Over the last few decades, Mars has become the most explored planet in the solar system (after Earth). It has hosted dozens of visitors. Indeed, eight missions currently operate on and around the Red Planet. The oldest of these arrived in 2001—the Mars Odyssey orbiter, which is expected to remain operational until 2025. More missions are planned as NASA, and perhaps other space agencies, work toward the goal of returning Mars samples to Earth and eventually sending humans.
Both these goals will require much more detailed maps of the ground. Rovers provide this kind of detail but can travel only a few meters a day. NASA’s Opportunity rover traveled an impressive 45 kilometers (28 miles) during its mission but took almost 15 years to do it.
So planetary scientists are looking for ways to explore the planet’s surface more rapidly. One idea is to launch a plane into the Martian atmosphere with an engine capable of keeping it aloft. Such a mission could cover vast distances but would be expensive, costing upwards of $350 million.
To read more, click here.