A SpaceX rocket system described by a former astronaut as potentially being “completely revolutionary” is scheduled for its first complete test flight on Monday morning.

The massive Starship rocket will launch from SpaceX’s Starbase facilities in Boca Chica, Texas.

Former NASA astronaut and a Senior SpaceX advisor, Garrett Reisman told Reuters that the rocket is a “game changer” for a number of reasons.

“SpaceX is hoping to carry humans to much further distances inside our solar system,” Reisman said. “A lot more humans at one time. And also do it much more cost-effectively, not only humans, but also taking cargo up to space, satellites, space telescopes. So, they’re trying to kind of break the mold and a lot of different fronts.”

The test mission will mark the first launch of SpaceX’s fully-stacked, 394-foot (120-meter) tall Starship rocket system, consisting of a Starship rocket sitting atop a “Super Heavy” first-stage booster with 33 rocket engines.

Unusually, Starship is constructed of stainless steel and uses methane gas as a propellant, whereas most rockets use hydrogen.

It’s sheer size and the potential for the craft to be fully reusable are what make it such major step forwards, said Reisman, who is a professor of astronautical engineering at the University of Southern California.

“I can’t emphasize enough how big this rocket is,” said Reisman. If you compare it to the rocket that NASA just launched, the SLS rocket. The SLS rocket was the biggest rocket we’ve ever successfully flown. It was 8.8 million pounds of thrust… the Starship and the super heavy booster that they’re going to try to launch tomorrow, that has 17 million pounds of thrust in the first stage.“

The rocket system is expected to deploy the Starship second stage into space, where it will complete a full orbit before reentering Earth’s atmosphere and splashing down dozens of miles off a coast in Hawaii.

The Super Heavy booster will attempt a landing in Texas near its launch site. SpaceX says Starship will be a fully reusable transportation system to carry crew and cargo to Earth orbit, the Moon, Mars and beyond.

“Right now when we launch crew Dragon, we could take four people in there up to the Space Station. Starship, theoretically, could carry maybe as many as 100 people at a time,” Reisman said.

“Starship, if it can be refueled on orbit, then has enough propellant to get from Earth to basically anywhere in the solar system,” he added.

But Reisman said there are numerous challenges to be overcome for a successful test flight.

SpaceX has test-launched the Starship booster five times - but those tests involved the booster launching just 6 miles above ground before attempting to land vertically on land. All but the final fifth test ended in explosions. After the successful landing on the fifth try, SpaceX began work toward Monday’s big test launch of the fully stacked system.

“What SpaceX really excels at is creating the circumstances while you’re developing a new vehicle to fail safely,” Reisman said. So, even if it explodes, “There’s nobody sitting in it”, he said. “The only thing we’re going to lose is the vehicle itself. But guess what? There’s a whole bunch of other vehicles ready to go.”

The rocket also has the potential to revolutionize the ratio of cost of fuel to the cost of the rest of the mission, Reisman said, creating a balance more similar to the much more cost-efficient airline industry, vastly expanding what missions can be funded. Production: Ashraf Fahim