scient and technology

Planck Chills Out

Artist's concept of Planck in space, with Earth in the background. Image credit: ESA› High-resolution JPEG (1.5MB)

June 12, 2009

A JPL-developed and -built cooler on the Planck spacecraft has chilled the mission's low-frequency instrument down to its operating temperature of a frosty 20 Kelvin (minus 424 degrees Fahrenheit). The so-called hydrogen sorption cooler was turned on June 4 and achieved the target temperature of 20 Kelvin eight days later. The cooler is part of a chain of coolers that works together to ultimately chill the high-frequency instrument down to 0.1 Kelvin -- an event scheduled to take place in a few weeks.

Planck is currently on its way to its final orbit at the second Lagrange point, which is located about 1.5 million kilometers (930,000 miles) from Earth, on the opposite side of our planet from the sun. Once there, it will look back to the dawn of time to study the birth of our universe.

scient and technology

Herschel's Cover Flips Open

Artist's concept of Herschel in space.
› Full-resolution JPEG (27MB)

June 15, 2009

The Herschel observatory has flipped its lid -- the cover protecting the telescope's instruments was successfully removed on June 14, 2009, at 2:54 a.m. Pacific Time. Herschel, a European Space Agency mission with significant participation from NASA, is already well on its way to an orbit around a point 1.5 million kilometers (930,000 miles) from Earth. That location, called the second Lagrange point of our Earth-sun system, is where Herschel will soon begin exploring the birth of stars and galaxies in our universe. The observatory detects infrared light, as does NASA's Spitzer Space Telescope, but sees longer wavelengths. This means that, among other things, Herschel will study objects cooler than those observed by Spitzer, for example earlier stages of star formation.

The cover is on the telescope's cryostat -- the chamber that chills the instruments. After launch, the telescope was kept warm to prevent the buildup of water ice, which would harm the observatory's performance. Once any water stuck on the spacecraft was gone, it was safe to let the telescope cool down. With that process complete, it was then safe to remove the cover. This was accomplished by sending a command to the spacecraft to release a latch holding the cover shut. The cover swung open and, for the first time, light from space fell on the instrument detectors.

scient and technology

JPL Wind Watcher Blows Into its Second Decade

Artist concept of QuikScat. Image credit: NASA/JPL

June 18, 2009

NASA's Quick Scatterometer, or QuikScat, mission was conceived, developed and launched less than two years after the unexpected loss of the Japan Aerospace Exploration Agency's Advanced Earth Observing Satellite-1 spacecraft, which carried the NASA Scatterometer in June 1997. Just two years later, on June 19, 1999, the QuikScat spacecraft carrying JPL's SeaWinds instrument was launched from Vandenberg Air Force Base, Calif.

Since its launch a decade ago, QuikScat has advanced Earth science research and helped improve environmental predictions using measurements of global radar backscatter from Earth's ocean, land and ice surfaces. QuikScat data help scientists better understand and predict the processes that drive our climate, such as ocean circulation and the global water cycle.

QuikScat data have revolutionized operational weather and storm forecasting. According to Paul Chang, ocean winds science team lead at the National Oceanic and Atmospheric Administration's National Environmental Satellite, Data, and Information Service/Center for Satellite Applications and Research, Camp Springs, Md., "QuikScat observations are now used around the world to support operational forecasting and warning of phenomena ranging from tropical and extratropical cyclones, fronts, localized coastal wind events such as gap winds and sea conditions driven by winds, to sea and lake ice extent and motion. The 10 years of observations from the QuikScat mission have provided critical information for the monitoring, modeling, forecasting and research of the atmosphere, oceans and climate."

In addition to its numerous weather forecasting and climate research applications, QuikScat data also help monitor changes in Arctic sea ice and icebergs, as well as snow and soil moisture changes on land. QuikScat's reliability, quality, resolution, coverage and longevity have made it the only global ocean wind speed and direction data to date that are appropriate for climate studies.

