Mars Rovers Spirit, Opportunity Exceeded Expectations

By Bob Granath

Androids rolling along distant planets were once only the stuff of science fiction. However, in recent years, mechanized trailblazers have become NASA’s precursors to human explorers. Among the most successful was the twin Mars Exploration Rovers (MERs), known as Spirit and Opportunity. Both far exceeded expectations for their work on the Red Planet.

The Mars Exploration Rovers were designed to search for and characterize a wide range of rocks and soils that hold clues to past water activity on Mars. Mission planners initially hoped the two rovers would operate for 90 Martian days, or sols. The term sol refers to the duration of a solar day on Mars, equal to 24 hours and 39 minutes on Earth.

What followed went far beyond expectations. After 90 sols, both MER-A (Spirit) and MER-B (Opportunity) still had plenty of life, and multiple mission extensions kept Spirit functioning until March 22, 2010. Opportunity last contacted NASA on June 10, 2018 having traveled more than 28 miles across the Martian surface.

“The two rovers are a testament to NASA ingenuity and the confidence and investment the American people have placed in their space program,” NASA Administrator Charlie Bolden said remarking on the rovers’ longevity in 2014. “Together, these amazing robots will go down in history for their tenacity and their many findings.”

Naming the Rovers

Names for the twin robotic explorers were selected through a contest with nearly 10,000 essays submitted by children. NASA, the Planetary Society in Pasadena, California, and the Lego Company, a Denmark-based toymaker, sponsored the contest. Prior to the launches, then NASA Administrator Sean O’Keefe announced that 9-year-old Sofi Collis of Scottsdale, Arizona wrote the winning entry. She was born in Siberia, but was adopted at age two and brought to the United States.

“I used to live in an orphanage,” Collis wrote. “It was dark and cold and lonely. At night, I looked up at the sparkly sky and felt better. I dreamed I could fly there. In America, I can make all my dreams come true. Thank you for the ‘Spirit’ and the ‘Opportunity.’”

Preflight processing for MERs A and B began in early 2003 as the hardware began arriving at NASA’s Kennedy Space Center. Preparations included testing of the 410-pound spacecraft inside the spaceport’s Payload Hazardous Servicing Facility. The rover systems were given thorough checkouts for mobility and maneuverability. During this time, engineers and scientists at Kennedy worked closely with counterparts from the Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology in Pasadena, California, where the Mars Exploration Rover project was developed.

During April and May 2003, Delta II Heavy launch vehicles were stacked at Cape Canaveral Air Force (now Space Force) Station’s Launch Complex Pads 17-A and 17-B. Spirit launched on June 10, 2003, and Opportunity followed on July 7, 2003.

Sheryl Bergstrom, manager of JPL’s resident office at Kennedy, had high praise for the Kennedy launch team.

“Members of the spacecraft team are to be credited for their efforts,” she said.

Albert Sierra, of Kennedy’s Launch Services Program (LSP) Mission Management office, also complimented the joint effort.

“The team worked closely together nearly three years on the integration and launch activities for both missions,” he said.

Following their seven-month trip to Mars, the rovers landed in widely separated equatorial locations on the Red Planet. Spirit successfully touched down on Jan. 3, 2004, at Gusev Crater, a Connecticut-size basin that appeared to have once held a lake. For Opportunity, NASA chose a location halfway around the planet from its counterpart. The second rover arrived three weeks later, on Jan. 24, in a broad plain named Meridiani Planum. The second site’s selection was based on a different type of evidence for a possibly watery past. Since experts consider water to be a requirement for living organisms, areas that once contained water are considered likely locations for evidence of past life forms.

“The instrumentation onboard these rovers, combined with their great mobility, will offer a totally new view of Mars, including a microscopic view inside rocks for the first time,” said Dr. Ed Weiler, then NASA’s associate administrator for Space Science.

Omar Baez, who was Kennedy’s Mars Missions launch director, now LSP launch director, put the landings in perspective.

“The hard geological science of reaching out and touching, drilling and analyzing the Martian surface is another stepping stone in exploring the universe,” he said.

Hitting the Jackpot

It didn’t take long to make the first important discovery, with Opportunity hitting the jackpot early. It landed close to a thin outcrop of rocks. Within two months, its versatile science instruments found evidence in those rocks that a body of salty water deep enough to splash in once flowed gently over the area. Preliminary interpretations point to a past environment that could have been hospitable to life and also could have preserved fossil evidence of it.

Scientists evaluating data from Spirit later identified a water-signature mineral called goethite in bedrock, one of the mission’s surest indicators yet for a wet history on Spirit’s side of Mars. Goethite forms only in the presence of water, whether in liquid, ice or gaseous form.

“Goethite, like the jarosite that Opportunity found on the other side of Mars, is strong evidence for water activity,” said Dr. Goestar Klingelhoefer of the University of Mainz, Germany, lead scientist for the iron-mineral analyzer on each rover, the Moessbauer spectrometer.

In April 2004, the two mobile robots successfully completed their primary 90-sol missions on opposite sides of Mars and went into bonus overtime work. Spirit went on to function effectively over 20 times longer than NASA planners expected. After becoming stuck in the soft Martian soil, the rover continued in a stationary science platform role until communication with it stopped on March 22, 2010. Spirit traversed 4.8 miles instead of the planned 0.4 mile, allowing more extensive geological analysis of Martian rocks and planetary surface features.

When Opportunity last contacted NASA in 2018, JPL’s Mars Exploration Rovers website reported that had traveled just over 28 miles, surpassing the longest distance driven by a vehicle on another world. The record previously was held by Russia’s Lunokhod 2 rover that traveled 23 miles on the Moon during 1973.

Mars Exploration Program

The missions of Spirit and Opportunity were part of NASA’s Mars Exploration Program, which includes three previous successful landers, the two Viking landers during 1976 and the Mars Pathfinder probe in 1997. The Mars Science Laboratory, known as Curiosity, joined its counterparts on the Red Planet on Aug. 6, 2012. On Sept. 22, 2014, NASA’s Mars Atmosphere and Volatile EvolutioN, or MAVEN, spacecraft began orbiting the planet to study its upper atmosphere.

On Feb. 18, 2021, NASA’s Perseverance rover successfully touched down on Mars and promptly began beaming back detained images and science data from the Red Planet. About the size of a car and weighing 2,263-pounds, Perseverance acts as robotic geologist and astrobiologist. A fundamental part of its mission is astrobiology, including the search for signs of ancient microbial life. The rover is investigating rock and sediment of Jezero’s ancient lakebed and river delta to characterize the region’s geology and past climate.

JPL Director Michael Watkins believes the Perseverance landing is another step toward landing humans on the Red Planet.

“Landing on Mars is always an incredibly difficult task and we are proud to continue building on our past success,” he said. “But, while Perseverance advances that success, this rover is also blazing its own path and daring new challenges in the surface mission. We built the rover not just to land but to find and collect the best scientific samples for return to Earth, and it’s incredibly complex sampling system and autonomy not only enable that mission, they set the stage for future robotic and crewed missions.”

No copyright is claimed for this feature that appeared in their original form on NASA.gov on Jan 9, 2014 at:

https://www.nasa.gov/content/nasa-celebrates-decade-of-mars-exploration-by-spirit-opportunity