In last month's issue, I summarized what we know about Saturn's moon,
Titan, and how the amazing discoveries by the international Cassini-Huygens mission over the last decade have transformed our view from a
blotchy dot in the sky into a fantastically diverse Earth-like world, with
vast equatorial deserts of giant organic sand dunes, and polar seas of
liquified natural gas. It is a world exotic, and yet familiar.
38 SERVO 06.2015
How I Came to Design
Titan is an easy place to explore. Unlike Jupiter’s moon, Europa, Titan does not expose spacecraft to severe radiation which can fry electronics in days. Also, whereas airless moons like Europa require
heavy and expensive rocketry and guidance to soft-land,
Titan has a giant soft cushion of an atmosphere. With
simple heat shields and parachutes, it is straightforward to
deliver hardware to Titan’s surface from space, and the
thick atmosphere and low gravity makes Titan a much
easier place to fly than Mars. While Mars’ entry and
descent is sometimes called ‘six minutes of terror,’ it is more
like a couple of leisurely hours on Titan. Titan’s only
challenge is that it is a billion miles away!
For 20 years or more, scientists have advocated various
ways to explore Titan — and there is almost no vehicle you
can imagine that wouldn’t work somewhere on this planet.
Rovers, hot-air balloons, landers, hovercraft, helicopters —
you name it. Take a robot helicopter from Earth to Titan,
and it could hover with only about a thirtieth of the power
needed to hover on Earth, for example.
There’s lots on Titan to explore — as the solar system’s
only just second largest moon (after Jupiter’s, Ganymede),
it has a huge area of terrain with river channels, mountains,
possibly ice volcanos, sand dunes, and, of course, the seas.
It is the three seas (Figures 1 and 2) — Kraken, Ligeia, and
Punga Mare — and the many small lakes that have attracted
the most attention from scientists since their discovery in
We know from just what few compounds are liquid at
Titan’s cold temperatures that they must be made mostly of
methane and ethane — the two main constituents of
natural gas on Earth. What we don’t know is in what