QuikScat accurately measures the speed and direction of winds at the ocean surface over 90 percent of Earth's surface twice a day, providing data in areas not sampled by buoys and other wind platforms. The scatterometer works by measuring the strength of radar signals that are bounced back from the ocean surface. As wind speeds increase, they disturb the ocean surface, generating more small waves. These small waves reflect the radar energy toward the radar, resulting in a stronger reflection. This is similar to the way that wind blowing at the beach on a sunny day causes the ocean surface to sparkle.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., developed QuikScat and manages the mission for NASA's Science Mission Directorate, Washington. QuikScat's mission team includes personnel from JPL; NASA's Goddard Space Flight Center in Greenbelt, Md.; Ball Aerospace and Technologies Corp., of Boulder, Colo.; the University of Colorado's Laboratory for Atmospheric and Space Physics in Boulder; and numerous principal investigators funded by NASA's Ocean Vector Winds science team.

scient and technology

Lunar Orbit is Divine for NASA Instrument

Artist's concept of Lunar Reconnaissance Orbiter. Image credit: NASA
› High-resolution JPEG (4MB)

June 23, 2009

PASADENA - Diviner, an instrument that will make the first maps of the temperature on the surface of the lunar polar regions, entered the moon's orbit this morning (June 23) aboard NASA's Lunar Reconnaissance Orbiter.

The instrument, a nine-channel radiometer built and project-managed by JPL, will measure very cold temperatures, and, for the first time, characterize the entire thermal environment of the moon. Diviner will also produce a map showing the composition of the moon, and a map showing how rocky the moon is.

In addition to creating a comprehensive atlas of the moon’s features with detailed information about surface and subsurface temperatures, Diviner will identify cold traps and potential ice deposits, as well as landing hazards such as rough terrain or rocks to be avoided by future manned missions to the moon.

JPL designed, built and manages the Diviner instrument for NASA’s Exploration Science Mission Directorate, Washington. UCLA is home institution of Diviner’s principal investigator, David Paige. NASA's Goddard Spaceflight Center, Greenbelt, Md., manages the Lunar Reconnaissance Orbiter. It is a NASA mission with international participation from the Institute for Space Research in Moscow.

scient and technology

Salt Finding From NASA's Cassini Hints at Ocean Within Saturn Moon

Cassini imaging scientists used views like this one to help them identify the source locations for individual jets spurting ice particles, water vapor and trace organic compounds from the surface of Saturn's moon Enceladus. Image credit: NASA/JPL/Space Science Institute. + Full image and caption

June 24, 2009

PASADENA, Calif. -- For the first time, scientists working on NASA's Cassini mission have detected sodium salts in ice grains of Saturn's outermost ring. Detecting salty ice indicates that Saturn's moon Enceladus, which primarily replenishes the ring with material from discharging jets, could harbor a reservoir of liquid water -- perhaps an ocean -- beneath its surface.

Cassini discovered the water-ice jets in 2005 on Enceladus. These jets expel tiny ice grains and vapor, some of which escape the moon's gravity and form Saturn's outermost ring. Cassini's cosmic dust analyzer has examined the composition of those grains and found salt within them.

"We believe that the salty minerals deep inside Enceladus washed out from rock at the bottom of a liquid layer," said Frank Postberg, Cassini scientist for the cosmic dust analyzer at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. Postberg is lead author of a study that appears in the June 25 issue of the journal Nature.

Scientists on Cassini's cosmic dust detector team conclude that liquid water must be present because it is the only way to dissolve the significant amounts of minerals that would account for the levels of salt detected. The process of sublimation, the mechanism by which vapor is released directly from solid ice in the crust, cannot account for the presence of salt.

"Potential plume sources on Enceladus are an active area of research with evidence continuing to converge on a possible salt water ocean," said Linda Spilker, Cassini deputy project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Our next opportunity to gather data on Enceladus will come during two flybys in November."

The makeup of the outermost ring grains, determined when thousands of high-speed particle hits were registered by Cassini, provides indirect information about the composition of the plume material and what is inside Enceladus. The outermost ring particles are almost pure water ice, but nearly every time the dust analyzer has checked for the composition, it has found at least some sodium within the particles.

"Our measurements imply that besides table salt, the grains also contain carbonates like soda. Both components are in concentrations that match the predicted composition of an Enceladus ocean," Postberg said. "The carbonates also provide a slightly alkaline pH value. If the liquid source is an ocean, it could provide a suitable environment on Enceladus for the formation of life precursors when coupled with the heat measured near the moon's south pole and the organic compounds found within the plumes."

However, in another study published in Nature, researchers doing ground-based observations did not see sodium, an important salt component. That team notes that the amount of sodium being expelled from Enceladus is actually less than observed around many other planetary bodies. These scientists were looking for sodium in the plume vapor and could not see it in the expelled ice grains. They argue that if the plume vapor does come from ocean water, the evaporation must happen slowly deep underground, rather than as a violent geyser erupting into space.

