Two Kinds of Webb Telescope Mirrors Arrive at NASA Goddard

It takes two unique types of mirrors working together to see farther back in time and space than ever before, and engineers at NASA's Goddard Space Flight Center have just received one of each type. Primary and Secondary Mirror Engineering Design Units (EDUs) have recently arrived at NASA's Goddard Space Flight Center in Greenbelt, Md. from Northrop Grumman Aerospace Systems in Redondo Beach, Calif. and are undergoing examination and testing. When used on the James Webb Space Telescope those two types of mirrors will allow scientists to make those observations.

"The Primary mirror EDU will be used next year to check out optical test equipment developed by Goddard and slated to be used to test the full Flight Primary mirror," said Lee Feinberg, the Optical Telescope Element Manager for the Webb telescope at NASA Goddard. "Following that, the primary and secondary EDU's will actually be assembled onto the Pathfinder telescope. The Pathfinder telescope includes two primary mirror segments (one being the Primary EDU) and the Secondary EDU and allows us to check out all of the assembly and test procedures (that occur both at Goddard and testing at Johnson Space Center, Houston, Texas) well in advance of the flight telescope assembly and test."

The primary mirror is actually composed of 18 smaller hexagonal mirrors that are assembled together into what appears to be a giant hexagon that sits atop the Webb telescope's sunshield. Webb Telescope's scientists and engineers determined that a primary mirror measuring 6.5 meters (21 feet 4 inches) across is what was needed to measure the light from these distant galaxies. Each of these mirrors is constructed from beryllium, a light and strong metal. Each of the 18 mirror segments weighs approximately 20 kilograms (46 pounds).

Why are the mirrors hexagonal shaped? Because a hexagon allows a segmented mirror to fit together without gaps. When Webb's primary mirror is focused on a distant star for example, that image will appear in all 18 mirror segments. To focus on the star and get one image, the mirror segments can then be tilted to align the 18 separate images into a single image.

Although there are 18 segments, there are three different optical prescriptions for the 18 segments: six segments of each prescription. The segment received is the first of the "A" prescription segments for which a total of 7 will be made - 6 flight and 1 spare. A prescription is similar to an eyeglass prescription and specifies a unique mirror curvature. Like eyeglasses, mirrors with the same prescription are interchangeable.

The primary mirror EDU that arrived at Goddard is also a flight spare. That means it can be used on the actual telescope. In fact, it could even be put on the telescope now if needed.

The primary mirror segment has already been cleaned and coated. Ball Aerospace & Technologies cleaned the mirror segment and Quantum Coating, Inc., in Moorestown, N.J., coated it. Ball Aerospace then took the mirror segment back, reassembled it with mounts and actuators and conducted final vibration testing.

Afterward, the mirror segment went back to the X-ray and Cryogenic Facility (XRCF) in Huntsville, Ala., where Ball performed final cryogenic acceptance testing on the segment before it came to NASA Goddard.

The secondary mirror on the Webb telescope will direct the light from the primary mirror to where it can be collected by the Webb's instruments. The secondary mirror is connected to "arms" that position it in front of the 18 primary mirror segments. It will focus all of the light from the 18 primary mirrors.

The secondary EDU at Goddard is not coated but can be, so it can be a flight spare once coated.

Eventually, the final flight mirrors will all come to NASA Goddard and be assembled on the telescope and the instrument module. Then, as a complete unit it will undergo acoustic and vibration testing at Goddard.

The James Webb Space Telescope is the world’s next-generation space observatory and successor to the Hubble Space Telescope. The most powerful space telescope ever built, Webb will observe the most distant objects in the universe, provide images of the very first galaxies ever formed and see unexplored planets around distant stars. The Webb Telescope is a joint project of NASA, the European Space Agency and the Canadian Space Agency.

For more information visit http://www.nasa.gov/topics/technology/features/two-webb-mirrors.html

Getting Ready for the Next Big Solar Storm

In Sept. 1859, on the eve of a below-average solar cycle, the sun unleashed one of the most powerful storms in centuries. The underlying flare was so unusual, researchers still aren't sure how to categorize it. The blast peppered Earth with the most energetic protons in half-a-millennium, induced electrical currents that set telegraph offices on fire, and sparked Northern Lights over Cuba and Hawaii.

This week, officials have gathered at the National Press Club in Washington DC to ask themselves a simple question: What if it happens again?

"A similar storm today might knock us for a loop," says Lika Guhathakurta, a solar physicist at NASA headquarters. "Modern society depends on high-tech systems such as smart power grids, GPS, and satellite communications--all of which are vulnerable to solar storms."

She and more than a hundred others are attending the fifth annual Space Weather Enterprise Forum—"SWEF" for short. The purpose of SWEF is to raise awareness of space weather and its effects on society especially among policy makers and emergency responders. Attendees come from the US Congress, FEMA, power companies, the United Nations, NASA, NOAA and more.

As 2011 unfolds, the sun is once again on the eve of a below-average solar cycle—at least that’s what forecasters are saying. The "Carrington event" of 1859 (named after astronomer Richard Carrington, who witnessed the instigating flare) reminds us that strong storms can occur even when the underlying cycle is nominally weak.

In 1859 the worst-case scenario was a day or two without telegraph messages and a lot of puzzled sky watchers on tropical islands.

In 2011 the situation would be more serious. An avalanche of blackouts carried across continents by long-distance power lines could last for weeks to months as engineers struggle to repair damaged transformers. Planes and ships couldn’t trust GPS units for navigation. Banking and financial networks might go offline, disrupting commerce in a way unique to the Information Age. According to a 2008 report from the National Academy of Sciences, a century-class solar storm could have the economic impact of 20 hurricane Katrinas.

As policy makers meet to learn about this menace, NASA researchers a few miles away are actually doing something about it:

"We can now track the progress of solar storms in 3 dimensions as the storms bear down on Earth," says Michael Hesse, chief of the GSFC Space Weather Lab and a speaker at the forum. "This sets the stage for actionable space weather alerts that could preserve power grids and other high-tech assets during extreme periods of solar activity."

