On Tuesday President Trump is expected to sign a NASA bill which will increase the overall budget of the space agency to $19.5 billion and refocus efforts on deep space exploration – with a manned mission to Mars seen as the next great challenge.

Sending a spaceship to Mars will be an extremely complex and ambitious project, with much of the technology needed to make the trip a success yet to be invented. NASA will rely heavily on feedback from planned missions by Elon Musk’s SpaceX – which is set to launch an unmanned spaceship to Mars as soon as 2018.

The Committee on Human Spaceflight said a mission to Mars was “the appropriate long-term goal for the human spaceflight program.” The reasons it cited included economic benefits, national prestige, scientific discovery, and a sense of shared destiny.

While the bill retains funding for the critical earth science department at NASA, not all programs dedicated to monitor climate change will be saved if Trump signs the bill – with four specific missions set to be culled.

While NASA is refocusing its efforts on exploring the unknown parts of space, countries like China and India are seeking to make their mark, hoping to end the dominance of Russia and the U.S. as the world’s foremost space-going nations.

Here are the key points of the bill:

What about the moon? – There was no mention of the moon versus mars debate in the bill, meaning it is still unclear if the NASA will ever send astronauts back to the surface of the moon — despite Trump administration memos which raises the possibility of sending humans back to the moon by 2020. China is currently planning a manned mission to the moon in 2036, while Russia wants to establish a lunar colony on the moon by 2030.

It’s all about Mars – The bill mentions the red planet 28 times in total, asking NASA to “study the feasibility” of a manned trip to Mars by 2033. The first steps will be the testing next year of the Space Launch System rocket and the deep space vehicle Orion, before a mission to establish a more permanent presence around the moon in 2021, which will test out systems such as long term living modules.

Reaching out – NASA wants to work with others in order to achieve its goals. The bill says it may invite its partners in the International Space Station program to help achieve its goal of reaching Mars, though the U.S. would take the lead role. The bill also endorses public-private partnerships as the foundation of future U.S. civilian space efforts — though it doesn’t go into specifics about what this might mean.