| 30 Years of Aerospace Technology |
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| Sep 30 2006 | |
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Page 4 of 4
advertisement: Technologically, the shuttle boasts the most complex engines ever made. The shuttle’s three main engines create a combined maximum thrust of more than 1.2 million pounds, and the system’s two solid rocket boosters provide thrust equal to 5.3 million pounds — enough to propel the 4.5-million-pound shuttle system out of Earth’s gravitational pull. The main engines burn liquid hydrogen, and as they push the shuttle toward orbit, they consume fuel at a rate that would drain an average swimming pool in less than 25 seconds, generating more than 37 million horsepower. NASA also has been at the forefront of aircraft innovation, with the introduction of the Blended Wing Body aircraft and the Hyper-X hypersonic scramjet aircraft. The Blended Wing Body (BWB) aircraft, being manufactured by Boeing’s Phantom Works, is a flexible, long-range military aircraft that could be used as a tanker, transport, or weapons carrier, but NASA and industry believe a large commercial BWB aircraft also could be developed. It is a hybrid shape that resembles a flying wing, and does not have a conventional fuselage. Cargo or passengers can board from the front or rear. The plane would consume 20% less fuel than a comparable conventional aircraft, and would generate less noise and emissions. It has a wingspan only slightly larger than a 747, and could operate from existing airport terminals. NASA’s Hyper-X program demonstrated alternatives to rocket power for space access, and featured the X-43A airbreathing hypersonic aircraft. In 2004, the X-43A set a world speed record of Mach 9.6 (about 7,000 mph). The aircraft employed a scramjet (Supersonic Combustion Ramjet) air-breathing engine that “rams” oxygen from the atmosphere through the vehicle into the fuel, rather than using a fuel tank. The airflow through the entire engine remains supersonic. In comparison to turbojets, ramjets have no moving parts, and the aircraft is significantly smaller, lighter, and faster, enabling it to carry more payload into space.
SpaceShipOne features a hybrid rubber- nitrous rocket motor propulsion system that combines liquid and solid propulsion. To reach space, a carrier aircraft lifts SpaceShipOne from the runway to an altitude of about 50,000 feet, where it releases the craft into a glide. The spaceship’s pilot then fires the rocket motor, reaching Mach 3 in a vertical climb. The craft then coasts to a height of 62 miles before falling back to Earth. The craft’s wing and tail are reconfigured into a high-drag configuration, slowing the craft in the upper atmosphere and automatically aligning it along its flight path. Once back in the atmosphere, it changes back to a glider and lands like an airplane on the same runway from which it left. Virgin Galactic is constructing a spaceport in New Mexico, and plans to begin commercial sub-orbital spaceflights by the end of this decade. Military Aerospace The JSF will be the most powerful single-engine figher ever built, and will be used to replace aging fighters for both the U.S. and the United Kingdom. More than 2,593 aircraft will be produced in three variations: a conventional takeoff and landing version, an aircraft-carrier version, and a short takeoff and vertical landing version. More than 80% of all parts, including the engines and key avionics units, are common to all three versions. A fully integrated weapons system allows JSF pilots to positively identify and strike mobile and moving targets in highthreat environments, day or night, in any type of weather. The first flight of the conventional takeoff and landing version is scheduled for late this year, with delivery of the aircraft scheduled for 2009. |
