. Which was BOSS, by the way.

"The Rogue Trader is free to explore the far regions of the galaxy, the areas where the Astronimicon does not reach" - The description of Rogue Traders FROM Rogue Trader, AKA the first 40k book ever. Page 166 if you're interested.

EDIT - I'm sorry, I was wrong. You're right, Rouge Traders aren't explorers, but their selling make up DOES mean they can't fight too much.

EDIT TWO! - Being scared of spiders disqualifies people from being explorers but a fear of snakes doesn't stop Indiana Jones?