When the SpaceX Falcon Heavy, the world's most powerful rocket, left the launch pad earlier this month, people of all ages gaped in awe at history being made before their eyes. As shown in the behind-the-scenes video below, even Elon Musk, the man who invested $100 million of his own money to start the aerospace company, was left wide-eyed and grinning.

"Holy flying f**k, that thing took off," he exclaimed in disbelief.

https://youtu.be/KO8FV3vNnPc

Many had never seen the Falcon 9 rocket perform a reentry burn and land, but on that day, millions were treated to the sight of two of the 122-foot boosters simultaneously descending back to Cape Canaveral. And let's not forget that there's now a Tesla Roadster in space cruising towards our solar system's asteroid belt.

If SpaceX was merely nudging the world's curiosity before, it's clear the company has now captured its complete attention. So what's next for Elon Musk and the more than 6,000 SpaceX employees daring to dream big and shoot for the stars?

Say hello to the world's first 3-D printed rocket engine

SpaceX's SuperDraco is the world's first fully 3D-printed rocket engines.
SpaceX's SuperDraco is the world's first fully 3D-printed rocket engines. (Photo: SpaceX)

A successor to the Draco rocket engine used on SpaceX's Dragon spacecraft, the more powerful SuperDraco will be used on the company's upcoming Dragon 2 crew vehicle. While it was designed like the original to be restarted multiple times, the thrust it delivers offers more than 200 times the power. It will be used for powered landings here on Earth, but NASA is also studying the feasibility of incorporating the SuperDraco into a Dragon-esque Mars lander for scientific investigation of the red planet.

More importantly, the SuperDraco engines will play a critical role in making SpaceX crewed missions some of the safest. In the event of an emergency during launch, the engines will fire and separate the Dragon 2 capsule away from a malfunctioning rocket at speeds over 100 mph in less than 1.2 seconds. The crewed spacecraft would then gently land back on Earth.

Another breakthrough regarding the SuperDraco is the way it's produced. In May 2014, SpaceX announced the flight-qualified version of the SuperDraco would become the first-ever full 3-D printed rocket engine. Not only will this allow for reduced lead times on production and cost savings, but also, according to the company, "superior strength, ductility, and fracture resistance."

Raptor: The Mars rocket engine

The 2016 test fire of a Raptor Engine.
The 2016 test fire of a Raptor Engine. (Photo: SpaceX)

With two to three times the thrust of the Merlin 1D engines that power the Falcon 9 and Falcon Heavy, the Raptor engine is designed to power the next generation of SpaceX's launch vehicles. In other words, this is the rocket engine Musk intends to use to place humans on Mars.

Unlike the Merlin engine, which runs on a mixture of kerosene and liquid oxygen (LOX), the Raptor will make use of densified liquid methane and LOX. Not only does the switch to methane as a fuel allow for smaller tanks and a cleaner burn, it also enables SpaceX to harvest the one thing Mars has plenty of: carbon dioxide. Using the Sabatier process, which generates methane, oxygen and water from a reaction between hydrogen and CO2, Mars colonists would not only have the necessary elements to survive long-term on the planet, but the fuel to make return trips back to Earth.

As former SpaceX propulsion engineer Jeff Thornburg told SpaceNews in 2015, having Raptor engines integrated into an interplanetary vehicle allows you to basically live off the land.

"Now that you don't need to take your propellant to get home as part of your camping gear and you can make it on Mars or you can make it somewhere else, now you can take a whole bunch more stuff," he said.

While the Raptor will not be 100 percent 3-D printed like the SuperDraco, it features a new metal alloy developed by SpaceX.

"Some parts of Raptor will be printed, but most of it will be machined forgings," Musk said in a recent Reddit AMA. "We developed a new metal alloy for the oxygen pump that has both high strength at temperature and won't burn."

The Big Falcon Rocket

While the Falcon Heavy is an incredible feat of engineering and gives SpaceX an advantage over its competitors, SpaceX is already planning for its obsolescence. Musk announced last fall that the company will place all of its resources behind the development of its upcoming BFR, or Big Falcon Rocket. This launch vehicle, which will be the largest rocket ever built, is intended to replace both the Falcon 9 and Falcon Heavy, allowing SpaceX to focus all of its attention on a single vehicle.

"I had a profound realization that if we can build a system that cannibalizes our own products and makes our own products redundant, then all of the resources, quite enormous, that are used for Falcon 9, [Falcon] Heavy and Dragon, can be applied to one system," Musk said.

Powering the first stage of this behemoth, which will top out at around 350-feet tall, will be 31 Raptor engines producing an estimated 11.8 million pounds of thrust. This easily eclipses the thrust of the Saturn V moon rocket (7.9 million pounds) and the Falcon Heavy (5 million pounds).

