Research and Development at NASA

Space Operations

 

The seven crewmembers of STS-114
From left, STS-114 astronauts Stephen Robinson, James Kelly, Andrew Thomas, Wendy Lawrence, Charles Camarda, Eileen Collins, and Soichi Noguchi.

NASA’s Space Operations Mission Directorate provides many critical enabling capabilities that make possible much of NASA’s science, research, and exploration achievements. It does this through the three themes of the Space Shuttle Program, the International Space Station (ISS), and Flight Support:

  • The Space Shuttle Program builds on the Shuttle’s primacy as the world’s most versatile launch system. T he Space Shuttle, first launched in 1981, returned to flight in 2005, with Discovery carrying the STS-114 crew to the ISS.

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    Discovery launched into a clear blue sky.
    On July 26, 2005, Space Shuttle Discovery launched into a clear blue sky on the historic Return to Flight mission, STS-114.

    The ISS establishes a permanent human presence in Earth orbit. It also provides a long-duration, habitable laboratory for science and research activities investigating the limits of human performance, expanding human experience in living and working in space, and enabling the commercial development of space.

  • Flight Support consists of Launch Services, Space Communications, and Rocket Propulsion Testing. These “enabling” services are critical for conducting space exploration, as well as aeronautical, materials science, biological, and physical research.

Humans in space are the primary focus of this directorate. Space is still the new frontier, and astronauts are the pioneers of that frontier. The directorate explains, explores, and chronicles the space projects humans are involved in now and will be involved in, come the future.

Space Shuttle: Return to Flight

Space Shuttle Discovery launched from Kennedy Space Center on July 26, 2005, ending a 2.5-year wait for the historic Return to Flight mission. STS-114 included breathtaking in-orbit maneuvers, tests of new equipment and procedures, a first-of-its-kind spacewalking repair task, and telephone calls from two world leaders.

Discovery touched down on August 9 at Edwards Air Force Base, California, following a successful reentry. The orbiter returned to Kennedy on August 21, atop a modified Boeing 747 called the Shuttle Carrier Aircraft. Discovery then entered the Orbiter Processing Facility, where it will be readied for mission STS-121.

Discovery is docked to the International Space Station.
Space Shuttle Discovery is docked to the International Space Station’s Destiny laboratory, with the Earth’s horizon in the background.

During STS-114, NASA accomplished a variety of goals while also learning some important lessons. At liftoff, a large piece of insulating foam broke off the External Tank. Now, NASA engineers are working to determine what caused this and how to prevent it from happening in the future.

Using the new Orbiter Boom Sensor System, Discovery crewmembers took an unprecedented up-close look at the orbiter’s Thermal Protection System. This collection of new data was expanded on flight day 3, when Commander Eileen Collins guided Discovery through the first-ever “rendezvous pitch maneuver” as the orbiter approached the ISS for docking.

The slow-motion backflip allowed Space Station crewmembers John Phillips and Sergei Krikalev to snap high-resolution photographs for mission managers to use to ensure Discovery was in good shape to come home.

During the first of three spacewalks, Mission Specialists Stephen Robinson and Soichi Noguchi tested new repair techniques for the

Astronaut in space attached to a robotic extension Stephen Robinson is attached to a foot restraint on the International Space Station’s Canadarm2. This robotic extension guided Robinson to the underside of Discovery, where he removed two pieces of ceramic fabric, known as “gap fillers,” that were protruding from heat-shielding tiles.

outer skin of the Space Shuttle’s heat shield and installed equipment outside the ISS. They also repaired a control moment gyroscope. Two days later, Robinson and Noguchi again ventured out into the vacuum of space to replace a different, failed control moment gyroscope, putting all four of the Station’s gyroscopes back into service.

When two thermal protection tile gap-fillers were spotted jutting out of Discovery’s underside, astronauts and other experts on the ground devised a plan to ensure that the protrusions would not cause higher-than-normal temperatures on the Space Shuttle during atmospheric reentry.

Ground controllers sent up plans to the Shuttle-Station complex for Robinson to ride the Space Station’s robotic arm beneath the Shuttle and, with surgical precision, pluck out the gap-fillers.

Shadow of spacewalking astronaut on underside of Shuttle
A close-up view of Discovery’s underside is featured in this image photographed by Robinson—whose shadow is visible on the thermal protection tiles—during the mission’s third session of extravehicular activities.

Work on the Shuttle underbelly had never been tried before, but with Mission Specialist Wendy Lawrence and Pilot Jim Kelly operating the robotic arms, Mission Specialist Andy Thomas coordinating, and fellow spacewalker Noguchi keeping watch, Robinson delicately completed the extraction during the third and final spacewalk.

“Okay, that came out very easily,” Robinson said, after carefully removing one of the fillers. “It looks like this big patient is cured.”

The crew received phone calls from U.S. President George W. Bush and Japanese Prime Minister Junichiro Koizumi, who offered congratulations and appreciation for the astronauts’ hard work.

Together, both the Discovery and ISS crews paid tribute to the astronauts of Columbia, as well as others who gave their lives for space exploration.

With the mission drawing to a close, the Multi-Purpose Logistics Module, Raffaello, was removed from the ISS and reinstalled in Discovery’s payload bay. Raffaello arrived with more than 12,000 pounds of equipment and supplies and carried about 7,000 pounds of Station material on the trip back to Earth. After 9 days of cooperative work, Discovery undocked from the ISS.

The STS-114 crew was given an extra day in orbit on August 8, when the first attempt to land at Kennedy was foiled by uncooperative weather. Even though cloudy skies reappeared at the Shuttle’s home port the next morning, NASA was ready with a backup plan: a landing at Edwards Air Force Base in the high desert of California, where the weather was perfect.

The Sun rises on Discovery back on Earth.
The Sun rises on Discovery as it rests on the runway at Edwards Air Force Base, California, after a safe landing August 9, 2005, to complete the STS-114 mission.

Capsule Communicator Ken Ham congratulated the returning crew on a spectacular test flight. “Stevie Ray, Soichi, Andy, Vegas, Charlie, Wendy, and Eileen—welcome home, friends.”

Those words, Collins said, were great to hear. “We’re happy to be back, and we congratulate the whole team for a job well done.”

International Space Station: Sustaining a Human Presence in Space

While awaiting Discovery’s arrival, Expedition 11 NASA Science Officer John Phillips and Commander Sergei Krikalev conducted the first of their three renal stone experiment sessions aboard the ISS. The renal stone experiment investigates whether potassium citrate, a proven Earth-based therapy used to minimize renal (kidney) stone development, can be effective as a countermeasure to reduce the risk of kidney stone formation for crewmembers in space. Astronauts are at an increased risk of developing kidney stones, because urinary calcium levels are typically much higher in space.

The renal stone investigation was designed as a double-blind study. The crewmembers do not know whether they are taking the potassium citrate or a placebo. Further, the principal investigator who interprets the data does not know in advance which crewmembers have taken the potassium citrate or which have taken the placebo. The principal investigator is studying the urine chemistry of the samples to determine each individual’s risk of renal stone formation. If the investigator’s hypothesis is correct, the crewmembers identified as having a lower renal stone formation risk will be those who had taken the potassium citrate pills in-flight as a countermeasure.

