NASA’s plans for sending people to Mars are intertwined with their plans to send humans to the Moon more consistently, and hopefully to be able to establish a human presence their within the decade. They plan to launch the Gateway, a spaceship that will orbit the moon to support future trips there. They plan to launch it in 2022. By having people live on the spaceship they can better understand “how the human body responds in a true deep space environment before committing to the years-long journey to Mars”.
SpaceX wants to establish a Mars base in the 2020s and plans to launch cargo flights by 2022. This seems a little ambitious to me, though granted I don’t know how long this has been in the works; however, I’d imagine it takes a very long time to design, plan, launch, and travel to Mars especially given NASA’s timeline and the 34-million-mile distance to Mars.