Mars to get a visitor — a mechanical miner

Mars is about to get another visitor: a three-legged, onearmed geologist to dig deep and listen for quakes.

Nasa’s InSight — a US$1 billion US-European effort — makes its grand entrance through the rose-tinted Martian skies on Tuesday, after a six-month, 480 million km journey.

It will be the first spacecraft to explore underground.

Nasa is going with a triedand-true method to get this mechanical miner to the surface of the red planet.

Engine firings will slow its descent and the spacecraft will plop down on its rigid legs, mimicking the landings of successful missions.

Once flight controllers in California determine the coast is clear at the landing site — fairly flat and rock free — InSight’s 1.8m 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 that before.

One experiment will attempt to penetrate 5m into Mars, using a self-hammering nail with heat sensors to gauge the internal temperature.

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.

By scoping out the insides of Mars, scientists could learn how our neighbour — and other rocky worlds, including the Earth and moon — formed and transformed over billions of years.

But first, the 360kg vehicle needs to get safely to the Martian surface.

The tensest time for flight controllers in Pasadena, California: The six minutes from the time the spacecraft hits Mars’ atmosphere and touchdown. InSight will enter Mars’ atmosphere at a supersonic 19,800 km/h, relying on its white nylon parachute and a series of engine firings to slow down enough for a soft upright landing on Mars’ Elysium Planitia, a sizable equatorial plain. The flatter the better so the lander doesn’t tip over and so the robotic arm can set the science instruments down.

Once its twin circular solar panels open, the lander will occupy the space of a large car.

It will be at least 10 weeks before the science instruments are deployed. Add another several weeks for the heat probe to bury into Mars. The mission is designed to last one full Martian year, the equivalent of two Earth years.