Each SpaceX lunar mission would launch on Falcon Heavy: a 230-foot-tall rocket that the company is preparing to fly for the first time.
Falcon Heavy has three boosters and 27 rocket engines — three times as many as Falcon 9, which is SpaceX's go-to launch system.
But Falcon Heavy won't dethrone NASA's now-retired Saturn V rocket as the most powerful in history. That Apollo-era launcher was about 130 feet taller and lifted more than twice the payload.
SpaceX lunar crews will "skim the surface of the moon, go quite a bit further out into deep space, then come back to Earth," Musk said.
next slide will load in 15 secondsSkip AdSkip AdThe six-day lunar circumnavigation flight will closely resemble Apollo 13's path around the moon — hopefully minus the growing and palpable threat of death, Lovell said.
"We had a very crippled spacecraft. ... We weren’t too sure that we we're going to get back," Lovell said of Apollo 13. "On one of Elon Musk's flights, if everything is working fine, and everything is going to be automatic, then they can sit back, relax, and enjoy the scenery."
SpaceX would drive lunar voyagers out to Launchpad 39A at Kennedy Space Center in Florida. It's the same pad NASA used for the Apollo missions, along with most of its space shuttle missions.
After taking an elevator to the top of the service structure, the crew would see their Crew Dragon capsule.
Each moon traveler would wear a simple spacesuit in case of pressure loss.
next slide will load in 15 secondsSkip AdSkip AdA Crew Dragon capsule is big enough to fit up to seven people. But many of these seats may be replaced with basic supplies (and hopefully a toilet) for the lunar mission.
"Two people in close quarters for a week is nothing. I mean, look at submarine crews that spend a couple months underwater," Lovell said. "Look at Scott Kelly, who was up there for a whole year orbiting. Two people just going around the moon in a spacecraft? That is very comfortable, a piece of cake."
Screens above the reclined seats would show computer readouts, the spacecraft's location, and other important information.
Should any of Crew Dragon's automated systems hit a snag, space-flyers could punch commands into the control panel.
Laying almost flat, the crew — hearts racing — would buckle up and await a countdown for launch.
next slide will load in 15 secondsSkip AdSkip AdFalcon Heavy's 27 engines are designed to light almost simultaneously. The force would rattle the spacecraft, then press the crew deeper and deeper into their seats as the rocket accelerates.
A little more than two minutes later, the crew would feel a bump as the rocket's two side boosters detach.
The boosters are designed to land themselves for later reuse, saving SpaceX millions of dollars.
Out the window, the crew could see Earth below.
Another bump would signal that the core booster — also reusable — has detached. Next, the crew would feel a powerful jolt as the second-stage engines fired up, further propelling the mission to roughly 24,000 mph, which is fast enough to escape Earth's gravity and venture out to the moon.
next slide will load in 15 secondsSkip AdSkip AdOutside the Crew Dragon's windows, they'd see the brilliant blue marble of Earth...
... Slowly shrink during the roughly 239,000-mile-trip to our planet's sole satellite.
Lovell said seeing the Earth this way deeply changed him. "You begin to realize how small and how significant the body is," he said."People often say, 'I hope to go to heaven when I die.' In reality, if you think about it, you go to heaven when you're born."
The moon, meanwhile, would grow larger and larger over about three days.
Asked if he had any advice for the first lunar crew, Lovell said."I'd tell them to take a camera and enjoy the scenery, and live the experience. Knowing that this has been done in the past, they just have to have faith in SpaceX that what they’re building is going to be very successful."
next slide will load in 15 secondsSkip AdSkip AdSoon, the moon would fill more of the window...
... And quickly fill it up.
The crew would skim about 100-200 miles above the moon, which is closer than the space station orbits Earth.
On the day side, they'd see now-famous craters in close detail...
... Along with a pockmarked mess of smaller craters caused by meteorites pelting the moon over billions of years.
next slide will load in 15 secondsSkip AdSkip AdLooping around from the far side of the moon, the crew would see the Earth "rising" over the airless lunar surface.
Fast-forward a few days, and the Crew Dragon would be getting close to Earth once more. The capsule would detach from its support trunk and begin its descent.
Ablative material lining the bottom of the Crew Dragon would insulate the spacecraft from the searing heat of atmospheric reentry, and also slowly burn away, carrying away heat to further protect the capsule.
"Coming back from the moon, they'll be hitting a velocity of close to 25,000 mph. And so they're going to have to hit quite a small, pie-shaped wedge with respect to the atmosphere, and make a safe landing," Lovell said. "If they come in too low, they'll skip out, like a skipping a stone on water — they're gone. And if they come in too steep, sudden deceleration will make 'em a fiery meteor."
Source: SpaceX/YouTube
Closer to the ground, thrusters would fire to slow down the Crew Dragon and guide it to landing.
But SpaceX may opt for a set of parachutes and an ocean splashdown, like the Apollo missions.
next slide will load in 15 secondsSkip AdSkip AdSpaceX hopes to launch its first lunar voyage by the end of 2018.
But 2019 is more likely, since SpaceX said it will launch the moon mission only after "operational Crew Dragon missions are underway for NASA."
"There's a market for at least one or two" voyages around the moon per year, Musk said. Each lunar voyage may cost upward of $230 million, perhaps more than $300 million.
Lovell, however, said that SpaceX's lunar joyrides aren't exciting to him — he'd rather see people do science, and land on the moon to establish a permanent outpost.
"I guess eventually, things will come to pass where they will go back to the moon and eventually go to Mars, probably not in my lifetime," he said. "Hopefully they'll be successful."