Later this year, SpaceX plans to launch its most powerful rocket yet from the same pad. The long-awaited Falcon Heavy is key to the Hawthorne company's plans to ramp up its defense business, send tourists around the moon and launch its first uncrewed mission to Mars.

But unlike the Saturn V, the Falcon Heavy will have plenty of competition.

Years in the works and the product of hundreds of millions of dollars of investments, a new generation of huge rockets will soon take to the skies. Their manufacturers range from space start-ups to aerospace giants to the space agencies of the United States, Russia and China.

Thanks to advances in fuel, materials and electronics, the new rockets, while physically smaller than some of the Space Age beasts, may be more efficient and cost-effective. They will be able to hoist massive spy satellites to a high orbit or ferry crews into deep space.

The rush of new rockets has prompted some to question whether NASA even needs to build its own massive new space vehicle — and whether there will be enough launch business to go around.