"Finding salt in the plume gives evidence for liquid water below the surface," said Sascha Kempf, also a Cassini scientist for the cosmic dust analyzer from the Max Planck Institute for Nuclear Physics. "The lack of detection of sodium vapor in the plume gives hints about what the water reservoir might look like."

Determining the nature and origin of the plume material is a top priority for Cassini during its extended tour, called the Cassini Equinox Mission.

"The original picture of the plumes as violently erupting Yellowstone-like geysers is changing," said Postberg."They seem more like steady jets of vapor and ice fed by a large water reservoir. However, we cannot decide yet if the water is currently 'trapped' within huge pockets in Enceladus' thick ice crust or still connected to a large ocean in contact with the rocky core."

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Cassini cosmic dust analyzer was provided by the German Aerospace Center. The Cassini orbiter was designed, developed and assembled at JPL. JPL manages the mission for the Science Mission Directorate at NASA Headquarters in Washington.

scient and technology

QuikScat Finds Tempests Brewing In 'Ordinary' Storms

QuikScat image of a mature North Atlantic extratropical cyclone from December 1, 2004. The color bar in the upper right indicates wind speed in knots. The storm’s hurricane-force winds, located to the south of the center of the low pressure system, are depicted as red wind barbs. Image credit: NOAA.
› Slide Show: QuikScat "Greatest Hits"(requires Flash)

June 25, 2009

Satellite, Now Entering Its Second Decade, Has Revolutionized Marine Weather Forecasts

"June is busting out all over," as the song says, and with it, U.S. residents along the Atlantic and Gulf coasts begin to gaze warily toward the ocean, aware that the hurricane season is revving up. In the decade since NASA's QuikScat satellite and its SeaWinds scatterometer launched in June 1999, the satellite has measured the wind speed and wind direction of these powerful storms, providing data that are increasingly used by the National Oceanic and Atmospheric Administration's (NOAA) National Hurricane Center and other world forecasting agencies. The data help scientists detect these storms, understand their wind fields, estimate their intensity and track their movement.

But tropical cyclones aren't the only storms that generate hurricane-force winds. Among others that do is a type of storm that dominates the weather in parts of the United States and other non-tropical regions every fall, winter and into spring: extratropical cyclones.

Extratropical Cyclones: Meteorological 'Bombs'

Scientists have long known that extratropical cyclones (also known as mid-latitude or baroclinic storms) sometimes produce hurricane-force winds. But before QuikScat, hurricane-force extratropical cyclones were thought to be relatively rare. Thanks to QuikScat, we now know that such storms occur much more frequently than previously believed, and the satellite has given forecasters an effective tool for routinely and consistently detecting and forecasting them.

These storms, which occur near busy trans-oceanic shipping lanes, pose a significant threat to life and property for those on the high seas, generating high winds and waves up to 30 meters (100 feet) high. When they make landfall, in areas like Alaska, the Pacific Northwest, New England and the U.S. mid-Atlantic coast, they produce strong winds, high surf, coastal flooding, heavy rains, river flooding and even blizzard conditions.

Take the "Hanukkah Eve" extratropical cyclone of Dec. 14-15, 2006, for example. That storm viciously raked the U.S. Pacific Northwest and British Columbia with torrential rainfall and hurricane-force winds exceeding 87 knots (100 miles per hour) in spots. Dozens of people were injured and 18 people lost their lives, while thousands of trees were downed, power was knocked out for more than 1.5 million residents and structural damage topped $350 million.

NOAA defines an extratropical cyclone as "a storm system that primarily gets its energy from the horizontal temperature contrasts that exist in the atmosphere." These low pressure systems have associated cold fronts, warm fronts and occluded fronts. Tropical cyclones, in contrast, don't usually vary much in temperature at Earth's surface, and their winds are generated by the energy released as clouds and rain form in warm, moist, tropical air. While a tropical cyclone's strongest winds are near Earth's surface, the strongest winds in extratropical cyclones are about 12 kilometers (8 miles) up, in the tropopause. Tropical cyclones can become extratropical, and vice versa.

