Abstract
The Moon and Mars have strong regional crustal magnetic fields as shown
by the observations of orbiting spacecraft. These crustal magnetic
fields indicate that a core dynamo was present in the past, and it is
believed that rocks formed from cooling lava retain a memory of the
strength and orientation of the magnetic field that existed during their
solidification. However, a major hurdle in understanding the crustal
magnetic field structure is the low spatial resolution limited by the
altitude of the orbiting spacecraft. Rovers are well suited for
exploring the detailed structure of the crustal magnetic fields, but
they also present a technical challenge due to the necessity that
sources of magnetic interference from the rover be removed from the
measurements. We designed a compact rover dedicated to measuring the
detailed spatial distribution of the surface magnetic field. The rover
is equipped with an array of magnetic sensors mounted in a rectangular
grid that aims to differentiate the rover components’ own magnetic
fields from the ambient magnetic field. Another magnetic sensor is
placed on top of an extendable arm to provide additional measurements
for verifying the ambient magnetic field inferred from grid-point
measurements. The rover consists of four wheels, a Raspberry Pi
single-board computer, control circuitry, and a chassis that holds the
magnetometers in a rectangular array. In the prototype of the rover,
commercial small-scale microelectromechanical systems (MEMS)
magnetometers are used for magnetic field measurements. The test results
from these design features can provide a useful reference for future
lunar or Martian surface missions with rover-based experiments that
measure crustal magnetic fields.