Saturday, December 18, 2010

Dragon flight highlights from SpaceX

Credit: SpaceX

A few days ago SpaceX sent out an email update on the COTS-1 flight of the Falcon 9 and the recovery of the Dragon Spacecraft. Here are the details.

"On December 8, SpaceX became the first commercial company in history to re-enter a spacecraft from Earth orbit. SpaceX launched its Dragon spacecraft into orbit atop a Falcon 9 rocket at 10:43 AM EST from Launch Complex 40 at the Cape Canaveral Air Force Station in Florida. The Dragon spacecraft orbited the Earth at speeds greater than 7,600 meters per second (17,000 miles per hour), reentered the Earth’s atmosphere, and landed just after 2:00 PM EST less than one mile from the center of the targeted landing zone in the Pacific Ocean following a nominal flight profile that included a roughly 9.5-minute ascent, two Earth-orbits, reentry and splashdown. Falcon 9 delivered Dragon to orbit with an inclination of 34.53 degrees."

Credit: SpaceX
"Dragon’s first-ever on-orbit performance was 100% successful in meeting test objectives including maintaining attitude, thermal control, and communication activities. While in orbit, eight free-flying payloads were successfully deployed, including a U.S. Army nanosatellite—the first Army-built satellite to fly in 50 years."

"Liftoff marked the second flight of SpaceX’s Falcon 9 rocket, which performed nominally during ascent. Nine Merlin engines, which generate one million pounds of thrust in vacuum, powered the first phase of flight. The rocket reached maximum dynamic pressure (the point at which aerodynamic stress on a spacecraft in atmospheric flight is maximized, also known as Max Q) approximately 1.5 minutes after launch.  The first stage separation occurred a little over three minutes into flight.  The single Merlin Vacuum engine of Falcon 9’s second stage then ignited to continue carrying the vehicle towards its targeted orbit. After stage separation, the nose cap at the front of the Dragon spacecraft safely jettisoned. The second stage fired for another four and a half minutes, until it achieved orbital velocity, and then the Dragon spacecraft separated from the second stage to begin its independent flight. After separation of the Dragon spacecraft, the second stage Merlin engine restarted, carrying the second stage to an altitude of 11,000 km (6,800 mi). While restart of the second stage engine was not a requirement for this mission (or any future missions to the ISS), it is important for future Geosynchronous Transfer Orbit (GTO) missions where customer payloads need to be positioned at a high altitude." 
"Shortly after separating from the second stage, the expected loss of signal occurred as the Dragon spacecraft passed over the horizon as viewed from the launch site We reacquired Dragon's video signal as expected as it passed over Hawaii, delivering the first ever video sent from Dragon on orbit. Draco thrusters, each capable of producing about 90 pounds of thrust, began the six minute deorbit burn at T+2:32.  For this particular mission, we could have lost two entire quads and still returned to Earth with only 8 or 10 engines working, but all thrusters performed nominally during the COTS Demo 1 flight."

"Dragon’s PICA-X heat shield protected the spacecraft during reentry from temperatures reaching more than 3,000 degrees F. SpaceX worked closely with NASA to develop PICA-X, a SpaceX variant of NASA’s Phenolic Impregnated Carbon Ablator (PICA) heat shield. SpaceX chose PICA for its proven ability. In January 2006, NASA's Stardust sample capsule returned using a PICA heat shield and set the record for the fastest reentry speed of a spacecraft into Earth's atmosphere — experiencing speeds of 28,900 miles per hour. NASA made its expertise and specialized facilities available to SpaceX as the company designed, developed and qualified the 3.6 meter PICA-X shield it in less than 4 years at a fraction of the cost NASA had budgeted for the effort. The result is the most advanced heat shield ever to fly. It can potentially be used hundreds of times for Earth orbit reentry with only minor degradation each time – as proven on this flight -- and can even withstand the much higher heat of a moon or Mars velocity reentry. At about 10,000 feet, Dragon’s three main parachutes, each 116 feet in diameter, deployed to slow the spacecraft's decent to approximately 16-18 ft/sec, ensuring a comfortable return ride that will be required for manned flights. Oversized parachutes are critical in ensuring a safe landing for crew members. Even if Dragon were to lose one of its main parachutes, the two remaining chutes would still ensure a safe landing."

Credit: SpaceX

"This was the first flight under NASA’s COTS program to develop commercial resupply services to the International Space Station. After the Space Shuttle retires, SpaceX will fly at least 12 missions to carry cargo to and from the International Space Station as part of the Commercial Resupply Services contract for NASA. The Falcon 9 rocket and Dragon spacecraft were designed to one day carry astronauts; both the COTS and CRS missions will yield valuable flight experience toward this goal."

The following HD video summary of the flight is posted on the SpaceX website.

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