On 7 May 2026, ESA and JAXA signed a Memorandum of Cooperation to deepen collaboration in planetary defence and a separate cooperation agreement for the Rapid Apophis Mission for Space Safety (Ramses) targeting asteroid (99942) Apophis. Ramses is planned for launch in 2028, with rendezvous before Apophis’s exceptionally close Earth flyby in April 2029; JAXA’s stated contributions include solar array wings, a thermal infrared imager, and an H3 launch opportunity.
Technically, Ramses is a live rehearsal for detecting how a near-Earth asteroid responds to extreme gravitational perturbation during a planetary flyby, which is directly relevant to impact-risk characterization, surface mechanics, and orbit prediction. For the Lunar Ark, the mission is a model for building resilient space-based surveillance and for preserving the operational knowledge needed to identify, track, and characterize objects that could threaten lunar infrastructure or Earth recovery capacity.
Ark priority: monitor Ramses schedule fidelity, payload integration, and any results on Apophis’s shape, spin, regolith behavior, and thermal response after Earth encounter. Integrate the mission’s sensor architecture, orbital-analysis methods, and international coordination model into long-term archive standards and into lunar civil-defense planning.
The single most important takeaway is that ESA and JAXA have converted Apophis into a near-term, joint planetary-defence stress test that can materially improve humanity’s ability to predict and mitigate asteroid hazards.