BUSAN, South Korea — China has changed the launch date and target for a mission that will try to demonstrate its ability to deflect an asteroid’s orbit.
He spoke at the Committee for Space Research (COSPAR) 45Thursday Science Assembly here July 15 Li Mingtao of the National Space Science Center of the Chinese Academy of Sciences said 2027 is the new launch date for a mission that will send one spacecraft to collide with a small asteroid and another to observe the impact.
The date is two years later than what another Chinese official announced at a conference in April 2023, saying the mission was then scheduled to launch in 2025. Li did not disclose the reason for the delay.
The mission also has a new objective. Li said the mission’s target will be asteroid 2015 XF261, a body estimated to be about 30 meters in diameter. This is roughly the same size as the mission’s earlier target, 2019 VL5.
He said the two probes will launch together on Long March 3B in 2027. The observation probe will make a flyby of Venus before arriving near the asteroid in early 2029. About three months later, in April 2029, the impactor will collide with the asteroid at a speed of 10 kilometers per second. This will happen when the asteroid is within seven million kilometers of Earth.
This schedule would mean that the asteroid impact would occur in the same month that another near-Earth asteroid, Apophis, would fly very close to Earth. Several space agencies are considering missions to study Apophis before or after the flyby. Li did not mention any plans to do so, but noted that 2029 will be a year of “asteroid awareness and planetary defense.”
The goal of the mission is to demonstrate a “kinetic impactor” approach to planetary defense by showing how a high-velocity impact can alter an asteroid’s orbit to avoid a potential collision with Earth. NASA demonstrated the same concept with its Double Asteroid Redirection Test (DART) mission, which collided with a moon orbiting the asteroid Didymos in 2022, changing its orbital period by more than half an hour.
One difference is that 2015 XF261 is significantly smaller than Didymos and its moon Dimorphos, allowing astronomers to directly measure the change in its orbit. One scientist at the COSPAR meeting noted the possibility that the impact could completely disrupt the asteroid, rather than deflect it.
“It has the potential to disrupt a small asteroid,” Li acknowledged, saying scientists had modeled the impact. “Even if we disrupt it, it will also provide a method, a way to deflect a small asteroid. It will provide an opportunity to study the internal structure of a small asteroid.”
The mission doesn’t have a name yet. But he said China is considering a global competition to choose a name and logo for the mission, part of an initiative that could also include design studies for future planetary defense missions.
Li said his center is exploring several other concepts for deflecting or disrupting an asteroid, including one that would use a launch vehicle’s upper stage as an impactor to increase the energy delivered. Another concept, inspired by NASA’s canceled Asteroid Redirect Mission, would try to intercept an asteroid. There is no timetable for these missions, he said.
China is also studying concepts for a space observatory that would search for near-Earth asteroids, similar to the development of NASA’s Near Earth Object Surveyor mission for launch in 2027. Li said the concepts explore several “new orbits” that include the Sun-Earth L. -1 Lagrange points, points leading or trailing the Earth in its orbit around the Sun, and even constellations of spacecraft in distant retrograde orbits around the Moon. There is no plan yet to develop this observatory, he said.