Extratropical cyclones occur in both the North Atlantic and North Pacific year-round. Those with hurricane-force winds have been observed from September through May. Their frequency typically begins to increase in October, peaks in December and January, and tapers off sharply after March. They can range from less than 100 kilometers (62 miles) in diameter to more than 4,000 kilometers (nearly 2,500 miles) across. They typically last about five days, but their hurricane-force winds are usually short-lived--just 24 hours or less. Because they can intensify rapidly, they're often referred to as meteorological "bombs." Wind speeds in extratropical cyclones can vary from just 10 or 20 knots (12 to 23 miles per hour) to hurricane-force (greater than 63 knots, or 74 miles per hour). During their development, they can trek along at more than 30 knots (35 miles per hour), but they slow down as they mature. At their seasonal peak, up to eight such storms of varying intensity have been observed at once in both the North Atlantic and North Pacific.

Early work by scientists at NASA, NOAA and other organizations demonstrated the effectiveness of using scatterometers for detecting these powerful and destructive winds. Scatterometers work by sending radar signals to the ocean surface and measuring the strength of the radar signals that bounce back. The higher the wind speed, the more the ocean surface is disturbed, and the stronger the reflection that is bounced back to the satellite.

Among those who pioneered these efforts at NASA was Senior Research Scientist Timothy Liu of NASA's Jet Propulsion Laboratory, Pasadena, Calif., who used data from the NASA Scatterometer, the predecessor to QuikScat, to study the transition of tropical cyclones into extratropical storms in 1997. In addition, Robert Atlas of NASA's Goddard Space Flight Center, Greenbelt, Md., demonstrated that scatterometer data were able to improve predictions of extratropical storm strength and location.

Raising Forecaster Awareness

Joe Sienkiewicz, chief of the Ocean Applications Branch at NOAA's Ocean Prediction Center, Camp Springs, Md., says QuikScat data have raised the awareness of forecasters to the occurrence of hurricane-force intensity conditions in extratropical cyclones and have significantly advanced their short-term wind warning and forecast processes.

"QuikScat winds have given forecasters at NOAA's Ocean Prediction Center a high level of situational awareness over the data-sparse waters of the North Atlantic and North Pacific Oceans," he said. "Ocean Prediction Center forecasters daily examine every QuikScat pass and patch of wind and frequently base wind warning and forecast decisions solely on QuikScat winds. Through confidence gained from QuikScat, the National Weather Service began issuing warnings for dangerous hurricane-force winds in extratropical cyclones in December 2000.

"From 10 years of QuikScat, we have learned that hurricane force winds in extratropical cyclones occur more frequently than thought, are most frequent in winter months, and the conditions are most often observed south of the cyclone center," he added.

Over the years, the number of storms observed with hurricane-force winds has steadily increased due to forecasters gaining confidence using the data, and improvements to the QuikScat data. From the fall of 2006 through 2008, NOAA's Ocean Prediction Center identified and issued warnings for 115 separate extratropical cyclones (64 in the Atlantic and 51 in the Pacific) that reached hurricane force.

As confirmed in a 2008 study, QuikScat substantially extends the ability of forecasters to detect hurricane-force wind events in extratropical storms. For the studied case, QuikScat was able to identify more than three-and-a-half times as many hurricane-force events as combined data from the European ASCAT sensor on the METOP-A satellite, directly-measured buoy and ship information, and model predictions.

Another study in 2002 found that incorporating QuikScat data increased the number of wind warnings the Ocean Prediction Center issued for extratropical cyclones by 30 percent in the North Atlantic and by 22 percent in the North Pacific. Between 2003 and 2006, the Ocean Prediction Center's forecasters successfully predicted hurricane-force winds two days in advance 58 percent of the time in the Atlantic and 44 percent in the Pacific. Considering that a successful forecast of hurricane-force winds requires accurate prediction of the timing and intensity of an explosive deepening cyclone, these numbers are impressive.

QuikScat data have been instrumental in the ability to forecast hurricane-force extratropical cyclones several days in advance, while they are still well out over the ocean. Forecasters can use the data to determine which numerical weather prediction models are handling a storm the best, thereby improving the accuracy of forecasts and increasing warning lead times. QuikScat data are available to forecasters within three hours of acquisition.

The availability of a consistent observing capability for extratropical cyclones from QuikScat has allowed NOAA to add a third "hurricane-force" warning category for extratropical cyclone winds, in addition to gale and storm, providing better warnings of a coming storm's severity. The U.S. Coast Guard broadcasts these warnings by radiofax, and they are posted online at: http://www.opc.ncep.noaa.gov .

