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From Hampton, Virginia, Langley
Research Center contributes to a broad range of aerospace technologies,
from making space access a routine venture, to developing down-to-Earth
ideas about aircraft safety and on-time operations. Langley is
also adding to our knowledge of atmospheric science, providing
scientific data for informed national decision-making about our
environment.
NASA's Space Launch Initiative
(SLI) has been established to find a more affordable and reliable
highway into space. Whether it is doing business in Earth orbit
or exploring distant worlds, the toughest part of the journey
is the first few hundred miles up through the atmosphere to space.
Consequently, it is critical that the airframe of any future
vehicle be optimized for maximum performance while incorporating
minimum weight--the classic aerospace dilemma.
Langley, world renowned for its
research into the performance of winged vehicles and space vehicles,
will lead the development and demonstration of airframe technologies
for SLI: lightweight temperature-resistant structures and materials,
aerodynamics, systems engineering and analysis to help define
needed technologies, and advanced cockpit technologies to improve
safety and reliability. Langley is working with Marshall Space
Flight Center in the development of cryogenic tanks to hold super-cold
liquid hydrogen fuel, with Ames Research Center on thermal protection
systems, and with Johnson Space Center on cockpit technologies.
The first experiment to be performed
on the International Space Station (ISS) was contributed by Langley.
The Materials International Space Station Experiment (MISSE)
is designed to evaluate the performance, stability, and long-term
survivability of more than 700 materials and components planned
for use by NASA, the Department of Defense, and commercial spacecraft
manufacturers. "Space is a hostile environment, destructive
to many materials," said William Kinard, program scientist
for MISSE. "New, affordable materials are the enablers for
advanced spacecraft. In-situ space testing, as provided by MISSE
on the ISS, is an essential part of the development process for
these new space materials."
For the next two decades, a series
of robotic missions made up of orbiters, landers, and rovers
will explore Mars looking for evidence of past or present life.
Langley will contribute aerodynamics, aerothermodynamics, atmospheric
flight simulation, guidance and control research--everything
required to make a successful flight through the atmosphere of
Mars. Langley performed a 70-day simulation of aerobraking around
Mars for the Mars Odyssey Orbiter, launched in April 2001. One
of the Center's jobs is to figure out how deep the orbiter should
go on each pass. If the passes are too deep, the solar panels
could burn up; if the passes are too shallow, the mission could
end up in a useless orbit. For the 2003 Mars Exploration Rovers,
Langley is developing the end-to-end flight simulation and aerodynamic
database for flight from atmospheric interface all the way to
touchdown on the surface of Mars.
Another group of researchers
are exploring revolutionary aircraft technologies in a program
called 21st Century Aerospace Vehicle. These researchers believe
that aircraft of the future will benefit by taking on some of
the form and function of birds. The aircraft will have "smart"
materials with embedded sensors and actuators. Sensors, like
the "nerves" of a bird, will measure the pressure over
the entire surface of the wing and direct the response of the
actuators--the "muscles." These actuators will change
the shape of the wing for optimal flying conditions. Intelligent
systems made of these smart sensors, micro processors, and adaptive
control systems will enable vehicles to monitor their own performance,
their environment, and their operators in order to avoid crashes,
mishaps, and incidents. Distributed as a network throughout the
structure, they will provide the means for imbedding a "nervous
system" in the structure and stimulating it to change shape.
They will also serve as the means for sensing any damage or impending
failure long before it becomes a problem.
In the near term, aircraft will
be safer thanks to NASA contributions to the national Aviation
Safety Program. For example, close calls between aircraft and
ground vehicles or other planes have grown steadily in recent
years, with 320 incidents reported in 1999 alone. Reducing runway
incursions has become the Federal Aviation Administration's number
one safety priority. In one research project, an advanced cockpit
display system, developed by engineers at NASA Langley, could
help prevent runway incursion incidents and near accidents on
airport runways, taxiways, and ramps. The system combines a head-down
display of an electronic moving map of airport runways and taxiways
with a head-up screen that gives the pilot real-time guidance.
The system shows and sounds an alert if another plane or vehicle
is about to encroach onto the runway. The system would improve
aviation safety and efficiency several ways, including allowing
more aircraft to land on time in bad weather.
