  Semiautonomous rover scaling is examined for exploration throughout the solar
system. Communications to a relay orbiter is a major constraint, due to power
requirements and decreasing antenna gain at small sizes. Also, analysis time
scales adversely for power hungry Raman or surface abrasion, and also for low
photon count gamma ray spectroscopy. 1 cm scale rovers with a MER like
capability should be possible, and could operate on solar power to 40 AU. At 2
cm, rovers powered by current RTGs are feasible, and are useful in the outer
solar system. Such rovers will return images, autonomously navigate from
interest point to interest point, and autonomously deploy instruments. Analyses
include elemental APX and gamma ray spectroscopy for elemental and Raman and IR
spectroscopy for molecular and or mineralogical compositions. They can be built
with current technology, the component size is similar to watch movements. Low
temperatures are not an obstacle. Very high temperatures, e.g. 390 to 480 C for
surface Venus, will require more work on high temperature electronics, but
current work suggests that dense ICs for Venusian conditions should be feasible
in the near future. Mm size rovers, designed primarily for imaging, are
feasible at inner solar system solar flux levels. If deployed in large numbers,
manufacturing developments would be needed to allow mechanised assembly of
multiple MEMS systems. Miniature, degassing to space, RTGs could provide power
in cold vacuum environments, as could advanced betavoltaic systems, though much
work would be required to develop the latter.
