Friday, April 29, 2011

Materials: Out of This World

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Space isn't empty. Space is considered an environment — an extreme environment, filled with entities that can be harmful to spacecraft.

In space, there are several environmental threats that can harm materials used to create spacecraft. These threats include ultraviolet rays and x-rays from the sun; solar wind particle radiation; thermal cycling (hot and cold cycles); space particles (micrometeoroids and debris); and atomic oxygen.

It is essential for NASA to research and understand how materials are affected by the environmental threats that exist in space. Since 2001, NASA and its partners have operated a series of flight experiments called Materials International Space Station Experiment, or MISSE. The objective of MISSE is to test the stability and durability of materials and devices in the space environment.

Testing on the International Space Station

MISSE experiments have been flown in space on five different occasions, and will be flown once more. During each mission, either one or two Passive Experiment Containers (PECs) are flown. PECs, which are attached to the exterior of the International Space Station, are about 2-feet by 2-feet and hold a variety of materials samples and devices whose reactions in space are of interest.

"Each PEC has two trays that are hinged like a suitcase. Samples are loaded onto the top surface of the trays, and then the PEC is closed to protect the samples during launch on the space shuttle," says Kim de Groh, the principal investigator for the MISSE Science program at Glenn. "The PECs are taken up to the space station, where an astronaut does a spacewalk and installs each PEC at its designated location on the outside of the space station. The PEC is opened by the astronaut and the trays are placed back-to-back and secured, exposing the samples to the space environment."

The PECs are positioned in either a ram/wake orientation or in a zenith/nadir orientation. The ram orientation is the direction in which the space station is traveling, and the wake orientation faces the direction traveled. The zenith orientation faces away from Earth into space, while the nadir orientation faces straight down to Earth. Each orientation exposes the samples to different space environmental factors.

Once installed, the samples remain outside of the space station, exposed to the environmental threats of space for a pre-determined period of time. Some of the experiments are active, meaning they produce and record data while still in space. Others are passive, meaning their data will be measured once they return to Earth.

Once the PECs are removed from the exterior of the space station, they are returned to Earth via another space shuttle mission or on a partner agency's spacecraft. Back on Earth, the effects of the space environment on each material sample are catalogued and studied.

Each MISSE PEC includes numerous different experiments with hundreds of test samples. Each individual experiment within MISSE is coordinated by a NASA center or partner agency. NASA's Glenn Research Center in Cleveland has flown experiments on every MISSE mission since 2001.

"Glenn has been very honored to be able to fly many environmental exposure experiments with more than 600 test samples on the space station as part of the MISSE program," Kim de Groh says.

Glenn's MISSE Experiments

The MISSE PECs that have already been flown are MISSE 1 & 2, 3 & 4, 5, 6A and 6B. MISSE 7A and 7B are currently flying, and will be returned to Earth during the STS-134 shuttle mission. MISSE 8A and 8B will be delivered to the space station during STS-134, scheduled for launch in April 2011.

The MISSE 7A and 7B PECs hold fifty-two experiments which explore materials, electronics and solar cells.

"On MISSE 7, Glenn has ten individual experiments with 155 samples," Kim de Groh says.

Glenn's ten MISSE 7 experiments include: Zenith Polymers Experiment; Nadir Tensile Sample Experiment; Atomic Oxygen Fluence Monitor; LIDS Docking Seals; Polymer Experiment; Atomic Oxygen Scattering Chamber; Atomic Oxygen Pinhole Camera; Flexural Stress Effects Experiment; Thermal Control Paints Experiment; and Spacesuit Fabrics Exposure Experiment.

Each experiment investigates how materials that are critical to space exploration are impacted by the exposure to the rigors of the space environment.

Space Suiting Up

When astronauts travel outside of a space vehicle—for a space walk outside of the space station or to explore the surface of a celestial body, such as the moon—they must wear spacesuits to protect themselves. The fabric that is used to create these spacesuits must be able to withstand the harsh environment of space for long durations while protecting the astronauts who wear the suits.

The Spacesuit Fabrics Exposure Experiment is designed to identify and evaluate the effect of long-term ultraviolet (UV) radiation on spacesuit fabric. Pristine fabric, or fabric with no contaminants on it, is tested, along with dust-damaged fabrics.

The experiment includes six samples of fabrics: new, state-of-the-art orthofabrics that are pristine; new orthofabrics that are dusted in a lab on the ground with a lunar dust simulant; Apollo era fabrics that are pristine; Apollo era fabrics that are dusted with lunar dust simulant in a lab on the ground; and Apollo 12 mission fabric which is dusted with real lunar dust.

The fabric from the Apollo 12 mission is a piece of the actual spacesuit worn by Alan Bean. The fabric, taken from the knee of the suit, is coated with lunar dust that accumulated on the suit when Bean wore the suit on the moon in 1969.

Comparing the effects of space on the historical fabrics with the effects of space on the modern fabrics will lead to a greater understanding of the efficacy of the new fabrics. Investigating the differences between the dusted fabrics and the clean fabrics will increase the knowledge of how spacesuit fabrics perform in a realistic setting.

"We want to document the appearance of the samples before and after flight to understand changes that occur as a result of long term exposure to the space environment," says Don Jaworske, the program manager for the MISSE Science program at Glenn and the principal investigator for the Space Suit Fabrics Exposure Experiment.

Put a Lid On It

When a spacecraft flies with humans as passengers, the spacecraft must be tightly sealed so that the air inside of the craft is breathable. The air inside the cabin must sustain life, so tight seals that protect the air are imperative.

The Low Impact Docking System (LIDS) Seal Experiment investigates how potential seal materials perform when they are subjected to the environmental threats in space.

"We are hoping these tests of different rubbers will help us develop a seal that will work well on NASA's next crew module. The seal will be used where the crew module docks to another spacecraft, such as the International Space Station, and is designed to seal in the cabin air and keep it from leaking out," says Henry de Groh III, the principal investigator for the LIDS Seal Experiment.

Thirty-four samples are included in the experiment. These include elastomer O-ring samples; aluminum samples with a microinch surface finish; and RTV (Room-Temperature-Vulcanizing) adhesive seals.

This experiment continues work begun on earlier MISSE missions, increasing and fine-tuning the knowledge of how to create the best seals that protect humans traveling in space. Each of these samples plays an important role in creating spacecraft seals that protect life by withstanding the damage caused by exposure to space.

Exposing Polymers

From the very first MISSE mission to the very last, Glenn has flown (and is scheduled to fly) samples as part of their Polymers Experiment series (flown on MISSE 2, 5, 6, 7 and 8). Currently, a variety of polymer samples are flying on MISSE 7 and additional samples will be flown on MISSE 8.

