A thousand years from now NASA's Deep Space
1 probe could make some archeologist very happy.
by Dr Tony Phillips
"We've got it in the
tractor beam, doctor!" called the pilot. "It's a small spaceship
- an old one by the looks of it."
"About a thousand years old, if
I'm right," replied the archeologist. "Will it fit in the cargo
hold? Beam it aboard, I want to take a look."
The air shimmered and the craft
materialized, suspended in midair. It was a boxy cylinder, about
the size of a person, with wings stretching 10 meters from tip-to-tip.
"Primitive solar arrays," he nodded. The walls of the craft were
blackened from long exposure to space radiation. There was one big
dent, as if the craft had strayed too close to an active comet,
and lots of tiny pits-a thousand years' worth of micrometeoroid
A genuine ship from the Early Space
Then he noticed a puffed-out
spot in the insulation, and a flap. Something was in there.
He reached inside and pulled out a compact disk. Scrawled across
it in marker pen were the words: Deep Space 1...
"That's how I imagine it will happen,"
says Marc Rayman, the project manager of NASA's Deep Space 1 (DS1)
mission, who tucked the CD inside his spacecraft just before it
was launched in 1998. "The CD is a time capsule," he explains. "It
contains information about the spacecraft and its mission, some
personal messages from our team and more than 800 drawings made
by schoolkids depicting what they think life might be like 1000
years from now."
In the next millennium, he says,
elementary students may send probes to other stars as science fair
projects. In such an advanced era, "archeologists will be very interested
in how we solved our engineering problems back in the late 20th
Problem-solving is what Deep Space
1 is all about.
Deep Space 1 is carrying 800 drawings by 20th-century
schoolkids; this is one of them. See the complete
collection at JPL's Space Place.
Its mission, sponsored by NASA's New Millennium
Program, was to test 12 cutting-edge technologies. Among them: an
experimental ion engine, a solar array that focused sunlight for
extra power, and an autopilot with artificial intelligence. "There
was a good chance DS1 wouldn't work at all; there were so many untried
systems on board," recalls Rayman.
Nevertheless, all 12
technologies checked out. They worked so well, in fact, that NASA
soon approved an extended mission, which Rayman and colleagues had
dreamed up even before DS1 left Earth - a visit to a comet. In Sept.
2001, with its technology tests completed and nothing to lose, DS1
swooped past the furiously evaporating nucleus of Comet Borrelly.
"We thought the spacecraft might be pulverized," recalls Rayman,
but once again DS1 defied the odds. It captured the best-ever view
of a comet's heart and emerged intact.
After the comet encounter,
the DS1 team conducted a few more technology tests. (That was the
"hyper-extended mission," says Rayman.) But time was running
out. In December 2001, DS1 had been operating three times longer
than originally planned, and it had nearly exhausted its supply
of hydrazine - a thruster-gas used to keep the solar arrays pointed
toward the Sun. Controllers had no choice but to deactivate the
The mission was over.
Or was it?
"I think of it as the
beginning ... of the archeology mission," laughs Rayman. "DS1 is
still going around the sun in a roughly circular orbit between Earth
and Mars - perfect for a time capsule."
space probes will never be recovered. The Voyager spacecraft, for
example, were flung out of the solar system by encounters with Jupiter
and Saturn. Ditto for Pioneer 10 and 11. Galileo will crash into
Jupiter next year - a deliberate move designed to protect possible
life on Jupiter's moon Europa from terrestrial contamination. And
Mars orbiters like Viking 1 and 2 will eventually disintegrate in
that planet's atmosphere.
highest-resolution photo of Comet Borrelly's nucleus,
which spans about 8 km from end to end and looks much
like a bowling pin.
Compared to those others,
the orbit of Deep Space 1 is stable and accessible.
with Mars and Earth, which happen every few years, and the gentle
push of sunlight will act to change the orbit over time - but not
much," says Jon Giorgini of the JPL solar system dynamics group.
"Using a simple solar radiation pressure model, I integrated the
orbit to the year 3002 AD. The orbit's eccentricity, perihelion
distance, and inclination will be about the same then as they are
"I can't say, however,
on which side of the Sun the spacecraft will be in 3002 - so the
archeologist might have to hunt around a bit." Just enough, perhaps,
to add to the thrill of discovery.
And when it's found?
"I think it'll go straight to the Smithsonian," predicts Rayman.
"The only real question is this: the Smithsonian branch on Earth
â€¦ or the one on Mars?"
does not have an "official" Deep Space 1 "archeology"
mission. It just happens that DS1 is well-suited for some future
archeologist to recover. Why 1000 years from now? It seemed appropriate
because DS1 is sponsored by the NASA's New