With a mass of six tonnes at lift-off from Earth, the six-metre-tall ERO spacecraft will have solar arrays covering a surface of 144 sq. metres and spanning more than 40 metres – among the largest ever built. During the ERO’s year-long voyage to Mars, solar electric propulsion will be employed for the cruise, followed by chemical propulsion for Mars orbit insertion. Solar electric propulsion will be utilised once again as ERO spirals down to a targeted circular rendezvous orbit at approximately 400 km. above the Mars surface.
While orbiting the Red Planet, the ERO is to provide communications coverage for the Perseverance Rover and the Sample Retrieval Lander – both developed by the U.S. National Aeronautics and Space Administration (NASA), which are two essential parts of the overall Mars Sample Return Campaign.
For the ERO mission’s second phase, the orbiter will detect, rendezvous with, and capture a basketball-size object called the Orbiting Sample (OS), which carries sample tubes collected on the Mars surface by the Sample Fetch Rover – an Airbus-developed four-wheel vehicle that will travel the planet to locate and pick up these samples.
The Orbiting Sample will be carried aloft by a Mars Ascent Vehicle to meet up with the ERO. After the Orbiting Sample’s rendezvous with ERO, an onboard Capture, Containment, and Return System (supplied by NASA) is to isolate the Orbiting Sample and transfer it within the ERO to an Earth Entry Vehicle (also supplied by NASA). Following a year-long return trip to Earth, ERO will deploy the Earth Entry Vehicle for touchdown at a pre-defined landing site.
In Airbus’ role as ERO’s prime contractor, the company will have overall responsibility for the orbiter’s mission, with spacecraft development centred in Toulouse, France, and mission analysis performed in the UK at its Stevenage operation.