A Dragon capsule developed, launched and operated by Space Exploration Technologies (SpaceX) had a successful debut flight Dec. 8, splashing down in the Pacific Ocean after executing a preprogrammed set of maneuvers in orbit designed to simulate approach and docking with the International Space Station.
The mission was the first under NASA’s $500 million Commercial Orbital Transportation Services (COTS) program, which includes agreements with both SpaceX and Orbital Sciences Corp.
SpaceX’s Falcon 9 rocket delivered Dragon into a low Earth orbit for a two-orbit test flight that ended with the capsule’s parachute return into the Pacific Ocean about 500 mi. west of Mexico shortly after 2 p.m. EST.
The capsule’s orbital checkout ended with a six-minute firing of four of its Draco thrusters, slowing the craft so it would re-enter the atmosphere for tests of its heat shield.
The Falcon’s nine liquid oxygen and RP-1 kerosene-fueled Merlin engines roared to life at 10:43 a.m. EST, catapulting the 157.8-ft.-tall rocket off the pad at Cape Canaveral Air Force Station’s Launch Complex 40 and into clear skies over the Atlantic Ocean. Nine minutes later, the Falcon 9’s second stage, also a Merlin engine, shut down and separated from the Dragon capsule. The targeted position was a 300-km. (186-mi.) circular orbit inclined 34.5 degrees.
The company’s first launch attempt at 9:06 a.m. was halted three minutes before liftoff due to a false abort on the ordnance interrupter ground feedback position. The problem was quickly fixed and SpaceX proceeded to the second of three available launch windows — dictated by the availability of NASA Tracking and Data Relay Satellites, which are supporting the mission.
SpaceX’s Falcon 9/Dragon is one of two systems NASA plans to use to deliver cargo to the International Space Station after the shuttles are retired next year. SpaceX shares a $3.5 billion launch services contract with Orbital Sciences Corp.
Launch was held up a day when cracks were discovered in the nozzle extension of the Falcon 9’s second-stage engine. SpaceX traced the root cause of the cracks, located in the aft end of the nozzle, to a GN2 vent line that “caused flutter of the thinnest portion of the nozzle extension, creating the cracks,” the company said in a statement.
Engineers cut off the bottom 4 feet of the nozzle extension and corrected the root cause by diffusing the vent. “The extension increases the efficiency of the Merlin engine in vacuum and is installed by default on all upper-stage Merlin engines, but that efficiency increase is not required for this mission,” company spokeswoman Kirstin Brost said in a statement.
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