NASA's human spaceflight programs have focused on missions within our own solar system. The farthest NASA has sent humans into space is to the Moon during the Apollo missions, with the furthest distance being approximately 400,000 kilometers (about 250,000 miles) from Earth.
Currently, NASA is planning to send humans back to the Moon through the Artemis program, with the goal of establishing a sustainable lunar presence. This program aims to send astronauts to the lunar surface, including the vicinity of the Moon's south pole, which would be a significant step beyond previous missions.
For interplanetary exploration, NASA has been working on the Artemis program's Orion spacecraft, which is designed to carry astronauts beyond Earth orbit. Orion is expected to facilitate missions to the Moon, but its capabilities also make it potentially suitable for crewed missions to other destinations in our solar system, such as Mars.
Mars, on average, is approximately 225 million kilometers (140 million miles) away from Earth. Sending humans to Mars and returning them safely would be an enormous technological and logistical challenge that would require advancements in propulsion systems, life support, radiation shielding, and resource utilization.
While NASA and other space agencies, along with private companies, are actively studying and developing the necessary technologies for crewed Mars missions, it is challenging to provide a definitive timeline for when such a mission could occur. It may be several decades before crewed missions to Mars become a reality.
It's important to note that space exploration is an ongoing and dynamic field, with advancements and mission plans evolving over time. The future of human space travel will depend on technological advancements, scientific discoveries, funding availability, and international collaborations.