Nasa

On Jan. 27, 2012, a large X-class flare erupted from an active region near the solar west limb. X-class flares are the most powerful of all solar events. Seen here is an image of the flare captured by the X-ray telescope on Hinode. This image shows an emission from plasma heated to greater than eight million degrees during the energy release process of the flare.

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Aurora Borealis Over the Midwest

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In this image taken on Jan. 25, 2012, the Aurora Borealis steals the scene in this nighttime photograph shot from the International Space Station as the orbital outpost flew over the Midwest. The spacecraft was above south central Nebraska when the photo was taken. The image, taken at an oblique angle, looks north to northeast.

Eastern Seaboard at Night

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An Expedition 30 crew member aboard the International Space Station took this nighttime photograph of much of the Atlantic coast of the United States. Large metropolitan areas and other easily recognizable sites from the Virginia/Maryland/Washington, D.C. area are visible in the image that spans almost to Rhode Island. Boston is just out of frame at right. Long Island and the New York City area are visible in the lower right quadrant. Philadelphia and Pittsburgh are near the center. Parts of two Russian vehicles parked at the orbital outpost are seen in left foreground.

This image was taken on Feb. 6, 2012.

Jupiter From the Ground

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This image of Jupiter and its moons Io and Ganymede was acquired by amateur astronomer Damian Peach on Sept. 12, 2010, when Jupiter was close to opposition. South is up and the "Great Red Spot" is visible in the image.

Ground-based astronomy will play a vital role in the success of NASA's Juno mission. Because Jupiter has such a dynamic atmosphere, images from amateur astronomers will assist the JunoCam instrument team predict what features will be visible when the camera's images are taken.

With its suite of science instruments, the Juno spacecraft will investigate the existence of a solid planetary core, map the planet's intense magnetic field, measure the amount of water and ammonia in the deep atmosphere and observe the planet's auroras.

Enceladus, Saturn's Moon

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Below a darkened Enceladus, a plume of water ice is backlit in this view of one of Saturn's most dramatic moons.

Dramatic plumes, both large and small, spray water ice from many locations along the moon's famed "tiger stripes" near the south pole of Enceladus. The tiger stripes are fissures that spray icy particles, water vapor and organic compounds.

The terrain seen here is on the leading hemisphere of Enceladus (313 miles, or 504 kilometers across). North is up. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Feb. 20, 2012. The view was acquired at a distance of approximately 83,000 miles (134,000 kilometers) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 165 degrees. Image scale is 2,628 feet (801 meters) per pixel

Dubai at Night

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City lights of Dubai, United Arab Emirates, are featured in this image taken by the Expedition 30 crew aboard the International Space Station. The City of Dubai--the largest metropolitan area within the emirate of Dubai--is a favorite subject of astronaut photography largely due to the unique artificial archipelagos situated directly offshore in the Persian Gulf, which were built such that their full design is only visible from the vantage point of an airplane -- or an orbiting spacecraft. The city presents an eye-catching appearance at night that vividly displays the urban development pattern. In this detailed image, taken with a long focal length lens and digital camera optimized for fast response and high light sensitivity, several interesting patterns can be observed. The highways and major streets are sharply defined by yellow-orange lighting, while the commercial and residential areas are resolved into a speckle pattern of individual white, blue and yellow-orange lights. Several large and brilliantly lit areas are large hotel and mall complexes, including the Burj Khalifa Tower, the world's tallest building at 2,717 feet, or 828 meters. The brilliant lighting of the city contrasts sharply with both the dark Persian Gulf to the northwest, and largely undeveloped and unlit areas to the southeast. Likewise, the clusters of lighting in the Palm Jumeira complex at bottom right correspond to the relatively small part of the archipelago that has been developed. Isolated areas of blurred city lights are due to patchy clouds.

Moscow at Night

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Moscow appears at the center of this nighttime image photographed by the Expedition 30 crew aboard the International Space Station, flying at an altitude of approximately 240 miles on March 28, 2012. A solar array panel for the space station is on the left side of the frame. The view is to the north-northwest from a nadir of approximately 49.4 degrees north latitude and 42.1 degrees east longitude, about 100 miles west-northwest of Volgograd. The Aurora Borealis, airglow and daybreak frame the horizon.

Landing Is A Variable In NASA CCiCap Choice

NASA managers looking for at least two commercial vehicles to take crews to the International Space Station have a choice of techniques for returning astronauts to Earth, from parachute landings on land to a gliding touchdown on a runway.

As they consider system-level proposals for the third phase of the Commercial Crew Program, known as Commercial Crew Integrated Capability (CCiCap), space agency evaluators are pondering the eventual use of propulsive vertical landing proposed by Space Exploration Technologies (SpaceX) and perhaps the secretive Blue Origin LLC.

Also on the table are the Boeing and Sierra Nevada entries presented at the National Space Symposium here this week, and an as-yet-undisclosed entry by ATK/Astrium based on the proposed Liberty Rocket.

Boeing and Sierra Nevada both plan to use the Atlas V to launch their crew vehicles. The similarity stops there, and landing is a big difference. Boeing’s CST-100 capsule will ride parachutes to an airbag-cushioned land landing at one of three sites in the continental U.S., while the Sierra Nevada Dream Chaser can return to a runway landing pretty much anywhere there’s 10,000 ft. of tarmac.

“We’ve got three parachutes; there’s six airbags,” says John Mulholland, vice president and manager of Commercial Programs for Boeing Space Exploration. “So we’ll be dual-fault tolerant with that system. Under a normal landing, it’ll be around four or five gs, so it’s really low loads on landing. But we are able to have a single parachute and a single parachute out.”

Inside the capsule, the crew seats are anchored to a “pallet” that sits on struts designed to give if the landing load exceeds 20 gs, Mulholland says. But normally airbags would use a two-stage design to hold the load well below that. “We’ve got an inner airbag that inflates, and then there’s an outer airbag that inflates, and the outer airbags actually have relief valves in them,” he says. “So right on landing, at a certain pressure it blows those relief valves, so it relieves that pressure, which takes a lot of the load out, and then it comes to rest on the inner airbags.”

Mulholland says his company probably will land first in the desert at White Sands, N.M., and has also picked Edwards AFB, Calif., as a landing site. A third site will be selected later. The capsule also is equipped with flotation devices to turn it upright in case of a water landing after a launch abort or mistargeted re-entry, he says.

Sierra Nevada’s Dream Chaser maintains the outer mold line of NASA’s experimental HL-20 lifting body, outfitted with a hybrid-motor pusher escape system to eject it from its Atlas V in a launcher failure. After that, it would fly a piloted return-to-landing site maneuver and land with about a 2g load on the crew.

If necessary, the Dream Chaser could do a trans-Atlantic abort to a runway landing at the international airport in Shannon, Ireland, says former astronaut Jim Voss, vice president of Sierra Nevada’s Space Exploration Group. “Everything that we’ve done right now shows that we can do nominal, we can do aborts, and we can get back to a runway landing, but we don’t think that’s good enough, so we have a bailout capability.”