It is possible? Is there life on Mars?
Ever since the Mariner 4 probe made the first successful visit to the Red Planet – a flying village in July 1965 – we have sent a series of missions that have given us all the fascinating details of the Earth's nearest neighbor – but not the answer to only question that really matters.
So take a look at the technology that can finally change the game.
This is Analytical Laboratory Drawer, or ALD – a sophisticated three-in-one box of instruments that will examine stone samples for biological chemical fingerprints.
On Thursday, the crane was carefully lifted and lowered into ExoMar's "Rosalind Franklin" rover, the six-wheeled buggy that will carry it over the Oxia plain in March 2021.
The 300kg robot, developed jointly by European and Russian space agencies, will have a drill that can dig up to 2m below the plane's dusty surface.
The outputs drawn by this tool will be passed through a door to the ALD, where the various mechanisms inside then will crush and prepare powders that can be released into small cups for analysis.
It will be a forensic examination, look at all aspects of the sample composition.
All previous rovers have skirted the big issue. They have essentially only asked whether the conditions for Mars today or earlier would have been beneficial to life – if ever there had been. They haven't actually got the equipment needed to really discover biomarkers.
Rosalind Franklin will be different. Its 54kg ALD has been built specifically to look for the complex organic molecules that originate from life processes.
Thursday's integration was slow and deliberate, understandable: ALD is in many ways the leading role in the Rosalind Franklin mission.
"It is wonderful to see the heart of the rover now installed," said Sue Horne, Space Exploration Manager at the UK Space Agency.
"Analytical Laboratory Drawer is the most important site for sampling martial samples on rover that allows us to understand the geology and possibly identify the signatures for Mars life. I can't wait to see what discoveries are in the store for this British rover building".
Engineers at Airbus UK are now working three shifts a day to get the rover ready.
Although it doesn't look like a vehicle at the moment, almost all components have now come to the Stevenage factory.
They sit on the shelves around the cleanroom's edge in bags and are waiting for their turn in the assembly sequence.
However, there are one or two outstanding objects, including the rover's British "eyes".
This is the camera system, or PanCam, which sits on the top of a mast and controls the robot on its survey list.
"We have just kept the delivery committee this week and PanCam should come to us in the next few days," says Chris Draper, operations manager for the Airbus aircraft model.
"We know that everything will go together, that is the beauty of system technology. Every part of the rover has been modeled in 3D, and everyone works with interface control drawings. If we assume that everyone does, then we know ALD, for example, will fit perfect in the rover. "
The Stevenage team has a tough deadline in early August to get the finished Rosalind Franklin rover out the door.
It must go to the company's Toulouse facility for a series of tests that ensure that the construction is robust enough to cope with the severe shaking experienced on a rocket trip to Mars.
Additional access controls then follow in France prior to delivery to the launch site of the famous Baikonur Cosmodrome in Kazakhstan.
Lifting must take place in July / August next year. This date is immoveable: you only go to Mars when it is focused on the earth and the possibilities have a range of 26 months.
Rover's name: Who was Rosalind Franklin?
In 1952, Rosalind Franklin at King's College London (KCL) investigated the atomic arrangement of DNA, using her skills as an X-ray crystallograph to create images for analysis.
One of her team's images, known as Photo 51, gave the key insights for Crick and Watson to build the first three-dimensional model of the two-stranded macromolecule.
It was one of the highest achievements of the 20th century science, which allowed researchers to finally understand how DNA stored, copied and transmitted the "life code" genetic.
Crick, Watson and KCL colleague Maurice Wilkins received the 1962 Nobel Prize for the breakthrough.
Franklin's fuzzy death meant that she could not be considered for the prize (noble is not awarded posthumously). Many claim, however, that her contribution has never received the attention it deserves, and has even been underpinned.
- BBC – In our time: Melvyn Bragg recalls the life of Rosalind Franklin