"We have a wide variety of polymers that are being flown so that we can determine each polymer's atomic oxygen erosion yield, which is how quickly the polymers erode in the space environment. Erosion yields are values that spacecraft designers need to know to in order to design durable spacecraft materials and components," says Kim de Groh, who is also the principal investigator for the Polymers Experiments.

The Polymers Experiments include numerous types of polymers that are used on spacecraft, as well as polymers that are not traditionally used on spacecraft, so the effect of space on different materials can be better understood for predictive model development. Teflon, Mylar, Kapton and Tedlar are included in the Polymers Experiments.

New polymers that have never been flown, as well as new samples of polymers that have been flown on previous missions, are included in the Polymers Experiments. Certain polymers may experience a different rate of erosion based on how long they are exposed to the space environment, making the comparative data sets from different MISSE missions insightful for long space flights.

Understanding how polymers respond to the harsh environment of space is critical to creating durable, safe spacecraft.

"If a spacecraft is being built with materials that are going to be exposed to atomic oxygen and will erode away over time (like polymers), you need to know how quickly they will erode. Therefore, we are collecting erosion flight data and documenting the data for spacecraft designers," Kim de Groh says.

The data that will be generated from the MISSE 7 and MISSE 8 Polymer Experiments will contribute to the ongoing evolution of how spacecraft are designed.

"Glenn's MISSE polymer erosion data has been widely requested," Kim de Groh says. "The flight data has directly impacted spacecraft materials design."

New Knowledge

The knowledge acquired from the previous MISSE missions, which will be increased and enhanced by the information from MISSE 7 and 8, has changed the way spacecraft are designed and maintained. From determining the best way to restore the Hubble Space Telescope to selecting materials for the next generation of landing modules, the contributions from MISSE are invaluable.

"The MISSE program has provided the space community with a unique opportunity to expose materials to the space environment for long durations," Kim de Groh says. "We are very grateful to have participated in each of the MISSE missions."

For more information visit http://www.nasa.gov/centers/glenn/shuttlestation/station/misse.html

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Thursday, April 28, 2011

TRMM Satellite Sees Massive Thunderstorms in Severe Weather System

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The Tropical Rainfall Measuring Mission or TRMM satellite again flew over severe thunderstorms that were spawning tornadoes over the eastern United States on April 28 and detected massive thunderstorms and very heavy rainfall.

TRMM, a satellite managed by both NASA and the Japanese Space Agency, captured the rainfall rates occurring in the line of thunderstorms associated with a powerful cold front moving through the eastern U.S. on April 28. TRMM flew over the strong cold front and captured data at 0652 UTC (2:52 AM EDT) on April 28, 2011. Most of the rainfall was occurring at moderate rates however, there were pockets of very heavy rainfall in Virginia, North Carolina, South Carolina, Georgia and Alabama where rain was falling at a rate of 2 inches (50 millimeters) per hour.

Tornadoes associated with this extremely unstable weather caused the deaths of at least 128 people in Alabama and 15 in Georgia.

TRMM data was also used to generate a 3-D look at the storm. TRMM's Precipitation Radar (PR) data was used by Hal Pierce of SSAI at NASA's Goddard Space Flight Center in Greenbelt, Md. to create a 3-D structure of those storms. The image Pierce created is a TRMM radar vertical cross section that shows some of these violent storms reached to incredible heights of almost 17 km (~10.6 miles).

For more information visit http://www.nasa.gov/topics/earth/features/severe-storms-20110428.html

Tuesday, April 26, 2011

The Big Picture Wins Big

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Remember life before cell phones? Or GPS? Or tablet computers? Kind of hard, isn't it? Air traffic management researchers feel the same way about life before the Future ATM (Air Traffic Management) Concepts Evaluation Tool, or FACET.

FACET is a computer program developed by NASA that generates simulations for managing air traffic scenarios. It provides a "big picture" view of what's happening in the skies overhead. For any given moment in time, it can show thousands of aircraft swarming through our national airspace. With each aircraft represented as a tiny icon, a FACET simulation can look like an "ant farm in the sky," with aircraft clustering around major airports like ants targeting a drop of peanut butter. You may have seen video generated from FACET on the morning news during air travel outlook reports.

Recently, the creators of this simulation software at NASA's Ames Research Center in California won NASA's 2010 Government Invention of the Year. The award, presented by NASA's Inventions and Contributions Board, is given to inventions that have made a significant contribution to NASA's goals and to broader communities; in this case, the aeronautics community. Nominations are rated on use, creativity, benefits to the community, and overall significance to humankind.


This series of FACET simulations shows a typical day in U.S. air travel, an atypical day (September 11, 2001), and even
daily air travel sorted by U.S. airlines. Video credit: NASA/Smithsonian Air and Space Museum

"As the world's population grows and air travel demand increases, our airspace will become more crowded," said Banavar Sridhar, NASA senior scientist for Air Transportation Systems. "FACET helps air traffic management researchers find ways to increase airspace capacity and establish more efficient routes with the least impact on the environment, thereby saving fuel and minimizing emissions."

One of the best things about FACET is that it doesn't need supercomputers to run, even when asked to crunch data from thousands of flight plans. The software can operate on a single computer, which was a big leap forward that really helps researchers. FACET can model current traffic patterns to see where improvements could be made, or model entirely new patterns that result from new flight operations techniques, like new merging and spacing rules, weather avoidance techniques, or approach patterns into airports.

How does it work? FACET uses aircraft performance profiles, airspace models, weather data, and flight schedules to model trajectories for the climb, cruise, and descent phases of flight for each type of aircraft. Then a graphical interface displays the traffic patterns in two and three dimensions, under various current and projected conditions for specific airspace regions or over the entire continental United States. You'll see examples of all of these different models in the video linked from this page.

According to FACET team members, the software has become a valuable tool for Federal Aviation Administration traffic flow managers and commercial airline dispatchers. They use FACET technology to do real-time operations planning by combining live air traffic data from FAA radar systems and weather data from the National Weather Service to create a real-time big picture of what's happening in the air. With that information, airspace system operators can reroute flights around congested airspace and severe weather to maintain safety and minimize delay.

This is one big picture that's having a big impact on air travel.

For more information visit http://www.nasa.gov/topics/aeronautics/features/big_picture_facet.html

Sunday, April 24, 2011

The Water Planet

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Viewed from space, the most striking feature of our planet is the water. In both liquid and frozen form, it covers 75% of the Earth’s surface. It fills the sky with clouds. Water is practically everywhere on Earth, from inside the planet's rocky crust to inside the cells of the human body.

This detailed, photo-like view of Earth is based largely on observations from MODIS, the Moderate Resolution Imaging Spectroradiometer, on NASA's Terra satellite. It is one of many images of our watery world featured in a new story examining water in all of its forms and functions.

