Next NASA Mission :The Nuclear Spectroscopic Telescope Array

Figure: NuSTAR (Credit: California Institute of Technology)

The NuSTAR mission will deploy the first focusing telescopes to image the sky in the high energy X-ray (6 - 79 keV) region of the electromagnetic spectrum. Our view of the universe in this spectral window has been limited because previous orbiting telescopes have not employed true focusing optics, but rather have used coded apertures that have intrinsically high backgrounds and limited sensitivity.

During a two-year primary mission phase, NuSTAR will map selected regions of the sky in order to:

(1) take a census of collapsed stars and black holes of different sizes by surveying regions surrounding the center of own Milky Way Galaxy and performing deep observations of the extragalactic sky;

(2) map recently-synthesized material in young supernova remnants to understand how stars explode and how elements are created; and

(3) understand what powers relativistic jets of particles from the most extreme active galaxies hosting supermassive black holes.

In addition to its core science program, NuSTAR will offer opportunities for a broad range of science investigations, ranging from probing cosmic ray origins to studying the extreme physics around collapsed stars to mapping microflares on the surface of the Sun. NuSTAR will also respond to targets of opportunity including supernovae and gamma-ray bursts.

The NuSTAR instrument consists of two co-aligned grazing incidence telescopes with specially coated optics and newly developed detectors that extend sensitivity to higher energies as compared to previous missions such as Chandra and XMM. After launching into orbit on a small rocket, the NuSTAR telescope extends to achieve a 10-meter focal length. The observatory will provide a combination of sensitivity, spatial, and spectral resolution factors of 10 to 100 improved over previous missions that have operated at these X-ray energies.



Figure: NuSTAR focal plane motherboard with one of the four CdZnTe detectors installed. NuSTAR will have two such units, providing for a total of two 4K high energy X-ray cameras.

NuSTAR has two detector units, each at the focus of one of the two co-aligned NuSTAR optics units. The optical units observe the same area of sky, and the two images are combined on the ground. The focal planes are each comprised of four 32×32 pixel Cadmium-Zinc-Tellurium (CdZnTe, or CZT) detectors manufactured by eV Products. CZT detectors are state-of-the-art room temperature semiconductors that are very efficient at turning high energy photons into electrons. The electrons are then digitally recorded using custom Application Specific Integrated Circuits (ASICs) designed by the NuSTAR Caltech Focal Plane Team.

A NASA Small Explorer (SMEX) mission, NuSTAR is currently in Phase C/D and is scheduled to launch into low-Earth equatorial orbit in February 2012.

NASA's Next Big Space Telescope to Cost an Extra $1.5 Billion

During cryogenic testing, the mirrors will be subjected to temperatures dipping to -415 degrees Fahrenheit, permitting engineers to measure in extreme detail how the shape of each mirror changes as it cools. Credit: NASA/MSFC/David Higginbotham/Emmett Given

source:space.com
11th November,2010.

WASHINGTON — NASA's James Webb Space Telescope (JWST) is expected to cost at least $1.5 billion more than current estimates and its launch will be delayed a minimum of 15 months, according to an independent review panel tapped to investigate escalating costs and management issues with the next-generation flagship astronomy mission.

U.S. Sen. Barbara Mikulski (D-Md.) called for the independent review in June to identify the root causes of cost growth and schedule delays on the JWST.

"The Webb telescope will now cost $6.5 billion, $1.5 billion more than the estimate included in NASA's February 2010 budget request, Mikulski wrote in a Nov. 10 letter to NASA Administrator Charles Bolden after reading the Oct. 29 report. "Its launch will be delayed by over a year, from June 2014 to September 2015."
Led by NASA's Goddard Space Flight Center in Greenbelt, Md., the James Webb Space Telescope is an infrared telescope with a 6.5-meter foldable mirror and a deployable sunshield the size of a tennis court. Northrop Grumman Aerospace Systems of Redondo Beach, Calif., is prime contractor. An Ariane 5 rocket provided by the European Space Agency is slated to launch the observatory to the second Lagrange point — a gravitationally stable spot 1.5 million kilometers from Earth.

In her letter, Mikulski said NASA must have a sense of urgency and frugality in correcting the JWST's management problems and present Congress with a realistic budget for the program.

"We cannot afford to continue with business as usual in this stark fiscal situation," she wrote.