They do it using data from a fleet of NASA spacecraft surrounding the sun. Analysts at the lab feed the information into a bank of supercomputers for processing. Within hours of a major eruption, the computers spit out a 3D movie showing where the storm will go, which planets and spacecraft it will hit, and predicting when the impacts will occur. This kind of "interplanetary forecast" is unprecedented in the short history of space weather forecasting.

"This is a really exciting time to work as a space weather forecaster," says Antti Pulkkinen, a researcher at the Space Weather Lab. "The emergence of serious physics-based space weather models is putting us in a position to predict if something major will happen."

Some of the computer models are so sophisticated, they can even predict electrical currents flowing in the soil of Earth when a solar storm strikes. These currents are what do the most damage to power transformers. An experimental project named "Solar Shield" led by Pulkkinen aims to pinpoint transformers in greatest danger of failure during any particular storm.

"Disconnecting a specific transformer for a few hours could forestall weeks of regional blackouts," says Pulkkinen.

Another SWEF speaker, John Allen of NASA's Space Operations Mission Directorate, pointed out that while people from all walks of life can be affected by space weather, no one is out on the front lines quite like astronauts.

"Astronauts are routinely exposed to four times as much radiation as industrial radiation workers on Earth," he says. "It's a serious occupational hazard."

NASA keeps careful track of each astronaut's accumulated dosage throughout their careers. Every launch, every space walk, every solar flare is carefully accounted for. If an astronaut gets too close to the limits ... he or she might not be allowed out of the space station! Accurate space weather alerts can help keep these exposures under control by, e.g., postponing spacewalks when flares are likely.

Speaking at the forum, Allen called for a new kind of forecast: "We could use All Clear alerts. In addition to knowing when it's dangerous to go outside, we'd also like to know when it's safe. This is another frontier for forecasters--not only telling us when a sunspot will erupt, but also when it won't."

The educational mission of SWEF is key to storm preparedness. As Lika Guhathakurta and colleague Dan Baker of the University of Colorado asked in a June 17, 2011 New York Times op-ed: "What good are space weather alerts if people don’t understand them and won’t react to them?"

By spreading the word, SWEF will help.

For more information visit http://www.nasa.gov/mission_pages/sunearth/news/next-solarstorm.html

James Webb Space Telescope ISIM on 'Spin Cycle'

Prior to taking a new telescope into space, engineers must put the spacecraft and its instruments through a "spin cycle" test for durability to ensure they'll still work after experiencing the forces of a rocket launch. Finding out they don't work once they're in orbit is too late. The structure that houses the science instruments of the James Webb Space Telescope is undergoing that cycle of tests during the weeks of May 23 and 30 at NASA's Goddard Space Flight Center in Greenbelt, Md. This structure is called the Integrated Science Instrument Module, or ISIM.

The Webb telescope will experience significant shaking and gravitational forces when it is launched on the large Ariane V rocket. The ISIM structure will house the four main scientific instruments of the telescope.

During the testing process, as the ISIM structure is being spun and shaken, engineers take measurements to compare with their computer models. If there are discrepancies, the engineers hunt for the reasons so they can address them. The huge centrifuge will spin at speeds close to 11 rpm, exposing the ISIM structure to about 10 times the force of gravity.

Webb is the successor to the Hubble Space Telescope and will serve thousands of astronomers worldwide. Webb will study the history of our Universe, ranging from the first luminous glows after the Big Bang, to the formation of planetary systems capable of supporting life on planets like Earth, to the evolution of our own Solar System. The Webb telescope is a joint mission of NASA, the European Space Agency and Canadian Space Agency.

For more information visit http://www.nasa.gov/topics/technology/features/isim-spin-test.html

The 'Eyes, Ears and Hands' of the Shuttle Test Team

When space shuttle astronauts are living and working in Earth orbit, their mission -- and, ultimately, their lives -- depend on all the shuttle orbiter's systems and controls working exactly as expected.

From the time a shuttle lands after a mission until it launches on its next spaceflight, a small group of specially certified United Space Alliance aerospace technicians called spacecraft operators act as the eyes, ears and hands of the test team at NASA's Kennedy Space Center in Florida. Their workspace is the orbiter crew module, the part of the shuttle where astronauts live and work in space. They focus heavily on the cockpit -- the nerve center of the space shuttle orbiter.

"The astronauts have a good job. They make it look easy," says Bill Powers, a spacecraft operator (SCO) since 1985. "Our job is just to make sure when they get the vehicle, there aren't any surprises."

Spacecraft operators are an integral part of the processing and test teams that ensure the shuttle is ready to fly.

Any time the orbiter is powered up -- meaning that its systems are on -- spacecraft operators are on duty.

"What SCOs do is take information from Engineering and the test conductor, and they do what the astronauts do on orbit," explains Chris Meinert. He's worked on the space shuttle since 1981, and became certified as a spacecraft operator in 1984.

Orbiter systems can be controlled in three ways. In "command," a ground controller can send a command through the shuttle's S-band antenna and, for example, turn on a fan or pump while the astronauts are asleep. "Copper path" involves a crew member physically throwing a switch in the cockpit to accomplish a task. Finally, the Launch Processing System, or LPS, is the ground command in which a signal from the Launch Control Center (LCC) travels down a wire to the launch pad.

Spacecraft operators take part in testing all three methods.

"In the LCC, you've got 15 or 20 different consoles, with many feet or yards separating them. But in the cockpit, you can see several different systems, all within arm's reach," says Meinert. "If there's something going on, we can give a report pretty quick as to what's the initial system that's either good or bad, and how the other systems are reacting to it."

More than 2,000 switches, displays and controls fill almost every surface of the flight deck, beginning with the center console in front of the commander's and pilot's seats and spreading out across the ceiling and walls. All this instrumentation is labeled and grouped into panels according to system. In order to operate the spacecraft, it's critically important to know its systems and how they interact.

"The better your knowledge of the systems, the better an SCO you are," says Meinert. "If you look at it as a number, who can remember 2,400 different things? But the panels are laid out for the crew, kind of logically, either as current flows, or as water flows, or as air flows."

The spacecraft operator certification requires one to two years of additional training. Not only must candidate technicians learn the shuttle's systems and the inner workings of the crew module, they also must learn "communication etiquette" and spend some time working in a Launch Control Center firing room.

