September 3, 2006, 7:02 AM CT

Atlantis Launch Set for Sept. 6

The six Atlantis crew members flew Saturday morning from their home base in Houston to the Kennedy Space Center in Florida, where they will begin final launch preparations for mission STS-115.

The countdown officially begins at 8 a.m. Sunday, at the T-43 hour mark, which includes over 30 hours of built-in hold time previous to a targeted 12:29 p.m. EDT launch on Wednesday. The launch time is the middle point in the launch window that extends for 10 minutes.

Atlantis' Crew and Mission

The STS-115 crew consists of Commander Brent W. Jett Jr., Pilot Christopher J. Ferguson and Mission Specialists Heidemarie M. Stefanyshyn-Piper, Joseph R. Tanner, Daniel C. Burbank and Steven G. MacLean, who represents the Canadian Space Agency.

With this mission, NASA is ready to get back to building the International Space Station, marking the first time in almost four years that a space station component has been added to the orbiting outpost. That also means the shuttle program is coming up on some of the most challenging space missions ever.

During their three spacewalks, crew members of Atlantis will install the P3/P4 integrated truss and a second set of solar arrays on the space station, doubling the station's current ability to generate power from sunlight and adding 17.5 tons to its mass.........

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August 24, 2006, 10:01 PM CT

One-Two Particle Punch Poses Greater Risk

It doesn't just matter how much radiation an astronaut is exposed to, time and the order in which charged particles strike human cells are important factors as well. That's the main finding of a study simulating radiation exposure conducted at the U.S. Department of Energy's Brookhaven National Laboratory and reported in the September 2006 edition of Radiation Research. In the study, human cells were three times more likely to develop properties similar to those in the initial stages of cancer when they were exposed to two types of high-energy particles in a short period of time.

The radiation field in space contains high levels of high-energy protons and much lower levels of high atomic number, high-energy (HZE) particles such as iron and titanium.

"Most people studying the effects of space radiation have looked at the effects of just one type of particle, either the protons or the HZE particles," said Brookhaven biologist Betsy Sutherland, the paper's lead author. "This is one of the first studies to try to imitate real space radiation conditions closely, where, on average, a cell will be hit by a proton first and then by an HZE particle. We decided to examine what this does to human cells."

To test the effect of dual-particle irradiation, Sutherland's team at the NASA Space Radiation Laboratory, a facility built at Brookhaven Lab specifically for space radiation studies, first exposed normal human cells to a beam of protons. Then, anywhere from 2.5 minutes to 48 hours later, they exposed the cells to iron or titanium particles.........

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August 22, 2006, 5:02 AM CT

First Direct Evidence For Dark Matter

Astronomers have discovered first direct proof that dark matter exists.

University of Arizona astronomers and their colleagues got side-on views of two merging galaxy clusters in observations made with state-of-the-art optical and X-ray telescopes.

"Nature gave us this fantastic opportunity to see hypothesized dark matter separated from ordinary matter in this merging system," said UA astronomer Douglas Clowe, leader of the study.

"Prior to this observation, all of our cosmological models were based on an assumption that we couldn't prove: that gravity behaves the same way on the cosmic scale as on Earth," Clowe said. "The clusters we've looked at in these images are a billion times larger than the largest scales at which we can measure gravity at present, which are on the scale of our solar system".

Douglas Clowe.

Clowe added, "What's amazing about this is that the process of galaxy clusters merging is thought to go on all of time. That's how galaxy clusters gain mass. But the fact that we caught this thing only 100 million years after it occurred -- so recently that it barely registers on the cosmic time scale -- is tremendous luck".

Astronomers have known since the 1930s that most of the universe must be made up of something other than normal matter, the stuff that makes stars, planets, all things and creatures. Given the way that galaxies move through space and scientists' understanding of gravity, astronomers theorize that the universe must contain about five times more dark matter than normal matter.........

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August 19, 2006, 9:19 PM CT

APL-Built Spacecraft Set for Aug 31 Launch

Two nearly identical spacecraft, destined to capture the first-ever 3-D views of the sun, are scheduled for launch on Aug. 31 aboard a Delta II rocket from Cape Canaveral Air Force Station, Fla., at 3:12 p.m. or 4:20 p.m. EDT. The window extends through Sept. 4 with two launch opportunities daily.

