China is planning its first mission to impact an asteroid in the name of planetary defense. The mission will serve a dual purpose: One craft will impact the asteroid while its partner observes the space rock to learn more about the solar system and its formation.
The China National Space Administration (CNSA) mission may have already selected its target — the near-Earth object (NEO) 2015 XF261, a nearly 100-foot-wide (30 meters) asteroid.
According to the small-body database managed by NASA's Jet Propulsion Laboratory (JPL), 2015 XF261 last came relatively close to Earth just this week, on Tuesday (July 9), when it passed within 31 million miles (50 million kilometers) of our planet. The space rock was traveling at around 26,000 mph (42,000 kph), roughly 30 times faster than the speed of sound.
The nonprofit Planetary Society reported that this is the latest development in asteroid impact mission planning for China, a country that has recently become increasingly interested in planetary defense.
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The Planetary Society pointed to a recent paper in the Journal of Deep Space Exploration that discussed the proposed 2015 XF261-targeting mission.
"For China's first near-Earth asteroid defense on-orbit verification mission, a defensive disposal demonstration will be carried out on the potential risk of near-Earth asteroids impacting the Earth," the study states.
"The scientific objectives of the on-orbit verification of asteroid defense and its specific scientific exploration mission will be designed and proposed," it adds. "A scientific payload demand analysis will be carried out, and payload configuration plans and exploration mission requirements will be proposed to provide a decision-making basis for the future implementation of asteroid defense missions."
Following the imapct of DART
The planned mission follows in the footsteps of a groundbreaking NASA planetary defense mission, the Double Asteroid Redirection Test (DART), which in September 2022 impacted the smaller body in the Didymos binary asteroid system.
The impact of the 1,260-pound (570 kilograms) DART spacecraft on the moonlet Dimorphos, which orbits a larger 2,560-foot (780 m) asteroid called Didymos, at 14,000 mph (22,500 kph) was deemed a success. The impact shifted the orbit of the two asteroids and demonstrated that, with enough lead time, a kinetic impactor could divert a smaller asteroid from an impending collision with Earth.
In October 2024, the European Space Agency (ESA) will launch the Hera spacecraft to the Didymos system to further assess the impact of the DART mission. Hera is expected to rendezvous with Dimorphos and Didymos in 2026.
China's two-spacecraft 2015 XF261 mission will combine the work of DART and Hera, impacting the NEO and observing its target for between six months and a year after the collision.
Asteroids like 2015 XF261 are thought to have been created from material left over after the formation of the planets around 4.6 billion years ago. As such, they offer the opportunity to study "unspoiled" material that was the building blocks of the solar system's worlds, including Earth.
The CNSA mission is expected to launch before 2030, and the final choice of its NEO target will depend on its launch schedule. In April 2024, SINA Technology reported that Wu Weiren, director of China’s Deep Space Exploration Laboratory (DSEL), set a more firm date for the mission's launch, stating it would blast off in or around 2027.
2015 XF261 is set to pass Earth in March and May 2027, but the asteroid will still be 20 million miles (32 million km) from our planet at the time, and the CNSA will need time to reach it. DART hit Dimorphos when its system was just 7 million miles from Earth, and that journey took 10 months to complete.
The CNSA could get another shot at punching 2015 XF261 in April 2028, when the asteroid will be around 13 million miles (21 million km) away. But the best opportunity for such a mission seems to come in April 2029, when the asteroid will come to within 4.2 million miles (6.8 million km) of Earth. Another good chance will come in April 2030, when 2015 XF261 approaches Earth within around 4.4 million miles (7.1 million km).
This isn't the first asteroid impact mission proposed by CNSA. In 2023, the Chinese space agency seemed to be planning a planetary defense test to launch in 2025.
This mission would have set its sights on a different asteroid, known as 2019 VL5. It's not known why the CNSA seems to have switched from this NEO, which is also about 100 feet (30 m) wide, to 2015 XF261.
