Scientist of the Day - Opportunity Rover
Artist’s conception of Opportunity on the surface of Mars, 2004 (Wikimedia commons)
Opportunity, the second of two Mars Exploration Rovers, was launched on July 7, 2003. It landed on Mars on Jan. 25, 2004, in an area on the Martian equator known as Meridiani Planum (its counterpart, the Spirit rover had landed on the other side of Mars, on Jan. 4, 2004). In its role as Martian rover, Opportunity had been preceded on Mars only by tiny Sojourner, which had emerged from its lander Pathfinder in 1996 and examined its local demesne for some 85 days before running out of juice (Pathfinder and Sojourner were later fictionally recovered by Mark Watney in the novel and film The Martian). Both Opportunity and Sojourner had been preceded on the Martian surface by the Viking Landers 1 and 2 in 1976, but neither of those were rovers.
Mars-bound rovers Opportunity and Spirit posing with the backup of Sojourner at Jet Propulsion Labs, 2003
Sojourner had been about the size of a toaster oven (second image). Opportunity, built and run by Jet Propulsion Labs (JPL), was more like a large 6-wheeled tool cart with a mast sticking up to human-eye level that held some of the cameras. Each wheel had its own motor, and all together they could drive Opportunity along at about 580 feet per hour, although it seldom travelled that far in a day. The rover had equipment that allowed it to analyze spectrometrically anything it encountered. It even had a rasp (called in typical NASA lexiconese a RAT, or Rock Abrasion Tool) so it could check out the interior of any rock (but not the meteorite, which would have dulled and ruined the bit).
The Eagle crater on Mars, where Opportunity landed on Jan. 25, 2004 (science.nasa.gov)
Opportunity landed right in the center of a small crater, the Eagle crater, and spokespersons took to calling its landing a bulls-eye, as if mission planners were aiming for it. In fact, no one even knew the crater was there until Opportunity took a photo (third image).
Heat Shield meteorite on the surface of Mars, as photographed by the Opportunity rover, 2005 (Wikimedia commons)
In 2005, Opportunity was sent to check out the heat shield that had protected its descent, and was now lying on the surface, when it stumbled on (if you can stumble on something moving at a tenth of a mile per hour) a rock that turned out to be a meteorite, the first ever found on Mars, or any other planet, for that matter. It came to be called the Heat Shield Meteorite, and we have quite a few detailed photos of this chunk of iron and nickel, which indeed looks quite different from the native Martian rocks (fourth image). Opportunity would later discover many more meteorites on the Martian surface, but you always remember your first.
Panorama of a rock outcropping on the rim of Erebus crater, taken by Opportunity, 2006 (Wikimedia commons)
Opportunity is considered one of NASA’s and JPL’s great success stories, because it had been designed to operate for 90 sols (a sol is a Martian day, a little longer than an Earth-day), like Sojourner, but it actually functioned for 5352 sols, from 2004 until June of 2018, when it had to be shut down due to a planet-wide dust storm, and could not be reawakened, perhaps because its solar panels were covered with dust. During those 14 1/2 years, Opportunity explored half a dozen small craters and sent back almost a quarter-million images of the Martian surface, many of them taken by its PanCam (panoramic camera), which were converted into breathtaking panoramas (fifth and sixth images).
Final panorama taken by Opportunity, May-June, 2018 (Wikimedia commons)
There have been many Martian rovers since Opportunity, but none have been nearly so memorable, since no one knew it was going to last for over 14 years. Thus every day that it woke up and moved 100 feet and took a new photo was a bonus, and it just kept plugging on until June 18, 2018, when it began a slumber from which it would never awaken. Perhaps Mark Watney's son will dig it up one day, and I will save his life.
William B. Ashworth, Jr., Consultant for the History of Science, Linda Hall Library and Associate Professor emeritus, Department of History, University of Missouri-Kansas City. Comments or corrections are welcome; please direct to ashworthw@umkc.edu.
