It was rare that technical conferences made headlines. Going into it, the expectations for the 2010 AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit were similar. Attendees represented industry, academia, and students. The expectations was for networking and the occasional minor leaks over drinks mixed in with paper sessions, technical discussions, and keynote presentations. The typical papers were academic or industry presentations with titles along the lines of “On the validation of porous nickel as substrate material for electrospray ion propulsion” dealing with minor, incremental improvements which together added up to millions of dollars in research in development for the next generation of jet and rocket engines. This year would see some presentations hold to that mold more than others. The two COTS competitors had been assigned to sequential slots in the same room, talking about applications of rocket propulsion testing and research in the field of commercial spaceflight.
As was expected, Rocketplane Kistler’s propulsion team gave a presentation which broke little from the typical mold. The team’s focus lay in the field of reusable engine design, comparing and contrasting the many engines the company was developing flight experience with on the K-1, starting from their aging-but-refit AJ-26 first and second stage orbital engines to the LOX/alcohol orbital maneuvering engines down to the cold gas thrusters used for attitude control of the stages during ascent, return, and for the K-1 OV’s maneuvers in space for payload deployment or berthing to the International Space Station. The AJ-26 was, as expected, the most complex of the three types and involved the most complex inspections and maintenance between missions. However, in spite of the challenges of a half-century-old staged combustion engine overhauled with American control systems, RpK’s team put a brave face on their turnaround operations, talking up their collaborations with Aerojet and what they were learning from other reusable high-power engines like the SSME. They didn’t comment on if the turnaround of the AJ-26s made the 9-day flight schedule they had once advertised impossible, but they did note that the engines weren’t the current limit on their 60-day reflights demonstrated to date and that they were continuing to expect the engines on LAP-1 and OV-1 to last in service for the dozen or so flights necessary to allow LAP-2 and OV-2 to finish integration and enter service within the next 18 months. They noted that this should ensure that Aerojet’s supply of 55 AJ-26 engines should last more than 165 missions--more than sufficient, they noted with a smile, for the contracted CRS flights plus any number of commercial contracts. Nevertheless, RpK presented their consideration of options for enhancing the K-1’s operational life and performance with a US-built licensed copy of the AJ-26 with enhanced capabilities. With Aerojet publically known to be gearing up to try and bid for the large hydrocarbon engine contract everyone expected if the Senate budget for NASA passed, this was widely seen as aligning RpK’s development with the priorities of their subcontractors as a way of once more trading design authority for lobbying support from established space players, as RpK already had with ATK’s well-timed contract to begin assembling LAP-2 and OV-2 just as Bill Nelson’s office had been gearing up to draft their final bill.
The presentation concluded with a review of the status of the AR-36 engine intended for use on the Rocketplane XP “Pioneer.” Though a kerosene/LOX engine like the AJ-26, the AR-36 had more in common with the K-1’s OMS engines: a simple pump powered by decomposition of hydrogen peroxide fed a low-pressure rocket engine with a vacuum-optimized nozzle, suited for in-flight ignition aboard the suborbital spaceplane. Testing of the engine had been in progress for more than a year, and the team announced that not only were they firing the engine at full power, but that hundreds of firings were well into a program of hours of total runtime, characterizing the engine’s startup, shutdown, and operations across the envelope. The lessons they had learned in preparing and flying the K-1, they said, were now being applied to the testing and design of the AR-36, culminating in their big announcement: multiple full-duration firings of the AR-36 with less than four hours of maintenance between flights, mostly consisting of topping off the tanks at the test stand. It was an achievement matching the best demonstrations by XCOR and Masten and radically exceeding the turnaround time possible from any single hybrid motor SpaceShipTwo was using. If rapid and reusable suborbital tourism was ever to happen, RpK’s propulsion team and their partners at Polaris and Aerojet now had a major leg up. The engine was still not yet fully qualified for flight, the RpK team stressed, but it was only due to their desire to have the engine fully understood on the test stand before they mounted it to the plane. By the time the Pioneer had completed its jet-powered tests, the rocket would be ready--and that time would surely be before the next summer’s conference.
