NASA

June 13, 2014

NASA begins testing of new spectrograph on agency’s airborne observatory

EXES, the Echelon-Cross-Echelle Spectrograph, made its first light commissioning flight on April 7, 2014 on NASA’s SOFIA flying observatory. The instrument, shown mounted to SOFIA’s telescope bulkhead, can split light from the telescope into an infrared “rainbow.”

Astronomers are eagerly waiting to begin use of a new instrument to study celestial objects: a high-resolution, mid-infrared spectrograph mounted on NASA’s Stratospheric Observatory for Infrared Astronomy, the world’s largest flying telescope.

This new instrument, the Echelon-Cross-Echelle Spectrograph, can separate wavelengths of light to a precision of one part in 100,000. At the core of EXES is an approximately 3-foot bar of aluminum called an echelon grating, carefully machined to act as 130 separate mirrors that split light from the telescope into an infrared “rainbow.”

SOFIA is a heavily modified Boeing 747 Special Performance jetliner that carries a telescope with an effective diameter of about 8-feet at altitudes of 39,000 to 45,000 feet, above more than 99 percent of Earth’s atmospheric water vapor. Lower in the atmosphere, at altitudes associated with most ground-based observatories, water vapor obscures much of what can be learned when viewed in the infrared spectrum.

“The combination of EXES’s high spectral resolution and SOFIA’s access to infrared radiation from space provides an unprecedented ability to study celestial objects at wavelengths unavailable from ground-based telescopes,” said Pamela Marcum, a program scientist at the SOFIA Science Center and Program Office in Moffett Field, Calif. “EXES on SOFIA will provide data that cannot be obtained by any other astronomical facility on the ground or in space, including all past, present or those observatories now under development.”

EXES successfully carried out its first two flights on SOFIA on the nights of April 7 and 9, according to Matthew Richter, leader of the team that is developing the instrument at the University of California, Davis, Physics Department. EXES is a collaboration between U.C. Davis and NASA’s Ames Research Center in Moffett Field.

“During the two flights, EXES made observations to investigate and characterize the instrument’s performance. All the main goals of these observations were successful, although further commissioning flights are required to test EXES in all of its modes,” said Richter.

On the first commissioning flight, EXES observed emissions from Jupiter’s atmosphere in two molecular hydrogen lines. These observations will be used to understand how gas rises from deep in Jupiter’s interior and mixes into the planet’s upper atmosphere.

During the second commissioning flight, EXES observed a young, massive star in the constellation Cygnus that is still embedded in its natal cocoon. The star, known as AFGL 2591, warms up the surrounding interstellar dust and causes ice coatings on the dust to evaporate. The warmed dust provides an excellent background infrared “lamp” to probe the chemical make-up of the intervening gas.

New stars and planets are forming from that material through processes similar to the ones that made the sun and Earth. These observations are designed to study water vapor around the protostar, and demonstrate that EXES can detect absorption from the lowest energy level of water molecules despite interference from water vapor from Earth’s atmosphere.

“Of the observations obtained during the instrument’s first flights, only one can be done from the ground, albeit with some difficulty, and the others are impossible from even the best ground-based telescope sites because the water in Earth’s atmosphere is opaque at these wavelengths,” Richter said. “While space observatories are above Earth’s atmosphere, the massive optical equipment required to separate the light as finely as EXES does – EXES weighs almost 1,000 pounds – would be a challenge to launch into space. In these observations, the spectral features we are studying are narrow, and finely dividing the infrared spectrum to detect them is exactly what EXES was designed to do.”

SOFIA is a joint project of NASA and the German Aerospace Center. The aircraft is based at and the program is managed from NASA Armstrong Flight Research Center’s facility in Palmdale, Calif. NASA’s Ames Research Center, manages the SOFIA science and mission operations in cooperation with the Universities Space Research Association headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart.




All of this week's top headlines to your email every Friday.


 
 

 

News Briefs October 24, 2014

M4/M9 Firing Range closure The Edwards AFB Combat Arms Firing Range is closed for M4 and M9 firing until further notice. Any required firing for PCS or deployments will temporarily be accomplished at March ARB, Calif. To schedule training, contact the Combat Arms section at 661-277-2103. It is strongly recommended that all firing be scheduled as soon...
 
 
town-hall

Edwards community holds town hall meeting

Air Force photograph by Jena Romo Col. Eric Leshinksy, 412th Mission Support Group commander, addresses the audience at a town hall meeting Oct. 15 at the Airmen and Family Readiness Center. The Edwards community gathered at th...
 
 
Instagram by Master Sgt. Sonny Cohrs

Online vigilance helps reduce risk

Instagram by Master Sgt. Sonny Cohrs The Air Force reminds us not to post information about deployment departures, locations, and on-going operations. However, even a simple photo of your family pet can reveal personal informat...
 

 
Air Force photograph by Rebecca Amber

Gathering of Eagles honors 70 years of TPS

Air Force photograph by Rebecca Amber Brig. Gen. Michael Brewer, 412th Test Wing commander, offered the closing remarks for the event, reminding the audience that fundraiser is about preparing for the future. The Flight Test Hi...
 
 
commissary

Giving ‘gift of groceries’? Think Commissary gift cards

No matter the occasion, Commissary gift cards are always available to help family members, friends and organizations give the gift of groceries. “Our gift cards are versatile,” said Randy Chandler, the Defense Commi...
 
 
Air Force photograph by Christian Turner

AFMC command chief visits with Edwards Airmen

Air Force photograph by Christian Turner Chief Master Sgt. Michael J. Warner, Air Force Materiel Command command chief, speaks to enlisted Airmen at Club Muroc Oct. 15. Warner held two enlisted calls speaking to junior Airmen i...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>