A brutal dust storm swallowed Mars last summer. The global storm saves the rover's power-driven curiosity, but the older solar-powered Opportunity rover was closed when the thick pond blocked the light from the sun. The opportunity has been silent since June 10, 2018, despite NASA's hundreds of attempts to contact it.
When a windy season on Mars began in November, researchers hoped that wind power could clear debris from their solar panels, but that hope seems to have been in vain. NASA continues to send recovery commands, but unfortunately it seems that the opportunity mission has finally ended.
At the same time, 2019 marks a historic milestone for the rover, who officially reached his 15th year on March 25th. This far exceeds the rover's original life expectancy of 90 days. Along with Spirit Rover, whose end came back in 2010, Mars Exploration Rover (MER) marks one of the most important scientific programs of modern times, finding evidence that Mars was once covered in liquid and returning iconic images of the planet's surface.
To honor Oppy's 15th birthday and knowing that we can never hear from the rover again, we asked some researchers from the MER mission and elsewhere to share their thoughts and memories about Opportunity, Spirit and their heritage.
Steve Squyres, lead researcher of Mars Exploration Rover Mission (MER) and professor at Cornell University:
I haven't given up yet. We have a list of things to try, and we are not finished until we try everything on it. But we get to the bottom of the list, so it's a good time to start thinking about these things. As far as it feels, it actually feels good … It's an honorable death. [The rovers] are not immortal. You know you will lose them sooner or later. To get a 90-day mission to be for 15 years and stop ending as a result of one of the most cruel dust storms to hit Mars in a very long time, we can go away with our heads kept high. The mission far exceeded what I could have expected.
The inheritance is tough … The heritage is inherited from both Liquor and Opportunity, and the spirit and heritage of the team who built them primarily, the team of engineers, researchers, managers, leaders and economic people. The reason why it has been such a success is because of what they did 15 years ago. This is where the credit belongs.
On the scientific heritage, Mars proved to be a much more interesting place than I expected. It changed how people look at Mars. The three landings that preceded ours were all on these flat, rugged plains – intentionally – because they were the safest places to land. It is the whole country we saw. That was what made me so excited to do a rover mission. We have these little scenic rovers that have climbed mountains and fallen into craters. Mars has become a really beautiful, beautiful and interesting place in the sense that you can imagine being there and walking in the ravines and see what they have seen. It changes our perspective.
The third part of the inheritance is the effect that these missions have had on the children. One of my loveliest dreams, and I know this, has probably happened, is an 8-year-old who watched TV 2004, the night we landed and thought of themselves, "Who do I think is cool but I can do better." I see evidence that the mission has made it, to some extent, inspiring young people to pursue a career in science, technology and technology with their own dreams.
Kirsten Siebach, the planet geologist, the rice university:
These rovers were the trailblazers. They had a huge impact. Having the opportunity on Mars has meant that we have new pictures from the surface on another planet since I was in high school. Our understanding of Mars has expanded, and I believe that it always maintains a level of excitement and interest. It has been an inspiration for those of us who work with Mars, students and everyone in the public who comes along. It makes Mars accessible and nearby … I think the legacy is important for the idea of exploring and motivating a generation to believe that we are so close to another planet and that we continue to explore the solar system and learn new things every day .. .
Everyone talks about the amazing technology that allows us to have a robotic run on another planet without mechanics in absurd conditions for 15 years. It's a great achievement. But for me and the people on the team there are all these 15 years. There were people here on earth at the science and engineering team who met three to five times a week and remedied the progress from the day before and carefully programmed what opportunity would be done the next day. For that team it is more than just a robot, and we will miss it …. It has been a lot of fun to work on, we are happy that it has been so successful. And that dust level was definitely an honorable death if we didn't hear it again.
Kevin Lewis, Assistant Professor at Johns Hopkins University:
I hope the opportunity comes back in a row! I was on the MER team back to elementary school (2003-2009), which is proof of how long the mission lasted – 15 years is about three consecutive Ph.D lengths! The opportunity made great science until it lost touch and explored new rock units that it should never have been able to reach through its original design parameters. Both the Spirit and Opportunity completely revolutionized how we do science on Mars, and it is safe to say that we would not have curiosity without the overwhelming success of the MER mission. Spirit and Opportunity * Figuratively * paved the way for Curiosity and future robbers through the Solar System through their pioneering technical and scientific achievements.
