On Wednesday, October 19, an experimental Mars lander from the European Space Agency (ESA) is going to touch down on the surface of the Red Planet, a practice mission to prepare for a rover landing.

This is all part of ESA’s ExoMars project, a two-part mission to search for signs of past or present life on Mars. This bit of the mission, which launched back in March, includes an orbiter and a lander. The following rover, meanwhile, will launch in 2020 and land in 2021.

The Russian-built lander is called Schiaparelli, and yesterday it separated from the parent orbiter spacecraft, called the Trace Gas Orbiter (TGO), on its solo journey towards Mars. There was a small blip following this separation when some data wasn’t being sent back properly, but that all seems to be sorted now.

The landing is scheduled to be fairly dramatic. Owing to the time delay between Earth and Mars because of the distance between the planets, the landing will be autonomous, with no input from the ground. As was similarly the case with the landing of NASA’s Curiosity rover on Mars in August 2012, this has been dubbed “six minutes of terror”, referring to the time it will take between entering the atmosphere and touching down on the surface.

ESA will be live streaming coverage of the landing here, which you will be able to watch from 9am EDT (2pm BST) on Wednesday. The landing itself is scheduled for 10:48am EDT (3:48pm BST), so make sure you tune in.

Schiaparelli itself is not hugely complex. It’s called an Entry, Descent, and Landing Demonstrator Module (EDM) because, well, that’s what it is. It has a few scientific instruments on board, but its main goal is to test how to land on Mars.

One reason for doing this is that the last time ESA attempted to land on Mars, it didn’t go so well. Their British-built Beagle 2 lander failed in 2003. Images later showed it had touched down, but its solar panels did not deploy properly, so it never had enough power to phone home.

Beagle 2 attempted to land using parachutes and airbags, but for Schiaparelli, things will be a bit different. The lander will be using parachutes, but about 1.1 kilometers (0.7 miles) above the surface, it will ignite thrusters to slow its speed from 250 kilometers per hour to just 4 km/h (155 miles per hour to 2.5 mph).

Then, 2 meters (6.6 feet) above the surface in a region called Meridiana Planum, the thrusters will turn off, and Schiaparelli will freefall the remaining distance, with a crushable structure absorbing the impact of touching down. The lander is scheduled to operate on the surface between two and eight Martian days (one Martian day is 40 minutes longer than an Earth day) before its power runs out.

^{How the Schiaparelli landing will play out. ESA/ATG medialab}

During the descent it will be taking images, so scientists can see how it all went. Unfortunately, there is no camera on board the lander to image the surrounding the surface, which is a bit of a shame considering the magnitude of the mission. Nonetheless, if successful, it will be a monumental achievement for ESA, which has never successfully landed a probe on another world aside from Philae on Comet 67P.

On the same day as the landing, the TGO spacecraft is also scheduled to enter orbit around Mars. It won’t start its experiments until the end of 2017, when it will spend a few years examining the Martian atmosphere.

The primary goal is to work out where Mars’ methane is coming from; some theories suggest biological processes may be at play. And there’s hope that the landing site for the ExoMars rover in 2021 may contain large amounts of methane to study up close. The TGO will also serve as a relay satellite for the rover, helping it communicate with Earth, through at least 2022.

The headline news on Wednesday, though, will most likely be reserved for the Schiaparelli lander. Here's hoping it all goes smoothly.