For more information visit http://www.nasa.gov/multimedia/imagegallery/image_feature_1925.html

Thursday, April 21, 2011

NASA's Arctic Ice Campaign Adds Second Aircraft

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NASA scientists conducting an airborne campaign right now in the Arctic to monitor changes in sea ice and ice sheet thickness have a new tool.

A second aircraft -- the King Air B200 -- arrived in Kangerlussuaq, Greenland, carrying an instrument that maps the icy surface from more than five miles (8 km) above, providing yet another perspective of Earth's changing polar regions.

The newest addition flew on April 13 to join Operation IceBridge -- a six-year airborne mission to monitor Earth's polar ice. The B200 will target the southeastern portion of the Greenland Ice Sheet, where NASA satellites have shown ice loss.

The flight marks the first trip to Greenland for the aircraft from NASA's Langley Research Center in Hampton, Va. The King Air is carrying the Land Vegetation and Ice Sensor (LVIS) instrument, a laser altimeter that can map large areas of sea ice and ice sheets.

IceBridge data provides a three-dimensional view of the Greenland Ice Sheet that will help predict future contributions to rising seas. A series of science flights designed to increase knowledge of ice sheet processes and sea level rise contributions are scheduled for April 15 through May 9.

Current estimates of sea level rise from Greenland are placed at .5 millimeters annually.

The B200 flights complement sea ice flights by the P-3B aircraft out of NASA's Wallops Flight Facility in Wallops Island, Va. The P-3B has been in Greenland since March 14. Flights were conducted from Thule for the first part of the mission and then out of Kangerlussuaq since April 1.

The P-3B is carrying a suite of instruments including a magnetometer, gravimeter, Airborne Topographic Mapper and camera systems.

Little Plane, Big Capability

From the outside the King Air looks like it could carry a dozen passengers, but inside, it is much smaller. There is only room onboard for a pilot, a crew member and one scientist.

"Being the only instrument on the plane gives us a lot of flexibility to optimize the flight plan to best utilize the unique capabilities of LVIS," said Bryan Blair, LVIS principal investigator from NASA's Goddard Space Flight Center in Greenbelt, Md. "LVIS works best at higher altitudes and the B200 is a very good platform for operating at 28,000 feet (8,534 m) for up to five hours."

Being small also has its disadvantages. There is less room to carry fuel and equipment and the flight crew must wear thermal dry suits in case of a loss of power over water. The U.S. Coast Guard immersion suits they wear are designed to keep them alive for 12 to 24 hours in freezing cold Arctic waters.

Operating on the King Air is a big change from other NASA planes used in previous IceBridge campaigns, such as the DC-8 and P3-B from getting the instrument integrated onto the smaller aircraft to having just one person fly along with it during the mission, said David Rabine, LVIS Instrument Engineer at Goddard.

The flights will be a little tougher than past flights on larger planes. There's no bathroom on the King Air and no room to walk around. No microwave or leather seats either, Rabine said.

Traveling to Greenland with the LVIS team are six King Air veteran crew from NASA Langley: pilots Les Kagey and Rick Yasky, flight operations engineer Luci Crittenden, crew chiefs Scott Sims and Rob White, and mission quality assurance specialist Carey Smith. They're all used to the long, difficult flights.

"It has been great working with the entire crew at Langley. They have worked very hard to accommodate us, and we enjoyed working with them," Blair said.

NASA's Beechcraft King Air B200 aircraft is a twin-engine turboprop. Its range is about 920 miles (1,480 km), depending on weight and the weather, and it can fly up to 298 miles per hour (480 kph). The maximum weight the aircraft can carry is 2,500 pounds (1,134 kg), or 500 pounds (227 kg) with full fuel load.

The twin-turboprop engine plane was built in 1982, but came to NASA Langley from NASA's Marshall Space Flight Center in January 1996. Many of its science flights have been geared toward atmospheric studies. This mission is a new venture for the King Air crew.

"This is one of our biggest projects," said Howard Lewis, director of Langley's Flight Research Services Directorate. "We've got a lot of Goddard instrument flights coming up."

The King Air flight plans will take LVIS to high altitudes, covering much of Greenland's coast and many of its outlet glaciers. Like all science flights, however, the King Air's flight plans are subject to weather and other changes or delays.

The small plane also means lower costs, less fuel use and better agility.

"It's a great airplane to do field missions with," said Dale Bowser, head of Langley's Research Systems Integration Branch.

For more information visit http://www.nasa.gov/topics/earth/features/icebridge-b200.html

Wednesday, April 20, 2011

Could Burning Fuel on the Space Station Ultimately Save Fuel on Earth?

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The price of gas is skyrocketing, but thankfully so is a potential mitigation. The recent mission of the Space Shuttle Discovery, which returned home on March 9, 2011, included the delivery of fuel and equipment for the Structure and Liftoff In Combustion Experiment, or SLICE, to the International Space Station. The goal of SLICE is to use microgravity flame studies to learn more about how combustion works and ways to make it more efficient.

Flame studies on Earth are hampered by gravity-induced instability -- picture a flickering candle flame -- which complicates analysis. This is due to buoyancy, which is when less dense materials rise within a fluid of greater density -- this time imagine a hot air balloon. Buoyancy is nearly absent in microgravity, making it possible to study a broader array of flame characteristics, such as the range of soot concentration and the flame temperature.

Project scientist and co-investigator Dennis Stocker explains the benefits of investigating flames in space, "It is possible to study spherical (i.e., one-dimensional) flames in microgravity, which is not possible in Earth gravity, but dramatically simplifies the otherwise complex analysis. Microgravity flames have large scales and long residence times, allowing for improved studies of the flame structure and soot, respectively…An understanding of lifting and lifted behavior is also valuable, because of the importance of flame stability and the potential benefits for combustion at fuel lean conditions where both optimum performance and low emissions can be achieved."

Here on Earth, knowledge from space station flame studies can contribute to reduced pollution. Stocker points out that even small gains in combustion efficiencies can lead to significant improvements, given the high use of fuels to warm homes, cook food, and fuel vehicles from cars to spacecraft. "While we benefit greatly from combustion, it is a significant source of greenhouse gasses and contributes to the global climate change. Furthermore, combustion-caused pollutants, like soot, harm our health and unwanted fire remains an important safety risk."

Scheduled to operate in late 2011 or early 2012, SLICE will study the combustion of gaseous fuels in the microgravity environment of the space station. These fuels include varied dilutions of methane and ethylene. Methane is the main component of natural gas and ethylene is an example of fuels with a higher soot production. These were selected because their combustion chemistry is well understood, making the flames easier to computationally model.

Astronauts will run the investigation while communicating with ground researchers at NASA Glenn Research Center and Yale University. The scientists will examine the characteristics of the flames, such as color, shape, and the lifted distance from the burner. The resulting data will contribute to practical improvements in areas such as turbulent combustion, ignition, and flame stability via improved flame computational models. Using these superior models, engineers could design more efficient combustion devices for use in everything from in-home stoves to power plants and vehicles.

