By Ken Kremer, AAAP, Spaceflight magazine & The Planetary Society
NASA’s twin Mars rovers Spirit and Opportunity surely rank as one of the greatest triumphs in the history of space exploration. Seven years ago this month the dynamic duo landed on opposite sides of the Red planet on Jan. 3 and Jan. 24, 2004. They were originally designed to operate for just 90 Martian days, or sols, with an outside possibility they might last a few months longer.
In actuality – during the extended mission phase – they have endured light years beyond the mere 3 month “warranty” proclaimed by NASA as the mission began with high hopes following the nail biting “6 minutes of terror” as the twins plunged through the Martian atmosphere and with no certainty as to the outcome of the landing.
Since 2004, the rovers longevity has far exceeded all expectations and no one on the science and engineering teams that built and operate the twins can believe they lasted so long and produced so much.
Spirit and Opportunity have accomplished a remarkable series of scientific breakthroughs, far surpassing the wildest dreams of all the researchers and NASA officials. Indeed both rovers are currently positioned at scientific goldmines on the red planet’s surface.
Opportunity is still alive and trekking across the Martian plains, now 84 months into the 3 month mission. By the time of her last dispatch from Gusev crater, Spirit had lasted for nearly six years of bonus mission time.

Photo 1: Spirit’s Last Picture Show - for now. Spirit’s final panoramic mosaic was taken on Sol 2175 in February 2010, a few weeks before entering hibernation mode in March 2010. Credit: NASA/JPL/Cornell, Marco Di Lorenzo, Kenneth Kremer
Spirit last communicated with mission controllers back on Earth on March 22, 2010. The rover had entered hibernation mode as the autumn sunlight available to power her life giving solar arrays was diminishing. NASA hopes to reawaken Spirit from a long slumber and reignite her illustrious campaign of exploration and discovery.
No one is giving up hope for Spirit and NASA is stepping up operational efforts to contact the plucky rover since the amount of Springtime Martian sunlight is now increasing over the next few months.
Although Spirit has been stalled at a place called ‘Troy’ since April 2009. she made a significant science discovery at that exact spot. Spirit examined the soil in great detail and found key evidence that water, perhaps as snow melt, trickled into the subsurface fairly recently and on a continuing basis. Our photomosaic herein shows the very last panoramic view taken by Spirit at ‘Troy’.
While driving on the western edge of an eroded over volcanic feature named ‘Home Plate’, she broke through a hard surface crust (perhaps 1 cm thick) and sank into hidden soft sand beneath. At ‘Troy’, Spirit discovered that the crust was comprised of water related sulfate materials and therefore found further evidence for the past flow of liquid water on the surface of Mars – a great science discovery!

Photo 2: The Long Journey of Opportunity: This collage of two maps and a new close up panorama of Santa Maria crater (bottom right) shows the route traversed by the Opportunity Mars rover during her 7 year long overland expedition across the Meridiani Planum region of Mars. Opportunity arrived at the rim of Santa Maria Crater on Dec. 16, 2010 on Sol 2451. The mosaic of Santa Maria at bottom right was taken by Opportunity about 5 meters from rim on Sol 2451. Credit: NASA/JPL/Cornell, Marco Di Lorenzo, Kenneth Kremer. This map mosaic published in the Jan. 17, 2011 issue of Aviation Week & Space Technology magazine, p. 45.
Meanwhile, Opportunity is blazing a trail of discovery in the Meridiani Planum region of Mars. She is currently exploring the stadium sized Santa Maria Carter which holds deposits of water bearing minerals that will further elucidate the potential for habitability on the Red Planet.
The rover arrived at the western edge of the relatively fresh impact crater on Dec. 16, 2010 (Sol 2451). This intermediate stop on the rover’s 19 km long journey from Victoria Crater to giant 14 km wide Endeavour Crater will provide important ground truth observations to compare with the orbital detection of exposures of hydrated sulfate minerals.
Opportunity is driving to different vantage points around the steep walled crater and snapping a series of gorgeous Martian vistas. The rock-strewn crater is a Martian geologists dream. The robot was imaged on New Years Eve in exquisite high resolution from Mars orbit while parked at the sharp edge as she was simultaneously snapping a multitude of awesome views peering inside the stunning and scientifically interesting crater.
Santa Maria is just 6 km from the western rim of Endeavour which shows spectral signatures of phyllosilicates, or clay bearing minerals, which formed in water about 4 billion years ago and have never before been directly analyzed on the Martian surface.

Photo 3: Opportunity’s surface view of Santa Maria on New Years Eve Dec 31 while being photographed overhead from Mars Orbit. Opportunity took this panoramic mosaic just meters from the crater rim on Dec. 29, 2010 (Sol 2464). Note rover tracks near rim at left, relatively clean solar panel at right and numerous ejecta rocks. Credit: NASA/JPL/Cornell, Kenneth Kremer, Marco Di Lorenzo.
Phyllosilicates form in neutral aqueous conditions that could have been more habitable and conducive to the formation of life than the later Martian episodes of more harshly acidic conditions in which the sulfates formed, that Opportunity has already been exploring during her 7 year long overland expedition.
Opportunity remains healthy and has abundant solar power for the final leg of the long eastward march to Endeavour which will resume in mid-February and should arrive at later in 2011.
Read more in my new 7 Year Anniversary stories online at Universe Today:
http://www.universetoday.com/82784/7-years-of-opportunity-on-mars-and-a-science-bonanza/
http://www.universetoday.com/82293/nasa-redoubling-efforts-to-contact-spirit/
Read my cover story about the Mars Rovers and Robonaut R2 in the Feb 2011 issue of Spaceflight magazine: http://www.bis-spaceflight.com/sitesia.aspx/page/184/id/2318/l/en-gb,en-gb,en-us
Please contact me for more info or science outreach presentations:
Email: kremerken@yahoo.com website: www.kenkremer.com
Editors Note: Ken and Marco’s panoramic photomosaic entitled “Opportunity at Santa Maria Crater” was featured on Astronomy Picture of the Day on January 29, 2011. Congratulations guys!!