China has selected the 2019 VL5 near-Earth object for the combined asteroid deflection and observation test for the 2025 launch. According to a presentation by Chen Qi of China’s Deep Space Research Laboratory at the 8th IAA Planetary Defense Conference in Vienna, Austria last week, the mission will use a Long March 3D rocket and will feature both an impactor and an observatory spacecraft. will carry the vehicle.

After launch, the two spacecraft will separate into different orbits. It is noteworthy that the observation spacecraft will first reach the asteroid for the first observations and evaluation of its topography. The impactor will slam into 2019 VL5, about 30 meters in diameter, at a relative speed of 6.4 kilometers per second to change the asteroid’s velocity by about five centimeters per second.

The Observer spacecraft will assess the asteroid after the collision, based on the mission profile presented at the conference. It will have optical, radar and laser remote sensing capabilities, as well as a dust and particle analyzer for target assessment. The mission profile states that the observer spacecraft will use a high-resolution camera to observe the impact ejection while in a 30-kilometer orbit perpendicular to the impactor’s orbit.

The small asteroid will also be observed during the annual observation windows in October and November by the Xuntian Space Telescope and ground-based telescopes, which are expected to enter an orbit similar to that of the Tiangong Space Station in late 2024. The mission combines elements of NASA’s Double Asteroid Redirection Test (DART) impactor mission and the European Space Agency’s Hera, which will later observe the DART target system.

NASA launched DART in November 2021. The DART spacecraft collided with the asteroid Dimorphos, a moon of the larger Didymos, on September 26, 2022. Dimorphos was found to alter its orbit, marking the success of the Earth’s first planetary defense asteroid deflection. show. ESA’s Hera mission will observe Didymos and Dimorphos later this decade to more precisely determine the effects of the DART collision.

The Chinese test will collide with a much smaller and less massive asteroid, but will launch both an impactor and an observer in a single launch. China’s test is part of a far-reaching planetary defense plan the country is developing to counter the threats posed by near-Earth asteroids, including an asteroid detection and early warning system. Planetary defense was listed as a key research area in China’s latest space file, published in early 2022.

According to Chen, breakthroughs have been made in several key technologies, including high-speed simulation of impact deflection. Chen also said that all countries can participate in the program. Earlier reports indicated that the mission initially targeted the asteroid 2020 PN1, and is scheduled to launch in 2026.

Like the previous target, 2019 VL5 is an Aten-class asteroid, a group of objects that orbit Earth but have an orbital period of less than one year. 2020 PN1 is now a backup target and other potential targets listed if the task should be launched in 2026 or 2027.

The targets for the test were chosen according to a set of principles. These include avoiding objects with orbital inclination of less than five degrees, relatively high viewable magnitudes and multi-observation capabilities, potential science value, and launch windows 2025-2027, considered hazardous before or after collision.