ESA has awarded Airbus a €491 million (US$522 million) contract to design and build the Earth Return Orbiter, which will return the first samples collected from the Red Planet by NASA's Perseverance rover to Earth.
Telescopes have been observing Mars since the days of Galileo and spacecraft have been landing successfully on it since the 1970s, but, aside from a handful of ancient meteorites, nothing from the Red Planet has ever been brought to Earth for study.
This is a problem because, despite becoming increasingly sophisticated, there are limits to what robotic landers and rovers can do. If uncontaminated samples of Martian rock and soil could be returned to Earth, scientists could conduct a much larger variety of tests much more quickly to answer questions like whether life could or once did exist on Mars. In addition, some of the samples could also be kept in anticipation of the development of new investigation methods.
This is the basic rationale behind the joint ESA/NASA Mars Sample Return project, of which the Earth Return Orbiter will be the final component when it lifts off atop an Ariane 6 rocket in 2026 at the start of its five-year mission.
The first part of the Mars Sample Return project is NASA's Perseverance rover, which is scheduled to land on Mars in February 2021. The rover will traverse the Martian landscape looking for areas where life, past or present, could exist and use its drill-equipped robotic arm to collect samples. These samples will be sealed in tubes that will be left on the ground in one or more caches.
For the second phase, the Surface Retrieval Lander will launch in 2026. This lander consists of a surface platform equipped with the robotic Sample Transfer Arm, the Sample Fetch Rover, and the Mars Ascent Vehicle.
After touching down near the sample caches, the Sample Fetch Rover will deploy, drive to the caches, and collect the tubes. It will then return to the lander where the robotic arm will take the tubes and place them in the Orbiting Sample capsule in the Mars Ascent Vehicle. The Mars Ascent Vehicle will then lift off and release the Orbiting Sample capsule in orbit.
This is where the Earth Return Orbiter comes into play. When it arrives in Mars orbit in 2027 thanks to its hybrid RIT-2X ion engines/chemical propulsion system, the six-ton spacecraft will act as a communication relay for the Surface Retrieval Lander and Perseverance. When the Orbiting Sample capsule launches, the Earth Return Orbiter will use its autonomous systems to rendezvous with the capsule. The Orbiting Sample will then be transferred to the Earth Return Orbiter, where it will be bio-sealed in a secondary containment system before being secured in the Earth Entry Vehicle.
The Earth Return Orbiter will then leave Mars orbit and begin its year-long journey to Earth. Finally, the Earth Entry Vehicle will be released and re-enter the Earth's atmosphere while the Earth Return Orbiter goes into orbit around the Sun. Once the it lands in the desert of Utah, the samples will be collected and placed in quarantine at a sample receiving and curation facility before being released for study.
"We’re bringing the full force of our experience gained on Rosetta, Mars Express, Venus Express, Gaia, ATV, BepiColombo, and JUICE to ensure this mission succeeds," says Jean-Marc Nasr, Head of Airbus Space Systems. "Bringing samples back to Earth from Mars will be an extraordinary feat, taking interplanetary science to a new level and Airbus is excited to take on this challenge as part of this joint international mission."
Source: Airbus