The second stage, known as the Interplanetary Transport System, is a spaceship powered by 6 Raptor engines and capable of carrying dozens of people or up to 330,000 lb. of cargo. All stages of the Big Falcon Rocket are designed to be reusable and land vertically.

In a press conference following the launch of the Falcon Heavy, Musk hinted that test flights of the spaceship portion of BFR could begin as early as 2019.

"I think we might also be able to do short hopper flights with the spaceship part of the BFR, maybe next year," he said. "By hopper tests I mean go up several miles and come down. We’ll do flights of increasing complexity. We want to fly out, turn around, accelerate back real hard, and come in hot to test the heat shield."

As for the booster itself, Musk believes seeing and hearing that one roar to life is still, "three to four years away."

A more powerful Falcon 9

Starting in May 2018, SpaceX will release an upgraded (and final) version of its workhorse Falcon 9 rocket.
Starting in May 2018, SpaceX will release an upgraded (and final) version of its workhorse Falcon 9 rocket. (Photo: SpaceX)

Falcon 9, the workhorse of the SpaceX fleet, has steadily been receiving upgrades since its first launch in 2010. The final revision, called Block 5, is scheduled to launch in May 2018 and will improve thrust and optimize the performance and stability of the booster's landing legs.

Perhaps the greatest benefit of this final revision of the Falcon 9 is the emphasis on reusability that SpaceX is building into the rocket. The Block 5 variant is expected to allow boosters to be reused up to 10 times with only inspections in-between flights and up to 100 times with refurbishment.

"The design intent is that the rocket can be reflown with zero hardware changes," Musk said last spring. "In other words, the only thing you change is you reload the propellant."

With Block 5, it's entirely possible that a booster could be landed, inspected, and then loaded with another payload and sent back into space within 24 hours.

"I think the F9 boosters could be used almost indefinitely, so long as there is scheduled maintenance and careful inspections," he added in his AMA.

Starlink Global Internet Array

A photo of the SpaceX Dragon cargo spaceship as taken from the International Space Station in April 2016.
A photo of the SpaceX Dragon cargo spaceship as taken from the International Space Station in April 2016. (Photo: NASA Johnson/Flickr)

To continue its march toward creating an interplanetary highway between Earth and Mars, SpaceX needs money — and lots of it. Developing the BFR rocket and spaceship alone, independent of everything else we'll need to survive on Mars, will cost an estimated $10 billion.

Enter Starlink, a "constellation" of low-Earth satellites that work together to provide low-cost access to high-speed Internet to every corner of the globe. Three years in the making, SpaceX will later this week launch two prototype Starlink satellites as part of the commercial payload for a Spanish radar observation satellite.

"Our focus is on creating a global communications system that would be larger than anything that has been talked about to date," Musk told Businessweek in 2015.

To achieve the kind of speeds many of us enjoy at home, the constellation SpaceX is developing will need to be dense. According to an application filed with the FCC, SpaceX is planning to launch 4,425 satellites, each about the size of a Mini Cooper and weighing 850 pounds, into 83 orbital plans between 1,110 to 1,325 kilometers above Earth. That's more than all of the active and inactive satellites currently floating around space combined.

It's an extremely ambitious project, and one that won't truly bear any fruit until 2024 at the earliest. That said, SpaceX has a unique advantage in that it can load its satellites onto every Falcon 9 and Falcon Heavy that someone else is paying for. This unparalleled launch access could provide the tipping point to making the dream of global broadband internet a reality.

Fly anywhere on Earth in under an hour

Within the "Dream Big" folder in Musk's head is a clever plan to use the BFR to shuttle people anywhere in the world in under an hour. Fancy a trip from New York to London? You'll be airborne for only 29 minutes. New York to Shanghai? 39 minutes. Once perfected, Musk says the ticket to fly at speeds approaching 17,000 mph would eventually be priced the same as one for a commercial airliner.

"If we're thinking of building this thing to go to the moon and Mars, why not to other places on Earth as well?" Musk said.

Critics, however, are quick to point out that the g-forces (as well as brief micro-gravity) during such a flight might not offer the kind of relaxing experience airline passengers have come to expect.

"The idea that a typical airline passenger would be able to go through the experience just doesn't compute," John Logsdon, professor emeritus at George Washington University's Elliott School of International Affairs and a faculty member at the university's Space Policy Institute, told CNBC. "Musk calls all of this 'aspirational,' which is a nice code word for more than likely not achievable."

If anything, SpaceX tends to feed off the impossible, daring to push the envelope of what's possible. Based on what's already been achieved, we likely won't be surprised if we're all one day living the dreams that Musk is conjuring in his head.

"I try to do useful things," he recently told Rolling Stone. "That's a nice aspiration. And useful means it is of value to the rest of society. Are they useful things that work and make people's lives better, make the future seem better, and actually are better, too? I think we should try to make the future better."

Michael d'Estries ( @michaeldestries ) covers science, technology, art, and the beautiful, unusual corners of our incredible world.