If you go outside after dark and look toward the western horizon you will notice a red “star” that is the planet Mars, some 80 million miles away and always on the minds of space lovers and cosmic adventurers.
As you look up and take in this planet, it is more than just a red point in the night sky. Thanks to NASA’s six decades of interplanetary exploration we look up and know Mars as a place similar to Earth in geology but a very hostile environment like Antarctica.
Last week NASA and the Jet Propulsion Lab in Pasadena, California said goodbye to one of the most incredible robot explorers ever built, the Mars Excursion Rover called Opportunity. Landing in January 2004 a week after its twin rover, Spirit, touched the surface, both robotic emissaries from Earth were built for a 90-day guaranteed mission. Spirit lasted 6 years before getting stuck and losing sunlight power; Opportunity was in its 14th year when a global Martian dust storm in August 2018 covered its solar panels and drained its energy. JPL’s scientists last heard from Opportunity on June 10, 2018, and after more than 800 contact attempts, it has been officially declared dead.
The legacy of both Spirit and Opportunity will be hard to match in many ways. One, while 20 or 30 planetary scientists expected to be working with the rovers for just 3 months, and maybe working another year to process the data, several hundred scientist have been involved in the complex day-to-day operation, spanning a generation of space scientists. That’s a lot of planetary surface experience—and necessitated annual financial extensions to pay them, an unexpected cost out of the NASA budget of about $20 billion a year.
And the second reason the Mars Excursion Rovers will be hard to top by NASA is their longevity that gave American taxpayers a big bang for their bucks. The MER program, as they are known on the space budget, was at a cost of $820 million to build both Spirit and Opportunity and launch them. Operating costs were several million dollars a year. That pales to the $2.2 billion cost of current NASA rover Curiosity, active on the surface of Mars since August 2012 on a two-year mission—now extended indefinitely until the nuclear-powered, SUV-sized rover fails.
Spirit and Opportunity were powered by solar cells, and their longevity is attributed to periodic winds and even dust devils that scour the Martian surface and cleared off the solar panels. Spirit got stuck in the Martian winter, and it’s solar panels were aimed away from the Sun; Opportunity probably suffered heavy dust that settled too thick to be blown off before its systems shut down from the cold, -20 below night.
Literally crawling along the surface at less than one-half-mile-an-hour—and for no more than football field-length a day—both rovers had artificial intelligence to avoid problem areas, technology now used on today’s vehicles. Spirit traveled 4.8 miles in six years, sending back nearly 125,000 images. Opportunity crawled 28 miles in its 14-plus years, sending back more than 217,000 photos. Both had other scientific experiments, including an abrasive wheel on its robotic arm to scour the rust-like coating on the surface of everything—a result of the millions of years of belching, giant volcanoes in Mars’ past.
Opportunity was blessed spacecraft from the start, flying the 60 million mile voyage to the Red Planet and landing inside a 30-foot crater on a flat plane—a cosmic hole in one! It came up upon several football-sized meteorites just lying on the ground, and spent years on the rim of 20-mile wide Endeavour Crater, peering inside from the rim at the layered terrain. Spirit and Opportunity
Both Spirit and Opportunity both found the evidence for the elixir of life on the surface—water. Not in liquid form, but frozen in the ground and frost on the surface—as well as lots of clay material that revealed a wet Mars like Earth but more than 3 billion years ago.
Where did all those lakes and seas go? And how did Mars evolve with gigantic volcanoes belching poisons that that tarnished the surface with rust? T h o s e questions are being answered by the current existing NASA rover Curiosity, now in its seventh year and climbing Mt. Sharp in the middle of the once water-filled Gale Crater.
This past 20 years have been the Golden Age for Mars exploration. There is still a small armada of robotic orbiters keeping Mars in 24/7 surveillance from a hundred miles high: NASA’s Odyssey, orbiting since October 2001; the European Space Agency’s Mars Express, December 2003; Mars Reconnaissance Orbiter, March 2006; and India’s first interplanetary spacecraft, Mangalyaan, September 2014; NASA’s MAVEN in September 2004; ESA/Russia’s ExoMars Trace Gas Orbiter since October 2006. And last November 2018 NASA landed the stationary robot Insight on Mars with a super sensitive seismometer that will drill into the surface and try to figure out the planet’s insides.
Scheduled for launch this Summer 2019 is the yet unnamed, $2.5 billion Mars 2020, which will continue the geological investigation being done by Curiosity, drill into the surface and leave rock samples for possible pick up and return by a future lander. But NASA and other countries don’t have new Martian orbiters in the pipeline—which are needed to relay data from the surface. When the current orbiters expire, we may face several decades without new Martian knowledge.
The bottom line of decades of studying Mars from the surface and orbit is this: Mars was once a warm, watery world with a thicker atmosphere and all the conditions right for supporting microbial life, at the least. And complex organisms at the most.
Yes, one day humans will land on Mars. Will it be in the next 10 years? 20 years? It’s hard to say. Fifty years after the first Apollo 11 landing on the Moon, it was taken for granted that there would be permanent bases on the Moon, much like Antarctica’s base camps. But that never materialized—the taxpayer money for the lunar expeditions has never been appropriated as the American public quickly turned apathetic to continued manned exploration of our celestial neighbor.
So we sent our robot emissaries. But the human instinct is to explore, and we will go back the Moon and eventually Mars. And one day there will be explorers standing around rover Opportunity, marveling at its history.
And that give us earthlings a lot to think about.