Up in outer space, right now, the European Space Agency’s Schiaparelli Lander is making a slight orbit around Mars — getting ready to come in for landing. If the spacecraft manages to safely touch down on the planet’s surface, it will be the first time ever that an ESA-led mission lands on the Red Planet.

The lander separated from the ExoMars Trace Gas Orbiter (TGO) on Sunday, and briefly used its powered thrusters to correct course and avoid a free fall to the planet’s surface. The two crafts launched together from Earth on March 14, 2016, in partnership with Russian Federal Space Agency Roscosmos.

The real test comes Wednesday, when Schiaparelli will plunge into the Martian atmosphere, and hopefully, land safely on its feet. The whole ordeal will take just under six minutes, and the lander is predicted to touch down at 10:48 a.m. Eastern Time.

Check out this video, which breaks down the entire process in real time:

Putting a lander on the Red Planet isn’t easy, Thierry Blancquaert, Manager of ESA’s Schiaparelli team, tells Inverse.

“The complication comes with the atmosphere that is dense enough to create a strong friction and generation of heat during the aerobraking, but also not dense enough to create enough braking on the parachute, so we have had to add the propulsion system,” Blancquaert says.

“If you take a different landing planet, like Titan, the atmosphere was very dense, and therefore, we have plenty of time to do even science during the descent.”

Getting a spacecraft through Titan’s atmosphere takes hours. By contrast, Blancquaert explains, it takes just six minutes between the time Schiaparelli hits the atmosphere to the time of touchdown.

Overview of Schiaparelli's entry, descent and landing sequence on Mars, with approximate time, altitude and speed of key events indicated.
Six minutes will determine the success or failure of Schiaparelli's landing on Mars.

The Schiaparelli Lander is a test of ESA technology to get rovers and scientific instruments on Martian ground, safely and securely. If it works, the landing will be proof-positive for the design to get the ExoMars rover to the surface in 2020, to look for signs of life.

The descent sequence will start when Schiaparelli hits the Martian atmosphere, about 75 miles up in the air, traveling at 13,000 miles per hour. A heat shield on the front of the craft, will work to slow the descent, and protect the instruments inside. Eventually, the heat shield will literally vaporize from the extreme temperatures generated by the the craft’s friction with the Martian atmosphere.

A few minutes later, the lander will be traveling at about 1,000 miles per hour, seven miles from the surface. A parachute will spring out from above the craft. About 40 seconds later, Schiaparelli will ditch what remains of the front shield. The chute will slow the lander’s descent to about 150 miles per hour, at which point both the parachute and the rear shield will be jettisoned.

The craft will use radar to calculate the distance to the surface, and its computer brain will control nine hydrazine thrusters to slow it down even more. The thrusters will bring Schiaparelli almost to a hover, about six feet from the surface, and then cut out. From there, it’s a short and gentle free fall, cushioned by a crumple zone on the bottom of the lander, designed to take the impact.

The entire entry, descent, and landing sequence will take place automatically, based on instructions the ExoMars team sent to the spacecraft last week, along with mediation by the lander’s internal computer.

The team has picked a relatively flat area of Mars, says Blancquaert, in hopes of a gentle landing. But the landing zone could only be narrowed down to an oval measuring about 60 by 10 miles, so there’s no guarantee that a crater or large rock won’t put a serious snag in the plan. The lander is designed to contend will rocks up to a foot high, he says.

While Schiaparelli’s primary mission is to test the landing system, it should also send some very cool scientific data back to Earth. A camera will start snapping photos when the lander is about half a mile above the surface, so we may get images of the descent and landing site. However, it’s dust-storm season, so there’s no guarantee that the photos won’t just show Red Planet sand, says Blancquaert.

Once on the surface, the lander will take measurements of wind speed, humidity, pressure, and temperature with its excess battery supply. Testing will occur for six hours per day for two days, maybe longer, and data will be relayed via spacecraft in orbit back to mission command. It will also take measurements of the Red Planet’s magnetic fields, which should provide new insight into how dust storms form.

Tune into the ESA’s website to watch live coverage of Schiaparelli’s landing on Wednesday.

Photos via ESA/ATG medialab, ESA/YouTube (1, 2)