Photo: SpaceX

"I am Elon Musk, CEO/CTO of a rocket company ... Zip2, PayPal, SpaceX, Tesla and SolarCity. Started off doing software engineering and now do aerospace & automotive ...

Looking forward to your questions."

With those words began a singular event on the Web, as Elon Musk, CEO of -- as he noted -- electric car company Tesla (TSLA 12.06%), of solar power lessor SolarCity (SCTY.DL), and private space exploration firm SpaceX as well opened himself up for questions on Reddit earlier this month.

You can imagine what happened next.

Fans swarmed. Bedlam ensued. And over the next several hours, Elon Musk fielded every question his fans could throw at him.

Missing in action
Curiously, while Elon Musk serves as titular head of two publicly traded companies, Tesla and SolarCity, neither of those got much attention in last Tuesday's Reddit discussion. (Indeed, Musk didn't mention either one by name, even once). Instead, all the action surrounded the one company that Musk has not yet deigned to IPO to the public: SpaceX.

But what did he have to say about it?


The spaceplane. Source: DARPA

Elon on ... spaceplanes

"If you want to get to orbit or beyond, go with pure rockets. It is not like Von Braun and Korolev didn't know about airplanes and they were really smart dudes."

There's been a lot of talk lately about spacecraft that fly into the upper atmosphere and from there release payloads into orbit. DARPA is working on one bird capable of high altitude payload delivery. Stratolaunch Systems has another. Britain's got a third. But Elon Musk isn't worried about these competitors at all. In fact, he seems to kind of dismiss them.

Elon on ... reusable rockets

"We could make the 2nd stage of Falcon reusable. ... There is no meaningful limit [to the number of times Falcon 9R could be refueled and relaunched]. We would have to replace a few parts that experience thermal stress after 40 cycles, but the rest of the engine would be fine."

Instead of spaceplanes, Elon Musk is placing his big bet on the potential to turn the SpaceX Falcon 9 rocket -- which already costs less than rockets launched by the United Launch Alliance (ULA) of Lockheed Martin (LMT -0.20%) and Boeing (BA -2.87%)-- into a true ULA-killer.

Key to this effort will be turning Falcon 9 into a "reusable" rocket -- one whose first, and potentially even its second stages can descend back to Earth after launch, and land safely for recovery, refueling, and relaunching with a new payload a few days later.

Musk thinks a reusable rocket can potentially save taxpayers $50 billion or more on the cost of satellite launches by the U.S. government. And as we now know from the Reddit discussion, Musk doesn't see "wear and tear" on a Falcon 9 rocket being a limiting factor in those savings. While there certainly must be some shelf life on how often any single rocket can be reused before it must be replaced (obsolescence alone is probably one such factor), Musk seems to be saying that for all intents and purposes, a properly maintained reusable Falcon 9 will be indefinitely reusable.

The mission to Mars

"Goal is 100 metric tons of useful payload to the surface of Mars. This obviously requires a very big spaceship and booster system. ... At first, I was thinking we would just scale up Falcon Heavy, but it looks like ... [the] default plan is to have a sea level and vacuum version of Raptor, much like Merlin. ... [Raptor will boast] a little over 230 metric tons (~500 klbf) of thrust per engine, but we will have a lot of them :)"

In the short term, Elon Musk and his reusable SpaceX Falcon 9 rockets pose a real threat to the economics of Boeing's and Lockheed's orbital satellite space launch franchise. Already, SpaceX is underpricing the competition, and if he succeeds in making Falcon 9 truly reusable, space launch prices will fall even further.

But SpaceX poses an even more existential threat to Boeing and Lockheed in the long term. That is to say, if you believe that the "long-term" future of spaceflight is to actually fly through space -- as opposed to just heaving chunks of metal into orbit, there to circle the globe.

SpaceX calls this threat the "Mars Colonial Transport," or "MCT," a true spacecraft capable of sending 100 tons of supplies and/or 100 live human passengers, between planets. For comparison, that's a goal already 25 times bigger than that of the Orion Multi-Purpose Crew Vehicle, which Lockheed Martin is building for NASA. And MCT will boast new "Raptor" engines to match.

With a nine-engine configuration similar to that used on the Falcon 9, a first-stage "Raptor 9" core would boast 4.5 million pounds of force -- roughly half the 8.4 million pounds of thrust offered by the Space Launch System that Boeing is developing for NASA. A three-part configuration featuring a core, and two "core-like" booster rockets, though, would provide 50% more thrust than Boeing's SLS.

In other words, at the same time as ULA is working out the details of its most advanced and most capable space launch system ever, SpaceX is, too. And its spaceship is both bigger and better.

The upshot: After hearing what Elon Musk had to say last week, Boeing and Lockheed Martin should be shaking in their spaceboots.


SpaceX already has the T-shirt. Now it just needs to build the spaceship. Photo: SpaceX