"When you're on the headset and you're working on a job, all you hear is a voice," says spacecraft operator Jay Beason. "The only thing you see is your end of the job. So we're required, as part of our training, to sit in the firing room on the test project engineer's console and do what they do. I found that experience invaluable."

Some spacecraft operators concentrate on horizontal processing, which primarily takes place inside the orbiter processing facility. Others specialize in vertical operations inside the Vehicle Assembly Building and at the launch pad. But all are able to fill in wherever they're needed.

The shuttle arrives in the orbiter processing facility (OPF) after landing, kicking off several months of work to "safe" the spacecraft and prepare it for its next flight -- an effort known to the shuttle team as the "processing flow." During horizontal processing -- while the orbiter still is oriented like an airplane in a hangar -- two spacecraft operators normally take turns working inside the crew module during the day, taking over for each other every two hours.

"On a typical SCO day, I might come in here and power up the ship, get it configured for whatever engineering needs or any testing that's going on -- whether it be aft, midbody or forward operations," says Greg Rose, who earned his SCO certification about a year ago.

"Days when I'm not in the 'SCO loop,' I could be working on anything outside the ship: forward reaction control system, doing thruster desiccant changeouts, hooking up quick disconnects here and there, hooking up water servicing, working on the nose landing gear," he adds.

Once the orbiter is brought to the Vehicle Assembly Building, lifted to vertical and attached to its external fuel tank and solid rocket boosters, the context of the work changes.

"In the OPF, you stand on the floor and you throw switches, and it's all logically laid out where you can read them," Meinert says. "But at the pad, you're standing on a wall and all of the overhead switches are upside down. You have to read upside down and backwards in order to get the right one."

But he explains that's not the only change.

"When the vehicle goes out to the launch pad, we arm it with pyrotechnics and we put nasty hypergolics inside it. We put ammonia in it. There are systems that are armed and ready, and they need monitoring. Testing at the pad has a bit more danger to it."

About three days before liftoff, the countdown officially begins. The orbiter is powered up the entire time, and four SCOs are there at any given time: two in the cockpit and two to provide relief. Every system has to be ready before the Astronaut Support Person (ASP) -- a NASA astronaut not part of the flight crew -- climbs in to configure the cockpit switches prior to boarding.

Some launch pad SCOs, such as Meinert, also are members of the Closeout Crew, helping the astronauts climb aboard, making sure the hatch closes correctly and ensuring the climate-controlled White Room is set up correctly for launch.

But a successful liftoff doesn't signal the end of the spacecraft operators' role in a mission. They also have a critical role on landing day and are some of the first people to approach an orbiter that's just returned from space.

"In the wintertime, when it's cool outside, the tiles make a crinkling sound. And sometimes the panels on the hatch are still pretty warm. It's just so alive," he says. "You know it's been somewhere."

After the returning astronauts, medical staff and ASP leave the crew module, control of the ship is transferred from NASA's Johnson Space Center in Houston back to Kennedy. At that point, two SCOs will settle into the cockpit and begin monitoring systems, flipping switches and installing guards on switches that need to stay in their current position. They'll stay on board until the shuttle is towed back to the processing facility. The procedure is the same at Edwards Air Force Base, Calif.

The space shuttle era is set to conclude with the STS-135 mission, when Atlantis' wheels roll to a stop for the last time. The spacecraft operators who remain will prepare the orbiters for their next assignment: as museum pieces.

They also have a tremendous record of success to enjoy.

"When you reach that moment at T-0, knowing that approximately eight hours earlier you were up there getting everything ready for the Closeout Crew and the flight crew to get on board, it gives you a real sense of pride," Beason says.

For more information visit http://www.nasa.gov/mission_pages/shuttle/flyout/sc_operators.html

WORF First Image Web Feature

A test photo of British Columbia's snow-capped west coast mountains is the first official image taken from the International Space Station's new Window Observational Research Facility, or WORF.

The image was taken to test the functionality of the control computer and camera associated with EarthKAM, an educational outreach project that allows Earth bound middle school students to take pictures of our home planet from the unique perspective of the space station, 220 miles above the Earth's surface. WORF was delivered to the station on the STS-131 mission of space shuttle Discovery in April 2010.

EarthKAM uses a Nikon D2X digital camera, and was set up in the WORF by Expedition 26 NASA flight engineer Cady Coleman on Jan. 17. EarthKAM ground controllers took the test photo. Expedition 26 also includes Commander Scott Kelly of NASA, European Space Agency astronaut Paolo Nespoli, and Russian cosmonauts Oleg Skripochka, Alexander Kaleri and Dmitry Kontratyev.

The test photo, designated ISS EarthKAM Image Winter 2011 #9362, is of an area of British Columbia, Canada, just north of Vancouver Island. The center point of the photo is 51 degrees, 48 minutes north and 127 degrees, 54 minutes west. Visible in the photo are Calvert and Hecate Islands on the Canadian coast and the southern portion of Hunter Island. Also visible are glaciers of the Ha-iltzuk Icefield near the 8,720-foot-tall -- 2,658-meter-tall -- Mount Somolenko. Mount Somolenko is a volcanic peak in southwestern British Columbia, that lies in a circular volcanic depression in the Pacific Ranges of the Coast Mountains called the Silverthrone Caldera.

While this isn't a particularly unique Earth observation image, it is notable that even though it was taken with a wider angle, 50mm lens and covers an area 124 miles/200 kilometers, by 83 miles/134 kilometers, it can be enlarged by more than 400 percent while keeping features in the photo identifiable. This is made possible by the high-quality optics of the Earth-facing window of the Destiny Laboratory, which was launched on Feb. 7, 2001.

The installation of WORF allowed removal of an internal "scratch pane" that has reduced the quality of images taken though the window. WORF also provides a highly stable mounting platform to hold cameras and sensors rock steady at the window, as well as the power, command, data, and cooling connections needed for their operation.

"With the WORF finally in place we can now for the first time make full use of the investment we made in having an optical quality window onboard the station for Earth science and observation," said former astronaut Mario Runco, who was part of the design and development teams for the Destiny window and WORF, and now serves as NASA's lead for Spacecraft Window Optics and Window/WORF Utilization at NASA's Johnson Space Center, Houston.