SLICE is a precursor to a series of future studies, known as the Advanced Combustion via Microgravity Experiments or ACME. Information from previous flame investigations is used to optimize scientific returns from each subsequent study. For instance, the Enclosed Laminar Flames or ELF investigation, flown on the space shuttle mission STS-87 in 1997, provided the basis for the hardware used for SLICE. The aim of SLICE and the entire ACME project is to advance energy technology -- something that may one day contribute to greater fuel efficiency via improved combustion and possibly less pain at the pump.

For more information visit http://www.nasa.gov/mission_pages/station/research/news/slice.html

Tuesday, April 19, 2011

Hurricane Earl: The Astronaut View

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The relatively placid view from the International Space Station belied the potent forces at work in Hurricane Earl as it hovered northeast of Puerto Rico on Aug. 30, 2010. With maximum sustained winds of 135 miles (215 kilometers) per hour, the storm was classified as a category 4 on the Saffir-Simpson hurricane scale as it passed north of the Virgin Islands.

In this photograph captured with a digital SLR camera by NASA astronaut Douglas Wheelock, Earl had a distinct eye that spanned about 17 miles (28 kilometers). Most of the storm had a seemingly uniform top, though the bottom edge of the image gives some sense of the towering thunderheads forming over the ocean. The solar panels of the ISS remind us that the sun is still shining, at least on ISS Expedition 24.

"Hurricane Earl is gathering some serious strength," Wheelock wrote from his perch on ISS. "It is incredible what a difference a day makes when you’re dealing with this force of nature. Please keep a watchful eye on this one...not sure if Earl will go quietly into the night like Danielle."

For more information visit http://www.nasa.gov/multimedia/imagegallery/image_feature_1922.html

Monday, April 18, 2011

ICESCAPE

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The terrain for the scientific work conducted by ICESCAPE scientists on July 4, 2010, was Arctic sea ice and melt ponds in the Chukchi Sea. The five-week field mission was dedicated to sampling the physical, chemical and biological characteristics of the ocean and sea ice. Impacts of Climate change on the Eco-Systems and Chemistry of the Arctic Pacific Environment, or ICESCPE Mission, is a multi-year NASA shipborne project. The bulk of the research will take place in the Beaufort and Chukchi Seas in summer of 2010 and fall of 2011.

For more information visit http://www.nasa.gov/multimedia/imagegallery/image_feature_1921.html

Sunday, April 17, 2011

NASA Names Mission Control for Legendary Flight Director Christopher Kraft

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NASA is recognizing Christopher C. Kraft Jr., America's first human space mission flight director, by naming the Mission Control Center in his honor for his service to the nation and its space programs.

Johnson Space Center Director Michael Coats made it official April 14 at a dedication ceremony and unveiling of a new nameplate on the building, designating the legendary building as the Christopher C. Kraft Jr. Mission Control Center.

“Dr. Kraft’s life stands as a testament to his dream of exploring space. A dream he realized here on Earth, in this building and at this center, through his engineering and managerial expertise,” said Coats. “He is a space pioneer without whom we’d never have heard those historic words on the surface of the moon, ‘Houston, Tranquility base here. The Eagle has landed.’ Those words effectively put Houston, and this building behind us, on the intergalactic map forever.”

Hundreds of NASA employees applauded as the nameplate was unveiled.

“When we started the Space Task Group in 1958, I don’t think any of us appreciated what we were up to, where we were going, what it was going to result in, the impact on the country, the impact on the world,” Kraft said. “Our experiences, our joys, were something that we were all extremely proud of. We still are today. It’s great to be in this country where we can do that sort of thing. I’m pleased as I can be to have you name this building after me and not because it’s me, but because it is the flight control people and those people here at the Johnson Space Center.”

“Without Dr. Kraft’s leadership, the concept of mission control would not be what it is today,” Coats added. “The dedicated people inside this building have accomplished incredible things over the last five decades based on the foundations laid by Dr. Kraft and his early flight control development team.”

In addition to Coats and Kraft, the ceremony featured additional remarks by John McCullough, current chief of the NASA flight director’s office; Gene Kranz, Kraft’s successor as flight director and former director of Mission Operations, and Glynn Lunney, a former flight director who worked with Kraft, and also a former Space Shuttle Program manager and vice president of United Space Alliance.

As flight director, Kraft managed all of the Mercury and several Gemini missions, and was in that role for America’s first human spaceflight, first human orbital flight, and first spacewalk. He also was one of the designers and implementers of the Mission Control Center, the heart of all NASA crewed space missions.

Kraft joined NASA's predecessor agency, the National Advisory Committee for Aeronautics, in 1945. In 1958, he joined the newly created NASA as one of the original members of the Space Task Group organized to design and manage Project Mercury. He moved from Langley Research Center in Virginia with that group to Houston in 1962, and was assigned to develop the facilities, systems and techniques necessary to support human spaceflights.

As a member of the flight operations division he was assigned the responsibility of putting together a “mission plan” for putting America’s first man into space. Instructions from his boss, Chuck Mathews were, “Chris, you come up with a basic mission plan. You know, the bottom-line stuff on how we fly a man from a launch pad into space and back again. It would be a good idea if you kept him alive.”

A vast set of challenges faced Kraft. He immediately recognized that during the fast-paced launch phase an astronaut could only do so much. He envisioned a team of specialists on the ground to monitor spacecraft health in real time. This involved defining/developing a first-of-a-kind operations facility, communications network, spacecraft tracking systems, telemetry, flight plans, timelines, constraints and flight rules, standard and contingency procedures as well as plans and techniques to locate and recover the astronaut and spacecraft after splashdown in the ocean. In addition, a group of engineers would need to be brought together and trained as a team to develop command and control protocols to for normal procedures as well as to immediately react to problems in real time.

Through his leadership the Mercury Control Center took shape at Cape Canaveral, Florida, and his concept of “Mission Control” was tested and developed successfully as he served as the Flight Director for seven unmanned and six manned missions during the Mercury Program.

In 1965, the Manned Spacecraft Center’s “Mission Control Center (MCC) in Houston supported its first human spaceflight during the second two-manned Gemini flight, Gemini IV. At the helm again was Kraft as he continued to “invent” the MCC operation during the Gemini Program’s first rendezvous and spacewalk.

During the Apollo program Kraft became the Director of Flight Operations responsible for the overall manned spaceflight planning, training, and execution. His leadership in this arena continued through Apollo 12 in 1969, at which time he became Deputy Director of what is now Johnson Space Center. He served as the Center Director from January of 1972 until his retirement in 1982, playing a vital role in the success of the final Apollo missions, the first manned space station, Skylab, the first international space docking during the 1975 Apollo-Soyuz Test Project, and the first Space Shuttle flights.