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During their initial session, Phillips and Krikalev performed a urine collection over the course of 24 hours and logged everything they ate and drank for 48 hours.

International Space Station floating above Earth
The International Space Station was photographed from Space Shuttle Discovery after the two spacecraft undocked.

This experiment is crucial to long-duration missions, since kidney stones can incapacitate a crewmember, and, in the worse case, threaten life if there is no way to get the astronaut back to Earth quickly.

In a previous ISS research effort, Expedition 10 Commander and NASA Science Officer Leroy Chiao and Flight Engineer Salizhan Sharipov conducted an experiment to shed more light on what is currently known about microgravity’s effects on human muscle and bone.

In carrying out the ADvanced Ultrasound in Microgravity (ADUM) experiment, Chiao and Sharipov performed ultrasound bone scans on each other by taking turns as operator and subject. The bone scans were taken of the shoulder, elbow, knee, and ankle, monitored remotely from the ground, and videotaped and photographed for downlink and analysis.

Since there is no room for a fully functioning staff of doctors aboard the ISS, nor is it feasible for a crewmember to return to Earth for a quick medical checkup, this experiment could lead to efficient diagnosing of medical problems with minimal use of onboard resources. Ability of crewmembers to use an ultrasound machine with remote instruction—sending information to the ground for analysis—can assist in timely treatment, as well as avert unnecessary evacuation. Crewmembers as far away as Mars could eventually be remotely examined by doctors on Earth using a modification of this technology. This type of capability is essential for long-term space exploration.

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Expendable launch vehicle on a launch pad
Many of NASA’s most famous missions—from those observing Earth, such as EOS, Aura, and Landsat, to interplanetary and deep space missions like the Mars Exploration Rover and Deep Space 1—are launched on expendable launch vehicles.

The Expedition 10 crewmembers also conducted a session with the Miscible Fluids in Microgravity experiment. Fluids do not behave the same on Earth as in the microgravity environment inside the orbiting Space Station. This experiment studies how miscible fluids, or those that completely dissolve, interact without the interference of gravity.

The test involved Chiao pulling tinted water from a syringe through a drinking straw and into another syringe containing a mixture of honey and water. The way the fluid interacted was videotaped and photographed for observation. This research could help scientists improve the way plastics and other polymers are produced on Earth and in space.

NASA’s Payload Operations team at Marshall Space Flight Center is coordinating the aforementioned ISS science activities.

Flight Support: Launch Service
s

Many of NASA’s most famous missions are launched on expendable launch vehicles (ELVs). These missions are unpiloted and can accommodate all types of orbit inclinations and altitudes/attitudes.

In 1997, Kennedy was assigned lead center program responsibility for NASA’s acquisition and management of ELV launch services. Its ELV Program Office provides a single focal point for these services, while affording NASA the benefits of consolidated and streamlined technical and administrative functions. The program, with its vision statement, “Global Leadership in Launch Service Excellence,” provides launch services for NASA, NASA-sponsored payloads, and other government payloads.

Primary launch sites are Cape Canaveral Air Force Station, Florida, and Vandenberg Air Force Base, California; other launch locations are NASA’s Wallops Island, Virginia; Kodiak Island, Alaska; and Kwajalein Atoll, in the Republic of the Marshall Islands, in the North Pacific.

Since 1990, NASA has been purchasing ELV launch services directly from commercial providers, whenever possible, for its scientific and applications missions that are not assigned to fly on the Space Shuttle. Because ELVs can accommodate all types of orbit inclinations and altitudes/attitudes, they are ideal for launching Earth-orbit and interplanetary missions.

Kennedy is also responsible for NASA oversight of launch operations and countdown management. A motivated and skillful team is in place to meet the mission of the ELV program: “To provide launch service excellence, expertise, and leadership to ensure mission success for every customer.”

In late-May 2005, NASA successfully launched a new environmental satellite for the National Oceanic and Atmospheric Administration (NOAA), using a Boeing Delta II 7320-10 ELV. The satellite, NOAA-18, aims to improve weather forecasting and monitor environmental events around the world.

NOAA-18 polar-orbiting satellite
NOAA-18 is the latest polar-orbiting satellite developed by NASA for the National Oceanic and Atmospheric Administration (NOAA). NOAA-18 will collect information about Earth’s atmosphere and environment to improve weather prediction and climate research across the globe.

The NOAA-18 spacecraft lifted off from Vandenberg Air Force Base, on the Delta II. Approximately 65 minutes later, the spacecraft separated from the ELV second stage.

“The satellite is in orbit and all indications are that we have a healthy spacecraft,” said Karen Halterman, the NASA Polar-orbiting Operational Environmental Satellites (POES) project manager, based at Goddard Space Flight Center. “NASA is proud of our partnership with NOAA in continuing this vital environmental mission,” she added.

NOAA-18 will collect data about the Earth’s surface and atmosphere. The data are input to NOAA’s long-range climate and seasonal outlooks, including forecasts for El Niño and La Niña. NOAA-18 is the fourth in a series of five POES with instruments that provide improved imaging and sounding capabilities.

NOAA-18 has instruments used in the International Search and Rescue Satellite-Aided Tracking System, called COSPAS-SARSAT, which was established in 1982. NOAA POES detect emergency beacon distress signals and relay their location to ground stations, so rescue can be dispatched. SARSAT is credited with saving approximately 5,000 lives in the United States and more than 18,000 worldwide.

An NOAA spacecraft launch
The National Oceanic and Atmospheric Administration’s spacecraft NOAA-18 leaped away from the smoke and steam clouds as it lifted off from Vandenberg Air Force Base in California. It was launched by NASA on a Boeing Delta II 7320-10 expendable launch vehicle.

NOAA manages the POES program and establishes requirements, provides all funding, and distributes environmental satellite data for the United States. Goddard procures and manages the development and launch of the satellites for NOAA on a cost-reimbursable basis.

Flight Support: Space Communications


Sophisticated signal-processing techniques and simple proof-of-principle antenna arrays built from PVC pipe, aluminum foil, and copper wire could revolutionize the way NASA obtains data from its Earth-observing satellites.

If the adaptive array system being studied by NASA and Georgia Institute of Technology (Georgia Tech) researchers ultimately proves feasible, it could make information from the Space Agency’s Earth-observing satellites more widely and rapidly available. The “off-the-shelf” technology has already demonstrated that it can successfully receive one satellite telemetry frequency.

“The dream would be to make these NASA information services available to anybody sitting at a computer, almost like video-on-demand,” explained Mary Ann Ingram, a professor at Georgia Tech’s School of Electrical and Computer Engineering. “Timely information from Earth-observing satellites could be useful in many ways, such as directing operations to fight a forest fire, for instance.”

