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Tuesday, November 29, 2011

The Suzaku Spacecrafts and Instruments

The Spacecraft


The Suzaku spacecraft weighs about 1,600 kg (3500 pounds) and it will be 7.1 meters (23 feet) long after the Extensible Optical Bench is extended in orbit. The five X-ray Telescopes (XRTs) and all the instruments (the X-Ray Spectrometer, the 4 X-ray Imaging Spectrometers, and the Hard X-ray Detector) will point in the same direction. This allows scientists to simultaneously study cosmic X-ray sources using the different capabilities of the various onboard instruments.

X-Ray Spectrometer (XRS)

The detectors in the X-Ray Spectrometer (XRS) are X-ray microcalorimeters. They work by monitoring the temperature of a tiny piece of silicon, and measuring the temperature rise that results when it absorbs an X-ray photon. As you might imagine, measuring the temperature increase from a single photon is fairly difficult. The detectors need to be kept extremely cold, almost to absolute zero (60 milliKelvin or 0.06 Kelvin, about -273 C, or about -460 F), requiring a complex cryogenic system which includes liquid helium and solid neon.

The XRS has a limited life of about 2.5 years before the neon and/or helium runs out. The XRS is special because, for the first time, it will provide both high spectral resolution (measuring small differences in the energies of X-ray photons) and high throughput (measuring lots of X rays) in one instrument.

X-ray Imaging Spectrometer (XIS)

There are 4 X-ray Imaging Spectrometers (XIS), each with a 1024x1024-pixel X-ray-sensitive Charge Coupled Device (a CCD, similar to what's in your digital camera, but sensitive to much more energetic light). The use of CCDs for astronomical X-ray spectroscopy was pioneered by the ASCA mission starting in 1993. The XIS has been developed by a collaboration of the Massachusetts Institute of Technology, ISAS, the University of Kyoto, and the University of Osaka. It was fabricated by MIT's Lincoln Laboratory.

For more info, visit: http://www.nasa.gov/mission_pages/astro-e2/spacecraft/index.html


Monday, November 28, 2011

Mars Rover Well-Equipped for Studies


The Mars Science Laboratory is taking a toolbox to Mars that any researcher would be proud of. A drill, metallic brush and even a laser are part of the gear set the Mars Science Laboratory called Curiosity is taking to the red planet in the most ambitious effort yet to discern exactly what is on the surface.

The spacecraft is to launch Nov. 26 atop a United Launch Alliance Atlas V rocket. Liftoff is slated for 10:02 a.m. It will take more than eight months for Curiosity to fly the 354 million miles on its path to Mars. Landing is expected in early August 2012.

Although calling the spacecraft a laboratory might suggest it will stay in one place, Curiosity actually is a rover that will travel some 12 miles inside Gale Crater during its 23-month mission. The size of a car or small SUV, the rover weighs nearly a ton and its scientific payload is 10 times more massive than the instrument sets taken to Mars by previous rovers.

"This is a vehicle on Mars, cruising around, drilling into rocks, chipping away at stuff to see what that planet's made out of," said Omar Baez, the launch director of the MSL mission. "And even if it didn't do that, if it just cruised around Mars and took pictures, the value in that is tremendous."

Curiosity will be the fourth NASA rover to touch down on Mars since July 1997, when the Pathfinder probe and its skateboard-sized Sojourner rover bounced onto the surface and began several months of analysis that suggested early Mars was a lot like Earth, with water at the surface and a thicker atmosphere.

Thursday, November 24, 2011

Mars Science Laboratory Launch Milestones

NASA's Mars Science Laboratory is tucked inside its Atlas V rocket, ready for launch on Saturday, Nov. 26, 2011 from Cape Canaveral Air Force Station in Florida. The Nov. 26 launch window extends from 7:02 a.m. to 8:45 a.m. PST (10:02 a.m. to 11:45 a.m. EST). The launch period for the mission extends through Dec. 18.

The spacecraft, which will arrive at Mars in August 2012, is equipped with the most advanced rover ever to land on another planet. Named Curiosity, the rover will investigate whether the landing region has had environmental conditions favorable for supporting microbial life, and favorable for preserving clues about whether life existed.

On Nov. 26, NASA Television coverage of the launch will begin at 4:30 a.m. PST (7:30 a.m. EST). Live launch coverage will be carried on all NASA Television channels. For NASA Television downlink information, schedule information and streaming video, visit: http://www.nasa.gov/ntv . The launch coverage will also be streamed live on Ustream at http://www.ustream.tv/nasajpl .


Wednesday, November 23, 2011

NASA's NPP Satellite Acquires First VIIRS Image


The Visible Infrared Imager Radiometer Suite (VIIRS) onboard NASA's newest Earth-observing satellite, NPP, acquired its first measurements on Nov. 21, 2011. This high-resolution image is of a broad swath of Eastern North America from Canada’s Hudson Bay past Florida to the northern coast of Venezuela. The VIIRS data were processed at the NOAA Satellite Operations Facility (NSOF) in Suitland, Md.