A vast set of challenges faced Kraft. He immediately recognized that during the fast-paced launch phase an astronaut could only do so much. He envisioned a team of specialists on the ground to monitor spacecraft health in real time. This involved defining/developing a first-of-a-kind operations facility, communications network, spacecraft tracking systems, telemetry, flight plans, timelines, constraints and flight rules, standard and contingency procedures as well as plans and techniques to locate and recover the astronaut and spacecraft after splashdown in the ocean. In addition, a group of engineers would need to be brought together and trained as a team to develop command and control protocols to for normal procedures as well as to immediately react to problems in real time.

Through his leadership the Mercury Control Center took shape at Cape Canaveral, Florida, and his concept of “Mission Control” was tested and developed successfully as he served as the Flight Director for seven unmanned and six manned missions during the Mercury Program.

In 1965, the Manned Spacecraft Center’s “Mission Control Center (MCC) in Houston supported its first human spaceflight during the second two-manned Gemini flight, Gemini IV. At the helm again was Kraft as he continued to “invent” the MCC operation during the Gemini Program’s first rendezvous and spacewalk.

During the Apollo program Kraft became the Director of Flight Operations responsible for the overall manned spaceflight planning, training, and execution. His leadership in this arena continued through Apollo 12 in 1969, at which time he became Deputy Director of what is now Johnson Space Center. He served as the Center Director from January of 1972 until his retirement in 1982, playing a vital role in the success of the final Apollo missions, the first manned space station, Skylab, the first international space docking during the 1975 Apollo-Soyuz Test Project, and the first Space Shuttle flights.

For more information visit http://www.nasa.gov/mission_pages/shuttle/behindscenes/kraft_mcc.html

Friday, April 15, 2011

Student Questions Needed: Earth Day Video Chat

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To celebrate Earth Day 2011, the Education Office at NASA's Jet Propulsion Laboratory in Pasadena, Calif., is hosting a live Web video chat where your students can ask a NASA/JPL scientist questions emailed in advance. Questions should be on the topic of Earth science. Our chat is best suited for students and afterschool groups in grades 4 - 6.

Our guest will be NASA/JPL research scientist Annmarie Eldering, who specializes in clouds, aerosols and trace gases in Earth's atmosphere. She is currently the deputy project scientist for the Orbiting Carbon Observatory-2, a NASA satellite mission now in development that will measure atmospheric carbon dioxide, the leading human-produced greenhouse gas driving changes in Earth's climate.

The live video chat will be streamed at http://www.ustream.tv/nasajpl2 on Thursday, April 21 at 10 a.m. PDT/ 1 p.m. EDT. The Web page is open to the general public. The program will be archived on the same page.

Classrooms are strongly encouraged to visit the Web page in advance to make sure their school provides access. We will run a video and audio feed all day on Wednesday, April 20 (starting at 9 a.m. PDT) so we also strongly suggest schools visit the page that day.

Questions should be emailed to jplspaceeducation@gmail.com and must be received by Monday, April 18, by noon PDT. Questions should include school or group name, city and state. Due to resources, we cannot answer all questions but will make every attempt to answer at least one question per class.

For more information visit http://www.nasa.gov/centers/jpl/education/earthday2011-20110413.html

Thursday, April 14, 2011

WISE Delivers Millions of Galaxies, Stars, Asteroids

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Astronomers across the globe can now sift through hundreds of millions of galaxies, stars and asteroids collected in the first bundle of data from NASA's Wide-field Infrared Survey Explorer (WISE) mission.

"Starting today thousands of new eyes will be looking at WISE data, and I expect many surprises," said Edward (Ned) Wright of UCLA, the mission's principal investigator.

WISE launched into space on Dec. 14, 2009 on a mission to map the entire sky in infrared light with greatly improved sensitivity and resolution over its predecessors. From its polar orbit, it scanned the skies about one-and-a-half times while collecting images taken at four infrared wavelengths of light. It took more than 2.7 million images over the course of its mission, capturing objects ranging from faraway galaxies to asteroids relatively close to Earth.

Like other infrared telescopes, WISE required coolant to chill its heat-sensitive detectors. When this frozen hydrogen coolant ran out, as expected, in early October, 2010, two of its four infrared channels were still operational. The survey was then extended for four more months, with the goal of finishing its sweep for asteroids and comets in the main asteroid belt of our solar system.

The mission's nearby discoveries included 20 comets, more than 33,000 asteroids between Mars and Jupiter, and 133 near-Earth objects (NEOs), which are those asteroids and comets with orbits that come within 28 million miles (about 45 million kilometers) of Earth's path around the sun. The satellite went into hibernation in early February of this year.

Today, WISE is taking the first major step in meeting its primary goal of delivering the mission's trove of objects to astronomers. Data from the first 57 percent of the sky surveyed is accessible through an online public archive. The complete survey, with improved data processing, will be made available in the spring of 2012. A predecessor to WISE, the Infrared Astronomical Satellite, served a similar role about 25 years ago, and those data are still valuable to astronomers today. Likewise, the WISE legacy is expected to endure for decades.

"We are excited that the preliminary data contain millions of newfound objects," said Fengchuan Liu, the project manager for WISE at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "But the mission is not yet over -- the real treasure is the final catalog available a year from now, which will have twice as many sources, covering the entire sky and reaching even deeper into the universe than today's release."

Astronomers will use WISE's infrared data to hunt for hidden oddities, and to study trends in large populations of known objects. Survey missions often result in the unexpected discoveries too, because they are looking everywhere in the sky rather than at known targets. Data from the mission are also critical for finding the best candidates for follow-up studies with other telescopes, including the European Space Agency's Herschel observatory, which has important NASA contributions.

"WISE is providing the newest-generation 'address book' of the infrared universe with the precise location and brightness of hundreds of millions of celestial objects," said Roc Cutri, lead scientist for WISE data processing at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, Calif. "WISE continues the long tradition of infrared sky surveys supported by Caltech, stretching back to the 1969 Two Micron Sky Survey."

So far, the WISE mission has released dozens of colorful images of the cosmos, in which infrared light has been assigned colors we see with our eyes. The whole collection can be seen at http://wise.ssl.berkeley.edu/gallery_images.html .

JPL manages and operates the Wide-field Infrared Survey Explorer for NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

For more information visit http://www.nasa.gov/mission_pages/WISE/news/wise20110414.html

Tuesday, April 12, 2011

STS-1: A Monumental Spaceflight Milestone Recalled

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It was 30 years ago this week that NASA ushered in a new era of spaceflight with the inaugural launch of space shuttle Columbia on April 12, 1981, setting the pace for three decades of monumental leaps in environmental and space science achievements.