Information from satellites such as Earth Observing-1 (EO-1) is now downlinked to various 11-meter dishes, primarily in the Arctic Circle, where subzero temperatures create maintenance and reliability issues for their complex aiming mechanisms. Typically, satellites such as EO-1 are in contact with these antenna systems 5 to 8 times a day, for 10 minutes at a time. The present antenna systems require resident crews to operate and maintain them.

Engine testing at White Sands Test Facility
Operation and Deployment Experiments Simulator (ODES) engine testing at White Sands Test Facility in New Mexico.

The NASA/Georgia Tech project envisions replacing these antennas with a network of inexpensive antenna arrays that would have no moving parts and use sophisticated software—instead of careful aiming—to gather data from the satellites. The network could lower operational costs while improving access to the information.

“When people use cell phones to make calls, there are no moving parts on the antennas,” noted Dan Mandl, mission director for NASA’s EO-1 program at Goddard. “What I would like to do is build a continuous cell-like network around the world that would provide almost unlimited opportunities to downlink data.”

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Mandl compared NASA’s existing downlink system to old-fashioned pay phones located off expressway exits. “If you witness an accident, you can open your cell phone and call for assistance,” he said. “But if you don’t have a cell phone, you have to get off the highway at the next exit and hunt for a pay phone. What we would like to do is give these satellites the equivalent of cell phones to allow anytime, anywhere contact.”

The proof-of-principle adaptive arrays being tested by Ingram and her research team are built from inexpensive components, including common PVC piping and aluminum foil. Signals from the four antennas are analyzed using a processing technique that learns to improve its performance, by constructively combining scattered and reflected versions of the signal and by suppressing noise and interference. This eliminates the need for costly front-end hardware and precise aiming of the antenna arrays, and enables flexibility in the location of the ground station.

“Instead of one big aperture from an 11-meter dish, we’re going to use several smaller apertures and connect them with digital signal processing,” Ingram explained. “A smaller aperture has a wider beam, so the tracking requirement won’t be as great. They may pick up interference, especially in tracking a satellite at a low-elevation angle, but because we combine multiple apertures, we can null out the interference.”

The arrays individually will not provide the same data rate as NASA’s large structures, but having more of them spread out around the world will compensate for that. Network capacity studies show that two ground stations, each with seven 0.75-meter dishes or eight electronically steered antennas, could equal the data capacity of NASA’s existing 11-meter dish in Poker Flats, Alaska, at a significantly lower cost.

And because an array does not depend on precisely aiming a dish, each one could potentially communicate with more than one satellite at a time. “What we’d really like to have is a shared antenna resource, in which software is used to separate out the signals,” Mandl explained. “As we get more satellites up in space, this will become more important.”

In testing performed at Georgia Tech, researchers were able to downlink EO-1 information in the S-band, a frequency used for transmissions at low data rates. They had to develop a special filter to eliminate interference from terrestrial repeater stations of popular satellite radio services.

“We have demonstrated the lower rates in S-band, and, during the upcoming year, we will work on X-band for higher rates,” Mandl said. “Ultimately, we would like to demonstrate Ka band, which is in the 27-28 gigahertz range. You could potentially get anywhere from 300 megabits to a gigabit of data in that stream.”

To extend satellite reception time, researchers are also examining several technical issues, such as array-based synchronization and optimization of the tilt angles of the planar apertures of the electronically steered antennas. This optimization could quadruple the download capacity for a ground station with eight electronically steered antennas.

If successful, the adaptive array project would give NASA more flexibility in design of future high-data rate satellites that may generate terabits of data on each orbit of the Earth. Reliably downlinking that amount of information will require a new approach, Mandl noted.

“If you are in the Arctic and the motor moving your dish breaks down, it may take a few weeks to fix it,” Mandl said. “If this could be done with no moving parts, using techniques of digital signal processing and software radio, one of the most desirable features will be a high level of reliability. That’s important for space applications and locations where you can just put equipment out there and not require an operator or maintenance crew.”

Flight Support: Rocket Propulsion Testing

Plasma energy generated in a vacuum
NASA scientists began generating plasma energy in a 9-inch vacuum chamber in NASA’s Propulsion Research Laboratory at the Marshall Space Flight Center. In partnership with researchers at the University of Texas at Austin, Johnson Space Center, and the University of Alabama, Marshall scientists are developing innovative magnetic nozzles capable of properly channeling superheated plasma without nozzle deterioration, causing the plasma to accelerate to velocities far faster than those of conventional chemical propulsion systems. Such component technology could support development of next-generation, plasma-propelled spacecraft capable of safely and quickly carrying robotic or human exploration missions deep into the solar system.

On July 6, 1962, NASA selected the White Sands Test Facility (WSTF) as the site for Johnson Space Center’s Propulsion Systems Development Facility. This site was chosen for its isolated location and topography, which minimized the inherent hazards of aerospace propulsion testing to the general population. WSTF began testing rocket engines in 1964. More than 310 engines have been tested, for a total number of firings exceeding 2.1 million. 

WSTF’s 300 and 400 Propulsion Test Areas were originally constructed to test the engines for the Apollo Command and Service Modules and the Lunar Module. In September 1964, the first firing test of the main rocket engine for the Apollo Command and Service Modules was conducted. The Lunar Module descent engine, which allowed the craft to land softly on the Moon, and the ascent engine, which was used to launch the craft from the lunar surface, were certified for flight after hundreds of firings in the 400 Area. The reaction control system, which consisted of the small thrusters that control the spacecraft attitude, was also certified for flight at WSTF.

Today, six test stands provide vacuum test capability, and three test stands provide ambient testing, 5,000 feet above sea-level, for the Space Shuttle, the ISS, and for other government agency tests.

Stennis Space Center is NASA’s primary center for testing and proving flight-worthy rocket propulsion systems for the Space Shuttle and future generations of space vehicles. Having conducted engine testing for 4 decades, Stennis is NASA’s program manager for rocket propulsion testing with total responsibility for conducting and managing all NASA propulsion test programs.

Exploration Systems

The Exploration Systems Mission Directorate is responsible for creating new capabilities and supporting technologies that enable sustained and affordable human and robotic exploration. This mission directorate is also responsible for effective utilization of ISS facilities and other platforms for research that support long-duration human exploration.

Plasma Energy Technology to Propel Deep-Space Missions

NASA scientists have begun generating plasma energy in a 9-inch vacuum chamber in NASA’s Propulsion Research Laboratory at Marshall. In partnership with researchers at the University of Texas at Austin, Johnson, and the University of Alabama, in Huntsville, Marshall scientists are developing innovative magnetic nozzles capable of properly channeling superheated plasma without nozzle deterioration, causing the plasma to reach very high velocities.

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NASA scientists work on a K-10 rover.
Susan Young Lee, lead hardware engineer, and Eric Park, computer scientist, working on a K-10 Rover in one of Ames Research Center’s robotics laboratories.

Such component technology could support development of next-generation, plasma-propelled spacecraft capable of safely and quickly carrying robotic or human exploration missions deep into the solar system. This could dramatically reduce travel times to Earth’s neighboring planets and extend the capabilities of future space exploration missions.

