NASA pulled off an amazing feat last August when it successfully landed the car-sized Curiosity rover on Mars, but just because it made history doesn't mean the organization is resting on its laurels.
The American space agency has already made known its plans to return to Mars in 2020 with another rover, but it's also moving forward with plans to study the red planet's atmosphere.
With the landing of multiple rovers on the Martian surface, though, why does NASA feel the need to keep sending robots back to the planet? According to project leader Adam Steltzner, the answer is fairly simple.
"Are we alone in the solar system, in the universe? Was there ever life on Mars? Could life have been supported in the environment of Mars? That's the science reason we put that huge Rover on the surface," he said to PBS Newshour. "The second reason we explore is because it's kind of in our DNA. We have over the span of human existence, explored our universe starting with what's over the next hill, what's over the next ocean, and eventually what is out in space."
Additionally, he said that just because we're already analyzing Mars with rovers doesn't mean that our current projects are enough. And that's probably why scientists are fixated on the red planet instead of shifting their sights towards other rocky globes such as Jupiter's moon Europa and Saturn's moon Titan. Every rover put on Mars has a uniquely different skillset aimed at answering its own set of questions.
"Each one has more capabilities and more aggressive scientific questions it's asking than the last," said Ashwin Vasavada, NASA's deputy project scientist. "This rover asks about are there potential habitable environments in ancient Mars history? ...The next rover in 2020 will most likely ask more direct questions about whether life actually was present in these environments."
Scientific organizations like the Planetary Society and American Astronomical Society's Division for Planetary Science have pledged support for NASA's continued focus on Mars, though they've suggested that the next rover be capable of collecting samples for an eventual return to Earth.
Outside of rovers, NASA is also working with Lockheed Martin to develop a spacecraft that will study the upper reaches of the Martian atmosphere. Dubbed MAVEN (Mars Atmosphere and Volatile Evolution probe), the plan is to launch the craft by November and have it send results back to Earth a year later.
Still, just because NASA is devoted to studying Mars in close detail doesn't mean it doesn't have ambitions to travel to Europa and Titan. The problem, as always, comes down to money. The agency's budget might be cut in the future as Washington tries to solve the country's fiscal woes, meaning a trip to Europa could be out of the question.
This isn't the first time that future NASA projects have been replaced with question marks (and it probably won't be the last), but Mars Exploration Manager Fuk Li is optimistic.
"It is tough," he said, "but space exploration is something that is kind of innate in the human spirit. You want to go out and see what is the unknown that is out there. And I think we'll continue to do so."
