Lockheed Martin, the contractor working with NASA to take humans to Mars, introduced a reusable moon shuttle on Wednesday that it envisions as a prototype for a vehicle ferrying astronauts between the surface of the Red Planet and an orbiting space station.

The so-called lunar lander concept that the Bethesda, Md.-based company unveiled at the International Astronautical Congress in Bremen, Germany, could take a crew of four people and 2,000 pounds of cargo back and forth between the moon and the Lunar Gateway module, an orbiting outpost NASA aims to build in the 2020s. It wouldn't need to refuel on the surface.

"NASA asked industry for innovative and new approaches to advance America's goal of returning humans to the moon, and establishing a sustainable, enduring presence there," said Lisa Callahan, general manager of Lockheed's civil space business. "This lander could be used to establish a surface base, deliver scientific or commercial cargo, and conduct extraordinary exploration of the moon."

Lockheed, like rivals including Boeing, is benefiting from a boom due to the White House's interest in space exploration and defense, with President Trump proposing missions to the moon and Mars while developing a Space Force. The defense budget the president signed earlier this year includes $1 billion for space programs, and the administration is asking Congress to allocate another $8 billion for such efforts over the next five years.

The lander that Lockheed described would be permanently docked with the Gateway, whose initial elements would include at least a propulsion system, living space, and airlock capabilities, allowing it to avoid the wear and tear associated with re-entry into Earth's atmosphere.

"The Gateway is key to full, frequent and fast reusability of this lander," said Tim Cichan, a Lockheed space exploration architect who discussed the concept at the Astronautical Congress. "That's a major advantage of the Gateway and of a modular, flexible, reusable approach to deep space exploration."

Not only would the craft facilitate exploration and development of Earth's most visible satellite, but operating it would also yield knowledge vital to Trump's vision for human exploration of Mars, even though there are crucial differences between the two bodies. The moon is exponentially closer to Earth, in case of emergencies, and its lack of an atmosphere reduces stress on the shuttle.

Lunar trips "will provide valuable operational experience utilizing the propulsion systems that will be necessary for landing on the surface of Mars," as well as refueling in orbit, Lockheed said in a white paper. They "will have a large influence on how we develop Mars missions since it greatly expands our capabilities to live and work on another planetary body."

The final Mars exploration vehicles, the company added, "will likely be a combination of systems that are identical to lunar systems, and those systems with lunar heritage but which need to be different to handle the differing environments."