DARE for Planetary Exploration

ALTADENA, CA Balloons outfitted
with innovative steering devices and robot probes could
be the future of planetary exploration. Dr. Alexey Pankine,
a fellow at the NASA Institute for Advanced Concepts
(NIAC), presented an analysis of balloon applications
for planetary science at the World Space Congress in
Houston, Texas last month. His study, entitled Directed
Aerial Robot Explorers or DARE, is funded by NIAC

At the center of the DARE concept are balloons that
can float in planetary atmospheres for many days. Balloons
have long been recognized as low-cost observational
platforms and are routinely used in observations of
the Earth’s atmosphere. In 1984, two balloons
were successfully deployed in the atmosphere of Venus
for a short mission. However, what has restrained the
wider use of balloons in planetary exploration was the
inability to control their paths in strong atmospheric
winds. Attaching an engine to a balloon would convert
it into an airship and make it too heavy, too power
dependent and too expensive to send to another planet
or high into the atmosphere.

Faced with this problem, Global Aerospace Corporation
has proposed to use an innovative device called the
StratoSail® that allows the user to control the
path of a planetary balloon. The device is essentially
a wing that hangs on a long tether (several kilometers)
below the balloon. Strong winds and denser atmosphere
at the wing altitude create a sideways lifting force
that pulls the entire system across the winds.

The DARE concept analyzes the use of the StratoSail®
device on several planets in our Solar System that have
atmosphere – Venus, Mars, Jupiter and Titan (a
satellite of Saturn). Dr. Pankine reports that a small,
light wing will pull the balloon with a velocity of
about 1 m/s across the winds on those planets. This
may not seem much, but applied constantly (without consuming
any power!) for the duration of a long mission (100
days) it would allow for pole-to-pole exploration of
the atmospheres of Venus and Titan, and targeted observations
of Mars and the vast Great Red Spot of Jupiter.

DARE platforms would carry high-resolution cameras
and other instruments to study surfaces and atmospheres
of the planets. Dr. Pankine envisions small probes being
deployed from DARE platforms over a site of interest.
These robot-probes would, for example, analyze atmosphere
during their descent on Venus and Jupiter or crawl around
after soft landing on the surfaces of Mars and Titan.

“The ability to alter the flight path in the
atmosphere and to deploy the probes would vastly expand
the capabilities of planetary balloons and make possible
breakthrough observations that are not feasible with
any other platform,” says Dr. Pankine. The figure
illustrates a DARE platform operating at Venus.