Tanya Harrison, planetary science and research director at Arizona State University's space technology and science initiatives, and science team collaborators at Mars Exploration Rover Opportunity:
The opportunity exceeded all expectations we could have had for her. She unlocked the mystery of the hematite signal detected from orbiters before her, taught us about both watery and windy past on Mars, and drove beyond any other rover beyond the earth. No matter what the red planet seemed to throw at her, she and her clear team of engineers managed to find a way around it – until this latest global dust storm. But it is only fitting that the thing that could finally take Oppy out was the strongest dust storm we have ever seen on Mars. Now she can rest and know that she made humanity proud as our little robot addict.
Ashwin Vasavada, Mars Science Laboratory / Curiosity Rover Project Researcher at NASA's Jet Propulsion Laboratory:
Opportunity rover was a real inspiration to me during the development of curiosity, because it showed how a virtual field geologist could really summarize the story of an old environment by studying the record in the rocks. Ancient waters flowing over the surface, playing between dunes, groundwater soaking the rocks, so good things … everything kept me going for the most difficult days to get curiosity to Mars.
Emily Lakdawalla, Senior Editor of Planetary Society:
Spirit and Opportunity really blew a new path for public communication on an active science mission when Steve Squyres and Jim Bell chose to make all the images available to the public when they arrived at Earth. They wanted to make sure that students could work with data and that it didn't have to be on a password-protected server … Jim and Steve said "No, we want the public to enjoy the adventure the same way we are". That decision was so visionary. It created this great international community of people who could follow the daily dream of exploring another planet through the eyes of the Andes and Opportunities. People would make mosaics and animations, discuss the rocks they saw and what the science team did. In many cases, people in Europe would see the pictures before the US team woke up – Squyres likes to control these forums because it was easier than managing [the server].
Cassini's team had no plan to share their images in this way. NASA's Jet Propulsion Lab (JPL), after seeing the Mars Exploration Rover mission, said, OK, we're going to share Cassini's images as well. Many other missions followed in their footsteps – all Mars landed missions, such as Curiosity, Phoenix and InSight. It has influenced the European Space Agency to become more open with its image data – their structure is different from NASA's structure, as the institutions build and deliver the cameras – but they could start sharing a camera called VMC that shares pictures [from Mars] as soon as they met the earth, and Rosetta shared their NavCam images fairly quickly. Juno and New Horizons shared their data fairly quickly … It had a profound influence on how assignments shared their tasks with the public.
I think it is interesting that when the opportunity originally went quiet many people were ready to write it off immediately. It may have been a more pragmatic thing to do, but it didn't take into account the feelings of the people who had kept the spaceship for so long. I think it is necessary for the team to exhaust all possibilities so that they can feel a little closure on the mission. Some of them I'm sure don't want to give up … It takes a huge emotional investment to keep these missions going. I guess I hope the opportunity will surprise us and come back. I'm probably not guessing, and I'm sorry for the engineers for their loss. People will have to take the time to mourn, and realize that it is emotionally difficult.
Abby Fraeman, Opportunity Rover Assistant Project Researcher at NASA's Jet Propulsion Laboratory:
I will primarily interact with the team regularly. These people have been working on this mission for a very long time, and even though people have left and others have come in, this really is a wonderful feeling of companionship. I can recognize everyone with their voice. I know we can trust people when we face challenges or difficult scientific issues. It is great fun to work through all these problems with the people involved. I will also miss waking up every morning to see what the rover sent, what the latest pictures are. Every day you see something that no human has ever seen before.
I have a very personal story with the rover. I was in high school when the Spirit and Opportunity landed. It was a program run by The Planetary Society called the Student Astronaut Program that brought high schools out to JPL to be where the night rover landed. I was there the night that Opportunity landed, and it was a wonderful experience that inspired me to go into planetary science.
The way that both the Spirit and Opportunity transformed Mars science was quite profound … It gave us a new perspective on the planet that we did not have in the year 2000. Robbers were sent to follow the water, and before we went there we did not no definitive evidence that there has ever been floating water on Mars before. It was the first images from Oppy, and later images from the Spirit, it was undeniable evidence that Mars had another climate that could support liquid water on the surface. It opened a whole new parameter space for questions that we could ask about martian evolution. These questions were answered by the curiosity rover, a larger new rover with more sophisticated instruments, and some of them will be answered by the test re-assignment. Some will need future assignments to answer. We didn't even know what questions would be asked before we got the results from Spirit and Opportunity.
I'm just glad it lasted as long as it has been. It is a praise for how successful and groundbreaking this mission was.