Douglas Isbell
Headquarters, Washington, DC                November 10, 1998
(Phone:  202/358-1753)

Bill Steigerwald
Goddard Space Flight Center, Greenbelt, MD
(Phone:  301/286-5017)

Linda St. Thomas
Smithsonian Institution, Washington, DC
(Phone:  202/357-2627)

RELEASE:  98-201

NASA TECHNOLOGY HELPS SMITHSONIAN 
PRESERVE THE STAR-SPANGLED BANNER

     A NASA infrared camera developed to explore Mars will 
assist the Smithsonian Institution in its three-year project 
to preserve the Star-Spangled Banner. 

     The camera, built at NASA's Goddard Space Flight Center, 
Greenbelt, MD, is taking images this week of the historic 
flag in infrared light to help preservationists identify 
deteriorated and soiled areas not obvious to the human eye.  
The camera, called the Acousto-Optic Imaging Spectrometer 
(AImS), was developed by Dr. David Glenar at Goddard.

     Considered a national treasure, the Star-Spangled Banner 
flew over Fort McHenry in Baltimore, MD, during the War of 
1812 and inspired the words that became the U.S. national 
anthem.  Despite receiving extra special care at the 
Smithsonian's National Museum of American History (NMAH), the 
flag is deteriorating from decades of exposure to light, air 
pollution and temperature fluctuations.

     "It gives me a feeling of great pride that a camera we 
developed to explore other planets is now exploring this 
historic artifact," said Dr. John Hillman, lead of the camera 
group at Goddard and NASA's representative on the Smithsonian 
team.  "The flag has never been viewed this way before, and 
we will see what cannot be seen with the unaided eye.  This 
exciting project is one of many practical applications for 
this imaging technology."

     AImS will take 72 separate images that will be pieced 
together using a computer to create a mosaic of the massive 
flag, which is 30 feet wide and 34 feet long.  Each image 
takes approximately 25 minutes to make and is composed of 200 
infrared wavelengths, or colors. 

     Infrared light is invisible to the human eye, lying 
beyond the red end of the visible portion of the 
electromagnetic spectrum.  A spectrometer in the camera will 
be used to separate the light and reveal its component 
wavelengths, similar to the way a prism separates visible 
light into a rainbow of colors.

     "Wool is the major component in the surface composition 
of the flag, and contaminants found on the surface of wool 
reflect infrared light differently than wool itself," Hillman 
explained.  "With AImS, we can identify where these 
differences are located on the flag.  We are looking for 
things that can't be seen easily, or at all, with the human 
eye, such as moisture and oils.  Moisture is of particular 
concern because, in the presence of light, it causes a 
chemical reaction that deteriorates wool."

     "I selected AImS because of its special ability to make 
an image with reflected infrared light," said Suzanne 
Thomassen-Krauss, chief conservator of the Star Spangled 
Banner Project at the NMAH.  "A typical infrared camera 
relies on thermal infrared, which is light emitted by an 
object due to its heat, but these cameras cannot identify 
contaminants on the flag because they are the same 
temperature as the flag itself."

     After the preservation effort is complete, the Star 
Spangled Banner will be returned to a newly renovated Flag 
Hall at the NMAH in Washington, DC.

     The AImS team is developing a demonstration camera for 
the Mars Instrument Development Program funded by NASA 
Headquarters.  Under this program, a camera using AImS 
technology could be a candidate for use on robotic Mars 
lander missions in 2005 and beyond.  The camera would be used 
to determine the mineral composition of Martian rocks.

     The camera also can be used to explore the invisible 
world here on Earth.  A cooperative agreement to use AImS in 
skin cancer research is in place with Goddard, Swales and 
Associates, Inc., and the Georgetown University Medical 
Center Department of Dermatology.  "We also have had 
preliminary discussions with the University of Arizona, 
Tucson, to use our camera to analyze prehistoric sites," said 
Hillman.

     In addition, Hillman may apply the camera in his 
personal efforts as a copyist at the National Gallery of Art, 
which involves detailed reproductions of classic art works to 
gain insights into the technique, motivations and intentions 
of the artist.

"AImS could permit a deeper understanding of a painting by 
revealing the underdrawing, which shows what the artist had 
in mind before applying the brush," Hillman said.  "Another 
potential application for this camera is to determine the 
pigment used in the paint, which can distinguish an authentic 
piece from a forgery."

     The AImS team includes Drs. Hillman and Glenar; Cheryl 
Vorvick and Chuck Peruso at Goddard; Dr. Nancy Chanover of 
the Astronomy Department at New Mexico State University in 
Las Cruces; Dr. Bill Blass of the University of Tennessee in 
Knoxville; and 
Dr. Jeff Goldstein of the Challenger Center for Space Science 
Education.

-end-