The new research project has two objectives: development of an innovative magnetic nozzle design capable of directing the flow of plasma, and determining how to efficiently eject the plasma from the nozzle to produce the greatest propulsive thrust.

Plasma is a highly conductive medium formed when a gas is heated and ionized—the process in which the gas’s neutral atoms shed electrons and acquire a positive charge. When properly channeled through a magnetic nozzle, plasma can be accelerated to velocities dramatically faster than those of conventional chemical propulsion systems.

Propellant in a plasma state can be accelerated with the use of electromagnetic energy sources to increase the propulsion system’s specific impulse—the equivalent of a car’s gas mileage. Such a nozzle, magnetically insulated against the superheated plasma flow, would enable plasma acceleration at temperatures far beyond those conventional materials can endure.

The second challenge is rooted in the physics of magnetized plasma flow. A plasma propulsion system requires magnetic coils to generate and channel the plasma. These coils produce closed magnetic field lines—circular loops of magnetic energy that form around the power source—and prevent the plasma from detaching and leaving the spacecraft.

The research consortium seeks to test mechanisms that allow the plasma stream—already properly shaped by the magnetic nozzle—to break away from the spacecraft, generating maximum thrust by dispersing the plasma at exactly the right moment following expulsion from the rear of the spacecraft. Eventually, NASA hopes to adapt this research to develop a new class of rockets incorporating magnetic nozzles and plasma propulsion systems.

NASA Develops Robot With Human Traits

NASA researchers envision futuristic robots that “act” like people, enabling these mechanical helpers to work more efficiently with astronauts. Human-robot cooperation, in turn, will enable exploration of the Moon and Mars, and even large-scale construction in extraterrestrial places. Because human crews will be limited to small teams, astronauts will need robot helpers to do much of each team’s work.

Though remotely controlled machines and robots that work entirely on their own are valid goals, a research team at Ames Research Center plans to focus on robots that are partly controlled by people and operate independently the rest of the time.

An eight-legged scorpion robot prototype
An eight-legged Scorpion robot prototype test under development at Ames Research Center is just one example of the innovative robotics work being done at that center.

There are three main areas under development. One is called collaborative control, during which the human being and the robot will speak to one another and work as partners. The second area is building robots with reasoning mechanisms that work similarly to human reasoning. Thirdly, the researchers will conduct field tests of people and robots working together.

Many experiments will occur in a special, indoor laboratory under construction at Ames, featuring a control room with a window looking out on robots working in a large area that will simulate the surface of a moon or planet. The control room will imitate a human habitat on the Moon or Mars.

The robots will help assemble buildings, test equipment, weld structures, and dig with small tools. Human-robot teams will use a checklist and a plan to guide their joint efforts. The robot development work will focus on specific tasks essential for basic exploration mission operations including: shelter and work hangar construction, piping assembly and inspection, pressure vessel construction, habitat inspection, resource collection, and transport.

Scientists say human-robot cooperation will result in a better outcome than human- or robot-only teams could accomplish. To make human-machine teaming a reality, a NASA multi-pronged effort is underway to develop robot intelligence. Similar to human thinking, it is designed to improve the mechanical workings of robots and to standardize human-robot communications.

Robots Will Search for Lunar Water Deposits


The Vision for Space Exploration spells out a long-term strategy of returning to the Moon as a step towards sending humans to Mars and beyond. The Moon, so nearby and accessible, is a great place to try out new technologies critical to living on alien worlds before venturing across the solar system.

Whether a Moon base will turn out to be feasible hinges largely on the question of water. Colonists need water to drink. They need water to grow plants. They can also break water apart to make air (oxygen) and rocket fuel (oxygen + hydrogen). Furthermore, water is surprisingly effective at blocking space radiation. Surrounding the base with a few feet of water would help protect explorers from solar flares and cosmic rays. The problem is that water is dense and heavy. Carrying large amounts of it from Earth to the Moon would be expensive. Settling the Moon would be so much easier if water were already there.

Astronomers believe that comets and asteroids hitting the Moon eons ago left water behind. (Scientists believe that Earth may have received its water in the same way.) Water on the Moon does not last long. It evaporates in sunlight and drifts off into space. Only in the shadows of deep, cold craters could an explorer expect to find any, frozen and hidden. Indeed, there may be deposits of ice in such places.

In the 1990s, two spacecraft, Lunar Prospector and Clementine, found tantalizing signs of ice in shadowed craters near the Moon’s poles—perhaps as much as a cubic kilometer. The data were not conclusive, though.

To find out if lunar ice is truly there, NASA plans to send a robotic scout. The Lunar Reconnaissance Orbiter, or “LRO” for short, is scheduled to launch in 2008 and to orbit the Moon for a year or more. Carrying six different scientific instruments, LRO will map the lunar environment in greater detail than ever before. LRO’s instruments will do many things: they will map and photograph the Moon in detail, sample its radiation environment, and hunt for water.

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The spacecraft’s Lyman-Alpha Mapping Project (LAMP) will attempt to peer into the darkness of permanently shadowed craters at the Moon’s poles, looking for signs of ice hiding there. By looking for the dim glow of reflected starlight, LAMP senses a special range of ultraviolet light wavelengths. Not only is starlight relatively bright in this range, but also the hydrogen gas that permeates the universe radiates in this range as well. To LAMP’s sensor, space itself is literally aglow in all directions. This ambient lighting may be enough to see what lies in the inky blackness of these craters.

The spacecraft is also equipped with a laser that can shine pulses of light into dark craters. The main purpose of the instrument, called the Lunar Orbiter Laser Altimeter (LOLA), is to produce a highly accurate contour map of the entire Moon. As a bonus, it will also measure the brightness of each laser reflection. If the soil contains ice crystals, as little as 4 percent, the returning pulse would be noticeably brighter.

One of LRO’s instruments, Diviner, will map the temperature of the Moon’s surface. Scientists can use these measurements to search for places where ice could exist. Even in the permanent shadows of polar craters, temperatures must be very low for ice to resist evaporation. Thus, Diviner will provide a “reality check” for LRO’s other ice-sensitive instruments, identifying areas where positive signs of ice would not make any sense, because the temperature is simply too high.

Not far from some permanently shadowed craters are mountainous regions in permanent sunlight, known romantically as “peaks of eternal sunshine.” Conceivably, a Moon base could be placed on one of those peaks, providing astronauts with constant solar power—not far from crater valleys below, rich in ice and ready to be mined.

NASA’s Desert ‘Rats’ Test New Gear

Astronauts train in the rugged Arizona desert.
The Remote Field Demonstration Test Site serves as sort of a dry run of a dry run. Researchers use the rugged terrain and varied climate to test prototype space suits and innovative equipment.

Arizona’s high desert is not quite as tough on equipment as the Moon or Mars, but few places on Earth can give prototype space suits, rovers, and science gear a better workout.

A NASA-led team headed for sites near Flagstaff, Arizona, in September, to test innovative equipment. Engineers and scientists led the Desert Research and Technology Studies (RATS) team from Johnson and Glenn Research Center. The team included members from NASA centers, universities, and private industry. Their efforts may help America pursue the Vision for Space Exploration to return to the Moon and travel beyond.

