Wednesday, December 30, 2009

NASA's WISE Space Telescope Jettisons its Cover

Artist's concept of NASA's Wide-field Infrared Survey Explorer

NASA's recently launched Wide-Field Infrared Survey Explorer opened its eyes to the starry sky today, after ejecting its protective cover.

Engineers and scientists say the maneuver went off without a hitch, and everything is working properly. The mission's "first-light" images of the sky will be released to the public in about a month, after the telescope has been fully calibrated.

"The cover floated away as we planned," said William Irace, the mission's project manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "Our detectors are soaking up starlight for the first time."

WISE will perform the most detailed infrared survey of the entire sky to date. Its millions of images will expose the dark side of the cosmos -- objects, such as asteroids, stars and galaxies, that are too cool or dusty to be seen with visible light. The telescope will survey the sky one-and-a-half times in nine months, ending its primary mission when the coolant it needs to see infrared light evaporates away.

WISE launched on Dec. 14 from Vandenberg Air Force Base in California. Once it was thoroughly checked out in space, it was ready to "flip its lid."

The cover served as the top to a Thermos-like bottle that chilled the instrument -- a 40-centimeter (16-inch) telescope and four infrared detector arrays with one million pixels each. The instrument must be maintained at frosty temperatures, as cold as below 8 Kelvin (minus 447 degrees Fahrenheit), to prevent it from picking up its own heat, or infrared, glow. The cover kept everything cool on the ground by sealing a vacuum space into the instrument chamber. In the same way that Thermos bottles use thin vacuum layers to keep your coffee warm or iced tea cold, the vacuum space inside WISE stopped heat from getting in. Now, space itself will provide the instrument with an even better vacuum than before.

Tuesday, December 29, 2009

Glittering Metropolis

globular cluster
Like a whirl of shiny flakes sparkling in a snow globe, Hubble caught this glimpse of many hundreds of thousands of stars moving about in the globular cluster M13, one of the brightest and best-known globular clusters in the northern sky. This glittering metropolis of stars is easily found in the winter sky in the constellation Hercules and can even be glimpsed with the unaided eye under dark skies.

M13 is home to over 100,000 stars and located at a distance of 25,000 light-years. These stars are packed so closely together in a ball, approximately 150 light-years across, that they will spend their entire lives whirling around in the cluster.

Near the core of this cluster, the density of stars is about a hundred times greater than the density in the neighborhood of our sun. These stars are so crowded that they can, at times, slam into each other and even form a new star, called a "blue straggler."

The brightest reddish stars in the cluster are ancient red giants. These aging stars have expanded to many times their original diameters and cooled. The blue-white stars are the hottest in the cluster.

Globular clusters can be found spread largely in a vast halo around our galaxy. M13 is one of nearly 150 known globular clusters surrounding our Milky Way galaxy.

Globular clusters have some of the oldest stars in the universe. They likely formed before the disk of our Milky Way, so they are older than nearly all other stars in our galaxy. Studying globular clusters therefore tells us about the history of our galaxy.

Monday, December 28, 2009

Passing of Stan Lebar

Stan Lebar next to an image of him with the lunar camera.
Stan Lebar, who led the Westinghouse Electric Corporation team that developed the lunar camera that brought the televised news images of Neil Armstrong stepping onto the moon to more than 500 million people on earth, died on Tuesday, Dec. 22, 2009.

During his long and distinguished career, other camera programs he managed for NASA included the Apollo Color TV Cameras, the Skylab series of TV cameras, and the TV cameras for the Apollo-Soyuz Test Program (ASTP).

From 1943 until the end of World War II, Lebar served in the Pacific Theater of Operations as an Air Force B-24 Ball Turret Gunner. After the war, he attended the University of Missouri and received a BS in Electrical Engineering in 1950. He joined Westinghouse Electric Corporation in 1953, and worked in the Aerospace Division, Baltimore, Maryland, until his retirement in 1986.

Thursday, December 24, 2009

Dreams of Flight Redefined

Terry Hill
Terry Hill once dreamed of being a pilot, but his ambitions have taken him beyond the friendly skies. Hill, now grown up, is working on the future of spaceflight for NASA. He’s helping to develop the next generation of spacesuits to send humans to the International Space Station, moon, Mars and beyond as part of NASA's Constellation Program.

“Never in a million years did I think I would be designing spacesuits for NASA as my job,” said Hill, the engineering project manager for the Constellation Spacesuit System at the NASA Johnson Space Center.

Prior to joining America's space program, the Texarkana, Texas native pursued his dreams of navigating the aerospace landscape. Hill got his start with a bachelor’s degree in aerospace engineering from the University of Texas (UT) at Austin.

