every year millions of visitors come to
washington dc to tour the national
archives
the nation's largest storehouse of
historic documents
this year marks the constitution's 200th
anniversary and to help monitor the
aging process of this document and
others like the declaration of
independence and the bill of rights the
national archives recently installed a
space-age camera designed by nasa's jet
propulsion laboratory in pasadena
california the national archives came to
nasa
with the request for the for nasa to
take a look at what kind of technology
could possibly be used to provide a
long-term monitoring system that would
allow them to
have baseline information
that was taken at the beginning of the
monitoring period and then to be able to
follow in a very detailed fashion
the
fate of the documents over the next 50
to 100 years
chris stevens team led by ed miller
designed the national archives camera
adapting technology normally used for
deep space missions
the camera images the documents by
scanning under green light a handful of
pre-designated postage stamp size areas
in this case a practice target is used
instead of a real document
during each pass of the scanner a
million bits of digital information are
collected
the system has the capability of going
back year by year to the exact same spot
in order to make comparative studies of
the condition of the documents
in addition a whole variety of image
processing techniques can be used
in the case of the first two letters in
the constitution the w and e of we the
people
the black and white image can be color
enhanced to more easily see areas where
ink has flaked off the parchment
there are other needs for the system
according to norvel jones of the
national archives preservation
we have concern that
changes do happen when documents are
exhibited there can be fading or changes
in contrast or paper can darken
and by
getting a baseline reading before an
item goes on exhibit and then monitoring
it after exhibit and keeping records on
items that are frequently requested that
we'd be able to
tell changes that were occurring before
any serious damage it happened
the monitoring system can also be a
valuable tool for determining what type
of active measures to take in order to
save and stabilize a document or piece
of artwork
the imaging system represents a
down-to-earth use of technology
developed over the years for outer space
probes like voyager which used it to
capture incredible pictures of our
nearby planets norvel jones sums up
nasa's link with the past at the time
that the constitution was created
pen and ink on parchment was about the
most permanent and best that you can do
and i think now in
honor of the 200th anniversary of the
constitution were able to use what is i
think now the best that you can do in
terms of
uh wrapping up new technology in order
to be able to assure that the documents
last not only 200 years longer but 2 000
years as long as we can imagine