SpaceX has been dominating the world of commercial spaceflights since it started launching cargos to the International Space Station (ISS).

But one of its most formidable competitors has come up with a "game changer": space trucks.

Tony Bruno, CEO of the United Launch Alliance (ULA), discussed the company's plans to develop a cargo carrier called space trucks, saying that these rockets will make space colonization more cost-effective, Quartz reports.

"I came here to transform the company, position it in this new competitive marketplace with all these different players," Bruno said in a report by Quartz.

ULA is a partnership between aerospace engineering giants Lockheed Martin and Boeing. The company's launch contract with NASA will expire in 2019, which means that ULA needs to continuously innovate to stay relevant in the commercial spaceflight competition.

With this, the company has thought to aggressively look for new ways to lower their costs by creating reusable rockets, a program SpaceX had already successfully demonstrated.

However, unlike SpaceX, ULA's rocket will have a reusable second stage (the portion of the rocket that sends the payload to its final journey) apart from a reusable first stage (the portion that propels the rocket into orbit). Also, instead of bringing the rocket back, ULA's reusable second stage will be left in space and remain in orbit.

"We realized that you don't have to bring it back in order for it to be reusable," Bruno told Quartz. "That's the big paradigm change in the way that you look at the problem - if you have an upper stage that stays on orbit and is reusable."

ULA's reusable stage is called Advanced Cryogenic Evolved Stage, which looks like a small and fat fuel tank with four rocket motors on the end. According to ULA, the rocket could efficiently store fuel in space and can be restarted and refueled while in space, where it will wait for cargo loads launched from Earth.

The commercial spaceflight industry is continuously growing, with companies like ULA and SpaceX making space travel even more valuable and feasible for many people. Other companies like Moon Express, Deep Space Industries and Planetary Resources also have plans to make space travel more cost-effective and are already developing their technologies with support from Silicon Valley investors.