A Boon to Shipping

These extratropical cyclone warnings have a great economic impact on the $200 billion global marine shipping industry. A recent study estimates improvements to warning and forecast services due to QuikScat save the container and bulk shipping industry $135 million a year by reducing their exposure to hurricane-force wind conditions in non-tropical storms over the North Pacific and North Atlantic. Without QuikScat, the severity of many extratropical cyclones would not be determined. The data are also vital to the fishing industry, offshore energy industries, search and rescue organizations, and agencies that track and manage marine hazards like oil spills.

Paul Chang, ocean winds science team lead at NOAA's National Environmental Satellite, Data and Information Service/Center for Satellite Applications and Research, Camp Springs, Md., said ocean vector wind measurements from QuikScat have become a basic part of NOAA's day-to-day forecasting and warning processes.

"The 10 years of observations from the QuikScat mission have provided critical information for the monitoring, modeling, forecasting and research of the atmosphere, oceans and climate," he said.

scient and technology

Ulysses Hears the Siren's Song

Artist's concept of Ulysses moving towards the Sun

June 26, 2009

PASADENA -- Ulysses, a joint NASA and European Space Agency mission, will officially cease operations Monday, June 29, when the command to switch off the transmitter is uplinked to the spacecraft. Ulysses, which operated for more than 18 years, had charted the unexplored regions of space above the poles of the sun.

The Ulysses orbital path is carrying the spacecraft away from Earth. The ever-widening gap has progressively limited the amount of data transmitted. Ulysses project managers, with the concurrence of ESA and NASA, decided it was an appropriate time to end this epic scientific adventure.

Space Shuttle Discovery launched Ulysses on Oct. 6, 1990. A combination of solid fuel motors propelled Ulysses out of low-Earth orbit and toward Jupiter. Ulysses swung by Jupiter on Feb. 8, 1992. The giant planet's gravity bent the spacecraft's flight path southward and away from the ecliptic plane, putting the probe into a final orbit that would take it over the sun's south and north poles.

The European Space Agency's European Space Research and Technology Centre and European Space Operations Centre has managed the mission in coordination with NASA's Jet Propulsion Laboratory. Ulysses is tracked by NASA’s Deep Space Network. A joint ESA/NASA team at JPL has overseen spacecraft operations and data management. Teams from universities and research institutes in Europe and the U.S. provided the 10 instruments on board.

scient and technology

Herschel Opens Its Infrared Eyes

Glowing light from clouds of dust and gas around and between the stars is visible clearly. These clouds are a reservoir of raw material for ongoing star formation in this galaxy. Blue indicates regions of warm dust that is heated by young stars, while the colder dust shows up in red.
› Full image and caption

June 26, 2009

The Herschel Space Observatory has snapped its first picture since blasting into space on May 14, 2009. The mission, led by the European Space Agency with important participation from NASA, will use infrared light to explore our cosmic roots, addressing questions of how stars and galaxies are born.

The new "sneak preview" image was taken in an early attempt to demonstrate that Herschel works, and, in particular, that its telescope is focused and correctly aligned with the science instruments, and to whet our appetites for what's yet to come. It shows the Whirlpool galaxy, which lies relatively nearby, about 35 million light-years away, in the constellation Canes Venatici.

The galaxy was first observed by Charles Messier in 1773, who gave the beauty its official name of Messier 51. Back then, astronomers, including William Herschel, the observatory's namesake, catalogued objects like these as fuzzy nebulae without knowing their true nature. Later, Messier 51 became one of the first of these fuzzy objects observed to have a spiral structure, a finding that eventually led to the revelation that galaxies full of stars exist far from our own.

The image is a composite of infrared light captured with Herschel's Photoconductor Array Camera and Spectrometer at three wavelengths: 70, 100 and 160 microns. Herschel's full wavelength range spans 55 to 672 microns. The blue and white areas show where stars are actively forming, while the brown regions contain cold dust. The brightest blue dot at top left is a smaller, companion galaxy.

Longer-wavelength light inherently does not produce pictures with resolution as high as those obtained at shorter wavelengths, such as visible light. However, because Herschel's mirror is the largest infrared astronomy mirror ever launched in space (3.5 meters, or about 11.5 feet across), it can take the sharpest pictures to date at the particular wavelengths it observes.

During its prime mission phase, NASA's Spitzer Space Telescope, also a space-based infrared telescope, could see shorter-wavelength light, with wavelengths ranging from 3.6 to 160 microns. Because the two telescopes are able to see, for the most part, different wavelengths of light, their results complement each other, highlighting the multifaceted features of cosmic objects. Spitzer's shorter-wavelength infrared view of the Whirlpool galaxy, in comparison to a visible-light view, can be seen at http://gallery.spitzer.caltech.edu/Imagegallery/image.php?image_name=ssc2004-19a .

