Subscribe free to our newsletters via your
. 24/7 Space News .




MICROSAT BLITZ
Emerging Optics Technology to Fly on Microsatellite
by Lori Keesey for Goddard Space Flight Center
Greenbelt MD (SPX) Jun 05, 2012


Goddard scientists designed and constructed this ground-based breadboard imaging system to test an emerging technology called the photon sieve. The technology could help scientists better understand the sun's poorly understood chromosphere. (Credit: Adrian Daw).

A kitchen gadget used to sift flour and other ingredients is the inspiration behind the name of an emerging technology that could resolve some of the more intriguing components of the sun's chromosphere - the irregular layer above the photosphere that contributes to the formation of solar flares and coronal mass ejections.

Adrian Daw and Douglas Rabin, scientists at NASA's Goddard Space Flight Center in Greenbelt, Md., are collaborating with researchers at the U.S. Air Force Academy (USAFA) in Colorado and other Air Force-affiliated organizations to build a small solar observatory equipped with the so-called "photon sieve," an eight-inch (20-centimeter) diffractive optic.

A version of this technology was successfully demonstrated in a ground test, paving the way for its flight on a tiny Cubesat satellite in 2014 - the Air Force-sponsored FalconSat-7 mission. That mission will demonstrate the practicality of deploying this emerging technology in space and possibly paving the way for a larger heliophysics mission in the future.

"We've studied the sun's corona for years and it's complicated. But the chromosphere, which can be seen as a thin pink layer during a total solar eclipse, is even harder to understand," Daw said. "Things are happening there at spatial scales we can't currently resolve with existing space- or ground-based telescopes."

Although a large observatory comparable in size to the Hubble Space Telescope could resolve currently unseen magnetic flux tubes and filamentary plasma within coronal loops, the cost to build a conventional large-aperture solar telescope is prohibitive, Daw said.

"The photon sieve could help us overcome this obstacle and help us provide a game-changing technology for high-resolution imaging in space," he said.

A Variant of Fresnel Zone Plates
The technology that could help bring these details to light is a variant of the Fresnel zone plate, which focuses light through diffraction rather than refraction or reflection. These devices consist of a set of alternating transparent and opaque concentric circular rings.

Light hitting the plate diffracts around the opaque zones, which are precisely spaced so that the diffracted light interferes at the desired focus to create an image taken by a camera.

The sieve operates largely the same. However, the rings are dotted with millions of holes, like a kitchen sieve or sifter, whose sizes and positions are configured so that the light diffracts to a desired focus.

As a result of its design, the sieve can be patterned on a flat surface and can be easily scaled up in size - particularly if constructed of a polyimide film similar to the ubiquitous Kapton, which spacecraft and instrument developers commonly use because it can withstand extreme temperatures and vibration.

But perhaps the most significant advantage is that the lightweight, easily rolled and deployed film need not be pulled to a perfect optical flatness like more traditional mirrors. In fact, surface requirements for traditional mirrors are 100 times more stringent - making the photon sieve ideal as a quick-turnaround space-based optic.

This appeals to the Air Force. In the event of a catastrophic loss of its current intelligence, surveillance, and reconnaissance satellites, the military would need a simple replacement system easily deployed from a small, inexpensive satellite, like a Cubesat.

Since its invention more than a decade ago by Lutz Kipp, a professor at Kiel University in Germany, researchers at the USAFA's Laser and Optics Research Center have experimented with different materials for making the sieve. USAFA's Geoff Andersen, Michael Dearborn, and Geoff McHarg initially experimented with chrome-coated quartz or glass, later focusing their efforts on lightweight polyimide films or membranes.

In laboratory testing, these sieves showed great promise for narrow and broadband imaging in visible wavelength bands, particularly in the H-alpha wavelength band ideal for detecting structure within the solar chromosphere.

