Tuesday will also see the SpaceX CEO speak at the International Astronautical Conference in Mexico, where he’s expected to reveal his plan for colonizing Mars. With a lot of time, money, and effort, Elon Musk thinks our planetary neighbor could be a second home for humans, a hedge bet in case things on Earth really go south. It’s hard to say exactly what he’ll share — when Musk is on stage, any topic is fair game — but we published our best guesses last week. Look no further if you want to be prepared. Musk isn’t the only one with big ambitions for Mars, however.

Musk isn’t the only one with big Mars ambitions

NASA has spent the better part of the last decade pumping up its own "Journey to Mars," with a loose goal of getting humans to the surface sometime in the 2030s. The agency built a crew spaceship called "Orion," which has flown (empty) once during a test in late 2014. NASA is also building (and testing parts of) a giant rocket, known as the Space Launch System, to one day carry that spaceship to Mars.

But the space agency’s goals are too loose for some, especially Congress. The technology, timeline, and budget have faced intense scrutiny, and the program was called a "time-wasting distraction" during a hearing in February. NASA’s Mars program also faces a hurdle the agency is deeply familiar with: election cycles. Incoming presidents and congressional regime changes can disrupt NASA’s budget and affect the overall attitude about the agency’s purpose. And even if funding stays steady, NASA officials have admitted that there is no concrete plan for the SLS rocket.

There is no plan B for Earth

That’s why the rise of private spaceflight companies is exciting. For the first time ever, there are multiple American entities outside of NASA that are pursuing space travel. Blue Origin, founded by Amazon CEO Jeff Bezos, has successfully flown (and landed) its suborbital rocket four times in the last year. And Bezos recently unveiled the company’s much larger rocket, New Glenn, which could someday take humans beyond the reaches of Earth. But Bezos has scoffed at the idea of using Mars as a "plan B for Earth" in the past.

The United Launch Alliance, a joint venture between Boeing and Lockheed Martin, has rockets capable of getting to Mars. But for now the ULA seems content with only using those rockets to send robots — not humans — to the planet. (Boeing is even separately working on a crew spaceship for NASA, but it will only be used to bring astronauts to the International Space Station.)

That leaves us with Mars One, which isn’t a private spaceflight company, but has driven the conversation almost as much as SpaceX. The Dutch non-profit spent the last few years pushing the idea of sending a select group of willing but untrained humans to Mars and filming it for a reality show. By all accounts, Mars One and the people who run it have a weak grip on the problems they’d face — an MIT study found that the life support systems proposed by Mars One would kill its astronauts within months of landing, for example. Mars One’s plans have also suffered delays, and the group was caught ginning up the number of applicants who were willing to sign up for the trip in the first place.

Who will Elon Musk be able to convince to go to Mars? How will he get them there? Most importantly, how will he keep them alive? We start getting answers to those questions tomorrow when Musk takes the stage. The Verge will be both on the ground in Mexico and covering the event from New York.

But this is just a taste of what’s to come in what’s promising to be another huge week on The Verge. First, let’s get caught up on the weekend that was.