Herschel is in the final stretches of its journey to the second Lagrange point of the Earth-sun system. The observatory will spend its lifetime, estimated to be at least three-and-a-half-years, orbiting this point, which is about 1.5 million kilometers (930,000 miles) from Earth on the opposite side of our planet from the sun. After a cover protecting the telescope's instruments was popped open on June 14, engineers and scientists commanded the telescope to take its first test picture. The telescope is still being commissioned, with science observations expected to begin later this year.

Herschel is a European Space Agency cornerstone mission, with science instruments provided by a consortia of European institutes and with important participation by NASA. NASA's Herschel Project Office is based at NASA's Jet Propulsion Laboratory. JPL contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, supports the United States astronomical community. Caltech manages JPL for NASA. More information is online at http://www.herschel.caltech.edu .

The NASA Herschel Science Center is part of the consortium that developed the Photoconductor Array Camera and Spectrometer.

scient and technology

New JPL Building Goes Green for the Gold

A rooftop, drought-resistant garden is among the "green" features of JPL's new Flight Projects Center building.

June 24, 2009

When residents of the top floors of JPL's new Flight Projects Center look out their windows down to the roof of the building's auditorium, they won't see black tar. Instead, they'll witness what looks more like Joshua Tree, Calif. -- desert, drought-resistant plants dotting sandy ground.

The plants do more than enhance the view; they are part of the building's many "green" features. In fact, the building is so green that JPL is going for the gold -- a gold certification, that is, under the Leadership in Energy and Environmental Design rating system, set up by the non-profit U.S. Green Building Council.

The six-story Flight Projects Center will house missions in the busy design and development phases, when engineers and scientists from all around the world must work together closely. The first tenants are expected to move in this September.

To achieve a gold-level certification, the building must meet certain criteria. In general, it must consume water, energy and resources efficiently; treat the environment in friendly ways; and create a healthy and comfortable indoor workspace. Some of the building's green assets are listed here:

• A green, living roof will keep the building cool in the summer and warm in the winter. The green roof will also help minimize storm water runoff into the Arroyo Seco, a dry riverbed near JPL.

• Outdoor lights will be used solely for safety purposes. The lights are directed toward the ground, reducing the amount of light pollution that escapes to the night sky.

• Desert plants on the roof and the rest of the landscape will require 72 percent less water than a typical landscape design in Southern California.

• Low-flow faucets and toilets will reduce water use by 40 percent compared with typical fixtures. The building will save an estimated 500,000 gallons of water every year.

• Improved wall insulation, efficient chillers and boilers, window shading devices and the green roof will greatly reduce energy needs.

• More than 75 percent of the waste generated during construction was diverted from a landfill to a local recycling facility. Wood was acquired from Forest Stewardship Council certified suppliers, ensuring sustainable harvesting of trees.

• The paints and other surface materials have low levels of undesirable, toxic fumes.

• The heating and cooling system is "smart" -- it knows whether people are in a room and adjusts the temperature and ventilation accordingly.

• The janitorial staff will use green cleaning products and practices.

• Showers and bike racks will encourage people to leave their cars at home, and bike or walk to work.

scient and technology

Mars Rover Yielding New Clues While Lodged in Martian Soil

Soft soil exposed when wheels of NASA's Mars Exploration Rover Spirit dug into a patch of ground.
› Full image and caption

June 25, 2009

PASADENA, Calif. -- NASA's Mars rover Spirit, lodged in Martian soil that is causing traction trouble, is taking advantage of the situation by learning more about the Red Planet's environmental history.

In April, Spirit entered an area composed of three or more layers of soil with differing pastel hues hiding beneath a darker sand blanket. Scientists dubbed the site "Troy." Spirit's rotating wheels dug themselves more than hub deep at the site. The rover team has spent weeks studying Spirit's situation and preparing a simulation of this Martian driving dilemma to test escape maneuvers using an engineering test rover at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

A rock seen beneath Spirit in images from the camera on the end of the rover's arm may be touching Spirit's belly. Scientists believe it appears to be a loose rock not bearing the rover's weight. While Spirit awaits extraction instructions, the rover is keeping busy examining Troy, which is next to a low plateau called Home Plate, approximately 3.2 kilometers (2 miles) southeast of where Spirit landed in January 2004.

