Aerospace Research and Development

The dance of a flame in the microgravity of space, reducing the roar of aircraft engines, and spearheading novel concepts that may make interstellar travel a reality one day are among the research fields being pursued at the NASA Glenn Research Center at Lewis Field in Cleveland, Ohio.

In March 1999, the Lewis Research Center was officially renamed the NASA John H. Glenn Research Center at Lewis Field, in recognition of America's first astronaut to orbit the Earth and his four terms of senatorial work on behalf of Ohio and the nation in the U.S. Congress. George William Lewis was the research director for the National Advisory Committee for Aeronautics, the predecessor to NASA.

"The blending of names reflects the pioneering research in aerospace technology that employees have performed throughout the center's history and will continue to perform in the future," observes Glenn's director, Donald J. Campbell.

Power, propulsion, and communications technologies are high-priority research domains being advanced at the center, so that U.S. leadership in these areas is ensured. Since the early formative years of the space agency, work in turbomachinery at Glenn has been underway.

Glenn's turbomachinery research goals are focused on technology that enables aircraft engine manufacturers to design advanced turbine engines. This research has included the development of new high-temperature materials, coatings, and lubrication systems; development and verification of design, modeling, and computational codes for workstation computers and visualization tools; basic research in flow physics and heat transfer; and combustion research. All of this work has been supported by materials testing, component testing, and prototype testing in facilities that simulate operating conditions of turbomachinery.

The effect of microgravity on combustion processes has been a major area of research guided by Glenn Research Center scientists. Knowledge about the physics of combustion may lead to more efficient combustion of materials, and therefore a savings of fuel.

Along with the U.S. aeropropulsion industry, Glenn is enabling technology for the next generation of subsonic gas turbine engines, which are environmentally friendly, fuel efficient, durable, and globally-marketable. For example, Glenn engineers are taking the technological steps to reduce nitrous oxide emissions--prime contributors to the development of smog--from gas turbine engines. Experimental and analytical work is also being performed in three areas of engine noise reduction: active noise control for fans, advanced low-noise fan designs, and jet noise.

In the field of general aviation, Glenn's advanced subsonic technology work is striving to improve the safety, performance, and ease-of-use of general aviation aircraft. Efforts at the center include advanced propulsion sensors and controls to allow simplified intermittent combustion engine and aircraft control rather than the approach taken over the last 40 years. Gains are being made in civil tilt rotor aircraft, too. While this subsonic aircraft can take off and land using less runway and appears viable in relieving air traffic congestion, Glenn experts are tackling noise, terminal-area operations, safety, weight reduction, and reliability issues.

High above Earth, the Advanced Communications Technology Satellite (ACTS) is trailblazing advanced communication technologies and services. Released into orbit by a Space Shuttle crew in 1993, the ACTS symbolizes Glenn's long history of developing state-of-the-art communications technology. The center has formed partnerships with industry, universities, and other government agencies to utilize the Ka-band spectrum through ACTS, to validate use of all-digital, high-bandwidth, on-demand, integrated multimedia services.

An array of microphones inside the Aero-Acoustic Propulsion Laboratory at the Glenn Research Center measures simulated aircraft engine noise during takeoffs. Acoustic data collected is used to certify aircraft engines, as specified by the Federal Aviation Administration (FAA).
		Work in ion propulsion technology at Glenn Research Center made possible the technology validation flight of the Deep Space 1 spacecraft. The fuel-efficient ion engine was tested in space in 1998-1999, and is to be utilized on 21st century deep space missions.

A major milestone in propulsion technology is the in-space shakeout of the ion engine aboard NASA's Deep Space 1, launched in late 1998. Glenn engineers have long been working on ion engines, technology that produces an almost imperceptible thrust that is equivalent to the pressure exerted by a sheet of paper held in the palm of a hand. While the xenon-fueled ion engine is slow to pick up speed, over the long haul it can deliver 10 times as much thrust per pound of fuel as liquid or solid fuel rockets. Ion drives are likely to be used on future deep space and Earth-orbiting missions that would otherwise be impractical or unaffordable with conventional propulsion systems.

Glenn's Fluids and Combustion Facility for the International Space Station is a modular, multi-user facility accommodating microgravity science experiments. In the absence of gravity, combustion takes place in a very different manner than on Earth. Gravity plays a role in why flames behave the way they do, smoke rises, and how large air circulation currents are established. These effects can mask the physical processes of combustion. Understanding what exactly is happening in the physics of combustion is sure to have major payoffs. Combustion powers our automobiles, generates our electricity, heats our homes, even cooks our food on the back-yard grill, and adds many pollutants to our skies. Microgravity research in this area aboard the Space Station could offer ways of increasing combustion efficiency, thus reducing pollution, global warming, and production and transportation costs.

Taking a long view into the 21^st century, current work at Glenn is studying futuristic propulsion concepts. Ultimate breakthroughs in space transportation are under review at the center involving propelling a vehicle without propellant mass, attaining the maximum transit speeds physically possible, and creating new energy production methods to power such devices. Nobody can predict where insights into these areas may take future robotic and human explorers.