Defense Technology International - October 2007 - (Page 14) TECH WATCH BILL SWEETMAN LOW-COST CARRIER For a rocket company that hasn’t yet done what a rocket company is supposed to do—put a payload successfully into orbit—Space Exploration Technologies (SpaceX) is brimming with confidence. In the cluster of old buildings in El Segundo, Calif., that have housed the company until now (and will continue to accommodate time-critical activities until the move to an old Northrop Grumman plant in neighboring Hawthorne), there is no doubt that the components coming together to make the third flyable Falcon 1 rocket will work on their next test, set for January. Elon Musk, PayPal billionaire and SpaceX founder, CEO and chief technical officer, says the company should have a positive cash flow this year and may even be profitable, depending on whether auditors let it count the progress payments from 11 launches under contract. SpaceX’s fortunes are important to the military goal of operationally responsive space, which envisions a culture of less costly satellites and launchers that would be designed, built and flown on a shorter cycle than with current spacecraft. The company’s goal is to launch small payloads with the Falcon 1, which costs $7 million for the basic rocket and $8.5 million for the more powerful Falcon 1e. SpaceX will lift big payloads for $35-55 million a shot with the heavy Falcon 9—one-quarter or less the price of any other rocket now in use. How is this done? Brian Bjelde, product manager for Falcon 1, reveals some answers on a tour of the El Segundo facility. Dominating one of the largest shops are sections of the 12-ft.-dia. fuel tank for the Falcon 9. It is made from flat aluminum sheets. In one tool, sheets are bent into half-barrel sections that are friction-stir-welded together. In another fixture, each barrel section is friction-stir-welded to the next, and the domes, from aerospace fabrication specialist Spincraft of New Berlin, Wis., are added—a complete tank in two steps without a fastener in sight. Pressurizing the tanks in flight helps them to resist flight loads without expensive internal ribs or chemically milled skins. The Spincraft domes are the only part of the tank made by a supplier. “One of the silver-bullet reasons for what we do is to control the key technology,” says Bjelde, explaining that space-rated hardware is generablatively cooled nozzle that first looked like the least expensive solution has repeatedly failed in ground tests, unable to take the full power that the rocket’s fuel pump and combustion chamber produce. The Merlin 1C, under development for the nine-engine Falcon 9 first stage, has a regeneratively cooled nozzle made from titanium tubing, and will be used exclusively for the Falcon 1 from January on. But that means another change, Bjelde says. The new engine produces more power than the Falcon 1 can take. From 2009, SpaceX will modify the structure and add a larger payload fairing to create the Falcon 1e. Other improvements developed for the Falcon 9 are flowing back into the Falcon 1; for instance, a thrust frame (engine mount) made from stock heat-treated aluminum, like the nine-pack for the bigger rocket, has replaced a hard-to-manufacture welded titanium structure. SpaceX’s confidence that the next Falcon will fly reflects its experience in the previous attempt: The rocket worked nominally in all respects, apart from excessive spin that induced fuel sloshing in the tanks, which starved the second-stage engine of fuel. The company plans five launches in 2008, including the first Falcon 9. It is also continuing work on the Dragon recoverable capsule, aimed at delivering supplies and astronauts to NASA’s space station. For military users, SpaceX—if it’s successful—will mark the end to assumptions that have limited development for decades. If the rocket is cheaper and faster to fly, it makes sense to build less expensive, more easily replaceable spacecraft. And if the spacecraft cost less to build and to launch, they don’t have to be designed to survive 10 years of radiation, and pre-launch checks can be routine rather than paranoid. Launching a rocket never will be as simple as flying an airplane, but the SpaceX approach—so far, running well ahead of the Defense Advanced Research Projects Agency QuickReach program—promises a real revolution in how the military uses space. I www.aviationweek.com/dti CORY STEWART/SPACEX Improved Merlin 1C motor fires. The secondary exhaust stream at left is from the turbopump. ally expensive to buy. And, he points out, if someone else has a problem related to a supplier’s component, SpaceX could find itself grounded and waiting for the problem to be resolved. “We build 70% of the vehicle in-house, including the tanks and motors.” In a corner of the shop, a machine tool that looks as if it might have made parts for the Navajo missile in the 1950s is carving cooling channels in a copper casting that will form the combustion chamber for the Merlin engine. The Merlins under construction represent another important feature of SpaceX—the rapid insertion of improvements. “We’ll fail, fail often and fail quickly,” says Bjelde. The idea is to “get to the final solution as fast as possible, then get the costs down.” In the case of the Merlin, the 14 DEFENSE TECHNOLOGY INTERNATIONAL OCTOBER 2007 http://www.aviationweek.com/dti
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