the resource processing
plant with some 40 pounds
of lunar soil.
Devising a robot for
such demands called for
numerous innovations, and
the team says it has at least
one major decision to make
before it begins construction
of the second generation
RASSOR prototype: keep
going with tracks like those
that tanks use or switch to
The tracks showed some
flaws in recent testing,
mostly relating to pebbles
and sand particles clogging
the gears and making the
track slip off. The group tried out
RASSOR on several surfaces at Kennedy,
including the crushed river rock dug up
from the crawlerway. The rock — even
though pulverized by the gigantic
crawlers — is not a great substitute for
lunar soil, the engineers explained. As
long as the robot handles that matter
well, however, they say they know it will
manage whatever the Moon soil offers.
Part of the problem (also mentioned)
might be the rubber material the tracks
are made of. A lunar version of the robot
would use a different material, possibly
metallic. For example, the lunar rover the
astronauts drove on the surface used
wheels made of stainless steel springs
rather than rubber. (SERVO examined this
topic in the article, Dust In The Wheels in
the June 2011 issue).
The team already is designing
RASSOR 2 — a prototype that would be
much closer to what NASA could launch
in the future. It’s expected to begin
testing in early 2014. SV
FIGURE 3. The RASSOR can climb over a large obstacle, such as a
boulder on the moon. Engineers on Earth used a stepping stool
to challenge the robot.
FIGURE 4. In the Lunar Regolith Challenge, Embry Riddle's
Prescott team adapted a novel "bucket drum"
technique originally concepted by NASA.
Photo courtesy of Joe Jacoby.
SERVO 04.2013 73