China Delays Asteroid Deflection Mission to 2027, Changes Target

China has announced the changing of target and a new launch date for their first planetary defence mission. The mission, originally slated for 2025, has been rescheduled to launch in 2027. This change comes with a new target: the asteroid 2015 XF261.

New Launch Date and Target

The mission’s new launch date of 2027 marks a two-year delay from the previously planned 2025 launch, no reasons behind this delay was provided. Li also revealed that the mission will now aim for asteroid 2015 XF261, a 30-meter-wide body. This size is comparable to the mission’s earlier target, 2019 VL5.

Two spacecraft will be launched together on a Long March 3B rocket. The observer spacecraft is set to perform a flyby of Venus before reaching the asteroid in early 2029. Approximately three months later, in April 2029, the impactor spacecraft will collide with 2015 XF261 at a speed of 10 kilometers per second, aiming to alter its orbit.

This impact will occur when the asteroid is about seven million kilometers from Earth.

A Year of Asteroid Awareness

Interestingly, the asteroid deflection mission’s impact date coincides with the close flyby of near-Earth asteroid Apophis in April 2029.

This event has already attracted the attention of several space agencies, which are planning missions to study Apophis. While Li did not mention specific plans to study Apophis, he highlighted that 2029 will be a significant year for “asteroid awareness and planetary defense.”

The primary objective of the mission is to demonstrate the “kinetic impactor” approach to planetary defense. This method involves altering an asteroid’s orbit through a high-velocity impact, potentially preventing a future collision with Earth. This concept was previously tested by NASA’s Double Asteroid Redirection Test (DART) mission, which successfully changed the orbital period of Dimorphos, a moon orbiting the asteroid Didymos, in 2022.

Potential for Disruption

A notable difference between China’s mission and NASA’s DART mission is the size of the target asteroid. At 30 meters across, 2015 XF261 is significantly smaller than Didymos and Dimorphos. This smaller size allows astronomers to more directly measure any changes in the asteroid’s orbit. However, it also raises the possibility of the impact disrupting the asteroid rather than merely deflecting it.

“It does have the potential to disrupt the small asteroid...Even if we disrupt it, it will also provide a method, a way to deflect a small-sized asteroid. It will provide an opportunity to study the internal structure of a small asteroid,” - , Li Mingtao from the National Space Science Center of the Chinese Academy of Sciences

Future Plans and Observatories

The mission has yet to be named, but China is considering a global competition to select a name and logo, part of a broader initiative that may include design studies for future planetary defense missions.

China is exploring several additional concepts for asteroid deflection or disruption, including using the launch vehicle’s upper stage as an impactor to increase energy delivery. Another concept, inspired by NASA’s canceled Asteroid Redirect Mission, would attempt to capture an asteroid. There are no timelines for these missions yet.

China is also studying concepts for a space-based observatory to search for near-Earth asteroids. This observatory would be similar to NASA’s Near Earth Object Surveyor mission, scheduled for launch in 2027. Chinese scientists are exploring several “novel orbits” for this observatory, including the sun-Earth L1 Lagrange point, positions leading or trailing Earth in its orbit, and even a constellation of spacecraft in a distant retrograde orbit around the moon. There is no schedule yet for the development of this observatory.

As the world continues to advance in planetary defense strategies, China's mission to deflect 2015 XF261 represents a significant step forward for the nation in planetary defence.