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atmospheres composed mostly of nitrogen. Earth’s atmosphere has a
few percent of water vapor, which makes all the difference; where would
we be without rain? Titan’s atmosphere has a few percent of methane,
natural gas, and because Titan is so far from the sun – and thus very
cold – this gas falls as rain. As water matters on earth, so methane mat-
ters on Titan, which, as a result, has rivers, lakes, and an ocean of liquid
methane the size of Lake Superior.
The NASA Jet Propulsion Laboratory is planning to explore Titan in a
mission, due to launch in 2018 – and to arrive in 2025. Tim Colonius,
Professor of Mechanical Engineering at Caltech, has made a mathemati-
cal simulation of a Titan-bound balloon. The idea is that a balloon for Titan
would do exactly the same job as a Rover on Mars. Instead of traveling
a few miles a year, as the rovers do, a balloon, by comparison, could fly
completely around Titan in perhaps six months, while traveling ten thou-
sand miles, propelled and steered by Titan’s winds. Up until a few months
ago, the idea of using a balloon in the atmosphere of Titan was only a
mathematical possibility; in reality, no one knew if a balloon could fly in
the extreme cold atmosphere of Titan.
I was determined to prove it could.
Because Titan is so distant from the sun, the atmosphere is very cold
– cold enough that methane falls as rain – and it is very dense. These
conditions are far, far removed from those in which any balloon has ever
been flown. So I developed the idea of a Titan Sky Simulator and was com-
missioned by JPL to design and build it.
With a small team, consisting mainly of UCSB sophomores Michael
Arnold and Brian Kerr, we built a structure in a warehouse in Goleta and
duplicated the atmosphere of Titan inside. Next, we flew a working proto-
type Titan hot air balloon within the structure’s simulated atmosphere. No
balloon has ever been flown below -70 degrees Celsius (-94 Fahrenheit),
as that is the coldest it gets in Earth’s stratosphere. On June 8, 2008, my
balloon flew inside the simulator at a record -170C (-274F), approxi-
mately the temperature of Titan.
Collecting fundamental engineering data flying at this low temperature
was the first practical step towards the ultimate launch of a Titan balloon.
The single most important thing my team and I are doing is getting funda-
mental engineering data to confirm that the mathematical computer simu-
lation could work. Now we can quickly test any idea for a Titan balloon.
In addition to Caltech’s Professor Colonius, Professor Phil Lubin, UCSB
head of the Department of Experimental Cosmology, is also interested in
this work; and I feel it is highly likely there will be some collaboration and
a continuing association here in Santa Barbara.
Even a journey to the stars begins with a single step, and this time,
one of those early steps has already been taken, right here in Santa
Barbara.
• • •
Because Titan is so distant from the sun, the
atmosphere is very cold – cold enough that
methane falls as rain – and it is very dense
• • •
This is an actual picture of
Titan, seen with Saturn’s
rings in the foreground
(source: NASA Jet
Propulsion Laboratory and/
or The European Space
Agency)
Dramatic illustration is a just-released artist’s
impression of how Titan’s lakes might look,
based on the latest scientific data (courtesy
of Jet Propulsion Laboratory, Pasadena)