On Friday, October 24th, SpaceX founder and CTO Elon Musk sat down for a one on one interview as part of MIT’s AeroAstro Centenial Symposium celebrating 100 years of that institution’s contribution to aero and astronautics.
The entire wide ranging interview (here) covers SpaceX, Tesla, Hyperloop and even electric supersonic aircraft, as well as Elon’s favorite book (LOTR) but time and again it came back to Mars, revealing some new insight into SpaceX’s long and short term plans.
First, and in some ways foremost, it is the immediate subject of Falcon 9 booster recovery which is making waves, or in this case, trying to avoid them. After two recovery efforts in which the 14 story first stage successfully came to a dead stop above the Atlantic, only to tip over and “explode” on impact, SpaceX has now committed itself, patent wars with Blue Origin be damned, to the construction of a 300′ by 170′ landing platform for near term recovery attempts. The platform, which will use thrusters to maintain a precise position, is currently being built in Louisiana, and providing it is completed and sets sail soon enough, could be in place as early as the next launch to ISS, the CRS-5 mission currently scheduled for early December.
Although very optimistic regarding his prospects over the coming year, assessed at 80-90% of a recovery and re-flight, Musk cautioned that the chances of a successful landing on the first attempt are probably less than 50%. Precision will definitely be required, as he reminded the audience that the deployed span of the booster’s four legs stretch out to 60 feet, leaving little room for error.
On the subject of the carbon fiber landing legs themselves, Musk noted that they serve a very effective double duty in increasing aerodynamic drag, reducing the terminal velocity by 50%. The corresponding reduction in the propellant required to achieve a soft landing is one of that major reasons retro-propulsion is not as fuel intensive as many experts had previously predicted.
One theme which emerged in the discussion is an interesting view of propulsive landings as representing a logical next stage in the evolution of rocketry, not only because they are required everywhere but on Earth anyway, but because they are simply better to begin with. From Musk’s point of view, the space age started with parachute landings then progressed to the next stage of landing with the use of wings or lifting bodies, and are now giving way to “propulsive landings with precision,” a phase we are likely to hear over and over again, joining “rapidly reliable reusability” as a key term in the SpaceX lexicon. Viewed from this perspective, among SpaceX’s two competitors in the final round of NASA’s Commercial Crew Competition, Boeing could be considered as offering a first generation solution in its airbag assisted parachute landing for CST-100, whereas Sierra Nevada is offering a second generation solution in a flying return for Dream Chaser. At the moment, SpaceX is the only company actively moving on to the third generation. While the Dragon V2 will be making its NASA landings by parachute, at least for now, there is no doubt based on the level of emphasis given by its founder, SpaceX is eager to integrate propulsive landing by Dragon ASAP.
There is also no doubt that even though the Falcon family is standing on the edge of a breakthrough in the art of rocketry, Elon Musk and SpaceX are in many ways already looking ahead to the as yet unnamed next generation of boosters to record the big gains required to achieve a two fold order of magnitude reduction in launch costs. To that end, the company has apparently scrapped plans to recover the Falcon 9 second stage, which Musk said would be very difficult given its low specific impulse and high altitudes in the case of ComSat launches. Instead the company will wait for its sub-cooled methane powered Raptor engines to provide reusable capacity “all the way to Mars” in a vehicle he once again suggested would be much larger than anything now flying. Musk stated the first tests could come in 5-6 years, although he was not specific about precisely what would be tested.
Responding to a question, Musk stated that the Merlin engines were his company’s weakest link, although he quickly doubled back to clarify that the term was meant to apply to the Keralox power plant’s specific impulse only, and not to its overall reliability, or even thrust to weight ratio places it among the best engines ever built. In responding to a question about the Mars One proposal, which was recently critiqued by students at MIT, Musk stated that although he would be willing to sell the group Dragon capsules and Falcon Heavies, he seriously doubted they had the funds to buy even one, and that they might want to wait a few years until the next generation of boosters begins to take shape.
If there is one thing which stands out about the interview, it is a subtle, but very important point. In looking ahead, Musk came down heavily in favor of orbital fuel depots, envisioning a two year cycle of fueling the “Mars Colonial Fleet” as it waits for a departure window. To this end, he stressed the need for highly efficient sun shielding (to protect against propellant loss.) While Musk was, as always, genuinely affirmative in assessing his view of NASA and the irreplaceable role it has played in the evolution of SpaceX, the brief mention of orbital refueling is very telling, and highlights the vast difference between SpaceX’s vision for reaching Mars, as well as everywhere else, and the path currently being undertaken by America’s space agency, which has gone to great length’s to downplay or completely ignore this critical enabling technology.
That however, may be okay as well. Challenging another taboo of publicly funded spaceflight, the value of international cooperation, (NASA Administrator Charles Bolden says “we cannot go to Mars without it”) Musk offered the observation that international competition, following something along the Olympic model, is probably a good thing, as national space agencies “marching in lockstep” tend to significantly slow progress.
In the end, it boils down to this; Even if NASA ultimately makes it to Mars first with some iteration of SLS, SpaceX is currently the only organization in the world focusing on how to go there time and again on an affordable basis. And to that that end, his company is going to focus on making the technology “better and better.”
That last point, one on which the discussion closed, is illustrative of what may come to be considered one of the two defining traits of SpaceX, both of which are covered extensively in this author’s newly released book, Here Be Dragons; The Rise of SpaceX and Journey to Mars; an unrelenting focus on the long term goal of creating a second civilization on the Red Planet, but an absolute willingness to change the course for getting there when both experience and circumstances demand.
