The company is no stranger to successful rocket landings -- they're considered routine at this point. With Falcon Heavy, however, there are challenges SpaceX just didn't have to face before. It has to separate and land the boosters in an elegant, coordinated fashion that avoids collisions and other erratic behavior. And of course, having three rockets increases the odds of failure. SpaceX has learned many lessons since it first unveiled plans for its heavy-duty rocket back in 2011, but this is a new chapter in its story. It has yet to know how well Falcon Heavy will fly in practice, and it isn't immune to problems even with years of experience under its belt.