"We are very excited to have a new camera system that appears to be functional and taking incredible images," said Karen Flammer, who manages EarthKAM operations at the University of California, can Diego. "The first student images were taken by Parkview Montessori in the Jackson-Madison County (Tenn.) School System, and Public School 229 - Dyker in Brooklyn, N.Y., part of the New York City Department of Education.

Parkview teacher Vickie LeCroy's students plan to study landforms, such as islands, mountains and deserts in the image they took of Mexico, and Dyker teacher Camille Fratantoni’s students plan to enrich their studies of earth science and learn more about NASA missions.

In addition to their educational outreach role with EarthKAM, the combination of the window and WORF adds to the station's capabilities as an Earth science remote sensing platform for high-resolution cameras and multi and hyperspectral imagers. Images from space have many applications, such as in the study of climate and meteorology; oceanography; geology and volcanology; coastal, agricultural, ranch and forestry management; and disaster assessments and management.

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

Landsat 5 Satellite Sees Mississippi River Floodwaters Lingering

In a Landsat 5 satellite image captured June 11, 2011, flooding is still evident both east and west of the Mississippi River near Vicksburg, Miss. Standing water is most apparent, however, in the floodplain between the Yazoo and Mississippi rivers north of Vicksburg.

On May 19, 2011, the Mississippi River reached a historic crest at Vicksburg. According to the Advanced Hydrological Prediction Service (AHPS) of the U.S. National Weather Service, the river reached 57.10 feet (17.40 meters) that day. By early June, flooding had receded considerably around Vicksburg, but water remained high.

On June 14, the AHPS reported that the Mississippi River reached 44.88 feet (13.68 meters) at Vicksburg. At that point, the river was in minor flood stage, and its level was forecast to continue falling through June 19.

The Landsat series of satellites is used by emergency managers to acquire a range of imagery, from floods to fires. Landsat has recently provided both images of the flooding of the Mississippi River and the fires raging in Arizona.

The Landsat Program is a series of Earth-observing satellite missions jointly managed by NASA and the U.S. Geological Survey. Landsat satellites have been consistently gathering data about our planet since 1972. They continue to improve and expand this unparalleled record of Earth’s changing landscapes, for the benefit of all. The next Landsat satellite is scheduled to launch in December 2012.

For more information visit http://www.nasa.gov/topics/earth/features/ms-flooding-20110616.html

Science Paper Details NASA EPOXI Flyby of Hyper Comet

Comet Hartley 2's hyperactive state, as studied by NASA's EPOXI mission, is detailed in a new paper published in this week's issue of the journal Science.

After visiting a comet and imaging distant stars for hints of extrasolar planets, you could say the spacecraft used for EPOXI had seen its fair share of celestial wonders. But after about 3.2 billion miles (5.1 billion kilometers) of deep space travel, one final wonder awaited the mission's project and science teams. On Nov. 4, 2010, the EPOXI mission spacecraft flew past a weird little comet called Hartley 2.

"From all the imaging we took during approach, we knew the comet was a little skittish even before flyby," said EPOXI Project Manager Tim Larson of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "It was moving around the sky like a knuckleball and gave my navigators fits, and these new results show this little comet is downright hyperactive."

The EPOXI mission found that the strong activity in water release and carbon dioxide-powered jets did not occur equally in the different regions of the comet. During the spacecraft's flyby of the comet – with closest approach of 431 miles (694 kilometers) – carbon-dioxide-driven jets were seen at the ends of the comet, with most occurring at the small end. In the middle region, or waist of the comet, water was released as vapor with very little carbon dioxide or ice. The latter findings indicate that material in the waist likely came off the ends of the comet and was redeposited.

"Hartley 2 is a hyperactive little comet, spewing out more water than most other comets its size," said Mike A'Hearn, principal investigator of EPOXI from the University of Maryland, College Park. "When warmed by the sun, dry ice -- frozen carbon dioxide -- deep in the comet's body turns to gas jetting off the comet and dragging water ice with it."

Although Hartley 2 is the only such hyperactive comet visited by a spacecraft, scientists know of at least a dozen other comets that also are relatively high in activity for their size and which are probably driven by carbon dioxide or carbon monoxide.

"These could represent a separate class of hyperactive comets," said A'Hearn. "Or they could be a continuum in comet activity extending from Hartley 2-like comets all the way to the much less active, 'normal' comets that we are more used to seeing."

The study provides several new twists in the unfolding story of this small cometary dynamo, including: (1) Hartley 2 has an 'excited state of rotation' because it spins around one axis, but also tumbles around a different axis; and (2) on its larger, rougher ends, the comet's surface is dotted with glittering blocks that can reach approximately 165 feet (50 meters) high and 260 feet (80 meters) wide. The block-like, shiny objects, some as big as one block long and 16 stories tall, appear to be two to three times more reflective than the surface average.

EPOXI was an extended mission that utilized the already "in-flight" Deep Impact spacecraft to explore distinct celestial targets of opportunity. The name EPOXI itself is a combination of the names for the two extended mission components: the extrasolar planet observations, called Extrasolar Planet Observations and Characterization (EPOCh), and the flyby of comet Hartley 2, called the Deep Impact Extended Investigation (DIXI). The spacecraft retained the name "Deep Impact." During its approach, encounter and departure from comet Hartley 2, the spacecraft beamed back more than 117,000 images and spectra.

JPL managed the EPOXI and Deep Impact missions for NASA's Science Mission Directorate, Washington. The EPOXI mission was part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. The University of Maryland, College Park, is home to Michael A'Hearn, principal investigator for EPOXI. Drake Deming of NASA's Goddard Space Flight Center, Greenbelt, Md., is the science lead for the EPOXI mission's extrasolar planet observations. The spacecraft was built for NASA by Ball Aerospace & Technologies Corp., Boulder, Colo.

For more information visit http://www.nasa.gov/mission_pages/epoxi/epoxi20110616.html

Keeping Cool With Heat Pipes on the Space Station

What happens when electronics overheat? The short answer is: nothing good! In microgravity, natural convection does not occur, which makes cooling equipment a challenge. So how do you keep electronic and computer components from overheating in space?

