Look up: ESA and JAXA to launch the Ramses mission to observe Apophis
On 13 April 2029, billions of people will witness a rare cosmic dice roll that has not been seen for countless generations.
The event is the close approach of Apophis: an asteroid approximately 375 m in diameter that will pass within 32,000 km of the Earth, only about 10 per cent of the distance to the Moon. While the asteroid poses no danger to the Earth, the proximity of a small celestial body of this size is an event that occurs only once every several thousand years.
“The whole world will talk about Apophis,” says Patrick Michel, planetary scientist at the French National Centre for Scientific Research (CNRS), Côte d’Azur Observatory. “And for me, to have ESA and JAXA together while everyone is watching is a fantastic message regarding international cooperation, a link between nations that we especially need at this time.”
At the end of November 2025, the Council Meeting at Ministerial Level for the European Space Agency was hosted in Bremen. The meeting is held every three years and brings together ministers from the 23 ESA member states to decide which of the proposed programs will reach the launch pad.
“Passing a mission is very complex,” explains Michel. “It’s not only about the science. You should never neglect any detail because it’s like a political election where you never know what will convince a guy to vote for you.”
Michel is a world expert on asteroid trajectories. He has watched multiple proposals come before the ESA Ministerial Council focussed on defending our planet against hazardous asteroids. Twenty years ago, the Don Quijote asteroid deflection mission concept was left in a drawer because of the absence of funding for the dual spacecraft design. The subsequent concept, AIM, which would have been launched at the same time as the NASA DART mission, was also turned down in 2016 despite being accompanied by a letter of support signed by more than 1000 people including Nobel Prize winners, astronauts, and celebrities. However, the next attempt was the Hera mission, which was accepted by the 2019 Ministerial Council and launched in 2024. Hera is en route to visit asteroid Didymos in November 2026 to investigate the result of the impact by the NASA DART mission to better understand kinetic deflection techniques.
“You have to be perseverant,” says Michel, who is the Hera Mission Principal Investigator. “That’s my first take-home message. It’s never easy, we must accept some failures along the way that should not discourage us.”
It was the experience gained by both the failures and successes that led to the latest triumph at the 2025 Ministerial Council: the decision to launch the Ramses mission to rendezvous with asteroid Apophis.
The Rapid Apophis Mission for SpacE Safety (Ramses) will accompany Apophis during the flyby of Earth in 2029 to study how the Earth’s gravity affects the asteroid. This is important for planetary defence, where understanding how asteroids respond to external forces will be key to deflecting a potential impact.
“Hayabusa2 showed that the response to an interaction with an asteroid is not necessarily easy to predict, because the environment is very low gravity,” explains Michel, who serves as ESA’s Project Scientist for Ramses, referring to the large crater and shaking created during the asteroid impact experiment by the JAXA Hayabusa2 mission. “In this unique time, nature is doing the job for us. Nature will provide the interaction, and we just have to observe.”
The Ramses mission to rendezvous with asteroid Apophis (ESA).
ESA will not visit Apophis alone. The Ramses mission is in partnership with JAXA, who will launch the spacecraft onboard the H3 rocket from Tanegashima Space Center, and provide a thermal infrared imager and flexible solar panels. For Fujimoto Masaki, Director General of the JAXA Institute of Space and Astronautical Science, Ramses was too important for JAXA not to support.
“Ramses needs to happen,” Fujimoto says firmly. “We have been working closely with ESA Space Safety Program, and this was a mission where we wanted to offer major cooperation.”
The launch of Ramses also supported a second JAXA project, the DESTINY+ mission to observe multiple asteroids during fast flybys that includes the active asteroid Phaethon. DESTINY+ had originally planned to fly on the smaller JAXA Epsilon S rocket, but was postponed after a failed ground test damaged facilities at the Noshiro Rocket Testing Center. With an H3 launch for Ramses, DESTINY+ could join the larger launch and include a flyby of asteroid Apophis before the arrival of Ramses, returning the first space images of the asteroid that will help tighten the Ramses operation plan.