The sand, grit, dust, rough terrain, and extreme temperature swings of the desert are attractive, simulating some of the conditions that may be encountered on the Moon or Mars. Crews wearing prototype-advanced space suits used and evaluated the new equipment for 2 weeks.

“For field testing, the desert may be the closest place on Earth to Mars, and it provides valuable hands-on experience,” said Joe Kosmo, Johnson’s senior project engineer for the experiments. “This work will focus on the human and robotic interaction we’ll need for future lunar and planetary exploration, and it will let us evaluate new developments in engineering, science, and operations,” he added.

Engineers in the Exploration Planning and Operations Center at Johnson provided mission control-type monitoring of the field tests.

The test equipment included:

  • New space suit helmet-mounted speakers and microphones for communications.

  • A “field assistant” electric tractor that follows test subjects in space suits, and is guided by space suit-mounted controls.

  • A wireless network, for use on other planets, that can relay data and messages among spacewalkers, robots, and rovers as they explore the surface.

  • A two-wheeled chariot that is pulled by the electric tractor to carry astronauts.

  • “Matilda,” an autonomous robotic support vehicle that can retrieve geologic samples.

  • Analytical equipment mounted on two mobile geology laboratories.

Science

NASA’s Science Mission Directorate carries out the scientific exploration of the Earth, Moon, Mars, and beyond; charts the best route of discovery; and reaps the benefits of Earth and space exploration for society. By combining Earth and space science, NASA is best able to establish an understanding of the Earth, other planets, and their evolution, bringing the lessons of our study of Earth to the exploration of the solar system and assuring the discoveries made here will enhance our work there.

Deep Impact Mission

Moment of impact during the Deep Impact Mission
Artist Pat Rawlings illustrates the moment of impact and the forming of the crater during the Deep Impact Mission.

Comets are time capsules that hold clues about the formation and evolution of the solar system. They are composed of ice, gas, and dust, primitive debris from the solar system’s distant and coldest regions that formed 4.5 billion years ago. Deep Impact, a NASA Discovery Program mission, is the first to probe beneath the surface of a comet and reveal the secrets of its interior.

At the culmination of the 6-year mission, on July 3, 2005, a 370-kilogram impactor was released from the Deep Impact spacecraft. The spacecraft watched from a safe distance while the impactor collided with comet Tempel 1 at 6.3 miles per second (10 kilometers per second) or 23,000 miles per hour (37,000 kilometers per hour), on July 4. The impact created a magnificent flash of light as an immense cloud of fine powdery material was ejected and subsequently captured in 4,500 images from the spacecraft’s cameras.

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Scientists continue to analyze the gigabytes of data collected from the 4th of July fireworks in deep space. It is estimated that the crater formed from the impact is between 165 and 820 feet (50 and 250 meters) wide. Analyzed data will be combined with that of other NASA and international comet missions. Results from these missions will lead to a better understanding of both the solar system’s formation and implications of comets colliding with planetary surfaces.

Mars Exploration Rover Mission

We’re going to overtime—for the third time.

View of Mars landscape from Spirit
Full frame experiment data record acquired on Sol 494 of Spirit’s mission to Gusev Crater, at approximately 16:37:46 Mars local solar time.

In April 2005, NASA approved up to 18 more months of operations for Spirit and Opportunity, the twin Mars rovers that have already surprised engineers and scientists by continuing active exploration for more than 20 months—well past their 3-month primary mission.

The rovers have proven their value with major discoveries about ancient watery environments on Mars that might have harbored life. Shortly after landing in January 2004, Opportunity found geological evidence of a shallow ancient sea. More than a year later, Spirit found a new class of water-affected rock. The Science Mission Directorate leadership decided to extend the mission through September 2006 to take advantage of having such capable resources still healthy and in excellent position to continue the Mars adventures.

With the rovers already performing well beyond their original design lifetimes, there is a distinct possibility that, at any time, a part could wear out and therefore disable the robotic explorers. Both rovers, however, show no signs of letting up, despite traveling through dust devils and sand traps. Through August 2005, Spirit and Opportunity have explored over 6.5 miles (10.5 kilometers) of Martian terrain.

Cassini-Huygens Mission


The Cassini spacecraft is embarking on a new mission phase that will give it a ringside seat at Saturn—literally. After concentrating on flybys of Saturn’s moons since arriving last year, Cassini began a 5-month study of the stately planet’s magnificent rings in April with 12 instruments onboard. Knowing how the rings form and how long they have been there are central questions for the Cassini-Huygens mission.

Mimas, one of the innermost moons of Saturn
In this true color view, Mimas, one of the innermost moons of Saturn, drifts along in its orbit, against the azure backdrop of Saturn’s northern latitudes.

In a spectacular kickoff to its first season of prime ring viewing, Cassini has confirmed earlier suspicions of an unseen moon hidden in a gap in Saturn’s outer “A” ring, known as the Keeler Gap.

The moon, provisionally called S/2005 S1, was first seen in a time-lapse sequence of images taken on May 1, 2005, as Cassini began its climb to higher inclinations in orbit around Saturn. A day later, an even closer view was obtained, which has allowed measurement of its size and brightness.

S/2005 S1 is the second-known moon to exist within Saturn’s rings. The other is Pan, which orbits in the Encke Gap of the “A” ring. Imaging scientists had predicted the new moon’s presence and its orbital distance from Saturn after a July 2004 sighting of a set of peculiar spiky and wispy features in the Keeler Gap’s outer edge. The similarities of the Keeler Gap features to those noted in Saturn’s “F” ring and the Encke Gap led imaging scientists to conclude that a small body, a few kilometers across, was lurking in the center of the Keeler Gap, awaiting discovery.

NASA scientists have also concluded that another Saturn moon, Phoebe, is an interloper to the Saturn system from the deep outer solar system.

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When Cassini flew by Phoebe on its way to Saturn on June 11, 2004, little was known about the battered, crater-filled moon at that time. During the encounter, scientists got the first detailed look at Phoebe, which allowed them to determine its makeup and mass. As new information unfolded, scientists were able to determine that Phoebe has an outer solar system origin, akin to Pluto and other members of the Kuiper Belt.

The rings of Saturn
Specially calculated Cassini orbits place Earth and Cassini on opposite sides of Saturn’s rings, a geometry known as occultation. Cassini conducted the first radio occultation observation of Saturn’s rings on May 3, 2005.

“Phoebe was left behind from the solar nebula, the cloud of interstellar gas and dust from which the planets formed,” said Dr. Torrence Johnson, a Cassini imaging team member at the Jet Propulsion Laboratory (JPL). “It did not form at Saturn. It was captured by Saturn’s gravitational field and has been waiting eons for Cassini to come along.”

Phoebe has a density consistent with that of the only Kuiper Belt objects for which densities are known. Phoebe’s mass, combined with an accurate volume estimate from images, yields a density of about 100 pounds per cubic foot (1.6 grams per cubic centimeter), much lighter than most rocks, but heavier than pure ice, which is about 58 pounds per cubic foot (0.93 grams per cubic centimeter). This suggests a composition of ice and rock similar to that of Pluto, and Neptune’s moon, Triton. Whether the dark material on other moons of Saturn is the same primordial material as on Phoebe remains to be seen.