What they lacked, however, was expertise in solar physics and some of the analytical tools needed to evaluate the sieve's deployment mechanisms. "They were looking for the best way to demonstrate their technology," Daw said.

"It's easier to test imaging technologies with a really bright source, like the sun. They contacted us to see if we wanted to collaborate. Of course we did. The collaboration is proving to be of great mutual benefit to both organizations."

Goddard's Contribution to FalconSat-7
Since joining the effort, which also involves the Air Force Research Laboratory and the Air Force Institute of Technology, both located at the Wright-Patterson Air Force Base in Ohio, Goddard has analyzed requirements for deploying the sieve and keeping the membrane relatively flat once the Cubesat reaches its 280-mile (450-kilometer) orbit.

Daw's team also designed and constructed a ground-based imaging system to test a glass version of the sieve. "Using this system, we took the first-ever solar images using such a device," Daw said. "In fact, these are the first images of any astronomical object using a photon sieve." The next step is carrying out ground-based tests of the membrane sieve, he added.

"These two accomplishments - a ground-based demonstration of the photon-sieve technology and the analysis of the deployment system - are major advances for deployable membrane optics," Daw said. As a result of these successes, he and his team are now investigating ways to extend the sieve's wavelength range to the extreme ultraviolet, which is most interesting to solar physicists. "This technology has lots of applications for heliophysics," Daw said.

.


Related Links
Technology news from Goddard
Microsat News and Nanosat News at SpaceMart.com






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle








MICROSAT BLITZ
Surrey engineers use games console technology to make space building blocks
Guildford, UK (SPX) May 29, 2012
Space innovators at the University of Surrey and Surrey Satellite Technology Limited (SSTL) are developing 'STRaND-2', a twin-satellite mission to test a novel in-orbit docking system based upon XBOX Kinect technology that could change the way space assets are built, maintained and decommissioned. STRaND-2 is the latest mission in the cutting edge STRaND (Surrey Training, Research and Nano ... read more


MICROSAT BLITZ
UA Lunar-Mining Team Wins National Contest

NASA Lunar Spacecraft Complete Prime Mission Ahead of Schedule

NASA Offers Guidelines To Protect Historic Sites On The Moon

Neil Armstrong gives rare interview - to accountant

MICROSAT BLITZ
Wind may have driven avalanches on Martian dunes

On The Hunt For Light-Toned Veins Of Gypsum

Mars missions may learn from meteor Down Under

Waking Up with the Sun's Rays

MICROSAT BLITZ
New Moon for India

Boeing Completes Software PDR Of New Crew Ship

NASA hails 'new era' in exploration

CU astronaut-alumnus Scott Carpenter looks back at 50th anniversary of Aurora 7 mission

MICROSAT BLITZ
What will China's Taikonauts do aboard Tiangong 1?

Why is China sending a woman into space?

China launches telecommunication satellite

Tiangong 1 Ready To Meet Shenzhou 9

MICROSAT BLITZ
Capillarity in Space - Then and Now, 1962-2012

Dragon on board

SpaceX Launches Falcon 9 Dragon on Historic Mission

SpaceX Dragon Transports Student Experiments to Space Station

MICROSAT BLITZ
Sea Launch Delivers the Intelsat 19 Spacecraft into Orbit

SpaceX Dragon capsule splash lands in Pacific

US cargo ship on return voyage from space station

US cargo vessel prepares to leave space station

MICROSAT BLITZ
Tiny Planet-Finding Mirrors Borrow from Webb Telescope Playbook

Astronomers Probe 'Evaporating' Planet Around Nearby Star with Hobby-Eberly Telescope

Venus transit may boost hunt for other worlds

NSO To Use Venus Transit To Fine-Tune Search For Other Worlds

MICROSAT BLITZ
Microsoft links Xbox with smartphones, tablets

E3 to showcase big videogame titles, hot trends

Windows 8 to dominate Taiwan computer show

Commonly used painkillers may protect against skin cancer




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights 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 Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement