As you read this, scientists and engineers at Nasa's Jet Propulsion Laboratory in California are raucously celebrating – as well as breathing a huge sigh of relief – following the successful landing of the on the planet Mars of Curiosity, also known as Mars Science Laboratory.
Launched via NASA"s Mars Science Laboratory spacecraft last November, the car-sized Curiosity rover landed on the Red Planet at 7.31am (CET) this morning bang on schedule after travelling 480 million kilometres in 8 months.
Armed with a laser-induced breakdown spectrometer, a robot arm capable of holding up to 30kg of equipment, and an instrument suite including an oven in which soil and rock samples can be baked, Curiosity"s mission is to detect if Mars possesses organic materials, amino acids and sugars.
Such evidence will determined if life could have previously existed on Mars, or even if it is still present below the surface.
Touching down safely on the fourth planet from the Sun in our Solar System was always going to be the hard part of this mission – a mission that cost NASA a cool $2.5 billion worth of hardware and involved ten years of blood, sweat and tears.
Curiosity"s mother ship hurtled into a defined 3 km wide target in the atmosphere of Mars at over 20,000 km/h!
But it was what unfolded over the next seven minutes that had the NASA boffins and space buffs gnawing at their fingernails, praying that none of the many potentialities for error turned into reality. Fortunately, it didn"t.
Given that the landing was successful, we can assume that everthing went more or less to plan, as outlined pretty dramatically in this NASA video, published in June, and in the accompanying artist"s impressions. But the margins were tight, that"s for sure.
NASA"s Seven Minutes of Terror Video – with animations, commentaries and dramatic music
A huge cone-shaped heat shield took the brunt of the craft"s initial entry into Mars"s atmosphere, at which point the temperature it was subjected to reached a blistering peak of 2,100 °C. Then a huge supersonic parachute deployed before the heat shield separated from the main craft to permit imaging and radar instruments to monitor the fast approaching surface.
Rocket engines then fired in order to slow down the probe further until it hovered 20 metres over Mars"s rusty-coloured surface. The spaceship"s hold opened and the Curiosity rover lowered via three nylon cables on to the Gale Crater, near Mars"s equator.
Explosive bolts helped to detach the cables before a final burst of the mother ship"s engines lifted it clear of the rover to crash land at a safe distance.
Such an unprecedentedly complex landing process was, of course, fraught with risks, both mechanical and atmospheric, from the beginning.
"Is it crazy? Well, not so much when you get to understand the concept," said director of the Mars Exploration Program, Doug McCuistion, last month.
He continued: "Is it risky? Landing on Mars is always risky. There are hundreds of discrete events that occur from release of the cruise stage, to parachute deployments, to heat shield deployments. All of these are unique and any one of them can cause problems.
"Going from 21,000km/h / 13,000mph to zero in seven minutes, that"s quite a challenge in itself.
"Then there is the unknown, there"s Mars. It throws things at you: Dust storms, atmosphere and density changes, wind… So it is a very unique and a very challenging environment."
The fact that Curiosity has successfully landed on Mars helps to defy the Red Planet"s reputation as a spaceship graveyard.
A glance at the scorecard would have told you that fewer than half of Earth"s missions to Mars had been successful before Curiosity was launched.
The British-backed Beagle 2 disappeared during its landing in 2003, while Russia"s 2011-launched Fobos-Grunt was left stranded in Earth"s orbit after rocket burns intended to set the craft on a course for Mars failed.
What"s even more impressive is the upscale that Curiosity represented in terms of Mars rovers.
Weighing in at one tonne, Curiosity is the size of a small car. Compare that to Sojourner, the first robot vehicle to land on the Red Planet (where gravity is a third of the Earth"s) in 1997, which was not much bigger than one of Curiosity"s wheels.
Now that Curiosity is safely on script to carry out its exploration of Mars, we may finally get an answer to the perennial question (and hit David Bowie song), Is there (or was there) life on Mars?
You can follow the Mars mission"s progress at http://www.jpl.nasa.gov/