Exploring space
Aurora is ESA’s first step in human space exploration outside the low Earth orbits used for the Russian space station MIR and the International Space Station (ISS). Through this programme ESA will elaborate a long-term plan for human exploration of space, with Mars as its main objective and the Moon a very likely intermediate step.
Why Mars?
Mars was chosen because it is the most Earth-like of the nine planets that make up the solar system and recent indications of the presence of water raise the likelihood of being able to find traces of life. It represents, however, a major leap for humankind. To give some idea of how far it is: Mars is an estimated 400 million km distant from the Earth at the farthest point of its orbit; the Moon is around 400 000 km; and the ISS is 'near' at approximately 400 km away from the Earth.
With today’s technology it will take over two years to reach Mars and to return. Depending on the orbit strategy, it is possible to either shorten the travel time - but then the crew will be obliged to stay over a year and a half on Mars to await the next return opportunity; or to shorten the stay on Mars to up to two months - but then more than two years will be spent in travelling to and from Mars and the increase in velocity needed for the return trip will be much higher.
To undertake such a mission will require tremendous efforts of organisation, logistics and technological development. How will the astronauts survive for such a long period in an unfriendly environment? What will they eat, what will they drink and more important still, how much can we recycle or produce on Mars itself?
Not least of the problems will be learning to cope with the psychological pressure and stress of living in a confined space, for a long period of time, with a small number of colleagues. Research and simulation on the ground, as well as experience gained from working on the ISS, will all help to meet and overcome these difficulties.
Robotic missions
Although a human exploration mission is the ultimate goal, no one will be visiting Mars until as much information as possible has been gathered about Mars and its environment, and a return vehicle has been tried and tested. A number of successively complicated robotic missions will be needed to test the technology needed for a human mission, to establish the conditions under which human presence is possible, and to see how automation and robotics can assist human exploration.