ESA’s proposed Hera mission, humankind’s first visit to a binary asteroid system, is set to undergo detailed study led by OHB System AG in Germany.
A multi-million euro contract awarded this week to the Bremen-based space company involves progressing the Hera mission, a further optimisation of the previous AIM mission. This will render Hera ready for presentation to European space ministers at ESA’s Ministerial Council next year, to take a final decision on flying the mission.
Building on the legacy of Europe’s Rosetta comet mission, Hera would fly to another small Solar System body, the Didymos pair of near-Earth asteroids.
A 160 m moon, informally called ‘Didymoon’ – about the same size as the Great Pyramid of Giza – orbits the 780 m-diameter mountain-sized main body. This smaller moon is Hera’s main focus. By 2026, when Hera is expected to arrive, Didymoon will have achieved historic significance: the first object in the Solar System to have its orbit measurably shifted by human effort.
A NASA mission called the Double Asteroid Redirection Test, or DART, is planned to collide with Didymoon in October 2022, attempting to deflect its orbit in a pioneering test of planetary defence. Hera will map the resulting crater as it surveys Didymoon’s surface, while also performing close-up measurement of the asteroid’s mass, building up a fuller picture of the collision and its aftermath.
Hera is envisaged as a technology-testing mission, featuring onboard autonomy resembling that of driverless cars, and two CubeSats to be deployed in the vicinity of Didymoon. These will enable testing of multi-satellite intersatellite link technology as well as gathering experience of low-gravity operations with miniaturised systems, paving the way for future asteroid mining efforts.
"We are excited to be working together with OHB System AG and partners in preparing this inspiring planetary defence mission,’ said Franco Ongaro, ESA Director of Technology, Engineering and Quality.
“The industrial team is an excellent example of Europe at its best, with nearly half of ESA Member States participating. With this work, they will be advancing European technical capabilities for small satellites in deep space with onboard autonomy for asteroid close-proximity operations.
“Together with its CubeSats, Hera will investigate the results of NASA's DART mission and complete the first international planetary defence endeavour safeguarding planet Earth."
Hera is being developed as part of ESA’s Space Safety and Security activities, fostering Europe’s capability to monitor space for hazards and protect Earth. Other elements include a new space weather mission, a network of asteroid-detecting ‘Flyeye’ telescopes as well as a space-debris removal mission and a space traffic management system.