Astronaut Charles “Pete” Conrad famously quipped as he stepped upon the Moon’s surface, “Whoopee! Man, that may have been a small [step] for Neil [Armstrong], but that’s a long one for me.” Conrad was not only spoofing his predecessor’s words, but also was poking fun at his small stature.
Likewise, one of the smaller rovers sent to Mars’ surface just completed a long step of its own. Opportunity, NASA’s Mars rover that recently passed its 10th year of operation, was announced to have broken the off-world distance record this week. The rover passed 25 miles (40 kilometers), surpassing the previous record holder, the Soviet Union’s Lunokhod 2 Moon rover.
NASA announced that a drive of 157 feet (48 meters) on July 27 put Opportunity over the previous distance record, which was set in 1973. According to Mars Exploration Rover Project Manager John Callas of California’s Jet Propulsion Laboratory (JPL), this achievement is doubly extraordinary in that Opportunity was not originally envisioned as being a “long distance runner.”
“Opportunity has driven farther than any other wheeled vehicle on another world. This is so remarkable considering Opportunity was intended to drive about one kilometer, and was never designed for distance. But what is really important is not how many miles the rover has racked up, but how much exploration and discovery we have accomplished over that distance,” Callas enthused.
Steve Squyres of Cornell University in Ithaca, N.Y., and principal investigator for NASA’s twin Mars rovers, Opportunity and Spirit, echoed Callas’ sentiment:
“The Lunokhod missions still stand as two signature accomplishments of what I think of as the first golden age of planetary exploration, the 1960s and ’70s. We’re in a second golden age now, and what we’ve tried to do on Mars with Spirit and Opportunity has been very much inspired by the accomplishments of the Lunokhod team on the Moon so many years ago. It has been a real honor to follow in their historical wheel tracks.”
Lunokhod 2 touched down upon the Moon’s surface at Le Monnier crater in January 1973, shortly after the United States’ final manned lunar mission (Apollo 17, which wrapped up in December 1972). It drove approximately 24.2 miles (39 kilometers) before the end of its mission in May of that year. According to NASA, this distance was determined by observing tracks photographed by the Lunar Reconnaissance Orbiter (LRO).
Furthermore, NASA stated: “Irina Karachevtseva at Moscow State University of Geodesy and Cartography’s Extraterrestrial Laboratory in Russia, Brad Jolliff of Washington University in St. Louis, Tim Parker of JPL, and others collaborated to verify the map-based methods for computing distances are comparable for Lunokhod-2 and Opportunity.” In tribute to the previous record holder, Opportunity’s team named a crater after Lunokhod 2.
At present time, Opportunity is located at the rim of Endeavour Crater. It is scheduled to visit a site appropriately dubbed “Marathon Valley” (as the rover is expected to surpass 26.2 miles in distance, the length of a marathon). At Marathon Valley, Opportunity will investigate the site’s geologic composition.
A previous AmericaSpace article written by Ben Evans in January of this year underscored Opportunity’s unexpectedly long mission, and the rover’s reputation as a fine workhorse. Evans wrote: “Glitches have scarred the mission from time to time: It got itself stuck in sand and suffered early problems with the shoulder portion of its robotic arm, but software upgrades in January 2007 expanded its capabilities and empowered it to make its own decisions about image transmission and whether to examine specific rocks. Periodic wind-driven ‘cleaning events’ have removed dust from its solar panels, allowing power output to rise, and at the time of writing Opportunity’s torch shows no sign of dimming.”
As far as manned lunar rovers go, Apollo 17 holds the record for distance traveled (22.3 miles, or 35.9 kilometers). This rover was operated by astronauts Eugene A. Cernan and Harrison Schmitt, the last two humans to walk on the Moon. As far as the lunar speed record is concerned, the moonwalkers of Apollo 16 and 17 have both claimed that title at various times (both rovers clocked in at a maximum speed of approximately 11 kilometers an hour, or 7 mph).
This week, space enthusiasts are celebrating the 43rd anniversary of Apollo 15, which introduced the lunar rover to the Apollo lexicon. The wheeled legacies of the Apollo and Lunokhod programs continue to “go the distance,” as Opportunity and Curiosity travel Mars’ surface.