It was an informative and exciting presentation, with much to look forward to...and the SpaceX presentation by Tom Markusic immediately afterwards almost completely blew it out of the minds of the attendees. The tone of the presentations was different almost from the first slide, when Markusic flashed up a busy slide full of equations, graphs of the Bessel functions grabbed from Wikipedia paired with the eye-crossing equations which governed them. Bessel functions were complex, in-depth...and irrelevant to the presentation as a whole. Indeed, the first slide was nothing but a joke about the complexity and depth of the typical presentation. Instead, much of the rest of Markusic’s presentation would consist of filling in a four-block diagram of engine programs one at a time, explaining their significance for SpaceX. While RpK had focused their presentation on the near term, development programs underway and vehicles already flying, SpceX presented almost no programs expected to be achieved within the next five years. Their existing Merlin 1C engines were hardly mentioned, and then only in the context of Merlin 2, a massive F-1 sized low-pressure gas generator engine derived from their work on Merlin, and the lowest-hanging fruit of the development options for future launch vehicle propulsion SpaceX presented as something they were considering.
Compared to a wish list including nuclear thermal propulsion, solar and nuclear electric tugs, and methane engines with applications for Mars ascent and descent propulsion, the Merlin 2 was almost mundane...perhaps deliberately considering the incendiary language included on the slide. In simple bullets, SpaceX’s propulsion team claimed that the could “develop and flight qualify the Merlin 2 engine in ~3 years at a cost of ~$1B”. Apparently, the audience noted, Aerojet and Rocketdyne weren’t the only ones considering the potential revenue from the hydrocarbon engine program and aiming to bring home the contract. However, Markusic continued, couching the Merlin 2 not in its value to the world at large, but to SpaceX’s future plans. His next slide was a lineup of familiar and unfamiliar rockets. It started with the Saturn V, the existing 11-metric-ton Falcon 9, and the long-expected Falcon 9 Heavy with its capability of just over 30 metric tons to LEO. However, the slide then went on to lay out how the Merlin 2 could enhance the family, with a single Merlin 2 replacing nine Merlin 1s. The revised Falcon 9 would see its performance improve by as much as a ton, while the Falcon 9 Heavy would be pushed to nearly 35 metric tons--nearly double the performance of the USAF’s mainstay Delta IV Heavy. However, these were only intermediate steps on the way to two new-diameter rockets. Falcon X was the first, whose 6-meter diameter lower stage (nearly as large as the Saturn IB or the K-1’s swollen LAP) could house 3 Merlin 2 engines, producing a single rocket which matched the Falcon 9 Heavy in performance. Clustered together, it produced Falcon X Heavy, which would launch 125 metric tons, nearly the same as the older Saturn V. However, the place of pride on the far right of the chart was held by Falcon XX: a 10 meter rocket powered by 6 Merlin 2s, larger than the Saturn V whose specifications it met or exceeded down the line, from sea level thrust to its startling 140 metric tons to LEO. If these were the dreams Elon Musk wanted his propulsion dream to support--and felt free for them to reveal publicly--no one could accuse him of thinking small. Even if it took a decade or more for the massive rockets to become reality, independent of whether NASA ended up with an HLV or not, and whether such a rocket were reusable or Shuttle-derived, these were no small dreams.
The detailed discussions of their studies of various engine testing methods, the benefits and detriments of various engine propulsion cycles, and concepts for a small hydrogen/oxygen upper-stage engine called “Raptor” washed over some in the audience, those either blown away by the vision of the lineup of massive rockets or who could barely believe the arrogance such a presentation showed. For the latter, the conclusion of the presentation held its own evidence of insanity, as it closed with a fake quote supposedly from the Dead Sea Scrolls in support of kerosene/oxygen propulsion and opposition to solid-rockets: “Black water shall elevate thy children to the heavens. Purify it. But thou shalt not combine it in a ratio greater than one kikkar to twenty shekkels, nor shalt thou burn rocks. Thus saith the lord.” It was a wild end to a wild presentation, and helped ensure which of the two presentations would be the topic of innumerable cocktail party discussions and dominate the internet in the coming days and weeks. However, in a sense both rivals had achieved their objectives. RpK had avoided stirring the pot as Congress considered a budget which could make RpK’s reusable experience the future of spaceflight, instead focusing on playing up the experience they were getting precisely by casting it as nothing new, simply presenting their successes with reusable rocket engines and their current and imminent achievements. SpaceX, trailing in launches and cost to access the space station, had helped focus attention on their future instead of the present.