Launching a rocket is the easy part. Bringing it back down is a whole lot trickier. Step 1: Finding a parking spot. Image source: Getty Images.

The news came last week. SpaceX has so far launched and landed five first-stage Falcon 9 "reusable" rockets (versus Boeing's (NYSE:BA) and Lockheed Martin's (NYSE:LMT) zero, a record equaled by Arianespace in Europe). SpaceX now expects to triple the rate at which it recovers used rockets.

And soon.

Triple the rockets, triple the fun

SpaceX intends to accomplish this feat through one simple fact of mathematics. Later this year, probably in November, SpaceX will begin launching large satellites into space with its Falcon Heavy launch vehicle, a rocket rated to carry anywhere from two to four times the payload that Falcon 9 can lift.

Falcon Heavy accomplishes this feat with the help of three separate "core" boosters, each equipped with nine engines, and each roughly the same size and configuration of a Falcon 9 core. And because SpaceX intends to make Falcon Heavy "reusable" just like Falcon 9, this means that when Falcon Heavy sends three boosters up, it will try to send all three boosters back down again to land on Earth.

Mother, may I?

Precisely how SpaceX plans to accomplish this engineering feat -- sending up three boosters tied together in one rocket, detaching them all, and sending them down to land separately -- isn't yet 100% clear. But SpaceX's intentions to complete the feat are crystal clear.

Last week, the company applied for federal permits to set up two new landing zones for its rockets at Cape Canaveral Air Force Station. These would be in addition to Landing Zone 1, where it has already landed two Falcon 9s successfully (SpaceX's other three rocket recoveries were conducted at sea). Assuming permission to build the new sites is granted, SpaceX would then have room to land three Falcon 9 cores separately, and simultaneously, at the Cape.

A riddle wrapped in a mystery inside an enigma, designed by Elon Musk

That fact alone is pretty amazing, as SpaceX continues to blaze a trail of "firsts" for its competitors at Boeing and Lockheed Martin (and Blue Origin) to try to follow. But here's a little factoid that may be even more amazing for investors in SpaceX's rivals today (and perhaps investors in SpaceX itself in the future):

SpaceX wants to send up and then recover three rocket boosters from each Falcon Heavy it launches. According to Elon Musk, each of those Falcon 9 boosters costs the company somewhere between $30 million and $35 million to build. Building three of them should therefore cost SpaceX something on the order of $90 million to $105 million per launch.

Now, would you like to know how much SpaceX is planning to charge customers for each Falcon Heavy rocket it launches?

$90 million.

Space math

All of which is extremely curious. If it costs at least $30 million to build Falcon 9's single first-stage booster, then mathematically speaking it should cost at least $90 million to build three of them for Falcon Heavy. And it should cost more than $90 million to build three first-stage boosters, plus a second stage booster, to build a cargo or transport capsule, pay for fuel, fund the launch infrastructure, and so on and so forth -- the entire "Falcon Heavy" launch package. Yet SpaceX is offering this package for just $90 million. 

So how does that work?

There's really only one way it can work: Somehow, by the time Falcon Heavy begins flying, the boosters used to build Falcon Heavy must cost less than the $30 million that SpaceX says these boosters cost when used on Falcon 9 today. While SpaceX is understandably proud of the fact that Falcon Heavy will increase the company's ability to lift cargo into space, instantly becoming "the most powerful operational rocket in the world by a factor of two," what's even more amazing about Falcon Heavy is what it will do to the cost of spaceflight. Namely, accelerate the rate of production of boosters, and permit SpaceX to lower the unit cost of each booster produced.

Space experts ranging from Vector Space's Jim Cantrell to Virgin Galactic's Richard Branson to Musk himself tell us that one of the best ways to bring the cost of space launch down is to increase the tempo of launches, enabling construction of rockets in volume to capture production efficiencies. SpaceX already charges much less for space launches than any of its U.S. or European competitors. If it can triple the rate at which it produces boosters for Falcon Heavy launches, and triple the rate at which it recovers those rockets for reuse (SpaceX estimates a rough 30% reduction in costs for launches employing reused rockets), then it could indeed cut the cost of space launch dramatically.

The logical conclusion? SpaceX has shown it can land rockets at sea and on land. Its next mission is to use mass-produced Falcon rockets to drive the cost of space launch straight into the ground.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.