Meanwhile, new observations have been made about Saturn’s largest moon, Titan. Huygens, a European Space Agency probe with six instruments onboard, landed safely on Titan on January 14, 2005, recording hundreds of megabytes of data during its descent through the atmosphere and while on the surface. Titan is the only known moon in our solar system that has a thick atmosphere. Huygens revealed that the thick atmosphere of this giant moon is rich in organic compounds, whose chemistry may be similar to that of primordial Earth several billion years ago.

“Titan is not just a dot in the sky; these new observations show that Titan is a rich, complex world, much like the Earth in some ways,” said Dr. Michael Flasar, the Composite Infrared Spectrometer (CIRS) instrument principal investigator at Goddard. In all, there will be 45 flybys of Titan during the Cassini-Huygens nominal mission, giving scientists more information to unravel the mysteries of its thick atmosphere and other Earth-like processes, such as tectonics, erosion, winds, and perhaps volcanism, which may have shaped Titan’s surface.

Swift Mission

A launch vehicle silhouetted against a sunrise
The Boeing Delta II launch vehicle for NASA’s Swift spacecraft is silhouetted against a rosy sky at sunrise, waiting for liftoff.

Scientists using the Swift satellite—launched on November 20, 2004—and several ground-based telescopes have detected the most distant explosion yet, a gamma-ray burst from the edge of the visible universe.

This powerful burst was detected September 4, 2005. It marks the death of a massive star and the birth of a black hole. It comes from an era soon after stars and galaxies first formed, about 500 million to 1 billion years after the Big Bang. Gamma-ray bursts are the most powerful explosions the universe has seen since the Big Bang. They occur approximately once per day and are brief, but intense, flashes of gamma radiation.

“We designed Swift to look for faint bursts coming from the edge of the universe,” said Swift principal investigator, Dr. Neil Gehrels, of Goddard. “Now we’ve got one, and it’s fascinating. For the first time, we can learn about individual stars from near the beginning of time. There are surely many more out there,” he added.

The Swift satellite is designed specifically for gamma-ray burst science. Its three instruments work together to observe gamma-ray bursts and afterglows in the gamma-ray, X-ray, and optical wavebands. The Burst Alert Telescope (BAT) monitors the entire sky to catch a gamma-ray burst and calculate an initial position. Within seconds of detecting a burst, Swift will relay the burst’s location to ground stations, allowing both ground-based and space-based telescopes around the world the opportunity to observe the burst’s afterglow. Armed with the position, the Swift spacecraft autonomously points two other onboard telescopes within their field-of-view, within 90 seconds. All three telescopes watch the gamma-ray burst and afterglow unfold. During Swift’s 2-year nominal mission, scientists should have data for approximately 200 gamma-ray bursts to determine their origin and study activities of the early universe.

Detecting Coastal Pollution

Back on Earth, a NASA-funded study of marine pollution in southern California concluded that space-based synthetic aperture radar can be a vital observational tool for assessing and monitoring ocean hazards in urbanized coastal regions.

Swift spacecraft with gamma-ray burst
An artist’s rendering of the Swift spacecraft with a gamma-ray burst in the background.

“Clean beaches and coastal waters are integral to southern California’s economy and lifestyle,” said Dr. Paul DiGiacomo, a JPL oceanographer and lead author of a study recently published in the Marine Pollution Bulletin. “Using southern California as a model system, we’ve shown existing high-resolution, space-based radar systems can be used to effectively detect and assess marine pollution hazards. This is an invaluable tool for water quality managers to better protect public health and coastal resources,” he added.

DiGiacomo and colleagues from JPL; the University of California, Santa Barbara; and the University of Southern California, Los Angeles, examined satellite radar imagery of the state’s southern coastal waters. The area is adjacent to 20 million people, nearly 25 percent of the U.S. coastal population.

“The key to evaluating and managing pollution hazards in urban coastal regions is accurate, timely data,” DiGiacomo said. “Since such hazards are usually localized, dynamic, and episodic, they’re hard to assess using oceanographic field sampling. Space-based imaging radar works day and night, regardless of clouds, detecting pollution deposits on the sea surface. Combined with field surveys and other observations, including shore-based radar data, it greatly improves our ability to detect and monitor such hazards.”

The study described three major pollutant sources for southern California: storm water runoff, wastewater discharge, and natural hydrocarbon seepage.

“During late fall to early spring, storms contribute more than 95 percent of the region’s annual runoff volume and pollutant load,” said JPL co-author Ben Holt. “Californians are accustomed to warnings to stay out of the ocean during and after storms. Even small storms can impact water quality. Radar data can be especially useful for monitoring this episodic seasonal runoff.”

DiGiacomo noted that a regional southern California marine water quality-monitoring survey is under way, involving JPL and more than 60 other organizations, including the Southern California Coastal Water Research Project. Its goal is to characterize the distribution and ecological effects of storm water runoff in the region. Space radar and other satellite sensor data are being combined, including NASA’s Moderate Resolution Imaging Spectroradiometers (MODIS). The sensors provide frequent observations, subject to clouds, of ocean color that can be used to detect regional storm water runoff and complement the finer resolution, but less frequent, radar imagery.

The second largest source of the area’s pollution is wastewater discharge. Publicly owned treatment works discharge daily more than 1 billion gallons of treated wastewater into southern California’s coastal waters. Even though it is discharged deep offshore, submerged plumes occasionally reach the surface and can contaminate local shorelines.

Natural hydrocarbon seeps are another local pollution hazard. Underwater seeps in the Santa Barbara Channel and Santa Monica Bay have deposited tar over area beaches. Space-imaging radar can track seepage on the ocean surface, as well as human-caused oil spills, which are often affected by ocean circulation patterns that make other tracking techniques difficult.

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Further research is necessary to determine the composition of pollution hazards detected by radar. “From imaging radar, we know where the runoff is, but not necessarily which parts of it are harmful,” Holt said. “If connections can be established, imaging radar may be able to help predict the most harmful parts of the runoff.”

While the researchers said environmental conditions such as wind and waves can limit the ability of space radar to detect ocean pollution, they stressed the only major limitation of the technique is infrequent coverage. “Toward the goal of a comprehensive coastal ocean observing system, development of future radar missions with more frequent coverage is a high priority,” DiGiacomo noted.

Detecting Airborne Pollution


NASA scientists have discovered that pollution could catch an airborne “express train,” or wind current, from Asia all the way to the southern Atlantic Ocean.

Globe showing ozone pollution from Asia The red arrows on this globe trace the fast track of ozone pollution from Asia as it contributes to the highest ozone episodes found in the South Atlantic.

Scientists believe that, during certain seasons, as much as half of the ozone pollution above the Atlantic Ocean may be speeding down a track of air from the Indian Ocean. As it rolls along, it picks up more smog from air peppered by thunderstorms that bring the pollution up from the Earth’s surface.

