The exploration of Mars has become a high-priority goal for the U.S. space agency, NASA.  Recent high-resolution images from spacecraft orbiting the planet indicate that liquid water may once have flowed there, and perhaps it still occasionally does.  The presence of liquid water suggests the possibility of life, either now or in the past.  This exciting prospect has spurred great interest in taking a closer look directly on the Martian surface itself.

Thus, on June 10 and July 7, 2003, NASA launched on separate Delta II rockets two identical Mars Exploration Rovers (MER).  For several months they coasted nearly halfway around the Solar System while orbiting outward.  On January 3 and 24, 2004, they landed using airbags at two different locations on opposite sides of the planet.  MER-A (named Spirit) landed in Gusev Crater, thought to have once been a large Martian lake.  MER-B (named Opportunity) landed on Meridiani Planum, thought to have once been a Martian sea.  After emerging from their landing enclosures (which were of no further use), these six-wheeled robotic geologists embarked on an extended period of exploring and data gathering.  The results so far at both locations indicate that Mars indeed once did have large amounts of liquid water.  Early in its history, Mars was a much warmer and wetter place than it is today.  At the time of this writing, after more than an Earth-year on Mars, both rovers are still healthy and active.  Their mission has been very successful and is still continuing.

A major part of a rover's scientific and engineering equipment are its cameras (its electronic eyes).  On each rover, there is a total of 9 cameras, each having one of four different lens types.  The cameras serve two functions.  First, they allow people on Earth to see what is out there for scientific evaluation and discovery.  Second, the operation of the rovers combines Earth-based control and target selection with on-board autonomous navigation.  The rovers must be smart enough to avoid getting into trouble.  Crucial for success (even survival) is their being able to see what is around them as they roam.  These spacecraft are prime examples of machine vision plus state-of-the-art artificial intelligence coordinated with a little help from Mission Control back home on Earth.

The author was privileged to have been asked to design all four lens types for these cameras.  They are described here to illustrate how the classic camera lenses can be successfully adapted to new and different applications in sometimes very exotic situations.