Nov 30 2011

From The Space Library

---

Revision as of 08:46, 10 February 2014

NASA Exercises Contract Option For TDRS-M Satellite Decision Will Retain Hundreds Of Jobs

WASHINGTON -- NASA has elected to exercise the first of two available contract options for procurement of an additional Tracking Data Relay Satellite (TDRS) from Boeing Satellite Systems, Inc. of El Segundo, Calif. The estimated value of the contract option is $289 million and extends the period of performance through April 2024. Exercising the option will allow Boeing Satellite Systems to retain at least 300 American jobs.

The TDRS-K Program contract, awarded in December 2007, is a fixed-price incentive contract that directs Boeing Satellite Systems to design, develop, fabricate, integrate, test, ship, provide launch support, conduct in-orbit checkout operations and provide sustaining engineering support for two TDRS spacecraft, TDRS-K and TDRS-L. The original contract included options for two additional spacecraft (TDRS-M and TDRS-N). This action exercises the option for TDRS-M.

"With the first-generation TDRS spacecraft retiring by 2015, NASA must continue to replenish the fleet," said Pete Vrotsos, network services director for Space Communications and Navigation at NASA Headquarters in Washington. "TDRS-M is the agency's first step in assuring the space network will meet NASA's and the U.S. government's relay satellite requirements by 2017."

NASA Awards Software Services Contract

FAIRMONT, W.Va. -- NASA has selected TASC Inc., of Andover, Mass., to provide software services to the agency's Independent Verification and Validation (IV&V) Facility in Fairmont, W.Va.

The services and support include independent verification and validation; software assurance; research and development and technical quality monitoring.

This cost-plus-award-fee contract has a total period of performance of five years, including options and a potential value of $133.9 million.

TASC will provide services for system software developed by or for NASA missions and other government, commercial and private organizations in partnership with the agency.

NASA's Swift Finds a Gamma-Ray Burst With a Dual Personality

WASHINGTON -- A peculiar cosmic explosion first detected by NASA's Swift observatory on Christmas Day 2010 was caused either by a novel type of supernova located billions of light-years away or an unusual collision much closer to home, within our own galaxy. Papers describing both interpretations appear in the Dec. 1 issue of the journal Nature.

Gamma-ray bursts (GRBs) are the universe's most luminous explosions, emitting more energy in a few seconds than our sun will during its entire energy-producing lifetime. What astronomers are calling the "Christmas burst" is so unusual that it can be modeled in such radically different ways.

"What the Christmas burst seems to be telling us is that the family of gamma-ray bursts is more diverse than we fully appreciate,” said Christina Thoene, the supernova study's lead author, at the Institute of Astrophysics of Andalusia in Granada, Spain. It's only by rapidly detecting hundreds of them, as Swift is doing, that we can catch some of the more eccentric siblings."

Common to both scenarios is the presence of a neutron star, the crushed core that forms when a star many times the sun's mass explodes. When the star's fuel is exhausted, it collapses under its own weight, compressing its core so much that about a half-million times Earth's mass is squeezed into a sphere no larger than a city.

The Christmas burst, also known as GRB 101225A, was discovered in the constellation Andromeda by Swift's Burst Alert Telescope at 1:38 p.m. EST on Dec. 25, 2010. The gamma-ray emission lasted at least 28 minutes, which is unusually long. Follow-up observations of the burst's afterglow by the Hubble Space Telescope and ground-based observatories were unable to determine the object's distance.

Thoene's team proposes that the burst occurred in an exotic binary system where a neutron star orbited a normal star that had just entered its red giant phase, enormously expanding its outer atmosphere. This expansion engulfed the neutron star, resulting in both the ejection of the giant's atmosphere and rapid tightening of the neutron star's orbit.

Once the two stars became wrapped in a common envelope of gas, the neutron star may have merged with the giant's core after just five orbits, or about 18 months. The end result of the merger was the birth of a black hole and the production of oppositely directed jets of particles moving at nearly the speed of light, followed by a weak supernova.