Airline passengers frustrated
with delays at U.S. airports may be able to reach their destinations
faster in the future because of advances in predicting aircraft
wake turbulence on final approach. With this new technology,
called Aircraft Vortex Spacing System (AVOSS), Langley developments
will help airliners achieve optimal spacing and efficiency. The
system determines how winds and other atmospheric conditions
affect the wake vortex patterns of different types of aircraft.
AVOSS uses a laser radar or lidar technology to confirm the accuracy
of those forecasts. The information is processed by computers,
which can then provide safe spacing criteria automatically. All
aircraft produce wake vortices that act like two small, horizontal
tornadoes trailing behind the wing tips that can be felt as mild-to-severe
turbulence by following aircraft. Lack of an accurate prediction
system forces air traffic controllers to use rigidly fixed distances
to separate different classes of aircraft, especially during
bad weather, causing air traffic delays that disrupt flight schedules
and increase costs. AVOSS is expected to provide the information
needed for safe, efficient separation, from approach to landing.
AVOSS is a part of the NASA Aviation Systems Capacity Program,
headquartered at Ames Research Center, Moffett Field, California.
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Clean
room personnel place material samples into trays to be installed
in the Passive Experiment Containers (PEC) for the Materials
International Space Station Experiment (MISSE); a project that
will characterize the performance of over 700 materials. |
This is
a pivotal time for NASA's general aviation efforts. The Advanced
General Aviation Transport Experiments (AGATE) program, based
at Langley, has concluded its seven-year research agenda, boasting
of many successes in its efforts to revitalize general aviation.
The government-industry-university consortium is a model for
how to work together to make the most of tax dollars on behalf
of the nation. Successes include the development of airborne
technologies like near real-time weather and synthetic vision
for safety and efficiency, and highway-in-the-sky displays to
aid in navigation. The FAA worked as an AGATE member to streamline
certification processes for new aircraft, helping make aircraft
of the future more affordable. Embry-Riddle Aeronautical University,
another AGATE member, worked to create simplified piloting curricula
to encourage more people to become pilots.
A new NASA-led program, housed
at Langley, called the Small Aircraft Transportation System (SATS),
will demonstrate how single-engine aircraft can offer an attractive
alternative to existing transportation systems for trips from
about 150 to 1,000 miles. SATS is seen as freeing people and
products from existing transportation system delays, by creating
access to more communities in less time. The SATS concept of
operations uses small aircraft for business and personal transportation,
for on-demand, point-to-point travel between smaller regional,
reliever, general aviation, and other landing facilities, including
heliports. The five-year SATS program will culminate in a joint
NASA/FAA/industry demonstration of selected operational capabilities
at designated "SATSLab" airports. The results will
establish the basis for future decisions by local, state, and
federal policy makers regarding SATS and air transportation.
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Langley
researchers and engineers are currently working on a concept
aircraft which will incorporate "smart" materials that
will allow the wings of a craft to change shape for optimal flying
conditions. |
Langley
is making use of measurements from aircraft and satellites to
better understand natural and man-made changes to our atmosphere.
Long-term, global studies include the tracing of seasonal airflow
from Asia across the Pacific in the Transport and Chemical Evolution
over the Pacific (TRACE-P) experiment. Emissions are expected
to increase in this part of the world as East Asia continues
to industrialize. This is an opportunity for researchers to study
how chemical reactions and movement affect the air as it moves
at a sun-filled tropical latitude. TRACE-P is the latest in a
long series of NASA-led Global Tropospheric Experiments (GTE)
aimed at a better understanding of worldwide chemistry of the
tropospherethe part of the atmosphere closest to the Earth's
surface.
In another study, Langley researchers
are helping to document the important role of polar stratospheric
clouds in the destruction of protective ozone over the Arctic.
Ozone in the upper atmosphere protects plants and animals on
the surface of the Earth from harmful ultraviolet radiation.
The Sage III Ozone Loss and Validation Experiment (SOLVE) revealed
large-scale characteristics of polar stratospheric clouds, including
their extent and chemical properties. In sunlight, these high-altitude
clouds help release ozone-destroying chlorine from otherwise
non-harmful gases. Once details of this process are incorporated
into chemistry and climate models, scientists will have a better
idea of the extent of future ozone destruction in the Arctic
and the possibility of an eventual "ozone hole" over
the Arctic.
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