In satellites used for communications, global positioning systems, and defense purposes, a heat pipe is the device used to regulate temperature and keep the overall systems operating reliably. A heat pipe is a simple device that can efficiently transfer heat from a hot spot to a cooler remote location without the use of a mechanical pump.

To further insights into the operation of a heat pipe in space, scientists launched an investigation called the Constrained Vapor Bubble, or CVB, to the International Space Station. The Constrained Vapor Bubble is the prototype for a wickless heat pipe and is the first full-scale fluids study in the Fluids Integrated Rack or FIR facility flown on the U.S. module of the space station. The experiment completed on March 1, 2011, when the crew removed the fourth module for return on STS-135.

A heat pipe is usually a sealed tube in which all the air is removed and a small amount of liquid is introduced under a partial vacuum. A portion of the liquid in contact with a hot surface evaporates into a vapor as it absorbs heat from the hot surface. The vapor condenses back to a liquid when the vapor comes in contact with a cool surface, thus releasing its stored or latent heat to the cold surface. The liquid then draws back toward the hot surface, due to the interaction of the individual liquid molecules and their attraction to the surface of the container -- a process called capillary action. The whole liquid and vapor cycle requires no moving parts and the heat transfer process can repeat indefinitely.

Nearly all heat pipes contain wicks or grooves that enhance capillary action and promote the pumping of the working liquid from the cool liquid pool back to the hot surface where the liquid can evaporate again. "The wicks or grooves are complex to fabricate inside the tube and add weight to the heat pipe. Heat pipes built without wicks hold open the possibility of significant weight savings for space flight," says Constrained Vapor Bubble Project Manager Ronald Sicker, NASA's Glenn Research Center in Cleveland.

The Constrained Vapor Bubble experiment represents state-of-the-art heat pipe research. It uses a cuvette pipe, which is a rectangular-shaped glass tube made of quartz, filled with a fluid called pentane. This design allows for temperature measurement along the Constrained Vapor Bubble with great accuracy. The transparency also enables observation of the fluid flow to allow scientists to measure the size and shape of the menisci -- the shape of the fluid as it climbs the interior walls of the cuvette.

Constrained Vapor Bubble heat pipes were operated on Earth and then launched into space and operated in the microgravity environment of the space station. "Heat pipes operate at a considerably higher temperature and pressure in microgravity than they do on Earth," explains Constrained Vapor Bubble Principal Investigator Joel Plawsky, Rensselaer Polytechnic Institute in Troy, New York. "The reason for this behavior is that in microgravity, there is no gravity-driven natural convection to help cool the heat pipe surface. The only way heat pipes can lose heat in space is to radiate that heat directly to the environment."

This investigation will help increase the understanding of the basic principles controlling these events and help improve efficiency of the cooling equipment. "The heat pipes offer the potential for ultra-reliable heat transfer, since they contain no moving parts like pumps or compressors that can eventually wear out and fail. However, it is one thing to use heat pipes in a machine and quite a different story to use them in human space vehicles. If heat pipes are to be used to support long-term manned exploration missions, their scope and scale would have to be greatly expanded and the risks of using them in microgravity better understood. Studying heat pipe performance in microgravity is thus critical, if we are to eventually use heat pipes as a primary heat transfer technology on long-term manned missions," added Plawsky.

The Fluids Integrated Rack also contains the Light Microscopy Module or LMM, which is a completely automated optical microscope that can be controlled from Earth. The microscope allows for recording visually the changes taking place within the Constrained Vapor Bubble and the recording of the liquid levels and the changes in the bubble of pentane vapor.

"The fluid mechanics and heat transfer provide the fundamental knowledge base necessary for designing and developing improved heat pipe technologies," said Plawsky. "The data we collect and analyze will also help solve fundamental problems in the fields of boiling, evaporation, condensation, adsorption, and evaporative self-assembly. The results of the experiment will benefit a whole host of technologies on Earth ranging from conventional air conditioning/refrigeration systems and devices to cool microelectronics to the fabrication of self-assembled systems such as photonic crystals."

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

Through the Looking Glass

The NASA logo on Bldg. 703 at the Dryden Aircraft Operations Facility in Palmdale, Calif., is reflected in the 2.5-meter primary mirror of the SOFIA observatory's telescope.

SOFIA--the Stratospheric Observatory for Infrared Astronomy-- is an airborne observatory, built to complement the Hubble, Spitzer and Herschel space telescopes, as well as major Earth-based telescopes.

SOFIA features a German-built 100-inch (2.5 meter) diameter far-infrared telescope weighing 20 tons mounted in the rear fuselage of a modified Boeing 747SP aircraft. It is one of the premier space science programs of NASA's Science Mission Directorate.

SOFIA is a joint program between NASA and the German Aerospace Center.

For more information visit http://www.nasa.gov/multimedia/imagegallery/image_feature_1974.html

NASA's Curiosity Continues Mobility Checkouts

Spacecraft specialists at NASA's Jet Propulsion Laboratory, Pasadena, Calif., have been putting the Mars Science Laboratory rover, Curiosity, through various tests in preparation for shipment to NASA's Kennedy Space Center in Florida this month.

A new set of images online shows the rover maneuvering its robotic arm and driving in JPL's Spacecraft Assembly Facility, where it was built. The images are available at: http://www.nasa.gov/mission_pages/msl/multimedia/index.html .

Assembly and testing work is on track for launch of the Mars Science Laboratory from Cape Canaveral Air Force Station, Fla., during the period from Nov. 25 to Dec. 18, 2011.

JPL, a division of the California Institute of Technology in Pasadena, manages the mission for the NASA Science Mission Directorate, Washington. This mission will land Curiosity on Mars in August 2012. Researchers will use the tools on the rover to study whether the landing region has had environmental conditions favorable for supporting microbial life and favorable for preserving clues about whether life existed.

For more information visit http://www.nasa.gov/mission_pages/msl/news/msl20110613.html

Aquarius Lifts Off!

