NASA Funds Dark Energy Space Telescope Development
Greenbelt MD (SPX) Aug 04, 2006
NASA has selected a team led by the National Optical Astronomy Observatory and NASA's Goddard Space Flight Center develop a concept for a space mission to characterize the mysterious dark energy that permeates the universe and is causing its expansion to accelerate.
Known as Destiny, the Dark Energy Space Telescope, the spacecraft would detect and observe more than 3,000 supernovae over its two-year primary mission to measure the expansion history of the Universe, followed by a year-long survey of 1,000 square-degrees of the sky at near-infrared wavelengths to measure how the large-scale distribution of matter in the universe has evolved since the Big Bang.
Used together, the data from these two surveys will have 10 times the sensitivity of current ground-based projects to explore the properties of dark energy, and will provide data critical to understanding the origin of dark energy, which is poorly explained by existing physical theories.
"Destiny's strength is that it is a simple, low-cost mission designed to attack the puzzling problem of dark energy directly with high statistical precision," said Tod R. Lauer, the principal investigator for Destiny and an astronomer at NOAO.
"We build upon grism technology used in the Hubble Space Telescope's Advanced Camera for Surveys to help us provide spectra of the supernovae as well as images," Lauer said. "Spectra are critical to diagnosing the properties of the supernova, but are very difficult to obtain with more traditional cameras."
Lauer said Destiny's grism camera, however, will take simultaneous spectra of all objects in its field, something that represents a major advantage, because it greatly increases the ability to detect and characterize these distant stellar explosions.
The discovery of a mysterious force now known as Dark Energy was announced in 1998 by two independent teams of astronomers who were studying distant supernovae as a way to measure how the expansion rate of the universe has changed over time.
The teams - both of whom used NOAO telescopes in Chile to discover the supernovae - were surprised to discover that, rather than slowing down, as had been expected, the expansion rate of the universe actually is speeding up as it ages.
To explain this phenomenon, scientists have been forced to conclude that the universe contains not only ordinary matter and dark (invisible) matter, but also an ingredient called dark energy that permeates all of space and propels this expansion. Understanding the origin and properties of dark energy probably is the most outstanding problem in cosmology.
"Destiny is designed to exploit two complementary paths - supernovae and large scale distribution of matter - to measure dark energy in a manner that is less susceptible to unknowns than any single technique," said Dominic J. Benford of Goddard, the deputy principal investigator for Destiny.
Destiny is one concept for JDEM, the Joint Dark Energy Mission, which NASA and the Department of Energy have jointly proposed to characterize dark energy.
DoE's Los Alamos National Laboratory in New Mexico is a partner in the Destiny mission.
If Destiny ultimately is selected to achieve the JDEM scientific goals, the spacecraft and its 1.65-meter telescope would be launched by a Delta IV or Atlas V expendable rocket into a stable orbit at the second Earth-Sun Lagrangian point as soon as 2013.
This location allows for stable and continuous operation of the instrument. Initially Destiny would continuously observe two patches of the sky for distant supernovae. Destiny's observations are planned to coordinate closely with those from current large ground-based telescopes and emerging facilities such as the Large Synoptic Survey Telescope (LSST).
Dawn Conducting The Comprehensive Performance Tests
Pasadena CA (JPL) Aug 04, 2006
Dawn continues to keep its human handlers very busy as preparations continue on schedule to meet the planned opening of the launch period on June 20, 2007. Much of June 2006 was devoted to conducting the comprehensive performance tests (CPTs) described in the previous log.
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2006 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA PortalReports are copyright European Space Agency. All NASA sourced material is public domain. Additionalcopyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement