Frankfurt, Germany (SPX) Jun 16, 2010
Metal mirrors made with extremely high precision and exactly positioned are the key elements of modern telescopes. A new production technique enables complex optical surfaces to be manufactured with excellent trueness of shape and hitherto unattained positional accuracy. The mirrors have been built for an infrared sounder telescope.

For space research as well as climate observation and weather forecasting satellites need increasingly powerful optical measurement and recording devices. They often consist of several aspherically shaped mirror elements which through their precise interplay provide the desired reflection of the incident light.

"All the mirrors must be produced and characterized with extreme precision, that is to an accuracy of less than one micrometer. They also have to be exactly positioned in relation to each other," explains Sebastian Scheiding from the Fraunhofer Institute for Applied Optics and Precision Engineering IOF in Jena. Up to now this positioning has been very time consuming as it takes place step by step.

First the individual mirrors are fitted in the telescope one after the other, then the imaging quality is measured.

If inaccuracies or errors are found, they are corrected by positional adjustments to the mirrors. Then further measurements and adjustments are made until all components are optimally arranged.

"We wanted to simplify this complicated and time-consuming adjustment process," says Scheiding. In the research project initiated by the German Aerospace Center (DLR) the scientist has therefore developed an innovative production technique which takes into account the later alignment of the components right from the outset.

For this purpose, the individual mirror surfaces are positioned in relation to each other as precisely during processing as they will be later in the telescope. This reduces to a minimum the errors and corrections made when the mirrors are being fitted. The assembly process is simple and reproducible.

"The trick is that we mount all the mirrors for a module in the same machine at the same time and assign them to a common system of coordinates.

To this end, each mirror blank is provided with defined, ultra-precise measurement marks and reference surfaces," explains Scheiding. These fixed marks embody the system of coordinates for diamond turning of the mirror shapes. At the same time, however, they fix the position of each mirror in relation to the adjacent mirrors. Finally they also serve as reference points for subsequent measurement processes to check the quality of the optical system.

The IOF demonstrates the degree of precision that can be achieved by such reference structures on the example of a mirror arrangement for an infrared sounder telescope (IRS-TEL). It incorporates two mirror modules, each of which has two juxtaposed aluminum mirror surfaces.

The shape of the metal mirror deviates only 126 nanometers from the ideal aspherical shape and the position of two mirrors in relation to each other is ten times more precise than for comparable conventionally produced mirror assemblies.

"As a result we can make optical systems of this type to a far greater degree of accuracy, but at the same time we're cheaper because the time-consuming adjustment process during final assembly is no longer required," says Scheiding.

Washington DC (SPX) Jun 16, 2010
The Naval Research Laboratory's (NRL's) Space Science Division is performing an intensive study of the Earth's upper atmosphere using a flotilla of NRL-built spaceflight experiments aboard four concurrent spaceflight missions, involving five satellites and the International Space Station.

These coordinated observations utilize both in situ and remote sensors to measure the composition, temperature, and density of the thermosphere and the electron density of the ionosphere, with the objective of understanding the influence of the lower thermosphere upon ionospheric structure and morphology.

The joint Taiwan-US COSMIC/FORMOSAT3 mission, a constellation of six micro-satellites, was launched from Vandenberg Air Force Base in April 2006. The NRL Space Science Division designed and built the Tiny Ionospheric Photometer (TIP) compact far-ultraviolet (FUV) sensors, which are being used onboard COSMIC to study the Earth's nighttime ionosphere.

The TIP photometers are among the highest sensitivity FUV airglow sensors ever flown. COSMIC is breaking new ground in the study of the Earth's ionosphere, especially in the areas of troposphere-ionosphere coupling and improved global specification of the ionosphere. Currently, TIP sensors aboard two COSMIC spacecraft are gathering ionospheric data for this study.

The Remote Atmospheric and Ionospheric Detection System (RAIDS) includes eight spectrographs, spectrometers, and photometers to comprehensively measure thermospheric and ionospheric airglow in the extreme-ultraviolet to near-infrared passband (55 to 874 nm).

The extant hardware, built jointly by NRL and The Aerospace Corporation, was adapted for operation on the Japanese Experiment Module Exposed Facility (JEM-EF) aboard the International Space Station (ISS).

RAIDS was launched through the DoD Space Test Program on September 10, 2009, aboard the maiden flight of the Japanese Aerospace Exploration Agency H-II Transfer Vehicle and reached the ISS on September 17, 2009 where it was attached to the JEM-EF.

RAIDS has been performing science operations since October 23, 2009, collecting temperature data around the globe in the 100 to 200 km altitude range, an altitude region with a paucity of previous temperature measurements.

Launched from Vandenberg Air Force Base, Calif., aboard an United Launch Alliance Atlas V launch vehicle, October 18, 2009, the Special Sensor Ultraviolet Limb Imager (SSULI) developed by NRL's Space Science Division and Spacecraft Engineering Department offers a first of its kind technique for remote sensing of the ionosphere and thermosphere from space.

Flying on-orbit the U.S. Air Force Defense Meteorological Satellite Program (DMSP) flight 18 satellite, SSULI's characterization of the Earth's upper atmosphere and ionosphere provide the necessary scientific data to support military and civil systems.

Offering global observations that yield near real-time altitude profiles of the ionosphere and neutral atmosphere over an extended period of time, SSULI makes measurements from the extreme ultraviolet (EUV) to the far ultraviolet (FUV) over the wavelength range of 80 nanometers (nm) to 170 nm with 2.4 nm resolution.

In the category of in situ sensors, NRL developed the Atmospheric Neutral Drag Experiment (ANDE), which was deployed by NASA's Space Shuttle Endeavour in July 2009.

The suite consists of two spherical spacecraft, Castor and Pollux, fitted with retro-reflectors for satellite laser ranging. Castor carries instrumentation developed by NRL, NASA/GSFC, and the U.S. Air Force Academy to measure the in situ upper atmosphere density, composition and winds.

The datasets retrieved will be applied to improving the current atmospheric density and wind models such as the NRL Mass Spectrometer and Incoherent Scatter-Radar (MSIS) model. The ANDE satellites, orbiting beneath the ISS, provide important validation of the RAIDS density measurements made in the same orbital plane.

This combined data set from multiple space vehicles in a variety of orbits and heterogeneous sensing techniques provides excellent spatial, temporal, and spectral coverage for atmospheric and ionospheric characterization.

Space Science Division scientists are applying this data to study the relationship between atmospheric dynamics and ionosphere morphology, to understand the influence of solar variability upon chemistry and thermal balance, and to develop next-generation remote sensing approaches to provide high-quality atmospheric specifications to future DoD global atmospheric models.

Moffett Field CA (SPX) Jun 16, 2010
NASA's Kepler Mission has released 43 days of science data on more than 156,000 stars. These stars are being monitored for subtle brightness changes as part of an ongoing search for Earth-like planets outside of our solar system.

Astronomers will use the new data to determine if orbiting planets are responsible for brightness variations in several hundred stars. These stars make up a full range of temperatures, sizes and ages. Many of them are stable, while others pulsate. Some show starspots, which are similar to sunspots, and a few produce flares that would sterilize their nearest planets.

Kepler, a space observatory, looks for the data signatures of planets by measuring tiny decreases in the brightness of stars when planets cross in front of, or transit them. The size of the planet can be derived from the change in the star's brightness.

The 28-member Kepler science team also is using ground-based telescopes and the Hubble Space Telescope and Spitzer Space Telescope to perform follow-up observations on a specific set of 400 objects of interest.

The star field that Kepler observes in the constellations Cygnus and Lyra can only be seen from ground-based observatories in spring through early fall. The data from these other observations will determine which of the candidates can be identified as planets. That data will be released to the scientific community in February 2011.

Without the additional information, candidates that are actual planets cannot be distinguished from false alarms, such as binary stars - two stars that orbit each other. The size of the planetary candidates also can be only approximated until the size of the stars they orbit is determined from additional spectroscopic observations made by ground-based telescopes.

"I look forward to the scientific community analyzing the data and announcing new exoplanet results in the coming months," said Lia LaPiana, Kepler's program executive at NASA Headquarters in Washington.

"This is the most precise, nearly continuous, longest and largest data set of stellar photometry ever," said Kepler Deputy Principal Investigator David Koch of NASA's Ames Research Center in Moffett Field, Calif. "The results will only get better as the duration of the data set grows with time."

Kepler will continue conducting science operations until at least November 2012, searching for planets as small as Earth, including those that orbit stars in a warm habitable zone where liquid water could exist on the surface of the planet.

Since transits of planets in the habitable zone of solar-like stars occur about once a year and require three transits for verification, it is expected to take at least three years to locate and verify an Earth-size planet.

"The Kepler observations will tell us whether there are many stars with planets that could harbor life, or whether we might be alone in our galaxy," said mission science principal investigator William Borucki of Ames.

Ames is responsible for the ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed the Kepler mission development. Ball Aerospace and Technologies Corp. in Boulder, Colo., developed the Kepler flight system, and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes the Kepler science data.

AFP - A Russian cosmonaut and two American astronauts blasted off Wednesday for a restaffing mission to the International Space Station, Russian television showed in a live broadcast.

Russian Soyuz spacecraft lit up the sky above Central Asia today as it soared into space to ferry two Americans and one Russian cosmonaut to the International Space Station.

The moon's interior may harbor 100 times more water than previous estimates, according to a new study that took a fresh look at samples of moon rocks collected by Apollo astronauts nearly 40 years ago.

Ancient Mars was covered by a vast ocean that blanketed more than a third of the red planet's surface, new research suggests.

A NASA contractor says the space agency is trying to prematurely halt work on the Constellation program, which the Obama administration wants to cancel.

A Russian rocket blasted off Tuesday with a French sun satellite and a Swedish experiment to demonstrate orbital formation flying.

A European comet-chasing spacecraft will zip by a large asteroid next month, snapping pictures all the way and potentially unlocking some of the mysteries surrounding the space rock.

Baby solar systems in the making have been observed in unprecedented detail to help reveal how planets are formed.

The latest Mars robot may be dead, but NASA scientists have plenty to keep them busy as they scout out four potential stomping grounds for an ambitious new rover pegged to be the next red planet explorer.

Interesting articles in our Community forum.

A new video of the recent landing of a Russian Soyuz spacecraft shows the touchdown on the Central Asian steppes of Kazakhstan from a rare ground-based view of the space capsule's jarring touchdown.

Houston may have been the home to NASA's Mission Control and the hub of U.S. human spaceflight program for more than 40 years, but the Texas metropolis has never produced a hometown astronaut. That is, until now.

A new director has stepped up to lead the Carl Sagan Center for Study of Life in the Universe at the SETI Institute, taking the reins from previous long-time director and SETI pioneer, Frank Drake.

Layers of Earth's atmosphere illuminated by sunset; seen by ISS astronauts.

The sun's temper ebbs and flows on what scientists had thought was a pretty predictable cycle, but lately our closest star has been acting up..

SPACE.com - A Russian Soyuz spacecraft lit up the sky above Central Asia today as it soared into space to ferry two Americans and one Russian cosmonaut to the International Space Station.

The Soyuz TMA-19 vehicle blasted off from Baikonur Cosmodrome in Kazakhstan today to bring three new crew members to the International Space Station. This was the 100th launch of missions in support of space station assembly, resupply and crew exchanges. The rocket lit up the early morning sky in Kazakhstan at 3:35 a.m. Wednesday local time, (5:35:19 p.m. EDT and 9:35 pm GMT on Tuesday). The Soyuz took eight and a half minutes to reach orbit, but it will take about 2 days to catch up to the ISS.
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