A shoebox sized spacecraft named Don Quijote will attempt to land on the surface of an asteroid and survive. The European Space Agency has contracted Spanish company EMXYS to build the first CubeSat designed to operate on an asteroid. It will be deployed by ESA's Ramses mission onto the Apophis asteroid before the rock passes closer to Earth than many satellites.
A rare flyby that becomes a free science experiment
Apophis is 375 meters across, roughly the size of a cruise liner. On 13 April 2029, it will fly past Earth at an altitude of 32,000 kilometers. That path takes it inside the orbit of geostationary satellites. ESA's programme manager for Mars and Beyond, Orson Sutherland, called the arrival a unique opportunity. Earth's gravity is expected to pull on the asteroid hard enough to trigger deformation and possibly set off asteroid quakes. Don Quijote will monitor those changes from the surface.
Tight deadline and reused spacecraft design
Ramses must launch on a Japanese H3 rocket by spring 2028. That gives the team less than two years for development, integration and testing. To speed things up, Ramses reuses design elements from ESA's Hera asteroid mission, which is set to reach the Dimorphos asteroid in November. Ramses will carry two CubeSats. One is Farinella, built by Italy's Tyvak International, which will carry a ground penetrating radar and a dust analyser. The other is Don Quijote, from Spain's EMXYS. EMXYS previously built a gravity measuring gravimeter for Hera's Juventas CubeSat, which will try to land on Dimorphos.
Landing on an unknown world with three instruments
Don Quijote must operate in deep space, land autonomously on a strange surface, survive there, perform science and relay results back to the Ramses mothership. EMXYS CEO José A. Carrasco noted that his company has built CubeSat platforms for low Earth orbit before, but never for this kind of challenge. The CubeSat carries three instruments. A new gravimeter comes from the Royal Observatory of Belgium with EMXYS. A magnetometer from Germany's Technische Universität Braunschweig will measure whether the asteroid has a magnetic field and how it changes when interacting with Earth's field and gravity. A seismometer from French aerospace centre ISAE-SUPAERO will perform the first seismic measurements ever taken on an asteroid.
Ramses mission manager Paolo Martino said the last main contract has been signed and the team can now implement the mission within a tight timescale. The asteroid will not wait. Don Quijote is set to become the first CubeSat to operate on an asteroid surface, turning a rare natural event into a direct measurement of how a large space rock responds to Earth's pull.
