Moment of truth awaits Europe's Schiaparelli Mars probe
The European Space Agency (Esa) is getting ready to put a probe on Mars.
Its Schiaparelli robot will attempt the risky descent to the surface in the coming hours, after a 500 million km journey from Earth.
The touchdown is regarded as a dress rehearsal for a much more important venture in four years' time when Esa will bid to place a very expensive rover on the planet.
This six-wheeled vehicle will drill beneath the surface to search for life.
Getting the smaller Schiaparelli robot down ought to be the simpler affair. But as the scientific record shows, Mars is not the most welcoming of places, even for the most sophisticated of hardware.
More than half of the missions despatched to Earth's near neighbour have failed. Many of these were lost on the way, missed their target, or crashed on arrival.