Built and operated for NASA by the Johns Hopkins University Applied Physics Laboratory (APL), in Laurel, Md., the two-year STEREO (Solar TErrestrial RElations Observatory) mission will explore the origin, evolution and interplanetary consequences of coronal mass ejections. These powerful solar eruptions are a major source of the magnetic disruptions on Earth and a key component of space weather, which can greatly affect satellite operations, communications, power systems, and the lives of astronauts in space.

"Building and testing two spacecraft simultaneously has been a technical and scheduling challenge, but an effort at which we've been successful," says Ed Reynolds, APL STEREO project manager. "The entire STEREO team is so proud and excited to launch the twin observatories and be part of the first mission to capture coronal mass ejections in 3-D".

To capture the sun in 3-D, the twin observatories will fly as mirror images of each other. One of the observatories will be placed ahead of Earth in its orbit around the sun and the other behind. Just as the slight offset between your eyes provides you with depth perception, this placement will allow the STEREO observatories to obtain 3-D images and particle measurements of the sun.........

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August 11, 2006, 6:50 AM CT

Antarctic snowfall hasn't changed in 50 years

The most precise record of Antarctic snowfall ever generated shows there has been no real increase in precipitation over the southernmost continent in the past half-century, even though most computer models assessing global climate change call for an increase in Antarctic precipitation as atmospheric temperatures rise.

"The year-to-year and decadal variability of the snowfall is so large that it makes it nearly impossible to distinguish trends that might be correlation to climate change from even a 50-year record," said Andrew Monaghan, a research associate with Ohio State University's Byrd Polar Research Center and lead author of an article on the topic reported in the Aug. 10 edition of Science magazine.

"There were no statistically significant trends in snowfall accumulation over the past five decades, including recent years for which global mean temperatures have been warmest," Monaghan said.

The findings also suggest thickening of Antarctica's massive ice sheets haven't reduced the slow-but-steady rise in global sea levels, as some climate-change critics have argued.

The study looked at both the West Antarctic Ice Sheet (WAIS), a marine ice sheet with a base below sea level, and the much thicker East Antarctic Ice Sheet (EAIS) that sits atop dry land. In recent years, large volumes of ice along the WAIS coast have melted at a faster rate than previously seen. Some observers have blamed global warming for the melting and for the increased calving of icebergs along the continent's margin.........

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August 10, 2006, 0:00 AM CT

An Oblique Look On The North Lunar Far West

This image, taken by the Advanced Moon Imaging Experiment (AMIE) on board ESA's SMART-1 spacecraft, provides an 'oblique' view of the lunar surface towards the limb, around the Mezentsev, Niepce and Merrill craters, on the far side of the Moon.

"This cratered terrain is similar in topography to near-side highlands," says SMART-1 Project scientist Bernard Foing, "while the far-side equator bulge can reach heights of 7 km, and the South Pole Aitken basin has depths down to 8 km".

AMIE obtained this sequence on 16 May 2006. The imaged area is centred at a latitude of 73º North and a longitude of 124º West(or 34 º further than the West limb seen from Earth).

Normally, the SMART-1 spacecraft points the AMIE camera straight down, in the so-called Nadir pointing mode. In this image, AMIE was looking out 'the side window' and pointing towards the horizon, showing all craters in an oblique view. The largest craters shown are Mezentesev, Niepce and Merrill, located on the lunar far side, not visible from the Earth. Mezentsev is an eroded crater 89 kilometres in diameter, while Niepce and Merrill have the same size 57 km.

Mezentsev is named after Yourij Mezentsev, a Soviet engineer (1929 - 1965) who was one of the first people to design rocket launchers. Joseph Niepce was the French inventor of photography (1765 - 1833), while Paul Merrill was an American astronomer (1887 - 1961).........

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August 7, 2006, 7:41 AM CT

Station Crew to 'Kick It Up a Notch' With Chef

The crew of the International Space Station will indulge next week in the ultimate "take-out" food, a meal delivered by a NASA space shuttle and designed by chef Emeril Lagasse of the Food Network's "Emeril Live." After tasting several of Lagasse's creations, the three-person crew will talk to the chef at 1:30 p.m. EDT Aug. 10 in a special hookup carried live on NASA TV.

