In an alien place called Meridiani Planum inside a rocky environment called “Perseverance Valley,” a robot rover the size of a topless golf cart is a little dusty and cranky, but still soldiering forward as it travels across the once water drenched surface of Mars at a top speed of 25 feet per hour.
I’m talking about NASA’s Mars rover Opportunity, breaking barriers in space craft endurance by entering its 5,000th day working the surface of the Red Planet after landing January 25, 2004 on a 90-day warranty.
The 14-year legacy of the Martian robot has been phenomenal and ranks up there with the long, extended missions of other NASA spacecraft like the proposed four-year mission of Cassini orbiting Saturn, which lasted 13 years. Most of NASA’s successful interplanetary spacecraft—more than two dozen—have gone beyond their promised lifetime and had extended missions, a tribute to America’s space engineers and a great value for the taxpayers funding the projects.
The focus of Opportunity and its amazing durability kicks off a year of Mars where the fourth planet from the Sun will be closest to Earth on July 27th than it will be for 17 years. Called an opposition when objects are closest to each other, the distance this summer will be at 35.8 million miles. That’s close on an astronomical scale, and just under the historically close opposition of Aug. 28, 2003 when Mars was 34.65 million miles away—the closest since the Stone Age 60,000 year ago and not to be matched until 2287 AD!
Mars and Earth are closest each other about every 26 months, and since the 1960s space scientists have been sending spacecraft during those opposition years, taking advantage of the shorter distance to save fuel and time. NASA will take advantage of the shortened distance in 2018 and launch a stationary lander this spring to listen the inside of Mars to further understand this world just half the size of Earth.
We have two rovers on the Martian surface (Curiosity landed in 2012) and six in orbit keeping a 24/7 surveillance of the Red Planet. Three NASA orbiters are Mars Odyssey since October 2001, Mars Reconnaissance Orbiter (MRO) since March 2006 and MAVEN since September 2014. India has its first interplanetary spacecraft, Mangalyaan, in orbit since September 2014, and Europe Space Agency’s ExoMars Trace Gas Orbiter took advantage of the 2016 opposition and orbited in October that year.
NASA’s Odyssey has enough fuel to last until 2025, and MRO until the 2030s. Both are critical relay stations for the rovers Opportunity and Curiosity, gathering data during overhead passes and then sending it to the Earth. MAVEN is an atmospheric research spacecraft that after its primary mission ends in 2019 it will be put in a higher orbit to serve as a telecommunications satellite for the rover and future landers.
Though it is having bouts of memory amnesia and its joints are sore, Opportunity has much to offer. It’s twin rover, Spirit, lasted six years until it got stuck in some fragile crust that rendered it helpless as the solar panels faces away from the Sun, draining the battery power and life out of the vehicle. Remember, Mars is a very cold world, more like Antarctica with brief temperatures above freezing for just a few hours in the Martian summer.
When launched in 2003, the two Mars Excursion Rovers (official name) were expected to have their power-making solar panels become useless when the pervasive Martian dust covered them, blocking sunlight. Surprisingly, Martian winds—especially the common dust devils—have periodically swept the panels clean and kept them in working order. Both Spirit and Opportunity were made with metal pieces of the World Trade Center Towers providing shields on critical cables.
Opportunity and Spirit weight 400 pounds, they are 5-feet long and 7.5 feet wide at the tips of the solar panels, only travel at less than one inch a second—that’s right, about 25 feet an hour! On a good day Opportunity might travel 200 feet. Its more than 28 miles of travel has the interplanetary record of any man-made vehicle, eclipsing Russia’s 1973 unmanned Lunokhod (27 miles) and 1972 Apollo 17 manned rover (21 miles).
The Martian day, called “sols,” is 24 hours, 37 minutes, which is 47 minutes longer than the 23-hour, 56-minute Earth day. And a Martian year is almost twice as long as on Earth, lasting for 687 Earth days, as compared to 365 days on Earth. The distance between Earth and Mars varies from no closer than 40 million miles to beyond 200 million miles, so the delay in signals from the planets can vary from between 5 and 20 minutes one-way. With mission controllers at the Jet Propulsion Laboratory in Pasadena, California, living in “Mars Time,” the working schedules have swung through all hours as Martian daytime is when orders are sent, while data is streamed at all hours from the Mars orbiters.
Opportunity has found abundant evidence for a previously more habitable Mars over the years, including evidence of that is traveling in a former ancient lake of salty water and groundwater. Currently, the rover has been at Endurance Crater for six years, impact area 14 miles wide and a quarter-mile deep. It is exploring an old water channel called Perseverance Valley that will take the rover to the crater floor by the end of 2018.
Taking advantage of the close launch window between Earth and Mars this year, NASA’s next Mars lander, InSight, is scheduled to launch this spring, May 5. InSight is a lander, not a rover, and will focus on probing the deep interior of the planet, including listening for marsquakes, to help scientists understand how Mars formed and evolved. It will arrive at Mars on November 26, 2018.
Meanwhile, rover Opportunity will keep on truckin’ and defying the odds of its survival, continuing to connect the mind of man with the reality of the surface of Mars.