On Friday, SpaceX CEO Elon Musk laid out his vision for SpaceX’s future: the company is going all-in on a next-generation vehicle called the BFR, or Big Fucking Rocket. This rocket, which will be capable of going to the Moon and Mars, will eventually become SpaceX’s primary vehicle for launching satellites and traveling to the International Space Station, too.

It’s a radical move for the company, which has a fairly reliable rocket already. But can SpaceX afford this change? In his presentation, Musk discussed how SpaceX plans to fund the cost of developing the vehicle — though he didn’t mention any dollar figures — as well as what it will be used for when it’s complete. His ideas may be enough to fund the transition and keep the company profitable, but there are some fairly obvious gaps in the plan.

Developing the rocket

Musk made one thing very clear: SpaceX’s future is the BFR. The company is no longer going to put resources into improving its current line of Falcon 9 vehicles or its bigger, next-generation Falcon Heavy. Instead, all of the company’s research and development resources will go into creating the new monster rocket. “He can now use those same now-proven people who have built flight hardware to now redesign the spacecraft,” Charles Miller, president of NexGen Space LLC, a space consulting firm, and a former member of the Trump administration’s NASA transition team, tells The Verge.

The revenue SpaceX currently receives from launching satellites and servicing the International Space Station will also go toward funding the development of the rocket, Musk said. Right now, business does seem to be good: SpaceX has a full manifest of customers, and the company significantly increased its launch frequency to 13 so far this year (up from eight last year). NASA is also paying SpaceX to send cargo, and soon astronauts, to the ISS.

Whether this is enough to fund the $10 billion development of a new rocket is unclear, though. And we’ll likely never know for sure. “The launch business is notoriously secretive in terms of prices,” Brian Weeden, a space expert at the Secure World Foundation, a nonprofit that specializes in space security, tells The Verge. “Plus, the price of launching a satellite depends on how much you’re willing to pay, where you want to go — it depends on a lot of stuff.”

it’s likelier that the company will need additional funds

It’s possible that SpaceX’s satellite business and NASA contracts are enough to fund the BFR’s development. But it’s likelier that the company will need additional funds — especially if Musk hopes to meet his “aspirational” deadline of sending the vehicle to the Red Planet by 2022. Private investment seems like an option. And another good source of money? The government.

Moon Base Alpha A post shared by Elon Musk (@elonmusk) on Sep 28, 2017 at 7:44pm PDT

Musk is now promoting how the BFR can send people to the Moon, a fairly naked play at piquing NASA’s interest. NASA is already studying how to put a station in the vicinity of the Moon. And a few key space advisors — including Vice President Mike Pence, who runs the National Space Council — have hinted at a return to the lunar surface. It’s possible that NASA may want to partially fund the BFR’s development in order to incorporate the vehicle in any future lunar plans.

It may be hard for NASA to ignore the BFR

However, there’s a major hurdle: NASA is currently developing a giant rocket of its own, called the Space Launch System. That vehicle has many ardent supporters in Congress, mostly from representatives of states where the rocket is being built. And Congress, of course, controls NASA’s funding — so it may be difficult to sway lawmakers who see the BFR as direct competition to the SLS. But the SLS is an incredibly costly vehicle that won’t fly people until as late as 2023. It may be hard for NASA to ignore the BFR if it starts flying people before then.

Once it’s built, then what?

Assuming SpaceX does get the money it needs to develop the BFR, then what? Will there be enough customers to help offset the development costs and make SpaceX profitable?

On Friday, Musk advertised a number of uses for the BFR, beyond just going to the Moon and Mars. He argued that the new system would essentially replace the Falcon 9 rocket and Dragon spacecraft, and that SpaceX could use the new vehicle to launch satellites, service the space station, and even clean up space debris in orbit. And the more uses a rocket has, the more potential customers the rocket has, too. “If they can responsibly transition their customers to this new vehicle, then it can cover what they need,” Phil Larson, a former SpaceX spokesperson and assistant dean at the University of Colorado’s college of engineering, tells The Verge.

A post shared by Elon Musk (@elonmusk) on Sep 29, 2017 at 12:46am PDT

But do satellite customers want to launch on the BFR? The vehicle would easily be the most powerful rocket ever built. Launching satellites on the spacecraft would be “overkill,” according to Miller. Plus, the space industry has recently been working on making satellites smaller, not bigger. “That’s a huge, huge rocket to launch satellites,” says Weeden. “And the trend seems to be going toward much smaller satellites.” SpaceX could conceivably pack a whole bunch of satellites into the BFR per flight, but there are a lot of smaller launch vehicles that might make more financial sense for customers.

“That’s a huge, huge rocket to launch satellites.”

In fact, the only way customers will want to fly their satellites on such a massive rocket is if it’s cheap. And Musk says it will be. He plans to make the rocket and spaceship combo a fully reusable system (unlike the Falcon 9, which is only partially reusable). Musk claims that this will make the BFR the cheapest rocket SpaceX has ever flown, even cheaper than the Falcon 1 — the very first, small rocket the company flew in 2008.

But there are still limits on just how reusable a rocket can be, says Miller. Rockets experience supersonic speeds, extreme heat differences, and intense vibrations when they travel to and from space. And the strain of this travel puts a lot of wear and tear on a vehicle. Miller says it’s conceivable that reusable rockets may have 100 flights in them, but that’s still not nearly as many as an airplane, which can make more than 10,000 flights in its lifetime. “If it only has 100 flights in the BFR, I don’t think it’s lower cost than the Falcon 1,” says Miller.

In order to fully reap the benefits of reusability, these rockets are going to have fly a lot — perhaps hundreds, or even thousands of times a year — to truly bring the cost of launch down. And there may not be enough satellites to justify so many launches. “How elastic is the launch market?” Jonathan McDowell, an astrophysicist at Harvard and spaceflight expert, tells The Verge. The average fleet of satellites launched each year could likely fit on just a handful of BFR launches. What else is there left to launch?

There are other options, of course, such as those potential lunar missions for NASA. And the Moon opens a lot of possibilities: a number of national space agencies — including Russia, China, and the European Space Agency — are looking to go there. It’s possible these countries may want to buy flights on the BFR to pull off their lunar plans. And there’s even more that the BFR could do that Musk didn’t advertise. There’s the potential for space tourism or building habitats in lower Earth orbit. And then there’s point-to-point travel here on Earth, though that may have its own logistical problems.

If the cost of the vehicle is low enough, it may eventually create its own demand. But that demand may not materialize for a while. Plus, SpaceX needs to build the BFR first — and given Musk’s lack of specificity in terms of cold, hard cash, it’s possible only SpaceX’s accountants know if the money is really there to do it.