Thirty years and 133 missions later, NASA is winding down the space shuttle program, with the three remaining shuttle orbiters and the prototype shuttle Enterprise slated to be enshrined at several museums around the country after the last two missions, STS-134 and STS-135, are flown.

At a ceremony at the Kennedy Space Center on April 12, 2011, NASA Administrator Charlie Bolden announced that the shuttle Atlantis would be placed on display at the Kennedy Space Center, Discovery would be donated to the Smithsonian's National Air and Space Museum Udvar-Hazy Center near Dulles Airport near Washington, D.C., Endeavour would be displayed at the California Science Center in Los Angeles, and the Enterprise prototype would be transferred from the Udvar-Hazy Center to the Intrepid Sea, Air and Space Museum in New York City.

With triumph came tragedy, however, with the loss of two shuttles and their crews, Challenger upon launch in 1986, and Columbia upon return in 2003.

After more than two years of checkout of Columbia following its delivery to NASA in 1979 and years of training by astronauts in shuttle simulators, the program kicked off with the successful launch of Columbia on mission STS-1. Columbia was boosted into orbit by seven million pounds of thrust supplied by its solid-propellant rockets and liquid-hydrogen engines. The flight, the first of four orbital flight tests of Columbia, served as a two-day demonstration of the first reusable, piloted spacecraft's ability to go into orbit and return safely to Earth.

The launch coincided with the 20th anniversary of the first human spaceflight, that of Russian cosmonaut Yuri Gagarin in the Vostok 1 capsule on April 12, 1961.

That first operational test flight from Launch Pad 39A at the Kennedy Space Center in Florida carried Commander John Young and Pilot Robert Crippen into orbit.

"We were delighted when we got into orbit," Young said at a 25th anniversary commemorative program at Kennedy in 2006. "We learned that we can build a complicated vehicle and make it work very well."

The early flights helped NASA build on its knowledge of the vehicle and its capabilities. On its first mission, Columbia carried as its main payload a Developmental Flight Instrumentation pallet with instruments to record pressures, temperatures, and levels of acceleration at various points on the vehicle during launch, flight, and landing. In flight, Young and Crippen tested the spacecraft's on-board systems, fired the orbital maneuvering system for changing orbits, employed the reaction control system for controlling attitude, and opened and closed the payload doors.

One of many cameras aboard--a remote television camera--revealed some of the thermal protection tiles had disengaged during launch. As Columbia re-entered the atmosphere from space at Mach 24 (24 times the speed of sound) after 36 orbits, aerodynamic heating built up to over 3,000 degrees Fahrenheit, causing some concern during the time when the shuttle was out of radio communications with ground stations. But at 188,000 feet and Mach 10, Young and Crippen reported that the orbiter was performing as expected. After a series of maneuvers to reduce speed, the mission commander and pilot prepared to land.

While multiplied thousands of onlookers witnessed from public viewing sites established on the east short of the lakebed and other vantage points at Edwards, Young and Crippen flew the orbiter Columbia to a picture-perfect, unpowered landing on Runway 23 on Rogers Dry Lake at Edwards AFB, Calif., to conclude it's first orbital flight on April 14, 1981.

"We learned that humans in space are very adaptable and capable. And we also learned that the vehicle required a lot of care and was not forgiving of mistakes," Crippen said.

For more information visit http://www.nasa.gov/topics/shuttle_station/features/sts1_recalled.html

Sunday, April 10, 2011

The View from Up Top

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A low pressure system in the eastern North Pacific Ocean is featured in this image photographed on Mar. 20, 2011 by an Expedition 27 crew member in the Cupola of the International Space Station. Just under ten feet in diameter, the Cupola accommodates two crew members and portable workstations that can control station and robotic activities. The multi-directional view allows the crew to monitor spacewalks and docking operations, as well as provide a spectacular view of Earth and other celestial objects as evidenced in this image.

For more information visit http://www.nasa.gov/multimedia/imagegallery/image_feature_1914.html

Thursday, April 7, 2011

New Theory: Titan Shaped By Weather, Not Ice Volcanoes

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Have the surface and belly of Saturn's smog-shrouded moon, Titan, recently simmered like a chilly, bubbling cauldron with ice volcanoes, or has this distant moon gone cold? In a newly published analysis, a pair of NASA scientists analyzing data collected by the Cassini spacecraft suggest Titan may be much less geologically active than some scientists have thought.

In the paper, published in the April 2011 edition of the journal Icarus, scientists conclude Titan's interior may be cool and dormant and incapable of causing active ice volcanoes.

"It would be fantastic to find strong evidence that clearly shows Titan has an internal heat source that causes ice volcanoes and lava flows to form," said Jeff Moore, lead author of the paper and a planetary scientist at NASA's Ames Research Center, Moffett Field, Calif. "But we find that the evidence presented to date is unconvincing, and recent studies of Titan's interior conducted by geophysicists and gravity experts also weaken the possibility of volcanoes there."

Scientists agree that Titan shows evidence of having lakes of liquid methane and ethane, and valleys carved by these exotic liquids, as well as impact craters. However, a debate continues to brew about how to interpret the Cassini data on Titan. Some scientists theorize ice volcanoes exist and suggest energy from an internal heat source may have caused ice to rise and release methane vapors as it reached Titan's surface.

But in the new paper, the authors conclude that the only features on Titan's surface that have been unambiguously identified were created by external forces -- such as objects hitting the surface and creating craters; wind and rain pummeling its surface; and the formation of rivers and lakes.

"Titan is a fascinating world," said Robert Pappalardo, a research scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif., and former project scientist for NASA's Cassini mission. "Its uniqueness comes from its atmosphere and organic lakes, but in this study, we find no strong evidence for icy volcanism on Titan."

In December 2010, a group of Cassini scientists presented new topographic data on an area of Titan called Sotra Facula, which they think makes the best case yet for a possible volcanic mountain that once erupted ice on Titan. Although Moore and Pappalardo do not explicitly consider this recent topographic analysis in their paper, they do not find the recent analysis of Sotra Facula to be convincing so far. It remains to be seen whether ongoing analyses of Sotra Facula can change minds.

Titan, Saturn's largest moon, is the only known moon to have a dense atmosphere, composed primarily of nitrogen, with two to three percent methane. One goal of the Cassini mission is to find an explanation for what, if anything, might be maintaining this atmosphere.

Titan's dense atmosphere makes its surface very difficult to study with visible-light cameras, but infrared instruments and radar signals can peer through the haze and provide information about both the composition and shape of the surface.

"Titan is most akin to Jupiter's moon Callisto, if Callisto had weather," Moore added. "Every feature we have seen on Titan can be explained by wind, rain and meteorite impacts, rather than from internal heating."