A Delta II rocket launches with the Aquarius/SAC-D spacecraft payload from Space Launch Complex 2 at Vandenberg Air Force Base, Calif. on Friday, June 10, 2011. The joint U.S./Argentinian Aquarius/Satélite de Aplicaciones Científicas (SAC)-D mission, set to launch June 10, will map the salinity at the ocean surface, information critical to improving our understanding of two major components of Earth's climate system: the water cycle and ocean circulation.

For more information visit http://www.nasa.gov/multimedia/imagegallery/image_feature_1972.html

NASA's 'Age of Aquarius' Dawns With California Launch

NASA's 'Age of Aquarius' dawned Friday with the launch of an international satellite carrying the agency-built Aquarius instrument that will measure the saltiness of Earth's oceans to advance our understanding of the global water cycle and improve climate forecasts.

The Aquarius/SAC-D observatory rocketed into space from Vandenberg Air Force Base in California atop a United Launch Alliance Delta II rocket at 7:20:13 a.m. PDT (10:20:13 a.m. EDT). Less than 57 minutes later, the observatory separated from the rocket's second stage and began activation procedures, establishing communications with ground controllers and unfurling its solar arrays.

Initial telemetry reports show the observatory is in excellent health. The SAC-D (Satélite de Aplicaciones Científicas) observatory is a collaboration between NASA and Argentina's space agency, Comisión Nacional de Actividades Espaciales (CONAE).

"Aquarius is a critical component of our Earth sciences work, and part of the next generation of space-based instruments that will take our knowledge of our home planet to new heights," said NASA Deputy Administrator Lori Garver. "The innovative scientists and engineers who contributed to this mission are part of the talented team that will help America win the future and make a positive impact across the globe."

Aquarius will make NASA's first space observations of the salinity, or concentration of salt, at the ocean surface, a key missing variable in satellite studies of Earth. Variations in salinity influence deep ocean circulation, trace the path of freshwater around our planet and help drive Earth's climate.

"Data from this mission will advance our understanding of the ocean and prediction of the global water cycle," said Michael Freilich, director of NASA's Earth Science Division in the Science Mission Directorate at agency headquarters in Washington. "This mission demonstrates the power of international collaboration and accurate spaceborne measurements for science and societal benefit. This would not be possible without the sustained cooperation of NASA, CONAE and our other partners."

In addition to Aquarius, the observatory carries seven instruments that will monitor natural hazards and collect a broad range of environmental data. Other mission partners include Brazil, Canada, France and Italy.

"This mission is the most outstanding project in the history of scientific and technological cooperation between Argentina and the United States," said CONAE Executive and Technical Director Conrado Varotto. "Information from the mission will have significant benefits for humankind."

Aquarius will map the global open ocean once every seven days for at least three years with a resolution of 93 miles (150 kilometers). The maps will show how ocean surface salinity changes each month, season and year. Scientists expect to release preliminary salinity maps later this year.

Aquarius will measure salinity by sensing thermal microwave emissions from the water's surface with three microwave instruments called radiometers. When other environmental factors are equal, these emissions indicate the saltiness of surface water. A microwave radar scatterometer instrument will measure ocean waves that affect the precision of the salinity measurement. Because salinity levels in the open ocean vary by only about five parts per thousand, Aquarius will be able to detect changes as small as approximately two parts per 10,000, equivalent to about one-eighth of a teaspoon of salt in a gallon of water.

During the next 25 days, the Aquarius/SAC-D service platform will be tested and maneuvered into its final operational, near-polar orbit 408 miles (657 kilometers) above Earth. Science operations will begin after the observatory's instruments are checked out. This commissioning phase may last up to 65 days.

Aquarius was built by NASA's Jet Propulsion Laboratory in Pasadena, Calif., and the Goddard Space Flight Center in Greenbelt, Md. NASA's Launch Services Program, at Kennedy Space Center in Florida, managed the launch. JPL will manage Aquarius through its commissioning phase and archive mission data. Goddard will manage Aquarius mission operations and process science data. CONAE is providing the SAC-D spacecraft, optical camera, thermal camera with Canada, microwave radiometer, sensors from various Argentine institutions and the mission operations center. France and Italy also are contributing instruments.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2011-178

NASA's Aquarius/SAC-D Launch Rescheduled

The launch of the international Aquarius/SAC-D mission is postponed 24 hours until Friday, June 10, from NASA's Space Launch Complex-2 at Vandenberg Air Force Base, Calif. The 5-minute launch window opens at 7:20 a.m. PDT (10:20 a.m. EDT).

The new launch date will allow the launch team to complete additional review of an inconsistency found in the Delta II launch vehicle flight profile for wind conditions on the day of launch. These data are used to steer the Delta II through upper level winds. The weather forecast for June 10 shows a 100 percent chance of favorable weather conditions for the launch.

The Aquarius/SAC-D (Satelite de Aplicaciones Cientificas) observatory is a collaboration between NASA and Argentina's space agency, Comision Nacional de Actividades Espaciales (CONAE).

Media are invited to see and photograph the Delta II with Aquarius/SAC-D at the launch pad on Thursday, June 9. Media will depart for the pad at 9:30 p.m. PDT from the Vandenberg Main Gate on California State Road 1.

Media covering the launch on Friday, June 10, will be escorted to the press viewing site from the Vandenberg Main Gate. Media should meet at 6 a.m. PDT at the pass and identification building.

Aquarius was built by NASA's Jet Propulsion Laboratory in Pasadena, Calif., and the Goddard Space Flight Center in Greenbelt, Md. NASA's Launch Services Program at the Kennedy Space Center in Florida manages the launch. JPL will manage Aquarius through its commissioning phase and archive mission data. Goddard will manage Aquarius mission operations and process science data. CONAE is providing the SAC-D spacecraft, optical camera, thermal camera with Canada, microwave radiometer, sensors from various Argentine institutions and the mission operations center. France and Italy also are contributing instruments.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2011-175

Opportunity Heads Toward 'Spirit Point'

When NASA's Mars Exploration Rover Opportunity reaches the rim of a large crater it is approaching, its arrival will come with an inspiring reminder.

This crater, Endeavour, became the rover's long-term destination nearly three years ago. Opportunity has driven about 11 miles (18 kilometers) since climbing out of Victoria crater in August 2008, with Endeavour crater beckoning to the southeast. The rover has about 2 miles (about 3 kilometers) to go before reaching the rim of Endeavour.