Bob Chatfield, a scientist at Ames, said, “Man-made pollution from Asia can flow southward, get caught up into clouds, and then move steadily and rapidly westward across Africa and the Atlantic, reaching as far as Brazil.”

Chatfield and Anne Thompson, a scientist at Goddard, used data from two satellites and a series of balloon-borne sensors to spot situations when near-surface smog could catch the wind current westward several times annually from January to April.

During those periods of exceptionally high ozone in the South Atlantic, especially during late winter, researchers noticed Indian Ocean pollution follows a similar westward route, wafted by winds in the upper air. They found the pollution eventually piles up in the South Atlantic. “We’ve always had some difficulty explaining all that ozone,” Thompson admitted.

“Seasonal episodes of unusually high ozone levels over the South Atlantic seem to begin with pollution sources thousands of miles away in southern Asia,” Chatfield said. Winds are known to transport ozone and pollutants thousands of miles away from their original sources.

Clearly defined, individual layers of ozone in the tropical South Atlantic were traced to lightning sources over nearby continents. In addition to ozone peaks associated with lightning, high levels of ozone pollution came from those spots in the Sahel area of North Africa where vegetation burned. However, even outside these areas, there was extra ozone pollution brought by the Asian “express train.”

The scientists pinpointed these areas using the joint NASA-Japan Tropical Rainfall Measuring Mission (TRMM) satellite to see fires and lightning strikes, both of which promote ozone in the lower atmosphere. Researchers also identified large areas of ozone smog moving high over Africa using the Total Ozone Mapping Spectrometer (TOMS) satellite instrument.

They further confirmed the movement of the smog by using sensors on balloons in the Southern Hemisphere Additional Ozonesondes (SHADOZ) network. A computer model helped track the ozone train seen along the way by the SHADOZ balloon and satellite sensors. The scientists recreated the movement of the ozone from the Indian Ocean region to the southern Atlantic Ocean.

Going to ‘Extremes’

Hundreds of feet under the Alaskan tundra, Marshall astrobiologist Dr. Richard Hoover ignored the eerie silence of the icy tunnel around him, and even the bones of woolly mammoths and steppe bison jutting from the jagged walls, frozen where they died tens of thousands of years ago.

Forget the fossils.

Hoover was instead poring over pale blue and white patches covering an ice wedge in the tunnel wall. It was a microbial community of bacteria and fungi, growing in total darkness, thriving at temperatures that have hovered below freezing for thousands of years.

For Hoover and his research colleagues, proof of life is the real find, especially in a subterranean tomb, sleeping under ice from the Pleistocene Age. In this unlikely place, they discovered a new life form, a never-before-seen bacterial species they have dubbed Carnobacterium pleistocenium. It is roughly 32,000 years old—and it is still alive.

NASA astrobiologist and University of Alabama scientist
Dr. Elena Pikuta, a scientist at the University of Alabama in Huntsville, and Dr. Richard Hoover, a NASA astrobiologist, lead a team of researchers who recently discovered a new life form: an “extremophile” that lives and thrives in conditions inhospitable to most life on Earth.

The bacterium—the first fully described, validated species ever found alive in ancient ice—is one of NASA’s latest discoveries of an “extremophile.” Extremophiles are hardy life forms that exist and flourish in conditions hostile to most known organisms, from the potentially toxic chemical levels of salt-choked lakes and alkaline deserts to the extreme heat of deep-sea volcanoes and hydrothermal vents. NASA and its partner organizations study the potential for life in such extreme zones to help understand the limitations of life on Earth and to prepare robotic probes and, eventually, human explorers to search other worlds for signs of life.

The search for extremophiles is a key element of the Vision for Space Exploration, which aims to reveal unimaginable life forms that could be thriving in conditions few Earth species could tolerate.

“The existence of microorganisms in these harsh environments suggests—but does not promise—that we might one day discover similar life forms in the glaciers or permafrost of Mars, or in the ice crust and oceans of Jupiter’s moon, Europa,” Hoover noted.

There are approximately 7,000 validly described species of bacteria, though far more are surmised to exist in nature. The vast majority of bacteria are harmless to humans. Only a very few—less than 1 percent of all known species—are dangerous, and many, Hoover noted, are valuable to human life, aiding us in numerous ways: aiding in the production of valuable proteins and life-saving drugs; culturing wine, dairy products, and other foods; and assisting in the biological extraction of gold and other precious metals from ore wastes.

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Carnobacterium pleistocenium could offer new breakthroughs in medicine, Hoover said. “The enzymes and proteins it possesses, which give it the ability to spring to life after such long periods of dormancy, might hold the key to long-term cryogenic, or very low-temperature, storage of living cells, tissues, and perhaps even complex life forms,” he said.

Aeronautics Research

The Aeronautics Research Mission Directorate is committed to developing tools and technologies that can help to transform how air transportation systems operate, how new aircraft are designed and manufactured, and how our Nation’s air transportation system can reach unparalleled levels of safety and security. Such tools and technologies will drive the next wave of innovation, enabling missions to be performed in completely new ways and creating new missions that were never before possible.

Array of NASA aircraft on display at Dryden
A collection of NASA’s research aircraft on the ramp at the Dryden Flight Research Center in July 1997: X-31, F-15, SR-71, F-106, F-16XL Ship #2, X-38, Radio Controlled Mothership, and X-36.

NASA has been at the forefront of aeronautics research for decades, and just recently celebrated the 90th anniversary of its predecessor, the National Advisory Committee for Aeronautics (NACA). From March 3, 1915, until its incorporation into NASA on October 1, 1958, NACA provided technical advice to the U.S. aviation industry and conducted cutting-edge research in aeronautics. NACA was created by President Woodrow Wilson, to “direct and conduct research and experimentation in aeronautics, with a view to their practical solution.” NASA has continued this tradition.

In the 1920s, NACA engineers developed a low-drag streamlined cowling for aircraft engines, which all aircraft manufacturers then adopted. This innovation resulted in significant operating cost savings. NACA engineers also demonstrated the advantages of mounting engines into the leading edges of multi-engine aircraft wings rather than suspending them, which also became an industry standard.

Through the 1930s, NACA engineers developed several families of airfoils. Many of these were successful as wing and tail sections, propellers, and helicopter rotors used in general aviation and in military aircraft.

During the 1940s, NACA researchers developed the laminar-flow airfoil, which solved the problem of turbulence at the wing trailing edge that limited aircraft performance. The research helped pioneer advances in transonic and supersonic flight. NACA also developed a supersonic wind tunnel, speeding the advent of operational supersonic aircraft and helping to determine the physical laws affecting supersonic flight. In 1945, Robert Jones, one of the premier aeronautical engineers of the 20th century, formulated the swept-back wing concept to reduce shockwave effects at critical supersonic speeds. Also in the mid-1940s, NACA engineers pioneered research in thermal ice prevention systems for aircraft.