At UT Austin, Hill discovered an interest in orbital mechanics and was hooked on working with projects pertaining to space. He decided to take on graduate school at UT Austin and received his master’s in aerospace guidance, navigation and control theory.

“It’s just been a series of unexpected but good events that lead me down this path, and I have found myself in a totally different place than I thought possible,” Hill said.

Hill said his graduate school experience was completely different from his undergraduate studies. His graduate studies focused more on understanding advanced concepts rather than basic engineering. While working on his master’s degree, Hill jumped on a new and exciting opportunity: working for NASA JSC as a primary investigator on his educational advisor’s contract.

Tuesday, December 22, 2009

NASA Scientists Find Evidence for Liquid Water on a Frozen Early Mars

Evidence suggests flowing water formed the rivers and gullies on the Mars surface, even though surface temperatures were below freezing
NASA scientists modeled freezing conditions on Mars to test whether liquid water could have been present to form the surface features of the Martian landscape.

Researchers report that fluids loaded with dissolved minerals containing elements such as silicon, iron, magnesium, potassium and aluminum, can remain in a liquid state at temperatures well below freezing. The results of this research appear in the May 21 issue of Nature magazine entitled "Stability Against Freezing of Aqueous Solutions on Early Mars."

"We found that the salts in water solutions can reduce the melting point of water, which may help explain how liquid water existed in a frozen Martian environment," said Alberto Fairén, a space scientist at NASA Ames Research Center, Moffett Field, Calif. and the lead author of the study.

To understand what formed the surface features on Mars, scientists have focused on the early Martian conditions. Was early Mars warm and wet, or cold and dry? Surface features throughout most of the Martian landscape suggest the presence of water ponds ranging from seas to lakes, and rivers and gullies formed by flowing water, which imply that early Mars was wet.

But there also is some evidence that suggests that Mars may have been permanently cold, with global temperatures well below the freezing point of pure water. To study the 'liquidity' of water on Mars, climate modelers first simulated various concentrations of greenhouse gases in its atmosphere. They found that these gases cannot efficiently raise the surface temperature above freezing.

Friday, December 18, 2009

Supernova Explosions Stay in Shape

At a very early age, children learn how to classify objects according to their shape. Now, new research suggests studying the shape of the aftermath of supernovas may allow astronomers to do the same.

A new study of images from NASA's Chandra X-ray Observatory on supernova remnants -- the debris from exploded stars - shows that the symmetry of the remnants, or lack thereof, reveals how the star exploded. This is an important discovery because it shows that the remnants retain information about how the star exploded even though hundreds or thousands of years have passed.

Supernova remnants Kepler and G292

"It's almost like the supernova remnants have a 'memory' of the original explosion," said Laura Lopez of the University of California at Santa Cruz, who led the study. "This is the first time anyone has systematically compared the shape of these remnants in X-rays in this way."

Astronomers sort supernovas into several categories, or "types," based on properties observed days after the explosion and which reflect very different physical mechanisms that cause stars to explode. But, since observed remnants of supernovas are leftover from explosions that occurred long ago, other methods are needed to accurately classify the original supernovas.

Lopez and colleagues focused on the relatively young supernova remnants that exhibited strong X-ray emission from silicon ejected by the explosion so as to rule out the effects of interstellar matter surrounding the explosion. Their analysis showed that the X-ray images of the ejecta can be used to identify the way the star exploded. The team studied 17 supernova remnants both in the Milky Way galaxy and a neighboring galaxy, the Large Magellanic Cloud.

Wednesday, December 16, 2009

Orion Launch Abort System Attitude Control Motor Test-fired

Orion Launch Abort System Attitude Control Motor Test-fired
NASA, Alliant Techsystems (ATK) and Lockheed Martin celebrated a major milestone with a ground test of a full-scale attitude control motor (ACM) for the Orion crew exploration vehicle’s launch abort system (LAS).

"The completion of the Demonstration Motor 1 hot-fire test is a substantial advancement in developing the ACM," said LAS Manager Kevin Rivers, of NASA’s Langley Research Center in Hampton, Va. "With an elaborate eight-valve control system that relies on advanced ceramic composites for several key components, the ACM is among the most complex solid rocket systems ever built."

The test performed at ATK’s facility in Elkton, Md., was the sixth in a series of ground tests of Orion’s attitude control motor system. The ACM is charged with keeping the crew module on a controlled flight path after it jettisons, steering it away from the Ares 1 crew launch vehicle in the event of an emergency, and then reorienting the module for parachute deployment.