Rover team members last week selected "Spirit Point" as the informal name for the site on the rim where Opportunity will arrive at Endeavour crater. The choice commemorates Opportunity's rover twin, Spirit, which has ended communication and finished its mission.

"Spirit achieved far more than we ever could have hoped when we designed her," said Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for the rovers. "This name will be a reminder that we need to keep pushing as hard as we can to make new discoveries with Opportunity. The exploration of Spirit Point is the next major goal for us to strive for."

Endeavour offers the setting for plenty of productive work by Opportunity. The crater is 14 miles (22 kilometers) in diameter -- more than 20 times wider than Victoria crater, which Opportunity examined for two years. Orbital observations indicate that the ridges along its western rim expose rock outcrops older than any Opportunity has seen so far. Spirit Point is at the southern tip of one of those ridges, "Cape York," on the western side of Endeavour.

Opportunity and Spirit completed their three-month prime missions on Mars in April 2004. Both rovers continued for years of bonus, extended missions. Both have made important discoveries about wet environments on ancient Mars that may have been favorable for supporting microbial life.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for the NASA Science Mission Directorate, Washington.

For more information visit http://www.nasa.gov/mission_pages/mer/news/mer20110608.html

Three Satellites See Eruption of Puyehue-Cordón Volcano from Space

NASA's Terra Satellite, the GOES-13 and GOES-11 satellites all captured images of the ash plume from southern Chile's Puyehue-Cordón Volcano this week. The volcano is located in Puyehue National Park in the Andes of Ranco Province of Chile.

The Terra satellite flew over the volcano on June 6 at 14:25 UTC (10:25 a.m. EDT). The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument captured a visible image of the eruption that showed the large ash plume blowing northeast, then to the southeast and over the Atlantic Ocean. The ash plume went at least as high as six miles on June 4 when it erupted, according to CNN International. Some 3,500 people were evacuated.

The Geostationary Operational Environmental Satellites called GOES-13 and GOES-11 also captured images of the volcano from a different vantage point in space that revealed the plume was visible from even farther away.

GOES-13 monitors the eastern U.S. and the Atlantic Ocean, while GOES-11 monitors the western U.S. and eastern Pacific Ocean. The GOES-11 satellite image, taken from the farthest vantage point of any of the satellites, still showed the triangular-shaped plume, even from its position over the western U.S., despite the large distance.

The GOES satellites are managed by NOAA, and imagery and animations are created with the GOES satellite data at NASA's GOES Project located at NASA's Goddard Space Flight Center, Greenbelt, Md.

For more information visit http://www.nasa.gov/topics/earth/features/20110606-volcano.html

NASA Commander Mark Kelly Appears at U2360° in Seattle

U2 delivered a surprise to the crowds at Quest Field, Seattle last night with a video message from Commander Mark E. Kelly. Bono dedicated 'Beautiful Day' to Gabby Giffords, before asking, “Imagine a man looking down on us from 200 miles up. Looking down at our beautiful crowded planet… What would he say to us…? What is on your mind Commander Kelly?”

Commander Kelly, on a 16-day mission with the Endeavour crew, recorded the message aboard the International Space Station, “Hello Seattle… from the International Space Station.” Before finishing on a line from David Bowie's 'Space Oddity' : “I’m looking forward to coming home. Tell my wife I love her very much… she knows.”

U2 approached NASA in 2009 with an idea to include a dialogue between the band and the crew of the International Space Station during U2's world tour. In 2009 and 2010, U2 incorporated footage from the space station’s Expedition 20 crew in its concerts. For the second half of the world tour, U2 asked Mark Kelly, Commander of space shuttle mission STS-134 to record some words during his flight to the station.

"Working with U2 is atypical for NASA," said Bill Gerstenmaier, NASA's associate administrator for Space Operations. "By combining their world tour with the space station's out-of-this-world mission, more people -- and different people than our normal target audiences -- learned about the International Space Station and the important work we are doing in orbit."

Speaking onstage in Houston last year, Bono said, "These are the very best people in the world -- dedicated to figuring how our little planet exists in this cosmos we call home."

U2360° has worked with NASA and the International Space Station throughout this tour - having previously linked up with Belgian astronaut Commander Frank De Winne, Michael Barratt of NASA, Bob Thirsk of the Canadian Space Agency, Koichi Wakata of the Japan Aerospace Exploration Agency, and Gennady Padalka and Roman Romanenko of the Russian Federal Space Agency as well as Cirque du Soleil founder Guy Laliberte during his visit to the International Space Station.

For more information visit http://www.nasa.gov/topics/shuttle_station/features/U2_ISS.html

New NASA Map Reveals Tropical Forest Carbon Storage

A NASA-led research team has used a variety of NASA satellite data to create the most precise map ever produced depicting the amount and location of carbon stored in Earth's tropical forests. The data are expected to provide a baseline for ongoing carbon monitoring and research and serve as a useful resource for managing the greenhouse gas carbon dioxide.

The new map, created from ground- and space-based data, shows, for the first time, the distribution of carbon stored in forests across more than 75 tropical countries. Most of that carbon is stored in the extensive forests of Latin America.

"This is a benchmark map that can be used as a basis for comparison in the future when the forest cover and its carbon stock change," said Sassan Saatchi of NASA's Jet Propulsion Laboratory in Pasadena, Calif., who led the research. "The map shows not only the amount of carbon stored in the forest, but also the accuracy of the estimate." The study was published May 30 in the Proceedings of the National Academy of Sciences.

Deforestation and forest degradation contribute 15 to 20 percent of global carbon emissions, and most of that contribution comes from tropical regions. Tropical forests store large amounts of carbon in the wood and roots of their trees. When the trees are cut and decompose or are burned, the carbon is released to the atmosphere.

Previous studies had estimated the carbon stored in forests on local and large scales within a single continent, but there existed no systematic way of looking at all tropical forests. To measure the size of the trees, scientists typically use a ground-based technique, which gives a good estimate of how much carbon they contain. But this technique is limited because the structure of the forest is extremely variable, and the number of ground sites is very limited.

