American Aerospace


Rare Opportunity


Seven years ago this week, NASA’s Mars Exploration Rover (MER) Opportunity landed at Meridiani Planum on the surface of the planet Mars.  Incredibly, the robotic rover continues to gather geological, atmospheric and astronomical data well beyond its design mission duration of ninety (90) Martian days. 

Mars is the 4th planet out from the Sun.  It has a diameter a little more than half that of Earth.  The duration of a day on Mars is a little more than that on Earth.   However, a Martian year is 88% longer than a terrestrial year.  While nebulous in comparison to the Earth, Mars has an atmosphere.  Atmospheric temperature ranges from -190F to +98F.

Mars has always been a source of curious speculation by we Earthlings.  Does or did Mars ever have water?  Does or did Mars ever have life in any form?  The quest to answer these and related questions has resulted in significant exploration of the Martian space, atmosphere and surface by robotic space vehicles sent from the Earth.

In 1976, Viking 1 and Viking 2 became the first American spacecraft to land on the surface of Mars.  In July of 1997, the Mars Pathfinder became the first successful United States robotic rover.  While a spectacular accomplishment, that first rover’s exploration capabilities and science output were modest.  Something more substantial was required to provide a quantum leap in our understanding of Mars.

That something was the Mars Exploration Rover (MER) of which there would be two (2) copies.  MER-A (Spirit) and MER-B (Opportunity) would be targeted to opposite hemispheres where each rover would investigate Martian geology up-close and personal.  Each was configured with a sophisticated suite of scientific equipment for doing so.  Together, the rovers were destined to provide the most detailed investigation of Martian geology in history.

Each MER weighs 408 lbs and measures 7.5-feet in width, 4.9-feet in height and 5.2-feet in length.  Six (6) independently-driven wheels provide for rover locomotion and hill-climbing.  Vehicle systems are typical with provision made for power generation, storage and distribution, vehicle guidance, navigation and control, data management, communication, and thermal control.

MER-A (Spirit) was launched on Tuesday, 10 June 2003 from SLC-17A at Cape Canaveral.  Following a nominal entry and descent, the rover landed near Gusev Crater at 04:35 Ground UTC on Sunday, January 4, 2004.  MER-B (Opportunity) was launched on Monday, 07 July 2003 from SLC-17B at Cape Canaveral.  MER-B safely landed near Meridiani Planum at 05:05 Ground UTC on Sunday, 25 January 2004.

Both MER vehicles have produced images of and obtained scientific data on a myriad of Martian geologic features as they have roamed the region around their respective landing sites.  They have operated for several thousand days beyond their 90-day design mission.  That stunning success is due in great measure to the talented and dedicated mission operations and science teams back here on Earth.

In truth, any attempt to accurately synopsize here the myriad discoveries and scientific contributions of Spirit and Opportunity does both a disservice.  Thus, to better grasp and appreciate the true scope and character of their incredible achievements, the reader is hereby invited to visit the following URL: 

Spirit was last heard from officially on Monday, 22 March 2010 (2,210 Mars days on the surface).  The senior rover had traveled 4.8 miles during its many exploratory surface roamings.  It is suspected that the vehicle is hibernating due to seasonally-low solar power levels.  The hope is that Spirit will revive from its cold winter slumber when spring arrives this March at Gusev Crater. 

As for Opportunity, it continues to continue!  As of this writing, the junior rover is conducting a site survey at Crater Rim.  It has been on the surface for 2,489 Mars days and has traveled in excess of 16.5 miles.  Where this marvelous story ends is not clear at present.  However, we do not have to wait for the day when MER-B finally goes silent to realize what has long been apparent; our noble exploratory marvel has afforded us a rare Opportunity indeed.

Categories: Aerospace, History
J. Terry White

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