"By serendipity, Troy is one of the most interesting places Spirit has been," said Ray Arvidson of Washington University in St. Louis. Arvidson is deputy principal investigator for the science payloads on Spirit and its twin rover, Opportunity. "We are able here to study each layer, each different color of the interesting soils exposed by the wheels."

One of the rover's wheels tore into the site, exposing colored sandy materials and a miniature cliff of cemented sands. Some disturbed material cascaded down, evidence of the looseness that will be a challenge for getting Spirit out. But at the edge of the disturbed patch, the soil is cohesive enough to hold its shape as a steep cross-section.

Spirit has been using tools on its robotic arm to examine tan, yellow, white and dark-red sandy soil at Troy. Stretched-color images from the panoramic camera show the tints best.

"The layers have basaltic sand, sulfate-rich sand and areas with the addition of silica-rich materials, possibly sorted by wind and cemented by the action of thin films of water. We're still at a stage of multiple working hypotheses," said Arvidson. "This may be evidence of much more recent processes than the formation of Home Plate...or is Home Plate being slowly stripped back by wind, and we happened to stir up a deposit from billions of years ago before the wind got to it?"

Team members from NASA's Johnson Space Center in Houston feel initial readings suggest that iron is mostly present in an oxidized form as ferric sulfate and that some of the differences in tints at Troy observed by the panoramic camera may come from differences in the hydration states of iron sulfates.

While extraction plans for the rover are developed and tested during the coming weeks, the team plans to have Spirit further analyze the soil from different depths. This research benefits from having time and power. In April and May, winds blew away most of the dust that had accumulated on Spirit's solar panels.

"The exceptional amount of power available from cleaning of Spirit's solar arrays by the wind enables full use of all of the rover's science instruments," said Richard Moddis of the Johnson team. "If your rover is going to get bogged down, it's nice to have it be at a location so scientifically interesting."

The rover team has developed a soil mix for testing purposes that has physical properties similar to those of the soil under Spirit at Troy. This soil recipe combines diatomaceous earth, powdered clay and play sand. A crew is shaping a few tons of that mix this week into contours matching Troy's. The test rover will be commanded through various combinations of maneuvers during the next few weeks to validate the safest way to proceed on Mars.

Spirit's right-front wheel has been immobile for more than three years, magnifying the challenge. While acknowledging a possibility that Spirit might not be able to leave Troy, the rover team remains optimistic. Diagnostic tests on Spirit in early June provided encouragement that the left-middle wheel remains useable despite an earlier stall.

"With the improved power situation, we have the time to explore all the possibilities to get Spirit out," said JPL's John Callas, project manager for Spirit and Opportunity. "We are optimistic. The last time Spirit spun its wheels, it was still making progress. The ground testing will help us avoid doing things that could make Spirit's situation worse."

Images and further information about Spirit and Opportunity are available at: http://marsrovers.jpl.nasa.gov and http://www.nasa.gov/rovers .

scient and technology

The von Kármán Lecture Series

Exploring the Moon

July 16 & 17

Several international space agencies are actively engaged in robotic as well as human exploration of the moon, including projects from China, Japan, India, Russia, Europe, Germany and the United Kingdom. NASA has also embarked on an active science and exploration program which includes three robotic missions planned for launch in 2009, 2011 and 2012, as well as human exploration starting in 2020. This presentation will discuss NASA’s current plans for returning to the moon for both science and exploration, as well as efforts to collaborate with international partners.

Speaker:	Dr. Leon Alkalai Manager, Lunar Robotic Exploration Office Jet Propulsion Laboratory
Location:	Thursday, July 16, 2009, 7p.m. The von Kármán Auditorium at JPL 4800 Oak Grove Drive Pasadena, CA › Directions Friday, July 17, 2009, 7p.m. The Vosloh Forum at Pasadena City College 1570 East Colorado Blvd. Pasadena, CA › Directions
Webcast:	For the webcast on Thursday at 7 p.m. Pacific time, click here If you don't have RealPlayer, you can download the free RealPlayer.