In 1952, NACA’s engineers formed the blunt body concept, which suggested that a blunt shape would absorb only a very small fraction of the heat generated during reentry into Earth’s atmosphere. The principle was significant for missile nose cones; the Mercury, Gemini, Apollo, and Space Shuttle craft; and unmanned probes. That same year, NACA began studying problems likely to be encountered in space.

The Lunar Landing Training Vehicle
The Lunar Landing Training Vehicle (LLTV) gave astronauts valuable training in the critical final phases of the descent onto the Moon.

In 1954, NACA proposed development of a piloted research vehicle to study the problems of flight in the upper atmosphere and at hypersonic speeds. This led to the development of the rocket-propelled X-15 research airplane.

With NACA’s transformation into NASA in 1958, research for space travel became a high-profile endeavor. NASA and Bell Aerosystems Company developed a Lunar Landing Training Vehicle (LLTV) simulator for the Apollo Program. This allowed a pilot to make a vertical landing in a simulated Moon environment. Donald “Deke” Slayton, then NASA’s astronaut chief, said there was no other way to simulate a Moon landing except by flying the LLTV.

Four decades of supersonic-combustion ramjet (scramjet) propulsion research culminated in 2004, with two successful flights of the X-43A hypersonic technology demonstrator. The X-43A attained a maximum speed of Mach 9.6, flying freely under its own power. It set world airspeed records for an aircraft powered by an air-breathing engine. The flights proved that scramjet propulsion may be a viable technology for powering future space-access vehicles and hypersonic aircraft.

NASA will continue to develop and validate high-value technologies that enable exploration and discovery. The Agency continues its legacy work in aeronautics with breakthrough developments in quieter supersonic and subsonic flight, and autonomous, high-altitude, long-endurance robotic aircraft.

Currently, among its many aeronautics research endeavors, NASA is working toward zero-emission aircraft; smoother, safer airline flights; and elimination of low-visibility-induced accidents.

APEX: Measuring Emissions So That Future Aircraft Fly Cleaner


NASA has been studying various types of emissions from commercial aircraft to develop ways to reduce them and protect the environment. In recent years, fine-particle emissions from aircraft have been identified as possible contributors to global climate changes and to lowering local air quality. These emissions are produced when a hydrocarbon fuel (such as modern jet fuel, which is primarily kerosene) does not burn completely. Incomplete combustion often occurs at the lower power settings used for aircraft descent, idling, and taxiing. This produces fine carbon particles, or soot, as well as particles of nonvolatile organic compounds. In addition, engine erosion and small amounts of metal impurities in jet fuel can be emitted in engine exhaust.

DC-8 airborne research laboratory in flight The DC-8 airborne laboratory flies three primary types of missions: sensor development, satellite sensor verification, and basic research studies of the Earth’s surface and atmosphere.

Another type of particle emission is formed when exhaust cools, converting volatile aerosols of sulfur compounds and organic compounds to small, solid particles. These types of emissions are not addressed by current international regulations, which focus on visible smoke, but the international community is concerned about the effects that these emissions may have and is identifying possible regulations. In addition, reducing all types of aircraft emissions is necessary for the U.S aircraft industry to remain competitive in the global market.

The DC-8 plane gathers data through remote sensing.
Data gathered by the DC-8 airborne laboratory at flight altitude and by remote sensing have been used for scientific studies in archaeology, ecology, geography, hydrology, meteorology, oceanography, volcanology, atmospheric chemistry, soil science, and biology.

Recently, Glenn took part in the successful Aircraft Particle Emissions Experiment (APEX). NASA’s DC-8 airborne laboratory was used with CFM-56 engines to improve understanding of particle emissions from commercial aircraft engines. It was the first and most extensive set of data obtained about gaseous and particulate emissions from an in-service commercial engine. Many different instruments were used, and a tremendous amount of data was obtained.

NASA scientists ran tests to investigate the effects of thrust and fuel type. The team used different engine operating settings to vary thrust, and three different fuels were used: a typical jet fuel, a fuel with high sulfur content, and a fuel with high aromatic compound content. In addition, the Environmental Protection Agency ran tests to simulate landing-takeoff cycles to study the emissions that would be created at an airport. It was the first time that so many different groups had worked together to study so many different aspects of the emissions from commercial aircraft engines.

Smoothing Out the Skies


Passengers on a Delta Air Lines jet could have a smoother ride, thanks to NASA-developed technology. Delta is installing a special production-prototype radar, which can detect turbulence associated with thunderstorms, on one of its B737-800 aircraft. The radar, called the Turbulence Prediction and Warning System (TPAWS), was developed for NASA’s Aviation Safety and Security Program at Langley Research Center.

NASA teamed with Delta Air Lines, of Atlanta; AeroTech Research (USA), Inc., of Newport News, Virginia; and Rockwell Collins, of Cedar Rapids, Iowa, for the in-service evaluation of the radar unit, which also includes turbulence hazard prediction capabilities.

“The TPAWS technology is an enhanced turbulence detection radar system, which detects atmospheric turbulence by measuring the motions of the moisture in the air,” said Jim Watson, the TPAWS project manager. “It is a software signal processing upgrade to existing predictive Doppler wind shear systems, also developed by NASA, that are already on airplanes.”

Turbulence reports safely guide Delta Air Lines flights. Dispatcher’s display of turbulence-encounter reports integrated with weather data. These reports are used to safely guide Delta Air Lines flights in real time.

The idea behind the turbulence detection system is to give flight crews advanced warning, so they can avoid turbulence encounters or advise flight attendants and passengers to sit down and buckle up to avoid injury. Turbulence encounters are hazardous, and they cost the airlines money and time in the form of re-routing flights, late arrivals, and additional inspections and maintenance to aircraft. Atmospheric turbulence encounters are the leading cause of injuries to passengers and flight crews in non-fatal airline accidents. Federal Aviation Administration statistics show an average of 58 airline passengers are hurt in U.S. turbulence incidents each year. Ninety-eight percent of those injuries happen because people do not have their seatbelts fastened.

NASA researchers say the TPAWS radar can detect about 80 percent of all atmospheric turbulence encounters. It can also detect thunderstorm-related turbulence at an average of 3 to 5 minutes ahead of the aircraft. According to studies done by Dryden Flight Research Center engineers, it takes a little more than a minute and a half to get 95 percent of passengers seated, carts stored, and flight attendants secured. Delta flight crews will use and evaluate the technology during regularly scheduled flights in the United States and South America. The prototype is expected to fly for 6 to 9 months.

Researchers from NASA, the companies involved, and the Federal Aviation Administration, will evaluate interim and final results of the turbulence prediction radar system. If the evaluation is successful, the technology may be adopted for new and existing aircraft.

NASA has already tested TPAWS on a research aircraft based at Langley. The TPAWS-equipped plane searched for turbulence activity around thunderstorms for 8 weeks. The jet flew within a safe distance of storms, so researchers could experience the turbulence and compare the radar prediction to how the plane responded to the encounters. After one severe patch of turbulence, a NASA research pilot said his confidence in the enhanced radar had “gone up dramatically,” since the plane’s weather radar had shown nothing at the same time the TPAWS display had shown rough skies ahead.

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