In celebration of the 30th Anniversary of NASA Tech Briefs, our features in 2006 highlight a different technology category each month, tracing the past 30 years of the technology, and continuing with a glimpse into the future of where the technology is headed. Along the way, we include insights from industry leaders on the past, present, and future of each technology. This month, we take a look at the past 30 years of Aerospace Technology.
Aerospace technology — which literally comprises both air and space technology — has seen some amazing advances in the past 30 years in the commercial aviation, space, and military areas, including the first (1976) and last (2003) commercial flights of the Concorde supersonic aircraft, and the first launch of the Space Shuttle (Columbia) in 1981. In 30 years, we’ve seen robotic rovers driving on the surface of Mars, and we’ve flown on the first jetliner completely designed and preassembled on computers — the Boeing 777. We watched Sally Ride become the first American woman in space, and today we are witnessing the advent of a new era in space travel — commercial space tourism.
The segment of aerospace to which Americans can most closely relate is commercial aviation. Most of us have flown on a jet airliner in the past 30 years, but many of us may not realize the extent to which the jet airplane has changed and improved over the past 30 years. Boeing and Airbus, the world’s two largest aircraft manufacturers, not only have improved upon their aircraft designs in the past 30 years, but are introducing two of the most technologically advanced airplanes ever made.
In the late 1960s, Boeing introduced what would become the most recognizable airplane, the 747. Twenty years later, Boeing re-designed the wide body jet with the 747-400, the world’s only 400-seat airplane. Today’s 747-400 features technologies that enable the plane to be faster, quieter, lighter, and easier for pilots to fly. The 747 features a wing that is 6 feet longer with a 6-foot-high graphite-expoxy winglet that reduces fuel consumption and extends the plane’s range to 7,260 nautical miles. Other improvements include graphite composite cabin floor panels, structural carbon brakes on the 16 main landing gear wheels, and lightweight aluminum alloy wing skins, stringers, and lower-spar chords. In the cockpit, a new flight deck with digital avionics replaces analog, reducing the number of lights, gauges, and switches from 971 to 365. This also enabled the number of crew members to decrease from three to two. Crews also can obtain an update of the plane’s mechanical condition while in flight — information that previously was available to maintenance personnel only when the plane was parked.
But with all the technical improvements made to the 747, there was still room for more. In the mid-1980s, Boeing invested in 3D CAD/CAM programs, and by 1989, the company was confident it could reduce the cost of rework caused by part interference and difficulty in properly fitting parts together in the final assembly. Boeing decided to digitally design and pre-assemble its new aircraft entirely on the computer. A year later, the 777 project was launched.
It would mark the first time that designers, manufacturers, tooling personnel, engineers, suppliers, finance personnel, and customers all would work jointly to create the plane’s parts and systems. The data shared and transferred on the network during the design phase totaled more than 1.8 trillion bytes. The 3 million parts were provided by more than 900 suppliers in 17 countries, and were designed and assembled by 238 design/build teams. The first 777 was within just 0.023" of perfect alignment; most airplane parts line up to within a half-inch of each other.
Technologically, the 777 boasts a fly-by-wire flight-control system — based on NASA technology developed in the 1970s — that uses wires to carry electrical signals from the pilot’s control wheel, column, and pedals to a primary flight computer, rather than relying on cables to move the ailerons, rudder, and elevator.
In June of this year, Boeing began assembly of its latest airplane, the 787 Dreamliner, a mid-sized, twin-engine jet that will use 20 percent less fuel than today’s mid-sized planes. As much as 50% of the primary structure — including the fuselage and wings — will be made of composite materials. Health-monitoring systems will allow the plane to monitor itself and report maintenance requirements to ground-based computer systems. It is scheduled to enter service in 2008.