VIIRS is one of five instruments onboard the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) satellite that launched from Vandenberg Air Force Base, Calif., on Oct. 28. Since then, NPP reached its final orbit at an altitude of 512 miles (824 kilometers), powered on all instruments and is traveling around the Earth at 16,640 miles an hour (eight kilometers per second).

"This image is a next step forward in the success of VIIRS and the NPP mission," said James Gleason, NPP project scientist at NASA's Goddard Space Flight Center, Greenbelt, Md.

VIIRS will collect radiometric imagery in visible and infrared wavelengths of the Earth's land, atmosphere, and oceans. By far the largest instrument onboard NPP, VIIRS weighs about 556 pounds (252 kilograms). Its data, collected from 22 channels across the electromagnetic spectrum, will be used to observe the Earth's surface including fires, ice, ocean color, vegetation, clouds, and land and sea surface temperatures.

Saturday, November 19, 2011

International Team to Drill Beneath Massive Antarctic Ice Shelf

An international team of researchers funded by NASA and the National Science Foundation (NSF) will travel next month to one of Antarctica's most active, remote and harsh spots to determine how changes in the waters circulating under an active ice sheet are causing a glacier to accelerate and drain into the sea.

The science expedition will be the most extensive ever deployed to Pine Island Glacier. It is the area of the ice-covered continent that concerns scientists most because of its potential to cause a rapid rise in sea level. Satellite measurements have shown this area is losing ice and surrounding glaciers are thinning, raising the possibility the ice could flow rapidly out to sea.

The multidisciplinary group of 13 scientists, led by Robert Bindschadler, emeritus glaciologist of NASA's Goddard Space Flight Center in Greenbelt, Md., will depart from the McMurdo Station in Antarctica in mid-December and spend six weeks on the ice shelf. During their stay, they will use a combination of traditional tools and sophisticated new oceanographic instruments to measure the shape of the cavity underneath the ice shelf and determine how streams of warm ocean water enter it, move toward the very bottom of the glacier and melt its underbelly.

"The project aims to determine the underlying causes behind why Pine Island Glacier has begun to flow more rapidly and discharge more ice into the ocean," said Scott Borg, director of NSF's Division of Antarctic Sciences, the group that coordinates all U.S. research in Antarctica. "This could have a significant impact on global sea-level rise over the coming century."

Scientists have determined the interaction of winds, water and ice is driving ice loss from the floating glacier. Gusts of increasingly stronger westerly winds push cold surface waters away from the continent, allowing warmer waters that normally hover at depths below the continental shelf to rise. The upwelling warm waters spill over the border of the shelf and move along the sea floor, back to where the glacier rises from the bedrock and floats, causing it to melt.

The warm salty waters and fresh glacier melt water combine to make a lighter mixture that rises along the underside of the ice shelf and moves back to the open ocean, melting more ice on its way. How much more ice melts is what the team wants to find out, so it can improve projections of how the glacier will melt and contribute to sea-level rise.

For more information, visit,
http://www.nasa.gov/topics/earth/features/pine-island-glacier.html

Friday, November 18, 2011

The Long Voyage of Discovery

It has flown to space more than any other craft, and it has carried more crew members to orbit. It was the first spacecraft to retrieve a satellite and bring it back to Earth. It has visited two space stations. It launched a telescope that has seen deeper in space and in time than ever before. And twice it has demonstrated the United States' will to persevere following devastating tragedy, returning America to orbit following the two worst accidents in space history.

Although all five vehicles that have comprised NASA's space shuttle fleet are unmatched in achievements, space shuttle Discovery is unique among the extraordinary.

In 38 trips to space, Discovery has spent 352 days in orbit, almost a full year. Discovery has circled Earth 5,628 times, all the while speeding along at 17,400 miles per hour. It has traveled almost 143 million miles. That equals 288 round trips to the moon or about one and a half trips to the sun.

Discovery has carried more crew members - 246 - than any space vehicle. Those have included the first female to ever pilot a spacecraft, the oldest person to fly in space, the first African-American to perform a spacewalk, the first cosmonaut to fly on an American spacecraft and the first sitting member of Congress to fly in space.

Wednesday, November 16, 2011

Dryden Tested Shuttle's Microwave Landing System

From August 1976 to February 1982, a Lockheed JetStar research aircraft at NASA's Dryden Flight Research Center on Edwards Air Force Base was used to test and certify the space shuttle’s Microwave Scanning Beam Landing System (MSBLS). This aircraft navigation system provided the precise position of the shuttle orbiter in relation to the runway to the shuttle pilots during landing approach.

The MSBLS consisted of specialized equipment installed on the aircraft and on the ground near the runways. Dryden pilots logged 671 flight hours during 346 missions to check out MSBLS equipment at the three primary shuttle landing sites.

