Second CubeSat added to ESAs Ramses mission for close study of Apophis

Second CubeSat added to ESAs Ramses mission for close study of Apophis
by Erica Marchand
Paris, France (SPX) May 21, 2025

ESA is expanding its Ramses mission to asteroid Apophis with the addition of a second CubeSat, further enhancing scientific efforts to study the asteroid during its extremely close approach to Earth on April 13, 2029. Apophis, measuring 375 meters across, will pass Earth at a remarkably close distance, offering a rare opportunity for in-depth observation.

The Ramses mission, which could be officially confirmed at ESA's Ministerial Council meeting this November, is scheduled to launch in 2028. The main spacecraft will rendezvous with Apophis and deploy two CubeSats to perform detailed studies before, during, and after the asteroid's flyby. These observations will assess changes in Apophis' orbit, shape, surface cohesion, and rotational dynamics caused by Earth's tidal forces.

The first CubeSat, announced in March, is designed for radar analysis of the asteroid's internal structure and surrounding dust. The newly announced second CubeSat, led by Spanish firm Emxys, will focus on surface features and geological properties. It will execute an autonomous approach and attempt a landing just kilometers from the asteroid. If successful, it will measure seismic activity from Apophis' surface.

"Landing on an asteroid is very challenging," said Ramses Project Manager Paolo Martino. "The irregular shape and surface properties make it difficult to identify a stable landing site, while the very weak gravity makes it hard to stay on the surface without bouncing off and drifting away."

"But the opportunity to study Apophis from the surface during this rare natural phenomenon is very exciting and scientifically valuable. Ramses' CubeSats will attempt higher risk, high reward activities that the main spacecraft cannot, such as a landing. In doing so, they will help us maximise the mission's scientific return, which is crucial, as an asteroid this large is thought to pass so close to Earth only once every few thousand years."

"This project marks a milestone for our company," said Jose A. Carrasco, CEO of Emxys. "To contribute to a mission that will monitor one of Earth's closest encounters with a large asteroid represents the highest level of scientific and technological challenge. We are proud to bring our capabilities to Europe's planetary defence efforts."

The CubeSat project brings together several European partners including GomSpace (Denmark), GMV (Spain), ISAE-SUPAERO (France), and the Royal Observatory of Belgium. Emxys previously contributed to ESA's Hera mission with the GRASS gravimeter on the Juventas CubeSat, currently en route to the Didymos asteroid system following humanity's first asteroid deflection attempt.