Tomorrow, SpaceX will conduct a routine satellite launch from Florida, but it’s not using an ordinary rocket. The mission will mark the debut of the Block 5 version of the company’s Falcon 9, the most advanced upgrade of the rocket to date and the last major version of the vehicle that SpaceX plans to make. Block 5 is designed to improve the Falcon 9’s reusability, and that’s something SpaceX really needs if it wants to turn many of its expensive, long-term plans into reality.

The entire point of landing and reusing rockets is to save money: instead of creating an entirely new rocket for each mission, SpaceX can simply reuse a vehicle that already exists and has been tested during flight. Many experts, including SpaceX CEO Elon Musk, have likened reusable rockets to airplanes. Airfare would be exorbitantly more expensive if a new plane had to be built for each flight.

“It’s possible they’re spending more on a refurbished rocket right now than on building a new one.”

Up until now, SpaceX’s rocket landings — while cool to watch — haven’t saved the company a ton of money. The maximum number of times a Falcon 9 has flown to space and back is twice. And before a vehicle can fly again, it’s taken apart, inspected, and refurbished by a legion of engineers over the course of many months. That takes time and money, which eats into the savings the company gets from not making a new rocket from scratch. “It’s possible they’re spending more on a refurbished rocket right now than on building a new one,” Greg Autry, an assistant professor at the University of Southern California who specializes in new space companies, tells The Verge.

Block 5 could change that. The vehicle boasts many upgrades that are meant to shorten the refurbishment and downtime needed between flights. For instance, its grid fins, which are used for steering the rocket back from space, are made out of titanium, so they won’t catch fire on the way back to Earth. The engines also have a new heat shielding to protect them from the high temperatures during the plunge through the atmosphere. And the structure that holds the engines to the rocket’s bottom is bolted down now, not welded, to make it easier to take apart and inspect.

If these improvements do cut down on the Falcon 9’s turnaround time, then SpaceX could finally start to see the cost savings it’s been boasting about. The Block 5 is also intended to increase the Falcon 9’s performance without the need for any more major upgrades. All of this combined could lead to larger profits, and that may help the company partially fund many of its ambitious projects, like launching thousands of satellites that can beam internet from space, or building a giant new rocket, the BFR, to take humans to the Moon and Mars.

Profit for Mars

Musk claims that Block 5 Falcon 9s can be used upwards of 100 times with minimal refurbishment. It’s an optimistic prediction: these rockets go faster than the speed of sound and experience extreme temperatures and forces that cause wear and tear. Plus, Musk is prone to exaggeration. A more reasonable number is upwards of at least 10 times, according to Andy Lambert, vice president of production for SpaceX. Even just 10 reuses would certainly cut down on manufacturing costs for the Falcon 9.

But it’s not enough to simply fly these rockets multiple times to save money. Operations need to change, too. SpaceX will have to reduce the workforce responsible for making a rocket flight-ready again. “Everybody talks about the airplane as the model of reusability,” says Miller. “What most people forget is there is not a standing army to turn your airplane around. There’s maybe a dozen people.” Labor costs were a big part of the reason why NASA’s mostly reusable Space Shuttle was so expensive to fly. But since Block 5’s upgrades could reduce the need for lengthy refurbishment, that would mean a smaller workforce that SpaceX has to pay for.

“What most people forget is there is not a standing army to turn your airplane around.”

It’s still unclear how much money this will save SpaceX in the long run. The company won’t give any concrete numbers about labor costs, but it says it intends to keep its baseline price the same for the Falcon 9: $62 million. Autry estimates each first stage — the 14-story section of the rocket that goes to space and back — runs between $30 to $40 million to make. And fueling costs only a few hundreds of thousands of dollars, according to Musk. If the company is able to substantially cut down on its labor costs, it could slash the cost of making the rocket by half. But Autry thinks that’s not realistic — at least for now. “I think the reality will be that it will take a long while to get to there,” he says. “But that means a savings of easily $10 million to $15 million.” Musk’s estimates are similar: about a 30 percent reduction in costs.

If SpaceX can make that happen, the next thing to do is increase launch frequency. The more launches, the more profit the company can make in a year. SpaceX is already working on that, though. In 2017, it pulled off a record 18 launches, more than any other company has done before. And this year, it’s already up to eight missions. By this time last year, it had only done five.

All the extra money can go into the development of the BFR, which SpaceX is going to build at the Port of Los Angeles, as well as thousands of satellites it needs to launch in the near future. The company’s satellite internet constellation, Starlink, just received regulatory approval by the Federal Communications Commission. But the FCC told SpaceX it needs to launch at least half of its first 4,425 satellites within the next six years in order to keep its license. If the Falcon 9 becomes cheaper, getting such a daunting amount of satellites into orbit is a little more feasible. “I don’t think he can afford to launch his big broadband satellite constellation without the Block 5,” says Miller.

A consistent rocket

Another important facet of the Block 5 is that it’s meant to stay more or less the same. Musk says that this is the last major upgrade of the rocket, as the company is now mostly focusing on the BFR development. “It’s the most improved Falcon 9 rocket that SpaceX has ever built and will ever build,” Laura Forczyk, a space consultant and owner of space research and consulting firm Astralytical, tells The Verge.

“It’s the most improved Falcon 9 rocket that SpaceX has ever built and will ever build.”

That’s something NASA is happy about: the Block 5 is the rocket that SpaceX will use to launch NASA astronauts to the International Space Station, as part of the Commercial Crew Program. So this version has been built to meet all of the space agency’s rigorous safety standards. NASA is requiring that SpaceX fly the Block 5 at least seven times successfully, without any major changes, in order to certify it for human flight. It’s a stringent requirement, especially for a rocket that’s flown numerous times before. In comparison, NASA’s future Space Launch System will only do one test flight before it’s certified to fly humans. And the Space Shuttle’s very first flight had humans on board. “SpaceX is going through a level of rigor and improvement that far exceeds everything that’s been done in human spaceflight,” says Autry.

But flying a consistent NASA-rated rocket could be helpful for SpaceX to gain new customers, too. SpaceX is known for tweaking its vehicles between launches, something that’s bothered many in the spaceflight industry, including those in the national security satellite market. NASA and old space contractors typically don’t introduce major changes in their rocket designs very often, and some think making quick alterations creates too much risk. But the Block 5 could silence those critics once and for all. That, combined with the rocket’s enhanced performance may mean more national security payloads on SpaceX’s manifest. “This will help them breaking into national security contracts they wish to get,” says Forcyzk.

Of course, who knows if SpaceX is truly done changing the Falcon 9. That’s what Musk has said, but he also recently suggested that the company is looking into ways to recover the top portion of the Falcon 9 rocket, called the second stage. That would mean making some big design changes to the Falcon 9 (especially since he might use a giant party balloon for the recovery).

It will be a while before we know the true benefits of the Block 5, but one thing is certain: these rockets need to fly a lot if SpaceX wants to really reap the rewards of reusability. “Getting something to fly twice, while that was a breakthrough, the benefits are getting something to turn around again and again and again,” says Miller.