Robots in the Race to the Moon

July 20

On July 20, 1969, astronauts Neil Armstrong and Edwin 'Buzz' Aldrin, landed an ungainly vehicle on the moon. Their lunar sojourn marked the conclusion of the "moon race" unleashed by President John F. Kennedy in May 1961. It was also the end of a longer series of lunar visits by robotic pathfinders, sent to prepare the way for men. In this talk, we'll explore the role of robots in opening the 'lunar frontier.'

scient and technology

NASA, Japan Release Most Complete Topographic Map of Earth

NASA and Japan's Ministry of Economy, Trade and industry (METI) released the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global Digital Elevation Model (GDEM) to the worldwide public on June 29, 2009.
› Full image and caption/related images

June 29, 2009

PASADENA, Calif. – NASA and Japan released a new digital topographic map of Earth Monday that covers more of our planet than ever before. The map was produced with detailed measurements from NASA's Terra spacecraft.

The new global digital elevation model of Earth was created from nearly 1.3 million individual stereo-pair images collected by the Japanese Advanced Spaceborne Thermal Emission and Reflection Radiometer, or Aster, instrument aboard Terra. NASA and Japan's Ministry of Economy, Trade and Industry, known as METI, developed the data set. It is available online to users everywhere at no cost.

"This is the most complete, consistent global digital elevation data yet made available to the world," said Woody Turner, Aster program scientist at NASA Headquarters in Washington. "This unique global set of data will serve users and researchers from a wide array of disciplines that need elevation and terrain information."

According to Mike Abrams, Aster science team leader at NASA's Jet Propulsion Laboratory in Pasadena, Calif., the new topographic information will be of value throughout the Earth sciences and has many practical applications. "Aster's accurate topographic data will be used for engineering, energy exploration, conserving natural resources, environmental management, public works design, firefighting, recreation, geology and city planning, to name just a few areas," Abrams said.

Previously, the most complete topographic set of data publicly available was from NASA's Shuttle Radar Topography Mission. That mission mapped 80 percent of Earth's landmass, between 60 degrees north latitude and 57 degrees south. The new Aster data expand coverage to 99 percent, from 83 degrees north latitude and 83 degrees south. Each elevation measurement point in the new data is 30 meters (98 feet) apart.

"The Aster data fill in many of the voids in the shuttle mission's data, such as in very steep terrains and in some deserts," said Michael Kobrick, Shuttle Radar Topography Mission project scientist at JPL. "NASA is working to combine the Aster data with that of the Shuttle Radar Topography Mission and other sources to produce an even better global topographic map."

NASA and METI are jointly contributing the Aster topographic data to the Group on Earth Observations, an international partnership headquartered at the World Meteorological Organization in Geneva, Switzerland, for use in its Global Earth Observation System of Systems. This "system of systems" is a collaborative, international effort to share and integrate Earth observation data from many different instruments and systems to help monitor and forecast global environmental changes.

NASA, METI and the U.S. Geological Survey validated the data, with support from the U.S. National Geospatial-Intelligence Agency and other collaborators. The data will be distributed by NASA's Land Processes Distributed Active Archive Center at the U.S. Geological Survey's Earth Resources Observation and Science Data Center in Sioux Falls, S.D., and by METI's Earth Remote Sensing Data Analysis Center in Tokyo.

Aster is one of five Earth-observing instruments launched on Terra in December 1999. Aster acquires images from the visible to the thermal infrared wavelength region, with spatial resolutions ranging from about 15 to 90 meters (50 to 300 feet). A joint science team from the U.S. and Japan validates and calibrates the instrument and data products. The U.S. science team is located at JPL.

For visualizations of the new Aster topographic data, visit: http://www.nasa.gov/topics/earth/features/20090629.html .

Data users can download the Aster global digital elevation model at: https://wist.echo.nasa.gov/~wist/api/imswelcome and http://www.gdem.aster.ersdac.or.jp .

For more information about NASA and agency programs, visit: http://www.nasa.gov .

JPL is managed for NASA by the California Institute of Technology in Pasadena.

scient and technology

NASA Wraps Up Icelandic Part of Arctic Ice Radar Mission

This image shows the Gulfstream III Arctic Ice Radar Mission flight tracks. The blue lines superimposed over a Google Earth image of Iceland shows the tracks flown by NASA's Gulfstream III science research aircraft during one of the Arctic Ice Radar Mission flights flown during the second week of June 2009. Image credit: NASA image / Roger Chao
› Larger image

June 29, 2009

A week in Iceland wrapped up NASA's six-week airborne radar expedition to study Arctic glaciers, ice streams and map surface topography. In total, the two JPL-built radars, the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) and Glacier and Land Ice Surface Topography Interferometer (GLISTIN), imaged about 250,000 square kilometers (97,000 square miles) of land and collected about six terabytes of data, which will now be processed.

Read more about the Iceland portion of the expedition: