During the coming months, NASA engineers will work with the companies to evaluate and refine the different designs. By next February, the end of the initial 10-month phase, NASA will have a good idea which of the landing systems has the best prospect of being ready for the first lunar landing, said Lisa Watson-Morgan, the program manager overseeing the effort.

Mr. Bridenstine and other NASA officials expressed confidence that the space agency would be able to meet the Trump administration’s goal of landing the first woman and next man on the moon by the end of 2024. The last lunar landing by humans, the Apollo 17 mission, occurred in 1972.

The NASA administrator was also optimistic that Congress would finance Artemis even with the federal government facing huge deficits because of economic fallout from the ongoing coronavirus pandemic. He said that NASA accounted for a small fraction of federal spending, and that the agency enjoyed broad support from both Republicans and Democrats.

“It’s important that this agency do this now, because our country and in fact the whole world has been shaken by this coronavirus pandemic,” Mr. Bridenstine said. “And yet we need to give people hope. We need to give them something that they can look up to, dream about.”

The three lander systems are very different, and NASA plans to select up to two of them for further development.