The end of the beginning of Mars exploration

More than any of its increasingly sophisticated predecessors, NASA's next robot on Mars will pave the way for getting humans to the Red Planet.

Why it matters: Rovers, landers and orbiters have beamed back invaluable data about Mars for decades, but the next phase in exploration depends on human explorers. One astronaut conducting science on Mars' surface could yield more efficient and quicker results than even the most advanced robot.

What's happening: NASA's Perseverance rover — expected to launch to Mars Thursday on a mission to hunt for signs of past life — marks the culmination of decades of robotic exploration of the Red Planet.

• NASA has methodically "followed the water" on Mars for about the past 20 years, and progressively found evidence that the planet was once habitable and pinpointed areas where life may have been preserved, like Perseverance's landing site in Jezero Crater.
• Perseverance, however, is the first mission with a real shot at finding actual signs of past life.
• "It's what we've been building up to for a long time now," planetary scientist Briony Horgan of Purdue University told Axios.

The big picture: This new chapter of exploration will also allow NASA to learn more about what's needed to make a human mission successful.

• One of the experiments — called MOXIE — flying to Mars aboard Perseverance is designed to figure out how to draw oxygen from the thin Martian atmosphere, a piece of tech that could eventually be used by crews.
• But more than the practical elements of finding ways for people to survive on Mars for the long haul, Perseverance opens the door for future missions that will map ice and water on the planet that can be studied and eventually used by explorers.
• "I see easily a couple more decades of this adventure unfolding," Jim Watzin, director of NASA's Mars Exploration Program, told Axios, referencing the future of human and robotic missions to the Red Planet.

Between the lines: Perseverance will also set up future robotic missions with its work on the Red Planet's surface.

• Scientists using the rover will cache samples of interesting Martian rocks and dirt that will be stored on the planet and eventually returned to Earth using a robotic sample return mission in the early 2030s.
• Those samples will allow scientists back on Earth to figure out exactly when Martian rocks formed, giving them a keen sense of the geological history — and possibly the history of life — on the planet.
• Some rocks could even help to determine the temperature of the Martian lake they were formed within.

"All of the things that we understand about the Earth from, for example, geology and geochemistry — they perfectly apply on Mars."

What's next: NASA plans to use the Moon and its Artemis program as a staging ground to get to Mars sometime in the 2030s.

• The space agency is also going to have to decide where its robotic Martian exploration program goes from here, with some scientists advocating for smaller, less expensive missions to help gather new data alongside the larger ticket spacecraft.