Callisto is almost the exact same size as Titan. It has a cratered appearance, and because of its cool interior, its surface features are not affected by internal forces. Moore and Pappalardo conclude that Titan also might have a cool interior, with only external processes like wind, rain and impacts shaping its surface.

The Cassini spacecraft, currently orbiting Saturn, continues to make fly-bys of Titan. Scientists will continue to explore Titan's mysteries, including investigations of the changes in the landscapes.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and several of its instruments were designed, developed and assembled at JPL.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2011-111

Wednesday, April 6, 2011

NASA's Next Mars Rover Nears Completion

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Assembly and testing of NASA's Mars Science Laboratory spacecraft is far enough along that the mission's rover, Curiosity, looks very much as it will when it is investigating Mars.

Testing continues this month at NASA's Jet Propulsion Laboratory, Pasadena, Calif., on the rover and other components of the spacecraft that will deliver Curiosity to Mars. In May and June, the spacecraft will be shipped to NASA Kennedy Space Center, Fla., where preparations will continue for launch in the period between Nov. 25 and Dec. 18, 2011.

The mission will use Curiosity to study one of the most intriguing places on Mars -- still to be selected from among four finalist landing-site candidates. It will study whether a selected area of Mars has offered environmental conditions favorable for microbial life and for preserving evidence about whether Martian life has existed.

JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Science Laboratory mission for the NASA Science Mission Directorate, Washington.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2011-108

Tuesday, April 5, 2011

NASA's Global Hawks Mark Year of Science Flights

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This week marks the first anniversary of the NASA Global Hawk project’s initial science mission. On April 7, 2010, Global Hawk No. 872 took off from NASA’s Dryden Flight Research Center on Edwards Air Force Base, Calif., for its first science foray over the Pacific Ocean in the Global Hawk Pacific 2010 - or GloPac - science campaign.

Since that first science flight a year ago, NASA's Global Hawks have flown 12 science missions totaling 330 flight hours. The aircraft traveled more than 107,000 nautical miles to as far south as the equator, to 85 degrees north latitude and west toward Hawaii.

"The Global Hawk's early missions have provided some exciting insights into its potential Earth system science use," said Randy Albertson, deputy director of the Airborne Science Program in NASA's Earth Science Division. "It's range and endurance enables observations over parts of the globe that are difficult to reach for extended measurements over vast areas, particularly over the oceans and polar regions."

The first science flight, one of several in the GloPac campaign, lasted just over 14 hours. The high-altitude, long-endurance aircraft flew to an altitude of 60,900 feet and approximately 4,500 nautical miles. The flight path took the aircraft to 150.3 degrees west longitude and 54.6 degrees north latitude, just south of Alaska's Kodiak Island.

The aircraft carried 11 instruments that allowed GloPac researchers to measure and sample greenhouse gases, ozone-depleting substances, aerosols and air quality in the upper troposphere and lower stratosphere. View GloPac instruments A joint project of the National Oceanic and Atmospheric Administration and NASA, the Global Hawk flew several tracks under NASA's Earth-observing satellites.

The GloPac mission paved the way for the multi-aircraft Genesis and Rapid Intensification hurricane mission of late summer 2010. That six-week NASA mission was a study of the formation and strengthening of tropical storms in the Gulf of Mexico and western Atlantic Ocean. Twenty passes were completed over the eye of Hurricane Earl during one Global Hawk flight. NASA's DC-8, WB-57 and Global Hawk flew simultaneously on several data-collection flights. View GRIP instruments

"The Global Hawk's early missions have provided some exciting insights into its potential Earth system science use," said Randy Albertson, deputy director of the Airborne Science Program in NASA's Earth Science Division. "It's range and endurance enables observations over parts of the globe that are difficult to reach for extended measurements over vast areas, particularly over the oceans and polar regions."

A third science campaign in early 2011, the Winter Storms and Pacific Atmospheric Rivers mission, or WISPAR, explored atmospheric rivers and arctic weather and collected targeted observations designed to improve operational weather forecasts. Led by NOAA, WISPAR successfully evaluated the capabilities of an automated dropsonde system, dispensing 177 sondes over the mission's three flights.

"To take a military asset, like Global Hawk, and modify it to enable Earth science research is a great accomplishment for the NASA Global Hawk team," said Chris Naftel, Global Hawk project manager at NASA Dryden. "The completion of three very complex science campaigns during the first year demonstrates the ability of this team to conquer a vast array of challenges."

The coming years will find NASA's Global Hawk flight activity and scientific outreach grow considerably with two Earth Venture series missions. The Airborne Tropical Tropopause Experiment, or ATTREX, will allow scientists to study chemical and physical processes that control the flow of atmospheric gases at different times of the year. The Global Hawk will deploy to several bases in the Pacific Ocean region during the course of the ATTREX campaign.

The second Earth Venture mission, dubbed Hurricane and Severe Storm Sentinel, will study hurricanes in the Atlantic basin from a temporary base at NASA’s Wallops Flight Facility in Virginia during the 2012 – 14 Atlantic hurricane seasons.

"The Global Hawk's potential is sparking innovative development of new Earth observation strategies among the nation's scientists and the international community as well," Albertson added. "It's a new catalyst for international scientific collaboration, facilitating substantial gains in our understanding of our planet, as well as providing societal benefits around the world."

For more information visit http://www.nasa.gov/topics/earth/features/globalhawk_anniversary.html

Monday, April 4, 2011

NASA Test Stand Passes Review for Next-Generation Rocket Engine Testing

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Forty-five years after its first Saturn V rocket stage test and 35 years after its first space shuttle main engine test, the A-2 Test Stand at NASA’s John C. Stennis Space Center achieved a milestone in preparation for its third major rocket engine test project.

A facility readiness review in mid-March indicated all major modifications have been completed on the historic A-2 stand to begin testing the next-generation J-2X rocket engine this summer.

The new test project comes as Stennis celebrates its 50th anniversary year. On Oct. 26, 1961, NASA publicly announced plans to build the south Mississippi facility to test the massive Saturn V rocket stages for the Apollo Program.

The first test of a Saturn V second stage at Stennis was performed at the A-2 stand on April 23, 1966. Stennis engineers tested 27 first and second Saturn V rocket stages for the Apollo Program, including those used to carry humans to the moon.

In the mid-1970s, the stand was modified from Apollo Program parameters to allow testing of space shuttle main engines. The first space shuttle main engine test on the A-2 stand was conducted 35 years ago, on March 31, 1976. In ensuing decades, Stennis engineers tested space shuttle main engines used to power more than 130 missions. The last scheduled space shuttle main engine test was performed on the A-2 stand in July 2009.

