Developing SpaceX’s Falcon Heavy rocket has proven more challenging than expected, according to SpaceX founder Elon Musk.
Musk said at a conference July 19 that he originally thought the project would be straightforward because Falcon Heavy is based on the existing Falcon 9. For instance, Falcon Heavy uses the same Merlin first-stage engine, though it triples the number of those engines to 27. But that initial view turned out to be “pretty naïve,” Musk conceded.
“It actually ended up being way, way harder to do Falcon Heavy than we thought,” Musk said. “At first, it sounds real easy. You just stick two first stages on as strap-on boosters. Man, how hard can that be? But then everything changes. All the loads change. Aerodynamics totally change. You’ve tripled the vibration and acoustics.”
SpaceX plans to conduct Falcon Heavy’s first flight test in 2017, a delay of several years, and use the heavy-lift rocket to send a privately crewed Dragon capsule around the moon in late 2018.
Musk also said that developing the crewed version of its Dragon cargo capsule has turned out to be “way more difficult” than developing the cargo version. While the crewed effort is “going really well” overall, SpaceX is facing more scrutiny.
“As soon as people enter the picture, it’s really a giant step up in making sure things go right,” he said. “The oversight from NASA is much tougher — not that it wasn’t tough for cargo but it’s really intense for crew. It can be a bit tough on my guys at SpaceX but I know where it’s coming from. It’s the right motivation.”
Musk, who spoke at the International Space Station Research and Development Conference in Washington, D.C., said SpaceX continues to work on increasing the reusability of its Falcon 9 rocket.
Later in 2017, SpaceX plans to try to recover the fairing that protects satellites during flight. The fairing costs about $5 million to $6 million.
“I think we’ve got a decent shot of recovering the fairing by the end of the year,” he said.
By 2018, SpaceX hopes to reach the point where a Falcon 9 booster can be re-flown within 24 hours of landing.
“The key to that is all you do is inspections and no hardware is changed, not even the paint,” Musk said.
The booster and fairing account for about 80 percent of the rocket’s cost. The remaining 20 percent is for the upper stage, which SpaceX hopes to eventually re-use for at least some missions.