Right now, SpaceX is riding a wave of success. Launch after launch, payloads are delivered into Earth orbit. And history made along the way with two reusable rockets and a Dragon capsule. SpaceX fans are now eagerly awaiting the first launch of the Falcon Heavy. But, SpaceX chief Elon Musk is trying to keep everyone’s expectations (including his own) in check.
At the ISSR&D (International Space Station Research and Development) conference on Wednesday, Musk stated plainly, “it ended up being way harder to do Falcon Heavy than we thought.”
“At first it sounds really easy to just stick two first stages on as strap-on side boosters. But then everything changes.”
And Musk does mean everything.
A quick look at Falcon Heavy
Musk’s description of two first stages slapped on as side boosters is pretty much what SpaceX is doing. 27 Merlin engines power Falcon Heavy’s first stage and produces more than 5 million pounds of thrust at liftoff. That’s like pointing 18 747 aircraft straight up and going full throttle at the same time.
That extraordinary amount of thrust will help lift more than 140,000 pounds of payload into low-Earth orbit. Or, 58,000+ pounds to GTO. And 37,000+ pounds to Mars. And 7,720 pounds to Pluto.
But the challenges are many.
“It’s guaranteed to be exciting,” Musk promised as he encouraged folks to go to Cape Canaveral to watch the Falcon Heavy launch.
He also cautioned, “there’s a lot of risk associated with Falcon Heavy, real good chance that the vehicle does not make it to orbit.”
“Major pucker factor, really, is like the only way to describe it.”
Everything from aerodynamics to engines presents challenges the folks at SpaceX have to overcome.
Lighting 27 almost simultaneously will be no easy feat. SpaceX’s Falcon Heavy page mentions the rocket can suffer from more than one unplanned engine shutdown at any point during the flight, but there’s still not much room for error.
SpaceX knows how to fire 9 Merlin engines at the same time. But 27? That’s uncharted territory for any U.S.-based company and NASA.
Those static fire tests most of see as routine before a Falcon 9 launch will be a critical testing phase for the Falcon Heavy. Musk recently said they might even do multiple tests to gather as much data as possible.
There will be a combined booster static fire. Maybe a few.
— Elon Musk (@elonmusk) May 25, 2017
This article dives deeper into on how lighting all 27 Merlin engines will work. It will look simultaneously when we see it happen, but there will be an imperceptible delay as two engines are fired at a time until all 27 are lit.
And it’s not just the engines. Aerodynamics play a huge role. Vibration at launch and flight. Max Q (Maximum dynamic pressure, or when the vehicle experiences the maximum amount of aerodynamic stress). Separation of the side boosters. There’s a lot of moving parts going on with the Falcon Heavy. Each part of the launch needs to perform almost flawlessly for the rocket to complete its mission.
And we haven’t even talked about landing the three first stages.
SpaceX’s slick Falcon Heavy animation shows each piece of the first stage touching down back near the launch pad.
SpaceX’s first Falcon Heavy launch will be an event that’s for sure. Many doubted the folks at SpaceX could land a rocket and now it seems routine. It’s hard to bet against SpaceX. The successful launch of Falcon Heavy and the landing of three first stage boosters feels more like a matter of ‘when’ than ‘if.’
Just don’t be surprised to see a few bumps in the road on the way there.