Lagasse sent NASA some of his special recipes for potential use in space. After the required testing and processing, five different meals were selected. Emeril's Mardi Gras jambalaya, mashed potatoes with bacon, green beans with garlic, rice pudding and mixed fruit were delivered to the station aboard the shuttle Discovery in July.

The station is home to NASA astronaut Jeff Williams, Russian cosmonaut Pavel Vinogradov and European Space Agency astronaut Thomas Reiter. Station crews usually live and work in space for six months. "Our research has indicated that quality, appetizing food is important for the health and morale of astronauts during space missions, especially long ones," said NASA's Vickie Kloeris, who oversees the development and distribution of food on the space station.

Menu options for shuttle and station crews are more extensive than ever before, with about 200 U.S. food items available. Russian food also is available.........

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August 3, 2006, 6:48 AM CT

Shockless Future Spacewalkers' Aim

Space Station crew members Jeff Williams and Thomas Reiter will work to avoid future shocks during a scheduled 6-hour-plus spacewalk Aug. 3.

They also will have a third station crew member for the first time in more than three years. Expedition 13 Commander Pavel Vinogradov will coach them through their prebreathe exercise program and help them suit up for their outing.

The station crew was reduced to two members in May 2003 in the wake of the Columbia accident. Since then, spacewalkers have had to reconfigure station systems before donning their spacesuits without help.

Once the spacewalk begins, Williams and Reiter will be coached through their tasks by Astronaut Steve Bowen. He will act as spacewalk intravehicular officer from the International Space Station Flight Control Room in Houston's Mission Control Center.

The first and longest major task of the spacewalk is installation of the Floating Potential Measurement Unit (FPMU). That device is designed to measure the electrical potential of the station so ways can be verified or devised to minimize arcing hazards as the ISS grows.

Williams, designated lead spacewalker (EV1), will wear the U.S. spacesuit with red stripes. Reiter, EV2, will wear the all-white suit.

They will spend about half an hour setting up equipment after they emerge from the Quest airlock shortly before 10 a.m. EDT. They'll then move with the FPMU to a camera mount near the upper outboard end of the S1 (starboard one) truss. Total time allotted for the installation is 1 hour, 50 minutes.........

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August 2, 2006, 9:21 PM CT

Wen To Research On Gravity

MIT Professor of Physics Xiao-Gang Wen has received a grant from the Foundational Questions Institute to fund his study of the relationship between quantum mechanics and gravity.

Wen is one of 30 researchers to receive funding in the inaugural round of grants awarded by the Foundational Questions Institute (FQXi).

FQXi, a new philanthropically funded agency, awards grants to researchers to investigate questions about the deep nature of the universe, including topics such as the fundamental constants of nature, the relationship between quantum mechanics and theories of gravity, the possible existence of other universes, time travel, extraterrestrial life and the ultimate theories of physics.

"Over the past century, scientists have discovered how the universe evolved and revolutionized our understanding of the nature of space and time, matter and energy. We're delighted to help give them a crack at new big questions and to see what they find," said Max Tegmark, MIT associate professor of physics and scientific director of FQXi.

The institute plans to help researchers focus on "big questions" that conventional funding sources are reluctant to support. FQXi is distributing $2 million in grants in its inaugural round. Wen will receive $94,924.........

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July 22, 2006, 11:40 PM CT

Finding Electrical Short Circuits In Airplanes

A preemptive spark lasting for nanoseconds that helps find potentially dangerous short circuits hidden in the miles of wiring behind the panels of aging commercial airliners has been patented by Sandia National Laboratories.

The rapid technique may make it financially feasible for airlines to quickly diagnose and repair the hard-to-locate intermittent faults that have plagued the industry and cost millions of dollars in lost revenue due to aircraft downtime.

The product, called PASD (Pulsed Arrested Spark Discharge) is expected to be marketed by September by licensee Astronics Advanced Electronic Systems of Redmond, Wash., and combined with that company's other patented test methods under the name ArcSafe.

Other possible uses eventually envisioned for PASD are as inexpensive tests for the wiring harnesses of passenger cars and new homes. Military tanks and the hard-to-reach wiring behind the steel bulkheads of submarines are also possible candidates.

The commercial product is about the size of a small suitcase. It can be plugged into aircraft-installed wire harnesses, 40 wires at a time, to check for the very small insulation breaks associated with intermittent faults.

Sandia is a National Nuclear Security Administration laboratory.........

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