FROM: NASA
Van Allen Probes - The Instruments
Dr. David Sibeck explains the instruments on the twin Van Allen Probes (formerly the Radiation Belt Storm Probes, RBSP). The Van Allen Probes will explore the Van Allen Radiation Belts in the Earth's magnetosphere. The charged particles in these regions can be hazardous to both spacecraft and astronauts. The mission also will allow researchers to understand fundamental radiation and particle acceleration processes throughout the universe.
FROM: NASA
A Reborn Planetary Nebula
These images of the planetary nebula Abell 30 show one of the clearest views ever obtained of a special phase of evolution for these objects. The inset image on the right is a close-up view of A30 showing X-ray data from NASA's Chandra X-ray Observatory in purple and Hubble Space Telescope data showing optical emission from oxygen ions in orange. On the left is a larger view showing optical and X-ray data from the Kitt Peak National Observatory and ESA's XMM-Newton, respectively. In this image the optical data show emission from oxygen (orange) and hydrogen (green and blue), and X-ray emission is colored purple.
A planetary nebula -- so called because it looks like a planet when viewed with a small telescope -- is formed in the late stage of the evolution of a sun-like star. After having steadily produced energy for several billion years through the nuclear fusion of hydrogen into helium in its central region, or core, the star undergoes a series of energy crises related to the depletion of hydrogen and subsequent contraction of the core. These crises culminate in the star expanding a hundred-fold to become a red giant.
Eventually the outer envelope of the red giant is ejected and moves away from the star at a relatively sedate speed of less than 100,000 miles per hour. The star meanwhile is transformed from a cool giant into a hot, compact star that produces intense ultraviolet radiation and a fast wind of particles moving at about 6 million miles per hour. The interaction of the UV radiation and the fast wind with the ejected red giant envelope creates the planetary nebula, shown by the large spherical shell in the bigger image.
In rare cases, nuclear fusion reactions in the region surrounding the star's core heat the outer envelope of the star so much that it temporarily becomes a red giant again. The sequence of events -- envelope ejection followed by a fast stellar wind -- is repeated on a much faster scale than before, and a small-scale planetary nebula is created inside the original one. In a sense, the planetary nebula is reborn.
Image Credit-NASA-ESA
FROM: NASA
NASA, ESA Use Experimental Interplanetary Internet to Test Robot From International Space Station
WASHINGTON -- NASA and the European Space Agency (ESA) successfully have used an experimental version of interplanetary Internet to control an educational rover from the International Space Station. The experiment used NASA's Disruption Tolerant Networking (DTN) protocol to transmit messages and demonstrate technology that one day may enable Internet-like communications with space vehicles and support habitats or infrastructure on another planet.
Space station Expedition 33 commander Sunita Williams in late October used a NASA-developed laptop to remotely drive a small LEGO robot at the European Space Operations Centre in Darmstadt, Germany. The European-led experiment used NASA's DTN to simulate a scenario in which an astronaut in a vehicle orbiting a planetary body controls a robotic rover on the planet's surface.
"The demonstration showed the feasibility of using a new communications infrastructure to send commands to a surface robot from an orbiting spacecraft and receive images and data back from the robot," said Badri Younes, deputy associate administrator for space communications and navigation at NASA Headquarters in Washington. "The experimental DTN we've tested from the space station may one day be used by humans on a spacecraft in orbit around Mars to operate robots on the surface, or from Earth using orbiting satellites as relay stations."
The DTN architecture is a new communications technology that enables standardized communications similar to the Internet to function over long distances and through time delays associated with on-orbit or deep space spacecraft or robotic systems. The core of the DTN suite is the Bundle Protocol (BP), which is roughly equivalent to the Internet Protocol (IP) that serves as the core of the Internet on Earth. While IP assumes a continuous end-to-end data path exists between the user and a remote space system, DTN accounts for disconnections and errors. In DTN, data move through the network "hop-by-hop." While waiting for the next link to become connected, bundles are temporarily stored and then forwarded to the next node when the link becomes available.
NASA's work on DTN is part of the agency's Space Communication and Navigation (SCaN) Program. SCaN coordinates multiple space communications networks and network support functions to regulate, maintain and grow NASA's space communications and navigation capabilities in support of the agency's space missions.
The space station also serves as a platform for research focused on human health and exploration, technology testing for enabling future exploration, research in basic life and physical sciences and Earth and space science.
FROM: NASA
A Nearby Stellar Cradle
The Milky Way and other galaxies in the universe harbor many young star clusters and associations that each contain hundreds to thousands of hot, massive, young stars known as O and B stars. The star cluster Cygnus OB2 contains more than 60 O-type stars and about a thousand B-type stars. Deep observations with NASA’s Chandra X-ray Observatory have been used to detect the X-ray emission from the hot outer atmospheres, or coronas, of young stars in the cluster and to probe how these fascinating star factories form and evolve. About 1,700 X-ray sources were detected, including about 1,450 thought to be stars in the cluster. In this image, X-rays from Chandra (blue) have been combined with infrared data from NASA’s Spitzer Space Telescope (red) and optical data from the Isaac Newton Telescope (orange).
Image Credit: NASA
FROM: NASA
Wind and Radiation on Mars
Curiosity monitors radiation and spots elusive whirlwinds on Mars.
Credit: NASA/JPL-Caltech