Having reached this milestone brings Constellation another step closer to flight-ready status and demonstrates progress toward improved flight safety for astronauts, which is at the core of Constellation Program success.

The launch abort system, mounted on top of the Orion crew module, centers around three solid propellant rocket motors: an abort motor, an attitude control motor; and a jettison motor. Successful tests of both the abort and jettison motors were completed in 2008. The attitude control motor consists of a solid propellant gas generator, with eight proportional valves equally spaced around the outside of the 32-inch diameter motor. Together, the valves can exert up to 7,000 pounds of steering force to the vehicle in any direction upon command from the crew module.

"Controllable solid rockets have only recently begun seeing application in spacecraft, and the ACM delivers an order of magnitude greater thrust than any of those systems," said Rivers. "It represents a significant technical advancement in controllable solid propulsion."

Hubble's Festive View of a Grand Star-Forming Region

Massive, young stellar grouping
Just in time for the holidays: a Hubble Space Telescope picture postcard of hundreds of brilliant blue stars wreathed by warm, glowing clouds. The festive portrait is the most detailed view of the largest stellar nursery in our local galactic neighborhood.

The massive, young stellar grouping, called R136, is only a few million years old and resides in the 30 Doradus Nebula, a turbulent star-birth region in the Large Magellanic Cloud (LMC), a satellite galaxy of our Milky Way. There is no known star-forming region in our galaxy as large or as prolific as 30 Doradus.

Many of the diamond-like icy blue stars are among the most massive stars known. Several of them are over 100 times more massive than our Sun. These hefty stars are destined to pop off, like a string of firecrackers, as supernovas in a few million years.

The image, taken in ultraviolet, visible, and red light by Hubble's Wide Field Camera 3, spans about 100 light-years. The nebula is close enough to Earth that Hubble can resolve individual stars, giving astronomers important information about the stars' birth and evolution.

The brilliant stars are carving deep cavities in the surrounding material by unleashing a torrent of ultraviolet light, and hurricane-force stellar winds (streams of charged particles), which are etching away the enveloping hydrogen gas cloud in which the stars were born. The image reveals a fantasy landscape of pillars, ridges, and valleys, as well as a dark region in the center that roughly looks like the outline of a holiday tree. Besides sculpting the gaseous terrain, the brilliant stars can also help create a successive generation of offspring. When the winds hit dense walls of gas, they create shocks, which may be generating a new wave of star birth.

The movement of the LMC around the Milky Way may have triggered the massive cluster's formation in several ways. The gravitational tug of the Milky Way and the companion Small Magellanic Cloud may have compressed gas in the LMC. Also, the pressure resulting from the LMC plowing through the Milky Way's halo may have compressed gas in the satellite. The cluster is a rare, nearby example of the many super star clusters that formed in the distant, early universe, when star birth and galaxy interactions were more frequent. Previous Hubble observations have shown astronomers that super star clusters in faraway galaxies are ubiquitous.

Tuesday, December 15, 2009

Magnetic Dance of Titan and Saturn To Be Main Attraction during Flyby

Artist's concept of Cassini's
When it flies by Saturn's largest moon, Titan, this weekend, NASA's Cassini spacecraft will study the interactions between the magnetic field of Saturn and Titan. The flyby will take place the evening of Dec. 11 California time, or shortly after midnight Universal Time on Dec. 12.

As Titan plows through the magnetic bubble, or magnetosphere around Saturn, it creates a wake in the magnetic field lines coming away from the planet. This flyby will allow Cassini's fields and particles instruments to study that wake about 5,200 kilometers (3,200 miles) away from the moon, a relatively unexamined region. Other instruments will also be taking a closer look at Titan's clouds.

At closest approach to Titan, Cassini will swing to within about 4,900 kilometers (3,000 miles) of the surface of the moon.

Cassini last zoomed by Titan two months ago. Although this latest flyby is dubbed "T63," planning changes early in the orbital tour have made this the sixty-fourth targeted flyby of Titan.

Titan is a kind of "sister world" to Earth because it has a surface covered with organic material and an atmosphere whose chemical composition hearkens back to an early Earth.

Friday, December 11, 2009

Galaxy Collision Switches on Black Hole

This composite image of data from three different telescopes shows an ongoing collision between two galaxies, NGC 6872 and IC 4970. X-ray data from NASA's Chandra X-ray Observatory is shown in purple, while Spitzer Space Telescope's infrared data is red and optical data from ESO's Very Large Telescope (VLT) is colored red, green and blue.