Last month, Airbus marked the first passenger flight of its A380, which seats about 555 passengers, and features high pressure hydraulics and variable-frequency electrical generation — both of which reduce weight and increase system performance. The A380 also incorporates carbon fiber reinforced plastic and composites in the center wing box and rear fuselage, an Autopilot Traffic Collision Avoidance System that provides additional protection to conventional air traffic systems, and Brake-to- Vacate technology, which allows pilots to select an appropriate runway exit when landing and regulate the aircraft’s speed and deceleration accordingly.
But perhaps the most advanced airplane of the past 30 years was a British and French collaboration — the Concorde. The supersonic Concorde, which entered commercial service in 1976 and was retired in 2003, flew more than 2.5 million passengers, and set a speed record by flying from New York to London in 2 hours, 54 minutes, and 30 seconds.
The Concorde stretched between 6 and 10 inches during flight due to heating of the airframe, and featured a distinctive “drop-nose” front to improve pilots’ visibility on takeoff and landing. The most powerful pure jet engines flying commercially, the four Rolls- Royce/Snecma Olympus 593s provided more than 38,000 pounds of thrust each with “reheat,” which added fuel to the final stage of the engine to produce the extra power needed for takeoff and the transition to supersonic flight.
Flying at up to 60,000 feet, the Concorde provided passengers with a view of the curvature of the Earth. On flights taking off after sunset, passengers could see a sunrise in the west — the sun appeared to move backward in the sky, since the plane was essentially “outrunning” the sun. When flying west, passengers landed several hours before they took off.
NASA — as well as aerospace companies such as Boeing, Northrop Grumman, and Lockheed Martin — has its roots in both air and space technology, focusing on everything from air traffic control and human spaceflight, to hypersonic transportation and military defense systems. Aerospace innovations developed by NASA in the past three decades include wing de-icing systems, in-flight weather forecasting tools, full plane parachutes for general aviation, a personal cabin pressure monitor and alarm, wind shear detection sensors, and advanced air traffic control and airport simulation systems. (Editor’s Note: An air traffic control software system called FACET recently was named 2006 NASA Software of the Year. See page 14 of this issue for more details.)
Obviously, it would be impossible in this article to highlight all of NASA’s aerospace innovations of the past 30 years, but the most significant is also the most technologically complex machine ever built — the Space Shuttle, or STS (Space Transportation System). The world’s first reusable spacecraft, the shuttle is also the first spacecraft to launch like a rocket and land like an airplane. The launch of the first shuttle, Columbia, in 1981, marked a new era in space travel. The shuttle would soon become the main cargo transport vehicle for construction of the International Space Station (ISS).
The three remaining shuttle orbiters — Atlantis, Discovery, and Endeavour — are significantly different today than when they were first launched. Following the Challenger and Columbia accidents, the orbiters have undergone thousands of modifications to improve safety, including engine and system improvements that have tripled the safety of flying the shuttle.
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 air breathing 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.
Commercial Space Travel
In 2004, a milestone was reached in aerospace history with the October launch of SpaceShipOne, the first nongovernment manned spacecraft to exceed an altitude of 100 km two times in two weeks, winning the $10 million Ansari X-Prize for Paul Allen and Burt Rutan. A year later, the rocket motor technology was licensed by Sir Richard Branson, who formed a company with Rutan called The Spaceship Company. The new company is building a fleet of commercial sub-orbital spacecraft and launch aircraft, as well as support equipment for commercial space line customers such as Branson’s Virgin Galactic.
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.
Again, space in this article prohibits a thorough look at the many innovations in military aerospace technologies, but one of the most ambitious projects of the past 30 years is the international Joint Strike Fighter (JSF) project. The F-35 JSF is a supersonic, multi-role stealth fighter plane that began a 12-year development cycle in 2001. The project, which includes eight other countries, is led by Lockheed Martin Aeronautics, and includes Northrop Grumman, BAE Systems, Pratt & Whitney, and General Electric Rolls-Royce.
The JSF will be the most powerful single-engine fighter 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 high threat 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.