With the all-civilian Inspiration4 crew mission back on Earth, SpaceX’s director of human spaceflight programs says the company is seeing increased interest in more private astronauts flights to orbit, and may expand its fleet of reusable Dragon spaceships to accommodate the growing demand.

SpaceX has four more Crew Dragon missions to the International Space Station under contract with NASA, plus four private crew missions to the station for Axiom Space, a Houston-based company with ambitions to build a commercial research outpost in low Earth orbit that could replace the ISS.

There’s also a contract with the space tourism company Space Adventures for a standalone Crew Dragon flight that will not go to the International Space Station, a solo mission similar to the Inspiration4 flight that ended Saturday with a successful splashdown in the Atlantic Ocean.

SpaceX also has a contract with NASA for resupply missions to the space station using the company’s fleet of Cargo Dragon capsules, which are based on the crew-rated spaceship, but fly without seats or launch escape rockets.

“We’ve got lots of great NASA missions for crew and cargo, and we’ve got the commercial astronaut missions,” said Benji Reed, the manager in charge of SpaceX’s crew programs, following the splashdown of the four-person Inspiration4 crew Saturday night.

Inspiration4, a privately-funded mission with a goal of raising money for St. Jude Children’s Research Hospital, is “just the beginning” of the commercial astronaut missions, Reed said.

SpaceX has flown two Crew Dragon spaceships, each certified for at least five missions.

The Crew Dragon Endeavour spacecraft is currently docked at the International Space Station on its second trip to orbit, and is due to return to Earth with its four-person team of NASA, European, and Japanese astronauts in November. The Crew Dragon Resilience spacecraft flew to the station on a six-month mission that returned to Earth in May, and then carried the Inspiration4 crew into orbit and back on their three-day flight.

SpaceX has built a new Crew Dragon capsule for the next launch of NASA astronauts to the space station, scheduled for Oct. 31 on a Falcon 9 rocket. That flight, designated Crew-3, will spend about a half-year docked with the station.

NASA commander Raja Chari will lead the Crew-3 mission, joined by pilot Thomas Marshburn — a veteran of two previous spaceflights — European Space Agency astronaut Matthias Maurer, and NASA astronaut Kayla Barron.

The Crew Dragon Resilience spacecraft is set to launch again in February with the first Axiom crew mission to the space station. That mission, known as Ax-1, will be commanded by veteran NASA astronaut Michael López-Alegría, who retired from the space agency in 2012 after nearly 258 days in orbit on four missions.

Three wealthy businessmen will join López-Alegría for an eight-day stay on the space station. The entire mission is scheduled to run about 10 days from liftoff through splashdown.

Reed did not say how many additional Crew Dragon spacecraft SpaceX is building beyond the new capsule for the Crew-3 mission launching next month. But the company could construct more, depending on market demand.

“We just couldn’t be happier with this kickoff,” Reed said after the return of Inspiration4. “We’ll evaluate our manifest as we as we go, and evaluate our fleet as well.”

He said there’s “tons of interest” from the private sector and wealthy individuals to fly to space on Crew Dragon missions. NASA is also widely expected to extend SpaceX’s commercial crew contract for additional government-sponsored Crew Dragon flights to the space station.

“I see our ability to already be able to transition into the kind of five or six mission range (per year),” Reed said.

The flight rate will be aided by SpaceX’s use of refurbished rockets and spacecraft. The Falcon 9 booster stage used for Crew Dragon launches is reusable, as is the Dragon spacecraft’s crew module. Dragon’s unpressurized trunk, which houses the craft’s solar panels, and the Falcon 9 rocket’s upper stage are single-use.

SpaceX’s next-generation Starship vehicle, currently undergoing testing in South Texas, will eventually also ferry people to and from space, he said. It’s designed to be fully reusable.

“On the horizon, of course, is Starship, and Starship will be able to carry a lot of people at once,” Reed said.

Japanese billionaire Yusaku Maezawa is planning to fly on a Starship mission around the moon and back, once the giant spacecraft is certified for human travel.

But SpaceX’s near-term business prospects for private crew missions appear strong, Reed said.

“I can’t really say specifics about numbers or anything like that, or exactly what they’re interested in,” Reed said. “I don’t even know myself at this point, but I know, for a fact, that the amount of people who are approaching us through our sales and marketing portals have actually increased significantly. So that’s exciting.”

Crew Dragon seats sell for about $55 million, according to NASA, which also charges private spaceflight operators for commercial astronauts for space station training and use of space station equipment.

The Inspiration4 mission was the first U.S. human spaceflight to orbit Earth without major participation from NASA. Advocates for commercial spaceflight said Inspiration4 opens a door for “everyday people” launch into space, where fewer than 600 people have flown since the dawn of the Space Age.

The price of a trip to space is still out of reach for most people. But SpaceX is striving to make space missions more “airline-like” with lower prices and less risk, Reed said before Inspiration4’s launch.

NASA’s inspector general says a seat on a Crew Dragon spacecraft for a six-month expedition to the International Space Station costs the agency more than $50 million.

Jared Isaacman, the billionaire who commanded the Inspiration4 mission, paid SpaceX less than that, according to officials familiar with the arrangement. But SpaceX and Isaacman have not disclosed the exact cost of the flight.

“We can’t talk about the price of the mission,” Reed said. “That’s obviously private.”

Axiom’s missions, unlike Inspiration4, will have an experienced astronaut at the helm of each Crew Dragon flight.

Isaacman and his crewmates trained with SpaceX for six months to prepare for the their voyage into orbit. They were prepared to take over and manually command the capsule, if necessary, but Crew Dragon spaceships are designed to run on autopilot, with oversight from ground controllers at SpaceX headquarters in California.

Axiom’s second mission, Ax-2, could launch in late 2022, pending NASA approval. Retired NASA astronaut Peggy Whitson and John Shoffner, an experienced race car driver and pilot, will fly on the Ax-2 mission with up to two unnamed civilian crewmates.

Officials have not announced crew members for Axiom’s third and fourth missions, or for the Space Adventures flight.

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