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.

Arrow missions

Arrow missions are technology demonstration missions intended to reduce the risks of Flagship missions. In fact, they are more flexible, cost less, are technically less complex and have a shorter development time.
The first two to be approved for study under ESA’s Aurora Programme are an Earth re-entry vehicle/capsule and a Mars aerocapture demonstrator.

Earth re-entry vehicle/capsule

This is a first step in preparation for the Mars sample return mission, one of the first Flagship missions to be studied under the Aurora Programme. A small spacecraft will be put into a highly elliptical Earth orbit and then propelled Earthwards in order to simulate the conditions that will be experienced by an interplanetary return capsule.

Mars aerocapture demonstrator

This Arrow mission aims to validate the technology needed to enable a spacecraft to brake into orbit around a planet by relying solely on friction with the planet’s upper atmosphere. The use of this technology can significantly reduce the amount of fuel needed for a Mars mission and, once validated, it could be used in future Flagship missions and eventually for a human mission.

More about Aurora

Aurora's origins

Aurora is part of Europe's strategy for space, endorsed by the European Union Council of Research and the ESA Council in 2001. This strategy calls for Europe to:

• explore the solar system and the universe
• stimulate new technology
• inspire the young people of Europe to take a greater interest in science and technology

As a result of this challenge, in 2001 ESA set up the Aurora Programme - a cooperative programme between the ESA Directorates of Science, Human Space Flight, and Technical and Operational Support.
The primary objective of Aurora is to create, and then implement, a European long-term plan for the robotic and human exploration of the solar system, with Mars, the Moon and the asteroids as the most likely targets.
A second objective is to search for life beyond the Earth. Future missions under the programme will carry sophisticated exobiology payloads to investigate the possibility of life forms existing on other worlds within the solar system.
It is clear from these objectives that the interdependence of exploration and technology is the basis of the Aurora Programme. On the one hand the desire to explore provides the stimulus to develop new technology while on the other, it is the introduction of innovative technology that will make exploration possible.

Exploring space

Curiosity about our world, and the Universe that surrounds us, has been the driving force behind human progress since prehistoric times. Today, the exploration of space remains one of the most stimulating and exciting areas of scientific research.
Many exciting and innovative ideas for future exploration have been proposed by industry and academia since the Aurora Programme began. In 2001 ESA received more than 300 replies when it asked the space community to put forward suggestions for future exploratory missions. This was followed in 2002 by another 'call for ideas' for the technology needed to make these missions possible. All proposals were accompanied by a preliminary time schedule and an assessment of feasibility and cost.
Suggestions received included an investigation of Pluto, the smallest and outermost planet in the solar system; establishing a launch site on the Moon; and the human exploration of Mars.
The Aurora Programme carefully assesses the feasibility - both technical and financial - of all the ideas received. European industry is then encouraged to develop the technology needed to bring these ideas to fruition.

Advanced technology

Each phase of exploration on the way to the human exploration of Mars will require increasingly complex technology. In some cases existing technology can be further developed or adapted, but in many cases European industry will be asked to come up with new innovative technology to make future exploration missions possible.
The technological studies to be carried out under the Aurora Programme will enable Europe to select which of the many technologies on offer should be given priority for development within Europe, as well as the value of the technologies offered by possible partners. Among the technology needed to make a human mission to Mars possible are: aerobraking, precision navigation and landing, propulsion systems that offer cheaper, faster travel; and life-support systems to enable humans to live in hostile space environments.

International cooperation

Close cooperation within ESA, as well as collaboration with European and Canadian industry and academia, is a key aspect of Aurora.
Although Aurora is an ESA programme and will promote European industry, many missions will involve international cooperation. For instance Canada, which has a cooperation agreement with ESA, is already participating in the Aurora Progamme.
International cooperation is important because it reduces costs and allows the countries involved to gain from one another's expertise. The Aurora programme will ensure that ESA achieves the maximum benefits from joint enterprises with international partners.


Step-by-step approach

Aurora's step-by-step approach means that missions will increase in complexity over time, culminating - if all goes well - in a human expedition to Mars by the year 2030. Steps on the way to Mars will probably include exploration of the Moon as well as:

• remote sensing of the Martian environment
• robotic exploration and surface analysis
• Mars sample return missions
• a robotic outpost

Not all these steps towards the ultimate goal of sending humans to Mars will necessarily be part of the Aurora Programme. As the result of international cooperation, various collaborating agencies will make a contribution to those missions that best meet their particular requirements and areas of expertise.


Exploration Programme Advisory Committee

All ideas received are examined to assess their feasibility and to ensure that they are in line with Europe’s space strategy. They are then sent to Aurora’s Exploration Programme Advisory Committee (EPAC) for further discussion. This body includes European experts from technology and science as well as an ESA astronaut.