To arrive at a carbon map that spans three continents, the team used data from the Geoscience Laser Altimeter System lidar on NASA's ICESat satellite. The researchers looked at information on the height of treetops from more than 3 million measurements. With the help of corresponding ground data, they calculated the amount of above-ground biomass and thus, the amount of carbon it contained.

The team then extrapolated these data over the varying landscape to produce a seamless map, using NASA imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Terra spacecraft, the QuikScat scatterometer satellite and the Shuttle Radar Topography Mission.

The map reveals that in the early 2000s, forests in the 75 tropical countries studied contained 247 billion tons of carbon. For perspective, about 10 billion tons of carbon is released annually to the atmosphere from combined fossil fuel burning and land use changes.

The researchers found that forests in Latin America hold 49 percent of the carbon in the world's tropical forests. For example, Brazil's carbon stock alone, at 61 billion tons, almost equals all of the carbon stock in sub-Saharan Africa, at 62 billion tons.

"These patterns of carbon storage, which we really didn't know before, depend on climate, soil, topography and the history of human or natural disturbance of the forests," Saatchi said. "Areas often impacted by disturbance, human or natural, have lower carbon storage."

The carbon numbers, along with information about the uncertainty of the measurements, are important for countries planning to participate in the Reducing Emissions from Deforestation and Degradation (REDD+) program. REDD+ is an international effort to create a financial value for the carbon stored in forests. It offers incentives for countries to preserve their forestland in the interest of reducing carbon emissions and investing in low-carbon paths of development.

The map also provides a better indication of the health and longevity of forests and how they contribute to the global carbon cycle and overall functioning of the Earth system. The next step in Saatchi's research is to compare the carbon map with satellite observations of deforestation to identify source locations of carbon dioxide released to the atmosphere.

For more information visit http://www.nasa.gov/topics/earth/features/earth20110531.html

Opportunity Passes Small Crater and Big Milestone

A drive of 482 feet (146.8 meters) on June 1, 2011, took NASA's Mars Exploration Rover Opportunity past 30 kilometers (18.64 miles) in total odometry during 88 months of driving on Mars. That's 50 times the distance originally planned for the mission and more than 12 times the distance racehorses will run next week at the Belmont Stakes.

Opportunity has passed many craters on its crater-hopping tour. One of the youngest of them is "Skylab" crater, which the rover passed last month. Rocks scattered by the impact of a meteorite surround the resulting crater in a view recorded by Opportunity on May 12. The view is at http://photojournal.jpl.nasa.gov/catalog/PIA14132 , and in 3-D stereo at http://photojournal.jpl.nasa.gov/catalog/PIA14133 .

This crater, informally named after America's first space station, is only about 9 meters (30 feet) in diameter. Opportunity passed it as the rover made progress toward its long-term destination, Endeavour crater, which is about 22 kilometers (14 miles) in diameter.

The positions of the scattered rocks relative to sand ripples suggest that Skylab is young for a Martian crater. Researchers estimate it was excavated by an impact within the past 100,000 years.

Opportunity and its twin, Spirit, completed their three-month prime missions on Mars in April 2004. Both rovers continued for years of bonus, extended missions. Both have made important discoveries about wet environments on ancient Mars that may have been favorable for supporting microbial life. Spirit has not communicated with Earth since March 2010.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for the NASA Science Mission Directorate, Washington.

For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2011-170

International Space Station Technology -- With Benefits for Fine Art

If art is in the eye of the beholder, then space aficionados may hail the International Space Station as a technological masterpiece. So it is an interesting coincidence that the research that went into developing the orbiting laboratory actually benefits fine art here on Earth. Paintings damaged by everything from lipstick to soot from a fire now have a safe method of restoration available, thanks to information originally intended for the building of the space station.

The journey to restoration began with early space research pointed at the eventual construction of the space station. This includes investigations such as Evaluation of Oxygen Interaction with Materials, or EOIM-III, conducted on the space shuttle as part of STS-46. This study looked at the material reactions to atomic oxygen, as well as vacuum ultraviolet radiation. The findings showed that atomic oxygen in low Earth orbit reacted with carbon containing materials.

Engineers built ground testing facilities based on results from atomic oxygen studies for the main goal of testing radiators, solar arrays, other external components in development for the space station. According to Sharon Miller with NASA's Space Environment and Experiments Branch at NASA's Glenn Research Center, the benefits beyond the intended space station goals were a surprise. "The uses of atomic oxygen for Earth applications were not planned. They are a result of knowledge gained by observing the effect of atomic oxygen on materials and discussions with knowledgeable individuals in the fields of art and medicine."

While atomic oxygen can be destructive in the space environment, on Earth it can delicately remove unwanted substances from items such as paintings by dissolving them over a period of time. Glenn Research Center houses a vacuum chamber that mixes oxygen and helium to create atomic oxygen. This chemical element does not naturally occur for long on Earth, but scientists have harnessed the ability to generate it using a concise pencil-beam machine. These resources enable the oxidation of debris to harmlessly reveal the paint underneath. Atomic oxygen also has sterilization benefits for medical tools, among other uses.

The need to study the space environment continues today on the space station in preparation for future exploration, building of new satellites for Earth orbit and continued use of the orbiting laboratory. One investigation in particular manages to enable multiple studies at once. The Materials International Space Station Experiment, or MISSE, continues the efforts started by predecessors like EOIM-III. This research allows scientists to determine the best materials for surviving the space environment.

Astronauts place the samples into a suitcase-like facility attached to the exterior of the space station. These test materials come from NASA centers, commercial companies, Department of Defense laboratories, and various partner agencies. MISSE-7 returned to Earth as part of the STS-134 mission on June 1, 2011. The study contained more than 700 different samples, selected for the long-duration space exposure. Researchers use the knowledge from the MISSE investigations to create models and tools for optimal spacecraft designs. This includes finding out which materials are most durable for specific mission goals.

The body of knowledge from space station research continues to build upon itself as NASA pursues future exploration missions. Miller points out the continued potential of such investigations. "The knowledge gained from the research being conducted on MISSE can lead to many more great discoveries, more knowledgeable selection of materials for future spacecraft and additional benefits to improve life here on Earth."

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