After a decommissioning period, Stennis employees spent 10 months converting the A-2 stand from space shuttle main engine parameters to those needed for the new engine test series. The March 16-17 facility readiness review identified no major actions, which means the A-2 Test Stand is ready to receive the J-2X engine and begin checkout testing activation of engine critical systems. Stand employees now will work through the final items to be completed before installation of a J-2X engine in early June.

"Some of the hardware was decades old and nearing the end of its serviceability," said Gary Benton, manager of the J-2X engine testing project at Stennis. "Also, the J-2X has different testing requirements than the space shuttle main engine. It was a major transition completed on a very demanding schedule."

The transition work from the space shuttle main engine project to the J-2X test project included structural, electrical and plumbing modifications to accommodate the different geometry of the J-2X engine, and included the installation of a new J-2X engine start system. Liquid oxygen and liquid hydrogen transfer lines that dated back to the 1960s also were replaced, as was other piping on the stand. Control systems also were upgraded on the stand.

The J-2X engine is being developed by Pratt & Whitney Rocketdyne for NASA as a next-generation engine that can carry humans beyond low-Earth orbit to deep space. Engineers at NASA's Marshall Space Flight Center in Huntsville, Ala., manage J-2X engine development. Stennis is preparing three stands to test the new engine. Power pack testing is scheduled on the A-1 Test Stand. Verification and sea-level testing will be conducted on the A-2 Test Stand. The A-3 Test Stand under construction and set for activation in 2013 will allow operators to test new engines at simulated altitudes up to 100,000 feet, a critical requirement for a deep space engine.

Plans now are to install a J-2X research-and-development engine on the A-2 Test Stand this summer. Testing will begin soon afterward and continue throughout the year. Various verification and start-sequence tests will be performed.

"This is the future for American space exploration," Benton said. "We are excited to play a key part in the progress of the nation's space program."

For more information visit http://www.nasa.gov/topics/technology/features/A2TestStand-033111.html

Sunday, April 3, 2011

Science Q&A with Eric Jensen, NASA atmospheric scientist

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The Mid-latitude Airborne Cirrus Properties Experiment (MACPEX) is an airborne field campaign to investigate cirrus cloud properties and the processes that affect their impact on radiation. The campaign will use the NASA WB-57 aircraft based at Ellington, Texas and start its science flights over Oklahoma on April 1, 2011. Ames project scientist Eric Jensen agreed to answer a few of our questions about the campaign.

If the field campaign is ultimately about the amount of sun radiation the Earth absorbs or reflects, why is the study selectively studying cirrus clouds and their ice crystals? Why not just study atmospheric clouds in general?

Eric Jensen: Cirrus clouds are high, wispy white clouds made of fine ice crystals with typical altitudes of 16,500 – 45,000 ft. Modeling studies have shown that predictions of future climate change are very sensitive to assumptions made about cirrus clouds in the models. Cirrus clouds are less well understood than liquid clouds in the lower troposphere (the lowest portion of the atmosphere), largely because of a lack of observations and appropriate instrumentation in the past.

How are ice crystals formed? How are their microphysical properties related to the amount of radiation Earth reflects or absorbs?

EJ: Cirrus ice crystals form on existing aerosols in the atmosphere; however, the details of this process are not well understood. Cirrus clouds affect climate in two ways: they scatter incoming solar radiation and they absorb outgoing infrared radiation. The balance between these effects depends on the number and size of ice crystals in cirrus clouds.

NASA’s WB-57 will be flying over Oklahoma in temperate middle latitudes. These mid-latitude regions, located midway between the equator and the poles in both the northern and southern hemispheres, experience the most changeable weather on Earth. Is the changeable weather important to your study?

EJ: Not really. The reason we are focusing on the mid-latitudes is that we have studied relatively few cirrus clouds in this region with the current instrumentation. There is also the practical matter that the aircraft is based at Ellington Airfield in Houston.

What types of atmospheric particles are needed to form the ice crystals in cirrus clouds? Are there any specific particles that are causing adverse effects to the climate?

EJ: Cirrus can form on aqueous sulfate aerosols or insoluble particles such as mineral dust. Anthropogenic aerosols, such as soot from aircraft, may be modifying cirrus clouds and thereby modifying climate.

Cirrus clouds have life cycles? How do cirrus microphysical properties evolve through the life cycles of the clouds?

EJ: Processes such as sedimentation, entrainment, and aggregation modify the distribution of ice crystal sizes and shapes as the clouds evolve. It is important to understand how these processes work and to properly represent these processes in climate models.

For more information visit http://www.nasa.gov/topics/earth/features/eric_jensen.html

Friday, April 1, 2011

NASA Airborne Radar Set to Image Hawaiian Volcano

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The Kilauea volcano that recently erupted on the Big Island of Hawaii will be the target for a NASA study to help scientists better understand processes occurring under Earth's surface.

A NASA Gulfstream-III aircraft equipped with a synthetic aperture radar developed by NASA's Jet Propulsion Laboratory in Pasadena, Calif., is scheduled to depart Sunday, April 3, from the Dryden Aircraft Operations Facility in Palmdale, Calif., to the Big Island for a nine-day mission.

The Uninhabited Aerial Vehicle Synthetic Aperture Radar, or UAVSAR, uses a technique called interferometric synthetic aperture radar that sends pulses of microwave energy from the aircraft to the ground to detect and measure very subtle deformations in Earth's surface, such as those caused by earthquakes, volcanoes, landslides and glacier movements.

As the Gulfstream-III flies at an altitude of about 12,500 meters (41,000 feet), the radar, located in a pod under the aircraft's belly, will collect data over Kilauea. The UAVSAR's first data acquisitions over this volcanic region took place in January 2010, when the radar flew over the volcano daily for a week. The UAVSAR detected deflation of Kilauea's caldera over one day, part of a series of deflation-inflation events observed at Kilauea as magma is pumped into the volcano's east rift zone.

This month's flights will repeat the 2010 flight paths to an accuracy of within 5 meters, or about 16.5 feet, assisted by a Platform Precision Autopilot designed by engineers at NASA's Dryden Flight Research Center on Edwards Air Force Base, Calif. By comparing these camera-like images, interferograms are formed that reveal changes in Earth's surface.

Between March 5 and 11, 2011, a spectacular fissure eruption occurred along the east rift zone. Satellite radar imagery captured the progression of this volcanic event.

"The April 2011 UAVSAR flights will capture the March 2011 fissure eruption surface displacements at high resolution and from multiple viewing directions, giving us an improved resolution of the magma injected into the east rift zone that caused the eruption," said JPL research scientist Paul Lundgren.

This injection of magma takes the form of a dike, a thin blade-like sheet of magma extending from the surface to several kilometers depth, with an opening of only a few meters.

"Our goal is to be able to deploy the UAVSAR on short notice to better understand and aid in responding to hazards from Kilauea and other volcanoes in the Pacific region covered by this study," Lundgren added.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2011-105