The panel, led by John Casani, special assistant to the director of NASA's Jet Propulsion Laboratory in Pasadena, Calif., attributed the cost growth and schedule delays to "budgeting and program management, not technical performance," according to the report, which characterized the JWST's technical progress as "commendable and often excellent."

However, the report notes that "there may be a number of low probability threats whose occurrence could cause an additional year delay in launch and a correspondingly higher cost."

The panel recommends restructuring the JWST project office at Goddard to emphasize cost and schedule ceilings. "The flawed practice by the Project of not adequately accounting for threats in the budgeting process needs immediate correction," the report states.

However, the report also found that "the JWST Project has invested funds wisely in advancing the necessary technologies and reducing technical risk such that the funds invested to date have not been wasted," according to the executive summary. "The management approach, however, needs to change to focus on overall life cycle cost and a well-defined launch date."

Bolden, in a Nov. 10 statement, said he agrees with the panel's findings and that NASA would overhaul the program's management structure.

"No one is more concerned about the situation we find ourselves in than I am, and that is why I am reorganizing the JWST Project at Headquarters and the Goddard Space Flight Center, and assigning a new senior manager at Headquarters to lead this important effort," Bolden said in the statement.

The NASA chief said he is encouraged by the panel's finding that the JWST is technically sound and that the project continues to meet its milestones.

"However, I am disappointed we have not maintained the level of cost control we strive to achieve — something the American taxpayer deserves in all of our projects," he said. "NASA is committed to finding a sustainable path forward for the program based on realistic cost and schedule assessments."

NASA balloon mission tunes in to a cosmic radio mystery

A mysterious screen of extra-loud radio noise permeates the cosmos, preventing astronomers from observing heat from the first stars. The balloon-borne ARCADE instrument discovered this cosmic static (white band, top) on its July 2006 flight. The noise is six times louder than expected. Astronomers have no idea why. NASA/ARCADE/Roen Kelly

January 7, 2009

Listening to the early universe just got harder. A team led by Alan Kogut of NASA's Goddard Space Flight Center in Greenbelt, Maryland, announced January 7, 2009, the discovery of cosmic radio noise that booms six times louder than expected.

The finding comes from a balloon-borne instrument named Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE). In July 2006, the instrument launched from NASA's Columbia Scientific Balloon Facility in Palestine, Texas, and flew to an altitude of 22 miles (35 km), where the atmosphere thins into the vacuum of space.

ARCADE's mission was to search the sky for heat from the first generation of stars. Instead, it found a cosmic puzzle.

"The universe really threw us a curve," Kogut said. "Instead of the faint signal we hoped to find, here was this booming noise six times louder than anyone had predicted." Detailed analysis ruled out an origin from primordial stars or from known radio sources, including gas in the outermost halo of our own galaxy. The source of this cosmic radio background remains a mystery.

Many objects in the universe emit radio waves. In 1931, American physicist Karl Jansky first detected radio static from our own Milky Way galaxy. Similar emission from other galaxies creates a background hiss of radio noise.

The problem, said team member Dale Fixsen of the University of Maryland at College Park, is that there doesn't appear to be enough radio galaxies to account for the signal ARCADE detected. "You'd have to pack them into the universe like sardines," he said. "There wouldn't be any space left between one galaxy and the next."

The sought-for signal from the earliest stars remains hidden behind the newly detected cosmic radio background. This noise complicates efforts to detect the very first stars, which are thought to have formed about 13 billion years ago - not long, in cosmic terms, after the Big Bang. Nevertheless, this cosmic static may provide important clues to the development of galaxies when the universe was less than half its present age. Unlocking its origins should provide new insight into the development of radio sources in the early universe.

"This is what makes science so exciting," said Michael Seiffert, a team member at NASA's Jet Propulsion Laboratory in Pasadena, California. "You start out on a path to measure something - in this case, the heat from the very first stars - but run into something else entirely, something unexplained."

ARCADE is the first instrument to measure the radio sky with enough precision to detect this mysterious signal. To enhance the sensitivity of ARCADE's radio receivers, they were immersed in more than 500 gallons of ultra-cold liquid helium. The instrument's operating temperature was just 2.7° Celsius above absolute zero.

This is the same temperature as the cosmic microwave background (CMB) radiation, the remnant heat of the Big Bang that was discovered as cosmic radio noise in 1965. "If ARCADE is the same temperature as the microwave background, then the instrument's heat cannot contaminate the cosmic signal," Kogut said.