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Friday, December 24, 2010

Dragon Spacecraft Returns to Earth: now just 20 more years to the DC-3

The SpaceX Dragon spacecraft successfully returned to earth, bringing us one giant leap closer to a commercial replacement for NASA's Space Shuttle program. This, along with the impending completion of Spaceport America and similar advances from a number of other companies, really heralds the beginning of an entirely new phase of space exploration.

For comparison, the first scheduled commercial airline flight in the United States was in 1914. The Ford/Stout Trimotor became the first successful commercial airliner in 1925. Boeing built the first 237 in 1933, followed by the Douglas DC-3 in 1935. 16,079 DC-3s were built, and a surprisingly large number of them remain in service to this day. It was, and is, one hell of an airplane.

If this is any reasonable indication, commercial civilian space travel could be commonplace and affordable by 2030. We just need somebody to invent a spacefaring equivalent of the DC-3.

DC-3: A collection of parts flying in loose formation

CAPE CANAVERAL -- 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.

This marks the first time a commercial company has successfully recovered a spacecraft reentering from Earth orbit. It is a feat previously performed by only six nations or government agencies: the United States, Russia, China, Japan, India, and the European Space Agency.
As the very first flight under the Commercial Orbital Transportation Services (COTS) program, COTS Demo 1 followed 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—a near bull’s-eye insertion.

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.

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.

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.

With recovery of the Dragon spacecraft, SpaceX became the first company in history to successfully re-enter a spacecraft from Earth orbit. SpaceX has only come this far by building upon the incredible achievements of NASA, having NASA as an anchor tenant for launch, and receiving expert advice and mentorship throughout the development process.

SpaceX would like to extend a special thanks to the NASA COTS office for their continued support and guidance throughout this process. The COTS program has demonstrated the power of a true private/public partnership and we look forward to the exciting endeavors our team will accomplish in the future.


The entire story, and lots more pictures, is here.

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