Conversation with Dr. Ed Stone
and colleagues discuss Voyager findings.
exploration days began in 1961 with his first cosmic-ray experiments
on Discoverer satellites. He has been a principal investigator
on nine NASA spacecraft missions and a co-investigator on
five other NASA missions. One of his most famous contributions
to space exploration is his continuing role as project scientist
for the Voyager mission, whose twin spacecraft studied Jupiter,
Saturn, Uranus and Neptune between 1979 and 1989. The Voyagers
are still traveling in space and are expected to continue
returning scientific information as they reach the outer bounds
of our solar system in the next few years.
will return fulltime to Caltech as a professor and scientist,
and a researcher still reaping the riches of Voyager data.
For either Voyager or other JPL missions, what has surprised
you the most in terms of scientific discoveries?
A: If I had to pick one surprise that stands out on
Voyager, it would be the volcanoes on Io
[one of Jupiter's
. Finding a moon that's 100 times more active volcanically
than the entire Earth, it's really quite striking. And this
was typical of what Voyager was going to do on the rest of
its journey through the outer solar system. This was really
look at the surprises
us at Jupiter, such as finding a magnetic field on Ganymede
[a Jovian moon]
and showing us up close that there's likely
an ocean beneath the icy crust of Europa
[another Jovian moon]
And Mars Global Surveyor has really rediscovered Mars for
us, with the discovery of gullies on canyon walls, which was
not expected at all since it was believed water was frozen
kilometers beneath its crust.
also expect there will be a lot to learn from the first digital
topographic map of Earth that will be produced from the Shuttle
Radar Topography Mission.
artist's concept shows Stardust, which will be the
first spacecraft mission to return cometary particles
What stands out for you when you think about the past decade?
A: It's hard to imagine a more exciting decade than
we've had. We have had many successes, and the level and the
pace of innovation at the Laboratory has dramatically increased.
The one thing I'm most pleased about is the fact that the
Laboratory continues to be the leading innovator in space
in this new era of going more often, landing and eventually
bringing samples back to Earth. For example, we have samples
coming back from a comet in 2006 from the Stardust mission;
this summer, we'll launch Genesis, which will bring back a
sample of the Sun.
What were the lessons learned from the Mars '98 losses?
A: We were changing to a new era of missions, and we
found the limit. We tried to do two missions for the price
of Mars Pathfinder, and it was just too hard.
future of Mars exploration may include "smart
landers," like the one shown in this artist's
learned a lot from this and have put in place new processes
and a better safety net so that today's project teams won't
face the same limitations as we had with Mars '98. We will
continue doing missions more often in this new era, but do
them in a robust way.
How do you see JPL beyond the next 10 years into the future?
A: Well, the next era might be going and staying, building
a permanent robotic base of operations elsewhere in the solar
system, which through modern communications is as accessible
as any place here on Earth. So what's out there becomes, effectively,
back here. JPL could be a key factor in realizing such an
era, which, I think, is a bridge to eventual human exploration
of the bodies in the solar system.