The International Space Station’s 3-D printer has manufactured the first 3-D printed object in space, paving the way to future long-term space expeditions. The object, a printhead faceplate, is engraved with names of the organizations that collaborated on this space station technology demonstration: NASA and Made In Space, Inc., the space manufacturing company that worked with NASA to design, build and test the 3-D printer.

This image of the printer, with the Microgravity Science Glovebox Engineering Unit in the background, was taken in April 2014 during flight certification and acceptance testing at NASA’s Marshall Space Flight Center in Huntsville, Alabama, prior to its launch to the station aboard a SpaceX commercial resupply mission. The first objects built in space will be returned to Earth in 2015 for detailed analysis and comparison to the identical ground control samples made on the flight printer prior to launch. The goal of this analysis is to verify that the 3-D printing process works the same in microgravity as it does on Earth.

The printer works by extruding heated plastic, which then builds layer upon layer to create three-dimensional objects. Testing this on the station is the first step toward creating a working “machine shop” in space. This capability may decrease cost and risk on the station, which will be critical when space explorers venture far from Earth and will create an on-demand supply chain for needed tools and parts. Long-term missions would benefit greatly from onboard manufacturing capabilities. Data and experience gathered in this demonstration will improve future 3-D manufacturing technology and equipment for the space program, allowing a greater degree of autonomy and flexibility for astronauts.

Image Credit: NASA/Emmett Given

Plasma shield

November 27, 2014

High above Earth’s atmosphere, electrons whiz past at close to the speed of light. Such ultrarelativistic electrons, which make up the outer band of the Van Allen radiation belt, can streak around the planet in a mere five minutes, bombarding anything in their path. Exposure to such high-energy radiation can wreak havoc on satellite electronics, and pose serious health risks to astronauts.

Now researchers at MIT, the University of Colorado, and elsewhere have found there’s a hard limit to how close ultrarelativistic electrons can get to the Earth. The team found that no matter where these electrons are circling around the planet’s equator, they can get no further than about 11,000 kilometers from the Earth’s surface — despite their intense energy.  

What’s keeping this high-energy radiation at bay seems to be neither the Earth’s magnetic field nor long-range radio waves, but rather a phenomenon termed “plasmaspheric hiss” — very low-frequency electromagnetic waves in the Earth’s upper atmosphere that, when played through a speaker, resemble static, or white noise.

Based on their data and calculations, the researchers believe that plasmaspheric hiss essentially deflects incoming electrons, causing them to collide with neutral gas atoms in the Earth’s upper atmosphere, and ultimately disappear. This natural, impenetrable barrier appears to be extremely rigid, keeping high-energy electrons from coming no closer than about 2.8 Earth radii — or 11,000 kilometers from the Earth’s surface.

“It’s a very unusual, extraordinary, and pronounced phenomenon,” says John Foster, associate director of MIT’s Haystack Observatory. “What this tells us is if you parked a satellite or an orbiting space station with humans just inside this impenetrable barrier, you would expect them to have much longer lifetimes. That’s a good thing to know.”

Foster and his colleagues, including lead author Daniel Baker of the University of Colorado, have published their results this week in the journal Nature.

Shields up

The team’s results are based on data collected by NASA’s Van Allen Probes — twin crafts that are orbiting within the harsh environments of the Van Allen radiation belts. Each probe is designed to withstand constant radiation bombardment in order to measure the behavior of high-energy electrons in space.

The researchers analyzed the first 20 months of data returned by the probes, and observed an “exceedingly sharp” barrier against ultrarelativistic electrons. This barrier held steady even against a solar wind shock, which drove electrons toward the Earth in a “step-like fashion” in October 2013. Even under such stellar pressure, the barrier kept electrons from penetrating further than 11,000 kilometers above Earth’s surface.

To determine the phenomenon behind the barrier, the researchers considered a few possibilities, including effects from the Earth’s magnetic field and transmissions from ground-based radios.

For the former, the team focused in particular on the South Atlantic Anomaly — a feature of the Earth’s magnetic field, just over South America, where the magnetic field strength is about 30 percent weaker than in any other region. If incoming electrons were affected by the Earth’s magnetic field, Foster reasoned, the South Atlantic Anomaly would act like a “hole in the path of their motion,” allowing them to fall deeper into the Earth’s atmosphere. Judging from the Van Allen probes’ data, however, the electrons kept their distance of 11,000 kilometers, even beyond the effects of the South Atlantic Anomaly — proof that the Earth’s magnetic field had little effect on the barrier.

Foster also considered the effect of long-range, very-low-frequency (VLF) radio transmissions, which others have proposed may cause significant loss of relatively high-energy electrons. Although VLF transmissions can leak into the upper atmosphere, the researchers found that such radio waves would only affect electrons with moderate energy levels, with little or no effect on ultrarelativistic electrons.

Instead, the group found that the natural barrier may be due to a balance between the electrons’ slow, earthward motion, and plasmaspheric hiss. This conclusion was based on the Van Allen probes’ measurement of electrons’ pitch angle — the degree to which an electron’s motion is parallel or perpendicular to the Earth’s magnetic field. The researchers found that plasmaspheric hiss acts slowly to rotate electrons’ paths, causing them to fall, parallel to a magnetic field line, into Earth’s upper atmosphere, where they are likely to collide with neutral atoms and disappear.

Mary Hudson, a professor of physics at Dartmouth College, says the data from the Van Allen probes “are providing remarkably detailed measurements” of the Earth’s radiation belts and their boundaries.

“These new observations confirm, over the two years since launch of the Van Allen probes, the persistence of this inner boundary, which places additional constraints on theories of particle acceleration and loss in magnetized astrophysical systems,” says Hudson, who did not participate in the research.

Seen through “new eyes”

Foster says this is the first time researchers have been able to characterize the Earth’s radiation belt, and the forces that keep it in check, in such detail. In the past, NASA and the U.S. military have launched particle detectors on satellites to measure the effects of the radiation belt: NASA was interested in designing better protection against such damaging radiation; the military, Foster says, had other motivations.

“In the 1960s, the military created artificial radiation belts around the Earth by the detonation of nuclear warheads in space,” Foster says. “They monitored the radiation belt changes, which were enormous. And it was realized that, in any kind of nuclear war situation, this could be one thing that could be done to neutralize anyone’s spy satellites.”

The data collected from such efforts was not nearly as precise as what is measured today by the Van Allen probes, mainly because previous satellites were not designed to fly in such harsh conditions. In contrast, the resilient Van Allen Probes have gathered the most detailed data yet on the behavior and limits of the Earth’s radiation belt.

“It’s like looking at the phenomenon with new eyes, with a new set of instrumentation, which give us the detail to say, ‘Yes, there is this hard, fast boundary,’” Foster says.

This research was funded in part by NASA.

By Jennifer Chu | MIT News Office

Magnetic fields emerging from below the surface of the sun influence the solar wind—a stream of particles that blows continuously from the sun’s atmosphere through the solar system. Researchers at NASA and its university partners are using high-fidelity computer simulations to learn how these magnetic fields emerge, heat the sun’s outer atmosphere and produce sunspots and flares.

This visualization shows magnetic field loops in a portion of the sun, with colors representing magnetic field strength from weak (blue) to strong (red). The simulation was run on the Pleiades supercomputer at the NASA Advanced Supercomputing facility at NASA’s Ames Research Center in Moffett Field, California. 

The knowledge gained through simulation results like this one help researchers better understand the sun, its variations, and its interactions with Earth and the solar system.

Image Credit: Robert Stein, Michigan State University; Timothy Sandstrom, NASA/Ames

> Related: NASA showcased more than 35 of the agency’s exciting computational achievements at SC14, the international supercomputing conference, Nov. 16-21, 2014, in New Orleans.

Europa’s Stunning Surface

November 27, 2014

The puzzling, fascinating surface of Jupiter’s icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA’s Galileo spacecraft in the late 1990s. This is the color view of Europa from Galileo that shows the largest portion of the moon’s surface at the highest resolution.

The view was previously released as a mosaic with lower resolution and strongly enhanced color (see PIA02590). To create this new version, the images were assembled into a realistic color view of the surface that approximates how Europa would appear to the human eye.

The scene shows the stunning diversity of Europa’s surface geology. Long, linear cracks and ridges crisscross the surface, interrupted by regions of disrupted terrain where the surface ice crust has been broken up and re-frozen into new patterns.

Color variations across the surface are associated with differences in geologic feature type and location. For example, areas that appear blue or white contain relatively pure water ice, while reddish and brownish areas include non-ice components in higher concentrations. The polar regions, visible at the left and right of this view, are noticeably bluer than the more equatorial latitudes, which look more white. This color variation is thought to be due to differences in ice grain size in the two locations. 

Images taken through near-infrared, green and violet filters have been combined to produce this view. The images have been corrected for light scattered outside of the image, to provide a color correction that is calibrated by wavelength. Gaps in the images have been filled with simulated color based on the color of nearby surface areas with similar terrain types.

This global color view consists of images acquired by the Galileo Solid-State Imaging (SSI) experiment on the spacecraft’s first and fourteenth orbits through the Jupiter system, in 1995 and 1998, respectively. Image scale is 1 mile (1.6 kilometers) per pixel. North on Europa is at right.

The Galileo mission was managed by NASA’s Jet Propulsion Laboratory in Pasadena, California, for the agency’s Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology, Pasadena. 

Additional information about Galileo and its discoveries is available on the Galileo mission home page at More information about Europa is available at

Image Credit: NASA/JPL-Caltech/SETI Institute

The Soyuz TMA-15M rocket launches from the Baikonur Cosmodrome in Kazakhstan on Monday, Nov. 24, 2014 as seen in this long exposure carrying Expedition 42 Soyuz Commander Anton Shkaplerov of the Russian Federal Space Agency (Roscosmos), Flight Engineer Terry Virts of NASA, and Flight Engineer Samantha Cristoforetti of the European Space Agency (ESA) into orbit to begin their five and a half month mission on the International Space Station. 

Image Credit: NASA/Aubrey Gemignani

The Soyuz TMA-15M spacecraft is rolled out to the launch pad by train on Friday, Nov. 21, 2014 at the Baikonur Cosmodrome in Kazakhstan.  Launch of the Soyuz rocket is scheduled for Nov. 24 and will carry Expedition 42 Soyuz Commander Anton Shkaplerov of the Russian Federal Space Agency (Roscosmos), Flight Engineer Terry Virts of NASA , and Flight Engineer Samantha Cristoforetti of the European Space Agency into orbit to begin their five and a half month mission on the International Space Station.

Image Credit: NASA/Aubrey Gemignani

On Nov. 20, 2004, NASA’s Swift spacecraft lifted off aboard a Boeing Delta II rocket from Cape Canaveral Air Force Station, Fla., beginning its mission to study gamma-ray bursts and identify their origins. Gamma-ray bursts are the most luminous explosions in the cosmos. Most are thought to be triggered when the core of a massive star runs out of nuclear fuel, collapses under its own weight, and forms a black hole. The black hole then drives jets of particles that drill all the way through the collapsing star and erupt into space at nearly the speed of light.

Astronomers at NASA and Pennsylvania State University used Swift to create the most detailed ultraviolet light surveys ever of the Large and Small Magellanic Clouds, the two closest major galaxies. Nearly a million ultraviolet sources appear in this mosaic of the Large Magellanic Cloud, which was assembled from 2,200 images taken by Swift’s Ultraviolet/Optical Telescope (UVOT) and released on June 3, 2013. The 160-megapixel image required a cumulative exposure of 5.4 days. The image includes light from 1,600 to 3,300 angstroms — UV wavelengths largely blocked by Earth’s atmosphere — and has an angular resolution of 2.5 arcseconds at full size. The Large Magellanic Cloud is about 14,000 light-years across.

Viewing in the ultraviolet allows astronomers to suppress the light of normal stars like the sun, which are not very bright at such higher energies, and provides a clearer picture of the hottest stars and star-formation regions. No telescope other than UVOT can produce such high-resolution wide-field multicolor surveys in the ultraviolet.

Pennsylvania State University manages the Swift Mission Operations Center, which controls Swift’s science and flight operations. Goddard manages Swift, which was launched in November 2004. The satellite is operated in collaboration with Penn State, the Los Alamos National Laboratory in New Mexico and Orbital Sciences Corp. in Dulles, Va. International collaborators are in the United Kingdom and Italy, and the mission includes contributions from Germany and Japan.

Image Credit: NASA/Swift/S. Immler (Goddard) and M. Siegel (Penn State)

MSH 11-62 Supernova Remnant

November 27, 2014

A long observation with Chandra of the supernova remnant MSH 11-62 reveals an irregular shell of hot gas, shown in red, surrounding an extended nebula of high energy X-rays, shown in blue. Even though scientists have yet to detect any pulsations from the central object within MSH 11-62, the structure around it has many of the same characteristics as other pulsar wind nebulas. The reverse shock and other, secondary shocks within MSH 11-62 appear to have begun to crush the pulsar wind nebula, possibly contributing to its elongated shape. (Note: the orientation of this image has been rotated by 24 degrees so that north is pointed to the upper left.)

Image credit:  NASA/CXC/SAO/P. Slane et al.

› Read feature

NASA’s green aviation project is one step closer to developing technology that could make future airliners quieter and more fuel-efficient with the successful flight test of a wing surface that can change shape in flight.

This past summer, researchers replaced an airplane’s conventional aluminum flaps with advanced, shape-changing assemblies that form seamless bendable and twistable surfaces. Flight testing will determine whether flexible trailing-edge wing flaps are a viable approach to improve aerodynamic efficiency and reduce noise generated during takeoffs and landings.

For the initial Adaptive Compliant Trailing Edge (ACTE) flight, shown in this image, the experimental control surfaces were locked at a specified setting. Varied flap settings on subsequent tests will demonstrate the capability of the flexible surfaces under actual flight conditions.

ACTE technology is expected to have far-reaching effects on future aviation. Advanced lightweight materials will reduce wing structural weight and give engineers the ability to aerodynamically tailor the wings to promote improved fuel economy and more efficient operations, while reducing environmental impacts.

> More: NASA Tests Revolutionary Shape Changing Aircraft Flap for the First Time

Image Credit: NASA/Ken Ulbrich

Mixing Paints

November 27, 2014

Nature is an artist, and this time she seems to have let her paints swirl together a bit.

What the viewer might perceive to be Saturn’s surface is really just the tops of its uppermost cloud layers. Everything we see is the result of fluid dynamics. Astronomers study Saturn’s cloud dynamics in part to test and improve our understanding of fluid flows. Hopefully, what we learn will be useful for understanding our own atmosphere and that of other planetary bodies.

This view looks toward the sunlit side of the rings from about 25 degrees above the ringplane. The image was taken in red light with the Cassini spacecraft narrow-angle camera on Aug. 23, 2014.

The view was acquired at a distance of approximately 1.1 million miles (1.8 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 127 degrees. Image scale is 7 miles (11 kilometers) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit and . The Cassini imaging team homepage is at .

Credit: NASA/JPL-Caltech/Space Science Institute