CAPE CANAVERAL, Fla. — Mars is about to get its first U.S. visitor in years: a three-legged, one-armed geologist to dig deep and listen for quakes.

NASA's InSight makes its grand entrance through the rose-tinted Martian skies on Monday, after a six-month, 300 million-mile journey. It will be the first American spacecraft to land since the Curiosity rover in 2012 and the first dedicated to exploring underground.

NASA is going with a tried-and-true method to get this mechanical miner to the surface of the red planet. Engine firings will slow its final descent and the spacecraft will plop down on its rigid legs, mimicking the landings of earlier successful missions.

That's where old school ends on this $1 billion U.S.-European effort.

Once flight controllers in California determine the coast is clear at the landing site — fairly flat and rock-free — InSight's 6-foot arm will remove the two main science experiments from the lander's deck and place them directly on the Martian surface.

No spacecraft has attempted anything like that before.

The firsts don't stop there.

One experiment will attempt to penetrate 16 feet into Mars, using a self-hammering nail with heat sensors to gauge the planet's internal temperature. That would shatter the out-of-this-world depth record of 8 feet drilled by the Apollo moonwalkers nearly a half-century ago for lunar heat measurements.

The astronauts also left behind instruments to measure moonquakes. InSight carries the first seismometers to monitor for marsquakes — if they exist. Yet another experiment will calculate Mars' wobble, providing clues about the planet's core.

It won't be looking for signs of life, past or present. No life detectors are on board.

The spacecraft is like a self-sufficient robot, said lead scientist Bruce Banerdt of NASA's Jet Propulsion Laboratory.

"It's got its own brain. It's got an arm that can manipulate things around. It can listen with its seismometer. It can feel things with the pressure sensors and the temperature sensors. It pulls its own power out of the sun," he said.

By scoping out the insides of Mars, scientists could learn how our neighbor — and other rocky worlds, including the Earth and moon — formed and transformed over billions of years. Mars is much less geologically active than Earth, and so its interior is closer to being in its original state — a tantalizing time capsule.

InSight stands to "revolutionize the way we think about the inside of the planet," said NASA's science mission chief, Thomas Zurbuchen.

But first, the 800-pound  vehicle needs to get safely to the Martian surface. This time, there won't be a ball bouncing down with the spacecraft tucked inside, like there were for the Spirit and Opportunity rovers in 2004. And there won't be a sky crane to lower the lander like there was for the six-wheeled Curiosity during its dramatic "seven minutes of terror."

"That was crazy," acknowledged InSight's project manager, Tom Hoffman. But he noted, "Any time you're trying to land on Mars, it's crazy, frankly. I don't think there's a sane way to do it."

No matter how it's done, getting to Mars and landing there is hard — and unforgiving.

Earth's success rate at Mars is a mere 40 percent. That includes planetary flybys dating back to the early 1960s, as well as orbiters and landers.

While it's had its share of flops, the U.S. has by far the best track record. No one else has managed to land and operate a spacecraft on Mars. Two years ago, a European lander came in so fast, its descent system askew, that it carved out a crater on impact.

This time, NASA is borrowing a page from the 1976 twin Vikings and the 2008 Phoenix, which also were stationary and three-legged.

"But you never know what Mars is going to do," Hoffman said. "Just because we've done it before doesn't mean we're not nervous and excited about doing it again."