Wednesday, October 10, 2012

This dazzling image shows the globular cluster Messier 69, or M 69 for short, as viewed through the NASA/ESA Hubble Space Telescope. Globular clusters are dense collections of old stars. In this picture, foreground stars look big and golden when set against the backdrop of the thousands of white, silvery stars that make up M 69.

Another aspect of M 69 lends itself to the bejeweled metaphor: As globular clusters go, M 69 is one of the most metal-rich on record. In astronomy, the term "metal" has a specialized meaning: it refers to any element heavier than the two most common elements in our Universe, hydrogen and helium. The nuclear fusion that powers stars created all of the metallic elements in nature, from the calcium in our bones to the carbon in diamonds. Successive generations of stars have built up the metallic abundances we see today.

Because the stars in globular clusters are ancient, their metallic abundances are much lower than more recently formed stars, such as the Sun. Studying the makeup of stars in globular clusters like M 69 has helped astronomers trace back the evolution of the cosmos.

M 69 is located 29 700 light-years away in the constellation Sagittarius (the Archer). The famed French comet hunter Charles Messier added M 69 to his catalogue in 1780. It is also known as NGC 6637.

The image is a combination of exposures taken in visible and near-infrared light by Hubble’s Advanced Camera for Surveys, and covers a field of view of approximately 3.4 by 3.4 arcminutes.

Wednesday, October 03, 2012

Blanketing NASA's Webb Telescope's Science Instrument Electronics

These engineers from Genesis Engineering Solutions are doing what’s called "blanket closeout" and it took two days to complete.

The gold louvers are composite mirrors, made of gold-coated carbon fiber, designed to remove the heat from inside the IEC to deep space. 

The IEC holds computing hardware for each of the science instruments. This special part of the telescope allows the computer hardware to operate at room temperature on the cold side of the telescope by directing heat away so that the telescope can deliver infrared imagery.

"As heat radiates off the panel that they are attached to, the mirrors focus it in a particular direction (namely, away from the telescope)," says Lutter. 

After the engineers completed blanketing, the IEC was then placed in the thermal chamber to be tested against the chill of a space-simulated environment. This process is called the thermal vacuum and balance test. During this test, temperatures drop to about 90 degrees Kelvin (-297.67 degrees Fahrenheit or -183.15 degrees Celsius). 

"This is important because we need to know how effective the IEC is at keeping heat away from the cold side of Webb," says Lutter. "If even a little heat escapes the IEC in the direction of the telescope, the telescope's sensitivity could be ruined."

Thursday, September 27, 2012

Hubble Catches Glowing Gas and Dark Dust in a Side-On Spiral

The NASA/ESA Hubble Space Telescope has produced a sharp image of NGC 4634, a spiral galaxy seen exactly side-on. Its disk is slightly warped by ongoing interactions with a nearby galaxy, and it is crisscrossed by clearly defined dust lanes and bright nebulae.

NGC 4634, which lies around 70 million light-years from Earth in the constellation of Coma Berenices, is one of a pair of interacting galaxies. Its neighbor, NGC 4633, lies just outside the upper right corner of the frame, and is visible in wide-field views of the galaxy. While it may be out of sight, it is not out of mind: its subtle effects on NGC 4634 are easy to see to a well-trained eye.

Gravitational interactions pull the neat spiral forms of galaxies out of shape as they get closer to each other, and the disruption to gas clouds triggers vigorous episodes of star formation. While this galaxy’s spiral pattern is not directly visible thanks to our side-on perspective, its disk is slightly warped, and there is clear evidence of star formation.

Along the full length of the galaxy, and scattered around parts of its halo, are bright pink nebulae. Similar to the Orion Nebula in the Milky Way, these are clouds of gas that are gradually coalescing into stars. The powerful radiation from the stars excites the gas and makes it light up, much like a fluorescent sign. The large number of these star formation regions is a telltale sign of gravitational interaction.

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Monday, September 10, 2012

NASA Mars Rover Curiosity Begins Arm-Work Phase

Before completing its final flight on the back of a 747 on September 20 the Space Shuttle Endeavour will visit the Bay Area, flying low over NASA Ames Research Center and possibly other area landmarks such as the Golden Gate Bridge. Endeavour will begin its multi-day cross-country journey by taking off near dawn on September 17 from Kennedy Space Center in Florida. The final stop of Endeavour’s tour will be Los Angeles International Airport, 12 miles way from its new museum home at the California Science Center.

Although the exact timing and path of the ferry flight will depend on weather conditions and operational constraints, the piggybacked duo are scheduled to conduct low-level flyovers of several locations along the planned flight path. These include the Kennedy Space Center Visitor Complex, Cape Canaveral Air Force Station and Patrick Air Force Base, in and around the Florida spaceport; NASA's Stennis Space Center in Mississippi and the agency's Michoud Assembly Facility in New Orleans; Houston, Clear Lake and Galveston, near NASA's Johnson Space Center; White Sands Test Facility near Las Cruces, N.M.; NASA's Dryden Flight Research Center at Edwards Air Force Base, Ames Research Center at Moffett Field, and various landmarks in multiple California cities. Social media users are encouraged by NASA to share their Endeavour sightings using the hashtags #spottheshuttle and #OV105, Endeavour’s orbiter vehicle designation.

After arriving at LAX, the shuttle will be removed from its 747 carrier aircraft and spend a few weeks in a United Airlines hanger being prepared for transportation and display. Endeavour then will travel through Inglewood and Los Angeles city streets on a 12-mile journey from the airport to the science center, arriving in the evening on Oct. 13. Beginning Oct. 30, the shuttle will be on display in the California Science Center's Samuel Oschin Space Shuttle Endeavour Display Pavilion.

Monday, September 03, 2012

NASA's IceBridge Seeking New View of Changing Sea Ice

This year scientists working on NASA's Operation IceBridge, a multi-year airborne science mission to study changing ice conditions at both poles, debuted a new data product with the potential to improve Arctic sea ice forecasts.

Using new data processing techniques, IceBridge scientists were able to release an experimental quick look product before the end of the 2012 Arctic campaign. The main challenge faced when producing data for seasonal forecasts is the time needed to crunch the numbers, something that has in the past taken IceBridge scientists more than six months to do after the data was collected in the spring. This is too late to use for Arctic sea ice forecasts of the annual seasonal minimum, which takes place in September.

The new product could potentially be used in seasonal sea ice forecasts in the future. "The community is excited about it," said IceBridge science team co-lead Jackie Richter-Menge of the U.S. Army Corps of Engineers Cold Regions Research Laboratory, Hanover, N.H. "We're hoping to build on this season's momentum and interest."

Scientists have been keeping an eye on Arctic sea ice in recent years because it is changing and they want to understand what those changes might mean. Arctic sea ice grows and recedes in a seasonal pattern, with a maximum coverage in March and a minimum in September. These high and low points vary from year to year, but there is a clear trend toward smaller minimums that mean more open water in the Arctic each summer and fall. This decrease in ice is already affecting ocean and terrestrial life in the Arctic, accelerating warming in the region and leading to economic and social changes.

"Sea ice is a sensitive indicator of a changing climate," said NASA researcher Nathan Kurtz at NASA's Goddard Space Flight Center, Greenbelt, Md. It can also act as a feedback to warming in the Arctic. Because ice is much lighter in color than ocean water it has a higher albedo, meaning it reflects more sunlight than water. "A loss of sea ice can cause the Earth as a whole to warm," Kurtz said. The loss of sea ice has also been linked to shifts in weather patterns and distribution of nutrients in the ocean.

Wednesday, August 08, 2012

Inside NASA’s Curiosity: It’s an Apple Airport Extreme… with wheels

Late last night, Mars Science Laboratory (MSL) Curiosity successfully navigated its way through Seven Minutes of Terror and touched down on the surface of the Red Planet, heralding a new age of extraterrestrial exploration that will eventually result in the human colonization of Mars.

At the heart of Curiosity there is, of course, a computer. In this case the Mars rover is powered by a RAD750, a single-board computer (motherboard, RAM, ROM, and CPU) produced by BAE. The RAD750 has been on the market for more than 10 years, and it’s currently one of the most popular on-board computers for spacecraft. In Curiosity’s case, the CPU is a PowerPC 750 (PowerPC G3 in Mac nomenclature) clocked at around 200MHz — which might seem slow, but it’s still hundreds of times faster than, say, the Apollo Guidance Computer used in the first Moon landings. Also on the motherboard are 256MB of DRAM, and 2GB of flash storage — which will be used to store video and scientific data before transmission to Earth.

BAE RAD750 single-board, radiation-hardened computerThe RAD750 can withstand temperatures of between -55 and 70C, and radiation levels up to 1000 gray. Safely ensconced within Curiosity, the temperature and radiation should remain below these levels — but for the sake of redundancy, there’s a second RAD750 that automatically takes over if the first one fails.

On the software side of things, NASA again stuck to tried-and-tested solutions, opting for the 27-year-old VxWorks operating system. VxWorks, developed by Wind River Systems (which was acquired by Intel), is a real-time operating system used in a huge number of embedded systems. The previous Mars rovers (Sojourner, Spirit, Opportunity), Mars Reconnaissance Orbiter, and the SpaceX Dragon spacecraft all use VxWorks. VxWorks also powers BMW iDrive, the Apache Longbow helicopter, and the Apple Airport Extreme and Linksys WRT54G routers (really).

I said that VxWorks is 27 years old, but that’s a bit unfair: The initial release was in 1985 (around the same time as MS-DOS 3.0), but it has been in constant development since then, reaching v6.9 last year. Why does Curiosity use VxWorks? It’s reliable, has a mature development toolchain, and presumably its low-level scheduling and interrupt systems are ideal for handling real-time tasks like EDL (entry, descent, and landing; aka, seven minutes of terror).

Friday, July 27, 2012

NASA's Space Launch System Passes Major Agency Review, Moves to Preliminary Design

The rocket that will launch humans farther into space than ever before passed a major NASA review Wednesday. The Space Launch System (SLS) Program completed a combined System Requirements Review and System Definition Review, which set requirements of the overall launch vehicle system. SLS now moves ahead to its preliminary design phase.

The SLS will launch NASA's Orion spacecraft and other payloads, and provide an entirely new capability for human exploration beyond low Earth orbit.

These NASA reviews set technical, performance, cost and schedule requirements to provide on-time development of the heavy-lift rocket. As part of the process, an independent review board comprised of technical experts from across NASA evaluated SLS Program documents describing vehicle specifications, budget and schedule. The board confirmed SLS is ready to move from concept development to preliminary design.

"This new heavy-lift launch vehicle will make it possible for explorers to reach beyond our current limits, to nearby asteroids, Mars and its moons, and to destinations even farther across our solar system," said William Gerstenmaier, associate administrator for the Human Exploration and Operations Mission Directorate at NASA Headquarters in Washington. "The in-depth assessment confirmed the basic vehicle concepts of the SLS, allowing the team to move forward and start more detailed engineering design."

The reviews also confirmed the SLS system architecture and integration with the Orion spacecraft, managed by NASA's Johnson Space Center in Houston, and the Ground Systems Development and Operations Program, which manage the operations and launch facilities at NASA's Kennedy Space Center in Florida.

"This is a pivotal moment for this program and for NASA," said SLS Program Manager Todd May. "This has been a whirlwind experience from a design standpoint. Reaching this key development point in such a short period of time, while following the strict protocol and design standards set by NASA for human spaceflight is a testament to the team's commitment to delivering the nation's next heavy-lift launch vehicle."

SLS reached this major milestone less than 10 months after the program's inception. The combination of the two assessments represents a fundamentally different way of conducting NASA program reviews. The SLS team is streamlining processes to provide the nation with a safe, affordable and sustainable heavy-lift launch vehicle capability. The next major program milestone is preliminary design review, targeted for late next year.

The first test flight of NASA's Space Launch System, which will feature a configuration for a 70-metric-ton (77-ton) lift capacity, is scheduled for 2017. As SLS evolves, a three-stage launch vehicle configuration will provide a lift capability of 130 metric tons (143 tons) to enable missions beyond low Earth orbit and support deep space exploration.

NASA's Marshall Space Flight Center in Huntsville, Ala., manages the SLS program. Across the country NASA and its industry partners continue to make progress on SLS hardware that will be integrated into the final design. The RS-25 core stage and J-2X upper-stage rocket engine in development by Pratt & Whitney Rocketdyne of Canoga Park, Calif., for the future two-stage SLS, will be tested at NASA's Stennis Space Center in Mississippi. The prime contractor for the five-segment solid rocket boosters, ATK of Brigham City, Utah, has begun processing its first SLS boosters in preparation for an initial qualification test next year, ahead of their use for the first two exploration missions. The Boeing Co. in Huntsville is designing the SLS core stage, to be built at NASA's Michoud Assembly Facility in New Orleans and tested at Stennis before being shipped to Kennedy.