Astronomers think that supermassive black holes exist at the center of most galaxies. Not only do the galaxies and black holes seem to co-exist, they are apparently inextricably linked in their evolution. To better understand this symbiotic relationship, scientists have turned to rapidly growing black holes -- so-called active galactic nucleus (AGN) -- to study how they are affected by their galactic environments.

The latest data from Chandra and Spitzer show that IC 4970, the small galaxy at the top of the image, contains an AGN, but one that is heavily cocooned in gas and dust. This means in optical light telescopes, like the VLT, there is little to see. X-rays and infrared light, however, can penetrate this veil of material and reveal the light show that is generated as material heats up before falling onto the black hole (seen as a bright point-like source).

Monday, December 07, 2009

Steering the Ares Rockets on a Straight Path

Ares I-X test rocket
The Ares I-X rocket stood more than 325 feet tall on the launch pad at NASA's Kennedy Space Center, Fla. Spectators watched in awe as its massive solid rocket motor blazed to life with a thunderous roar, and the spacecraft rose off the launch pad.

But what steered this rocket on its path as it climbed through Earth's atmosphere? The answer is a roll control system.

The roll control system used for the recently completed Ares I-X test flight is different from the system being developed for its sister vehicle the Ares I, but operates on the same premise.

For the Ares I-X test flight the roll control system performed two primary functions for the vehicle: It rolled the vehicle 90 degrees after liftoff to emulate the Ares I roll attitude at launch, and was used to maintain a constant roll attitude during ascent up to stage separation. The system began operating just after the rocket cleared the tower at launch and shut down just before first stage separation.

Ares I-X rocket looking back at the launch padUnlike the system being designed for Ares I, the Ares I-X roll control propulsion system components were harvested from decommissioned Peacekeeper missiles, which were to be dismantled by the U.S. Air Force as part of the second Strategic Arms Reduction Treaty, called START II. The use of Peacekeeper parts for the roll control system – and shuttle parts for the first stage of Ares I-X – was an effective means for NASA to reduce the cost and development time of this flight test.

Thursday, December 03, 2009

Another Stall of Right-Rear Wheel Ends Drive

Spirit's right-rear wheel stalled again on Sol 2099 (Nov. 28, 2009) during the first step of a two-step extrication maneuver. This stall is different in some characteristics from the stall on Sol 2092 (Nov. 21). The Sol 2099 stall occurred more quickly and the inferred rotor resistance was elevated at the end of the stall. Investigation of past stall events along with these characteristics suggest that this stall might not be result of the terrain, but might be internal to the right-rear wheel actuator. Rover project engineers are developing a series of diagnostics to explore the actuator health and to isolate potential terrain interactions. These diagnostics are not likely to be ready before Wednesday. Plans for future driving will depend on the results of the diagnostic tests.

Before the Sol 2099 drive ended, Spirit completed 1.4 meters of wheel spin and the rover's center moved 0.5 millimeters (0.02 inch) forward, 0.25 millimeters (0.01 inch) to the left and 0.5 millimeters (0.02 inch) downward. Since Spirit began extrication on Sol 2088, the rover has performed 9.5 meters (31 feet) of wheel spin and the rover's center, in total, has moved 16 millimeters (0.63 inch) forward, 10 millimeters (0.39 inch) to the left and 5 millimeters (0.20 inch) downward.

Tuesday, December 01, 2009

NASA Moon Mission Wins Second-Best of 'What's New' Award by Popular Science

The Lunar Reconnaissance Orbiter (LRO) is cited as one of the best innovations in aviation in the December issue of Popular Science.

"It is an honor to be selected by Popular Science for Best of What’s New in aviation," said Craig Tooley, LRO project manager from NASA’s Goddard Space Flight Center in Greenbelt, Md. "There was tremendous excitement about the United States returning to the moon after many years. I believe our selection is a result of that excitement."

Each year, the editors of Popular Science review thousands of products in search of the top 100 tech innovations of the year; breakthrough products and technologies that represent a significant leap in their categories. The winners -- the Best of What's New -- are awarded inclusion in the much-anticipated December issue of Popular Science, the most widely read issue of the year since the debut of Best of What's New in 1987. Best of What's New awards are presented to 100 new products and technologies in 11 categories: Automotive, Aviation and Space, Computing, Engineering, Gadgets, Green Technology, Home Entertainment, Security, Home Technology, Personal Health and Recreation.

"For 22 years, Popular Science has honored the innovations that surprise and amaze us -- those that make a positive impact on our world today and challenge our views of what’s possible in the future." said Mark Jannot, editor-in-chief of Popular Science. "The Best of What’s New Award is the magazine’s top honor, and the 100 winners -- chosen from among thousands of entrants -- represent the highest level of achievement in their fields."