NASA’s InSight probe is designed to study the interior of Mars and achieve two science objectives. It seeks to discover through the interior processes and structure of Mars how rocky planets formed and evolved. The probe will also measure tectonic activity and the rate of meteor strikes on the Red Planet. However, InSight’s journey to Mars must pass through five critical phases.

The launch of InSight

InSight is scheduled to launch on the morning of May 5 from Vandenberg Air Force Base in California on top of an Atlas V. The launch window, however, extends two hours each day until June 8 until Earth and Mars move out of alignment for a relatively quick journey.

The cruise to Mars

The cruise to Mars starts when the InSight, enclosed in an aeroshell, separates from the Atlas V and lasts for six months until it is 60 days out from the Red Planet. During the cruise phase, NASA controllers will conduct a number of systems checks to determine the health of the probe and a number of course corrections. The craft will be maneuvered to keep its communications array pointed toward Earth and its solar panels toward the sun.

Mars approach

As soon as the InSight is 60 days away from Mars, interactions between the probe and NASA flight controllers will intensify. The final course corrections will be made. The software that will control InSight’s entry into the Martian atmosphere, descent, and landing on the surface will be loaded and tested.

The Deep Space Network will increase its monitoring of InSight to make sure that it is on course for a safe landing on Mars in late November 2018.

Entry, descent, and landing on Mars

While NASA has become experienced in landing numerous robotic probes on Mars, dating back to the Viking landers in the 1970s, this phase is always the terrifying one with the most potential to go wrong.

InSight, which weighs 1340 pounds (608 kilograms) will plunge into the Martian atmosphere at 14,100 miles per hour (6.3 kilometers a second). Its aeroshell will protect the probe from the heat of entry into the Martian atmosphere and start to slow it. Tiny rockets will fire to maneuver InSight toward its planned landing site in the eastern Elysium Planitia.

At a certain point, the aeroshell will be jettisoned, and parachutes will deploy, slowing InSight’s descent further. Three shock absorbing landing legs will deploy. In the final descent phase, the chutes will jettison, and 12 descent engines will fire to bring the probe to a safe landing.

Science operations

One minute after landing, InSight will begin its science operations. Instruments, including a seismograph and a heat probe, will slowly deploy. A camera will start sending back images of the probe’s landing site. The science mission will last for at least one Martian year, which is 728 Earth days.