Aurora Board of Participants

The Aurora Board of Participants (ABP) has the final decision on the choice of missions and technology. This Board is made up of representatives of all the ESA Member States that have joined the Aurora Programme, as well as Canada. At present it has 10 members.

Industry

Once an exploration mission and the associated technology have been approved, European and Canadian industry will be invited to tender for the work needed to bring the project to fruition. The Aurora Programme office will carefully follow each project at all stages to ensure that everything is proceeding to plan.

The ultimate challenge

Flagship missions

These are major missions to advance scientific and technical knowledge in preparation for a human mission. The first Flagship missions to be approved for industrial studies by the Aurora Board of Participants are the ExoMars mission and the Mars Sample Return.

ExoMars

ExoMars is the first Aurora Flagship mission to be assessed. Its aim is to further characterise the biological environment on Mars in preparation for robotic missions and then human exploration. Data from the mission will also provide invaluable input for broader studies of exobiology - the search for life on other planets.
This mission calls for the development of a Mars orbiter, a descent module and a Mars rover. The Mars orbiter will have to be capable of reaching Mars and putting itself into orbit around the planet. On board will be a Mars rover within a descent module.

After their release and landing on the surface of Mars, the orbiter will transfer itself into a more suitable orbit where it will be able to operate as a data relay satellite. Initially it will act as a data relay for the ExoMars rover but its life may be extended to serve future missions.

The Mars descent module will deliver the rover to a specific location by using an inflatable braking device or parachute system. Both systems are sufficiently robust to survive the stresses of atmospheric entry and their landing accuracy will be sufficient for this mission.

Using conventional solar arrays to generate electricity, the Rover will be able to travel a few kilometres over the rocky orange-red surface of Mars. The vehicle will be capable of operating autonomously by using onboard software and will navigate by using optical sensors. Included in its approximately 40 kg exobiology payload will be a lightweight drilling system, a sampling and handling device, and a set of scientific instruments to search for signs of past or present life.
In order to be successful ExoMars will require advanced technology in the following areas:

• rover systems
• landing systems
• an inflatable braking device
• power supply
• autonomy and navigation

Although this presents a considerable technological challenge for European and Canadian industry, it will bring to fruition many years of technological development both at ESA and national level.

Mars sample return mission

This complex Flagship mission calls for five spacecraft: an Earth/Mars transfer stage, a Mars orbiter, a descent module, an ascent module and an Earth re-entry vehicle. When the orbiter is in low-altitude orbit around Mars the descent module will be released and descend to the surface of Mars. On board the landing platform of the descent module will be a device to collect samples and an ascent vehicle.

Once samples of Martian soil have been collected they will be loaded on to the Mars ascent vehicle. This will then be launched into orbit around the planet to rendezvous with the Earth re-entry vehicle. After the rendezvous has taken place the Earth re-entry vehicle will return to Earth on a ballistic trajectory with the precious samples. These will then be recovered and isolated in a ‘curation’ facility to prevent contamination of the samples and to allow scientists to analyse them in safety.

An inflatable braking device will probably be used for the descent through the Martian atmosphere, similar to that proposed for the ExoMars mission. For re-entry into the Earth’s atmosphere a parachute or inflatable device system is envisaged.
A number of new technologies will be required to carry out this pioneering mission. These include the landing system on Mars, the Mars ascent vehicle, the rendezvous system in Mars orbit and the Earth re-entry vehicle or capsule. In principle all of these can be tested in a near-Earth environment except for the final qualification of the rendezvous and docking system, which should preferably be carried out in a Mars orbit. The technology required for this Flagship mission will be developed during a series of technology-driven arrow missions.

Some important factors influencing the design and development of the mission are:

• Landing site This may remain open for some time until knowledge of the Martian geochemical, biological and environmtnal characteristics progressively improve, through previous missions to the planet. This means that the spacecraft design will have to be sufficiently robust to cope with a variety of different landing sites that will be selected at a later stage of the programme.
  
• Sample size A soil sample of 500 grammes is being considered in line with the recommendations of the International Mars Exploration Working Group (IMEWG).
  
• Sample collection A miniature drill will be needed to collect samples of Martian soil at a certain depth. Samples will be taken from underneath the upper layer of soil as this is expected to be completely sterile due to the high level of radiation. The level will be high because unlike the Earth’s atmosphere, that on Mars does not filter radiation. Signs of past forms of life will probably not be found on the surface due to the high oxidisation levels, which destroy identifiable bio-signatures.
  
• Sample protection Careful measures will be needed to protect the sample. On the one hand it will be necessary to avoid contamination of Mars by organisms from Earth and on the other, it will be essential to ensure that no Martian organism – if any exist – contaminates the Earth.
  
  If all goes according to plan, this challenging and complex mission could be launched as early as 2011.