Michel believes that the strong support from JAXA for Ramses was an important factor in the Ministerial Council’s decision.
“It was a strong message that was well received,” says Michel. “Having an agency who is recognised as an expert in small bodies being motivated to be a partner helped a lot of convince the member states.”
The design for the Ramses spacecraft is inherited from the Hera mission, but with a smaller antenna and solar panels due to the much closer approach of Apophis compared to asteroid Didymos. Hera had been developed in four years and surprisingly both launched on time and come under budget, factors that leveraged further support as Ramses must be finished in a similar time frame.
“Apophis doesn’t wait!” exclaims Michel. “And we couldn’t start to plan earlier because Hera first needed to launch so that we could prove that we could do it!”
JAXA is also a collaborator on Hera, providing the thermal infrared imager that will next fly on Ramses. In fact, the two agencies have been in close contact since ESA first considered the Don Quijote mission due to the JAXA expertise in asteroid exploration with Hayabusa and later Hayabusa2. With the creation of the ESA Space Safety Program that combines the fast development timeline of the technology-focussed missions with scientific objectives, the partnership between ESA and JAXA has deepened as the program mirrors the design of the ISAS small body program.
“The excitement of a mission is not only the pure science value,” says Fujimoto. “Ramses is also the opportunity to take the cooperation between ESA and JAXA to a higher level.”
Such international collaborations do bring complications, as both agencies must go through independent approval processes for funding. However, the value of such partnerships is far more than sharing costs: it is in the differences that are brought to the table.
“If our expertise simply overlapped, then the collaboration would be just a question of money,” explains Michel. “That would be satisfying for maybe the tax payers, saving money on both sides, but scientists want to find partners who bring expertise, new instruments, or new approaches.”
One example was the decision by the JAXA ISAS team to include the small carry-on impact experiment onboard Hayabusa2. While careful design ensured that the spacecraft was not in danger, Michel feels that many space agencies would have balked at an experiment that involved an explosive impact. Yet the experiment allowed Hayabusa2 to collect pristine subsurface material from the asteroid and examine the result of an impact on a rubble pile structure. The willingness by the JAXA team to accept risks that benefit the mission was a valuable counterpoint, especially for planetary defence missions which must be developed on tight timescales.
“The acceptance that some level of risk exists—and that missions can potentially be developed more rapidly by embracing that risk—was, I believe, a key inspiration for the ESA program,” says Michel.
Of course, collaborations between different countries can be difficult. ESA is a collaboration between multiple countries in Europe, but Michel acknowledges that the cultural difference is far more marked with Japan.
“Germany, Italy, and France may not have the same culture, but we can still throw things at each other,” jokes Michel. “We don’t do that with the Japanese!”
But Michel feels that learning how to translate the small but important differences, such as the meaning of a silence during a meeting, is part of the excitement of an international collaboration.
“The ties you form are deep,” Michel explains. “It takes time, but once you have it, we know each other well and it works fantastically afterwards.”
This is Michel’s second take-home message to people building careers in the space industry.
“There is nothing better than enriching each another with different cultures and ways of working,” says Michel firmly. “This is why cooperation between ESA and JAXA is so fantastic.”
The arrival of Apophis may be the strongest demonstration of this idea. While the asteroid does not pose a risk to the Earth, the international presence of two space agencies exploring the event together to learn how to protect our planet is a powerful message. For Michel, it’s a message that will be as valuable as the science.
“When everyone looks at Apophis, we will have two main agencies together on the asteroid. And that’s a great message. I wouldn’t have been so satisfied with just one agency there.”
Further information:
Ramses: ESA’s mission to asteroid Apophis (external site)
Hera: Binary Asteroid System Exploration (JAXA site)
From Cosmos:
A rebel alliance: the small mission collaboration between ESA and ISAS
July 5: the day the world was due to end
Protecting our home world: The Planetary Defence mission fleet
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