The particle jets produced gamma rays. Jet interactions with gas ejected before the merger explain many of the burst's signature oddities. Based on this interpretation, the event took place about 5.5 billion light-years away, and the team has detected what may be a faint galaxy at the right location.

"Deep exposures using Hubble may settle the nature of this object," said Sergio Campana, who led the collision study at Brera Observatory in Merate, Italy.

If it is indeed a galaxy, that would be evidence for the binary model. On the other hand, if NASA's Chandra X-ray Observatory finds an X-ray point source or if radio telescopes detect a pulsar, that goes against it.

Campana's team supports an alternative model that involves the tidal disruption of a large comet-like object and the ensuing crash of debris onto a neutron star located only about 10,000 light-years away. The scenario requires the break-up of an object with about half the mass of the dwarf planet Ceres. While rare in the asteroid belt, such objects are thought to be common in the icy Kuiper belt beyond Neptune. Similar objects located far away from the neutron star may have survived the supernova that formed it.

Gamma-ray emission occurred when debris fell onto the neutron star. Clumps of cometary material likely made a few orbits, with different clumps following different paths before settling into a disk around the neutron star. X-ray variations detected by Swift's X-Ray Telescope that lasted several hours may have resulted from late-arriving clumps that struck the neutron star as the disk formed.

In the early years of studying GRBs, astronomers had very few events to study in detail and dozens of theories to explain them. In the Swift era, astronomers have settled into two basic scenarios, either the collapse of a massive star or the merger of a compact binary system.

"The beauty of the Christmas burst is that we must invoke two exotic scenarios to explain it, but such rare oddballs will help us advance the field,” said Chryssa Kouveliotou, a co-author of the supernova study at NASA's Marshall Space Flight Center in Huntsville, Ala.

NASA, Library of Congress Establish Honorary Astrobiology Chair

WASHINGTON -- NASA and the Library of Congress have established the Baruch S. Blumberg NASA-Library of Congress chair in Astrobiology at the Library's scholarly research organization, the John W. Kluge Center in Washington. The chair is named for the late Nobel Laureate and founding director of the NASA Astrobiology Institute, Baruch "Barry" Blumberg.

Astrobiology is the study of the origins, evolution, distribution and future of life in the universe. Astrobiology addresses three fundamental questions: How did life begin and evolve? Is there life elsewhere? What is the future of life on Earth and beyond?

Blumberg was awarded the 1976 Nobel Prize in physiology or medicine for discovery of the Hepatitis B virus and development of a vaccine to prevent Hepatitis B infection. He served as the NASA Astrobiology Institute director from 1999 to 2002. The institute's mission is to promote interdisciplinary research in astrobiology, train the next generation of astrobiologists, provide scientific and technical leadership for NASA space missions, and share astrobiology's discoveries with learners of all ages.

"Relationships with external research organizations are critical to NASA's success as a leader in science and technology," NASA Chief Scientist Waleed Abdalati said. "Opportunities like the Blumberg chair really help strengthen those relationships."

At the Library of Congress, Blumberg was a founding member of the Scholar's Council, a 12-member group of distinguished scholars which advises the Librarian of Congress on matters of scholarship.

"This collaboration between NASA and the Library of Congress is an unparalleled opportunity to broaden public discourse on the intersection of astrobiology and its societal implications," said NASA Astrobiology Institute Director Carl Pilcher of NASA's Ames Research Center at Moffett Field, Calif. "Astrobiology uses the tools of modern science to address questions with philosophical, ethical and theological implications. The chair will be able to use the vast resources of the Library of Congress to explore these issues."

An annual international competition will be held to select a chairperson, who will serve in residence at the Kluge Center for up to one year, beginning in fall 2012.

Likely research topics include the societal implications of discovering life beyond Earth, exploring whether life is rare in the universe, or the ways astrobiology influences and is influenced by culture.

"For many years, Barry worked in his inimitable and energetic way to connect scholars from astrobiology with those studying the humanities," said Librarian of Congress James H. Billington. "We are delighted to be moving forward with this important opportunity to examine the societal implications of this frontier field."