UPDATE February 7, 2018: The Falcon Heavy rocket has successfully lifted off on its maiden flight. (Full story)
The first flight of SpaceX's long awaited Falcon Heavy rocket is scheduled for January 31. If all goes well, it will be the most powerful operational booster in the world – at twice the capacity of its nearest rival. According to SpaceX, it will be able to lift the equivalent of a fully loaded 737 airliner into orbit, but how powerful is the Falcon Heavy overall? To get a sense of perspective, let's see how it stacks up to the granddaddy of all space rockets, the Saturn V.
Though it hasn't flown yet, the Falcon Heavy is already a pretty impressive bird. If successful, it will not only be the biggest rocket in the world today, but it will be a general purpose launcher that was developed for commercial use solely through private funding. It will also be largely reusable, depending on the mission and payload, and promises to bring the cost of everything from Earth orbital payloads to interplanetary missions way down. And that's not even mentioning that it will be the first to launch an electric supercar into space.
If we compare it to the Saturn V rocket that was built for the NASA Apollo program in the 1960s, there are some very obvious differences between the two before we even get down to the statistics. The most apparent is that the Falcon Heavy is a general purpose rocket designed to carry out a whole range of jobs for a variety of customers. It's also designed as an evolution of the Falcon 9 rocket and will share its reusability as a way of keeping down costs.
The Saturn V, on the other hand was a very specialized rocket intended for only one thing – to send the Apollo missions to the Moon. Though it's final task was to lift the Skylab space station into orbit in 1973, that was basically all it ever did in the 13 times that it flew. Built by Boeing, North American, and Douglas along with an army of subcontractors, it was the brainchild of space pioneer Wernher Von Braun and a direct descendant of the V2 rocket of the Second World War.
The Saturn V was also strange because where the Falcon Heavy was first conceived of 13 years ago and still hasn't gone practical, the Saturn went from conception to operational flight in only seven years. Even then, the Saturn's evolution was one of constantly aiming at a moving target as the spacecraft it was meant to launch kept changing in both basic conception and details. It was also mind-bogglingly expensive as the American government spent the equivalent cost of a small war on its development.
But the result was the world's largest, most powerful rocket. You'll notice there are no qualifiers there. The Saturn V was the biggest by a wide margin and remains so to this day. And if we compare it to the Falcon Heavy, which will be the most powerful rocket of today, we can see by how much the Apollo launcher excelled.
Let's look at the basic statistics. The Falcon Heavy stands 230 ft (70 m) tall, its core has a diameter of 12 ft (3.66 m), and when fully assembled with its side boosters is 40 ft (12.2 m) wide and weighs 3,132,301 lb (1,420,788 kg). The Saturn V with its three stages in place, tops out at 363 ft (110.6 m) tall, has a diameter of 33 ft (10.1 m), and tips the scales at 6,540,000 lb (2,970,000 kg).
Of course, size isn't everything. The Empire State building is bigger than both the Saturn V and the Falcon Heavy, but it can't fly for toffee. On the other hand, the two-stage Falcon Heavy has nine Merlin 1D main engines in each of its first stage elements burning supercooled liquid oxygen and kerosene to produce 5,548,500 lb of thrust. Then the second stage takes over with its single Merlin 1D engine to punch 210,000 lb of thrust
That's remarkable when compared to the Atlas and Ariane rockets of today, but now let's look at the Saturn V. Its S-IC first stage has five Rocketdyne F1 engines that, when set loose, generate a staggering 7,610,000 lb of thrust as it burns kerosene and liquid oxygen.
Then comes the S-II second stage with its five Rocketdyne J-2 putting out 1,155,800 lb of thrust from a mix of liquid oxygen and liquid hydrogen. But where Falcon Heavy has already used up its stages, the Saturn still has its S-IVB third stage and its single J-2 engine that can manage a respectable 225,000 lb of thrust.
Leaving aside minutiae like specific impulse and burn times, what does all this mean at the end of the day? It means that the Falcon Heavy can put a payload of 140,700 lb (63,800 kg) into low Earth orbit at an inclination of 28.5 degrees. It could also reach escape velocity to send 35,000 lb (16,000 kg) to the Moon.
Saturn V? Its low Earth orbit throw weight is over twice the Heavy's at 310,000 lb (140,000 kg) with a 30° inclination. Getting to escape velocity, it can loft 107,100 lb (48,600 kg) into lunar orbit. That's the equivalent of nine full grown elephants – without their spacesuits.
But where the Falcon Heavy comes out ahead is in economy. The estimated cost of a Saturn V launch in today's dollars is a whopping US$1.16 billion. Meanwhile, the upper estimate for Falcon heavy is US$90 million. That's million with an "M."
So, which rocket comes out ahead? In terms of sheer numbers, the Saturn V wins hands down, but the contest is a bit unfair. Saturn V was a Cold War project with a main objective to put a man on the Moon as part of the struggle to prove the superiority of the Free World over the Soviet Union. It was a cost-is-no-object machine intended to win a bloodless battle for world supremacy.
Falcon Heavy, on the other hand, is a business venture. Its job is to make a profit for SpaceX's investors and its development always had one eye on the ledger at all times. Its design is different, its function is different. To compare it with the Saturn V is a bit like comparing a nuclear strike carrier with the Queen Mary 2. Beyond a certain point, the exercise becomes meaningless.
Besides, the Saturn V is no competition to the Falcon Heavy, if for no other reason that no more Saturns could be built. True, the complete microfilm plans for the giant rocket and its support systems are carefully stored by NASA, but the men and women who built Saturn are all dead or retired, the machine tools used to build it are all broken up, and most of the components are no longer manufactured.
What Falcon Heavy must worry about is what comes next.