Opportunity, also known as MER-B (Mars Exploration Rover – B) or MER-1, and nicknamed Oppy, is a robotic rover that was active on Mars from 2004 until 2018. Opportunity was operational on Mars for 5111 sols (14 years, 138 days on Earth). Launched on July 7, 2003, as part of NASA's Mars Exploration Rover program, it landed in Meridiani Planum on January 25, 2004, three weeks after its twin, Spirit (MER-A), touched down on the other side of the planet. With a planned 90-sol duration of activity (slightly less than 92.5 Earth days), Spirit functioned until it got stuck in 2009 and ceased communications in 2010, while Opportunity was able to stay operational for 5111 sols after landing, maintaining its power and key systems through continual recharging of its batteries using solar power, and hibernating during events such as dust storms to save power. This careful operation allowed Opportunity to operate for 57 times its designed lifespan, exceeding the initial plan by 14 years, 47 days (in Earth time). By June 10, 2018, when it last contacted NASA, the rover had traveled a distance of 45.16 kilometers (28.06 miles). Mission highlights included the initial 90-sol mission, finding meteorites such as Heat Shield Rock (Meridiani Planum meteorite), and over two years of exploring and studying Victoria crater. The rover survived moderate dust storms and in 2011 reached Endeavour crater, which has been considered as a "second landing site". The Opportunity mission is considered one of NASA's most successful ventures. Due to the planetary 2018 dust storm on Mars, Opportunity ceased communications on June 10 and entered hibernation on June 12, 2018. It was hoped it would reboot once the weather cleared, but it did not, suggesting either a catastrophic failure or that a layer of dust had covered its solar panels. NASA hoped to re-establish contact with the rover, citing a recurring windy period which was forecast for November 2018 to January 2019, that could potentially clean off its solar panels. On February 13, 2019, NASA officials declared that the Opportunity mission was complete, after the spacecraft had failed to respond to over 1,000 signals sent since August 2018.
Objectives The scientific objectives of the Mars Exploration Rover mission were to:
Search for and characterize a variety of rocks and soils that hold clues to past water activity. In particular, samples sought include those that have minerals deposited by water-related processes such as precipitation, evaporation, sedimentary cementation, or hydrothermal activity. Determine the distribution and composition of minerals, rocks, and soils surrounding the landing sites. Determine what geologic processes have shaped the local terrain and influenced the chemistry. Such processes could include water or wind erosion, sedimentation, hydrothermal mechanisms, volcanism, and cratering. Perform calibration and validation of surface observations made by Mars Reconnaissance Orbiter (MRO) instruments. This will help determine the accuracy and effectiveness of various instruments that survey Martian geology from orbit. Search for iron-containing minerals, and to identify and quantify relative amounts of specific mineral types that contain water or were formed in water, such as iron-bearing carbonates. Characterize the mineralogy and textures of rocks and soils to determine the processes that created them. Search for geological clues to the environmental conditions that existed when liquid water was present. Assess whether those environments were conducive to life.
Mission timeline
Opportunity and Spirit rovers were part of the Mars Exploration Rover program in the long-term Mars Exploration Program. The Mars Exploration Program's four principal goals were to determine if the potential for life exists on Mars (in particular, whether recoverable water may be found on Mars), to characterize the Mars climate and its geology, and then to prepare for a potential human mission to Mars. The Mars Exploration Rovers were to travel across the Martian surface and perform periodic geologic analyses to determine if water ever existed on Mars as well as the types of minerals available, as well as to corroborate data taken by the Mars Reconnaissance Orbiter (MRO). Both rovers were designed with an expected 90 sols (92 Earth days) lifetime, but each lasted much longer than expected. Spirit's mission lasted 20 times longer than its expected lifetime, and its mission was declared ended on May 25, 2011, after it got stuck in soft sand and expended its power reserves trying to free itself. Opportunity lasted 55 times longer than its 90 sol planned lifetime, operating for 5498 days from landing to mission end. An archive of weekly updates on the rover's status can be found at the Opportunity Update Archive.
Launch and landing
Spirit and Opportunity were launched a month apart, on June 10 and July 8, 2003, and both reached the Martian surface by January 2004. Opportunity's launch was managed by NASA's Launch Services Program. This was the first launch of the Delta II Heavy. The launch period went from June 25 to July 15, 2003. The first launch attempt occurred on June 28, 2003, but the spacecraft launched nine days later on July 7, 2003, due to delays for range safety and winds, then later to replace items on the rocket (insulation and a battery). Each day had two instantaneous launch opportunities. On the day of launch, the launch was delayed to the second opportunity (11:18 p.m. EDT) in order to fix a valve.
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