The first American spacecraft expected to land on the moon in nearly 50 years will be an unmanned robotic lander.The aerospace company Astrobotic Technologytold Reuters it expects to launch the spacecraft named Peregrinein the summer of 2021 from Florida's Cape Canaveral.The company said Peregrine will be the first American spacecraft to land on the moonsince Apollo astronauts last touched down there in 1972.The mission will bring technology and experiments to the moon to prepare for human flights by 2024.The spacecraft will use the Vulcan rocket developed by an alliance between U.S. aerospace companies Boeing and Lockheed Martin.Tory Bruno is chief executive of the United Launch Alliance (ULA).Bruno told Reuters, "Our first flight on Vulcan is also the first big step in going back to the moon."The Vulcan rocket was selected over the reusable rocket from SpaceX, a company owned by Elon Musk of carmaker Tesla.It is powered by engines from Blue Origin, a company started by Jeff Bezos of Amazon.Blue Origin also is working on a heavy-lift rocket.Astrobotic is based in Pittsburgh, Pennsylvania.It is one of nine companies chosen by the American space agency NASAto develop vehicles and technology to explore the lunar surface over the next ten years.NASA Administrator Jim Bridenstine is pushing private companies to design and develop technologyfor low-Earth orbit and lunar exploration.He wants NASA to be one of many customers for the technology and to prepare for deeper space exploration.For ULA, the launch serves as the first of two certification flights for the U.S. Air Force.Vulcan will replace the older Delta and Atlas rockets.Those rockets have been used for space missions and by the U.S. military for many years.As the U.S. prepares to return to the moon, other countries have launched their own missions to the moon.In January, an unmanned Chinese spacecraft successfully touched down on the far side of the moon.An Israeli robotic lander, however, crashed on its final descent in April.And India landed a Chandrayaan-2 rover in July.The vehicle is on its way to the moon's south pole, unexplored by any other nation.