At 6 a.m. last Friday, Andy Chantrill, a 25-year-old software
designer, had just completed his 14th straight hour searching
for Steve Fossett, the millionaire aviator and adventurer who
vanished in northern Nevada on Sept. 3.
But Mr. Chantrill had not been hiking the rugged countryside
or flying over it in one of the many aircraft that have been
looking for signs of the small plane that Mr. Fossett piloted
without filing a flight plan.
No, Mr. Chantrill was in his flat in Castle Donington, England,
hunched over his laptop and scouring digital satellite images
of parts of the 17,000-square-mile search area where officials
believe Mr. Fossett's plane probably crashed.
Welcome to the new world of search and rescue.
Two Internet giants, Amazon.com and Google, have joined forces
to coordinate a "distributed search" on the Web where the latest
satellite pictures are being examined by a volunteer army of
more than 20,000 people around the world.
The search is made possible by Amazon's Mechanical Turk, an
interactive Internet application that enables potentially large
numbers of people to perform tasks online that are coordinated
by computers.
In the search for Mr. Fossett, Google has been providing satellite
images of the search area which have been reduced to manageable
size - quadrants representing 278 square feet, at a resolution
that makes them appear as if the terrain is being viewed from
a height of 1,500 feet.
The images are then distributed to volunteers who have registered
online to help with the search. Each image is reviewed by 10
volunteers, who have an hour to examine it on their computers.
If they see nothing, they check a box and move on to the next
image. If one of them spots something that merits closer scrutiny,
the information is passed on to search coordinators in Nevada.
Mr. Chantrill said: "Sometimes an image pops up. I see something
bright and interesting. My heart skips a beat and then sinks
when I realize that it's just farm machinery or something. I
don't know if I'm addicted. I am motivated."
Amazon first used its Mechanical Turk to assist a search operation
earlier this year for James Gray, a renowned Microsoft computer
scientist, who failed to return from what was to have been a
daylong solo sailing trip to scatter his mother's ashes in the
Pacific Ocean west of San Francisco.
He was never found, but the potential for the technology as
a search tool for missing vehicles, aircraft and boats took
hold among the scientists who helped.
Peter Cohen, the director of Amazon's Mechanical Turk application,
said he hoped that distributed searches would become more common.
The search for Mr. Fossett in some ways is a special case; he
is a wealthy and famous adventurer who has flown solo around
the planet in a balloon and holds the record for the longest,
nonstop airplane flight - more than 25,000 miles.
Nonetheless, Mr. Cohen said, "I still have an inherent belief
that people will care about what happens to other people and
there will always be a way to harness that concern."
In tandem with the high-tech search, aircraft have been crisscrossing
the Nevada mountains and desert for days. On Friday, about 20
planes went aloft and searchers on the ground spread across
six counties in Nevada and California. National Guard units
from the two states are also helping, at a cost of about $200,000,
and the all-volunteer Civil Air Patrol has expended about $12,000
in fuel, officials said. As of Friday, the search was still
on.
For all of the online legwork, though, sweat, shoe leather
and aircraft have proved more fruitful so far. Searchers on
the ground and in the air have discovered seven old airplane
crash sites in the Sierra Nevada, some decades old.