The JetStar was first flown to Long Island, N.Y., where the AIL Division of Cutler Hammer installed MSBLS equipment. Preliminary trials took place at the Grumman Corporation’s microwave test facility at Peconic, New York. In August 1976, NASA research pilots flew 21 MSBLS approaches to lakebed Runway 17 at Edwards. A laser tracking system provided the airplane’s exact position in flight to validate the accuracy of the MSBLS. These tests certified Runway 17 for use by the prototype orbiter Enterprise in the Approach and Landing Test program in 1977.

NASA Dryden's now-retired Lockheed JetStar flies a low landing approach to lakebed runway 35 at Edwards past the data monitoring system pole of the space shuttle's microwave scanning beam landing system in 1977. A second set of MSBLS ground stations were installed for the main 15,000-foot concrete runway at Edwards, and tested with the JetStar making numerous landing approaches over the course of 83 flights through October 1977.

Dryden pilots took the JetStar to NASA’s Kennedy Space Center, Fla., in April 1978 for certification of runway 33/15. By December, the crew had completed more than 100 data runs. A year later, the JetStar crew began a series of 46 MSBLS flight tests at Northrup Strip, later renamed White Sands Space Harbor, near White Sands, N.M.

Thursday, November 10, 2011

Boosters Gave Fiery Muscle to Shuttle Launches


When Atlantis’ STS-135 mission lifted off from Launch Pad 39A on July 8, 2011, on NASA’s final space shuttle launch, it was carried aloft by the last two solid rocket boosters (SRBs) assembled at Kennedy Space Center for the Space Shuttle Program. Two of the SRB’s major components also helped launch Columbia on the first space shuttle launch.

External Fuel Tank/SRB Vehicle Manager Alicia Mendoza said the cylinder on the left-hand forward motor segment and the forward skirt on the right-hand forward assembly flew on STS-1 in 1981.

“Components flown on the first and last missions of the program are a fitting testament to the robustness of the reusable design of the SRBs,” Mendoza said. “Even of greater significance is the professionalism of the unique team of thousands of individuals who have retrieved, refurbished and assembled the hardware during the past 30 years.”

For three decades, the twin SRBs provided the main thrust to help send space shuttles and hundreds of astronauts on 135 missions into space.

The SRBs generated a combined thrust of 5.3 million pounds, which is equivalent to 44 million horsepower or 400,000 subcompact cars. Each SRB was 149.2 feet tall, which is only two feet shorter than the Statue of Liberty. However, each 700-ton loaded booster weighed more than three times as much as the famous statue. The left SRB sported a black stripe on the forward assembly, just below the nose cone, to distinguish it from the right SRB during re-entry into the atmosphere and retrieval operations out in the Atlantic Ocean.

Several facilities at Kennedy were used to process the SRBs major components. The boosters arrived in eight segments by railcar from ATK in Utah. “It takes 22 days to build the four segments into a flight-ready SRB stacked on the platform,” Mendoza said.

At Kennedy, about 600 NASA, USA and ATK engineers and technicians worked to process the SRBs from beginning to retrieval until after launch. “Their skill, dedication and passion are the reasons for the success of this great nation’s Space Shuttle Program,” Mendoza said.

Wednesday, November 09, 2011

Drag Chute Reduced Shuttles' Brake and Tire Wear


The landing of space shuttle Endeavour on the 15,000-foot concrete runway at Edwards Air Force Base, Calif., to conclude shuttle mission STS-49 in 1992 demonstrated a new capability for the shuttle fleet. A 39-foot-diameter braking parachute was used to slow the vehicle, relieving stress on the brakes and tires and reducing the landing rollout by as much as 2,000 feet.


Engineers had initially considered such a feature for the shuttle, but eliminated it from preliminary designs in 1974 after deciding it wouldn’t be needed for planned lakebed landings at Edwards. Endeavour was the first orbiter to be built with the drag chute that would soon become a standard feature on the shuttle fleet.

In 1990, researchers at NASA's Dryden Flight Research Center at Edwards used the center's modified NB-52B to test the drag parachute system that would be used on the shuttle orbiters. In a series of eight chute deployment tests, the B-52 landed at speeds ranging from 160 to 230 miles per hour on one of the lakebed runways, as well as on the 15,000-foot concrete strip.

Instrumentation on the B-52 obtained data during chute deployments to validate predicted loads that an operational shuttle orbiter would sustain with a drag chute deployed during landing and rollout. Successful test results led to incorporation of the drag chute system on Endeavour as it was being built. The other three orbiters – Columbia, Discovery and Atlantis – were retrofitted with the system as they underwent normal periodic maintenance.

Endeavour’s first landing on May 16, 1992 was the first operational demonstration of the system. The drag chute was deployed as the nose gear touched down, and the orbiter came to a stop following a landing roll of 9,490 feet. Though this fairly typical rollout was the result of conservative mission planning, subsequent landings of Endeavour demonstrated that the drag chute could reduce landing rollouts by 700 to 1,500 feet.