NASA wants to send humans to Mars in the 2030s - here's the step-by-step timeline

NASA may say an early goodbye to the International Space Station (ISS) in order to kick-start missions to Mars.

The Trump administration's priorities for NASA, outlined in the proposed 2019 budget, suggest a hard, early cutoff for funding the ISS. The budget would also halt work on a high-end next-generation telescope and gut NASA's $100 million dollar education program.

It's all with an eye toward the administration's ultimate goal of getting humans to Mars by the 2030s. That's a vision former President Obama shared, but his ideas for what to do at the space agency in the meantime focused more on exploring asteroids and previously undiscovered corners of the solar system, not putting people back on the moon, which Trump wants to do soon.

Astronomers aren't happy about the changes, but the space agency says it has to make hard fiscal choices in the name of ferrying people back to the moon and eventually to Mars on a limited budget. After all, if you're going to travel almost 35 million miles into space and touch down on the surface of Mars, you might need extra cash.

The final decision on the plan is up to Congress, which will either greenlight the administration's new NASA proposal in full or make changes.

Assuming that the administration's plan gets approved as-is, here's what NASA is planning to do in order to reach Martian soil: