HELSINKI — China has selected near-Earth object 2019 VL5 for a combined asteroid deflection and observation test to launch 2025.
The mission will use a Long March 3B rocket and carry both an impactor and observer spacecraft, according to a presentation by Chen Qi from China’s Deep Space Exploration Laboratory at the 8th IAA Planetary Defense Conference in Vienna, Austria, last week.
The two spacecraft will separate into different trajectories after launch. Notably, the observer spacecraft will reach the asteroid first for initial observations and evaluating its topography.
The impactor will smash into the roughly 30-meter-diameter 2019 VL5 with relative velocity of 6.4 kilometers per second, with the aim of altering the asteroid’s velocity by around five centimeters per second.
The observer spacecraft will then evaluate the asteroid after the impact, according to a mission profile presented at the conference.
It will carry optical, radar and laser remote sensing payloads and a dust and particle analyzer for assessing the target. The mission profile states that the observer spacecraft will use a high-resolution camera to observe the ejecta from the impact while in a 30 km orbit perpendicular to the path of the impactor.
The small asteroid will also be observed during annual observation windows in October and November ground-based telescopes and the Xuntian space telescope, which is set to launch into a similar orbit as the Tiangong space station around the end of 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 impacted the asteroid Dimorphos, a satellite of the larger Didymos, Sept. 26, 2022. It was found to have altered the orbit of Dimorphos, marking a success for the world’s first planetary defense asteroid deflection demonstration.
ESA’s Hera mission will observe Didymos and Dimorphos later this decade to more finely determine the effects of the DART collision.
The Chinese test will impact a much smaller, less massive asteroid, but launch both impactor and observer in a single launch.
China’s test is part of a wide planetary defense plan being devised by the country to counter the threats posed by near Earth asteroids, including an asteroid detection and early warning system. Planetary defense was noted as a key area of research in China’s most recent space white paper, released in early 2022.
Breakthroughs on multiple key technologies have been made, including high-speed impact deflection modeling simulations, according to Chen. Chen also stated that all nations are welcome to participate in the program.
Earlier reports noted that the mission was initially targeting asteroid 2020 PN1 and launching in 2026.
Like the previous target, 2019 VL5 is an Aten-class asteroid, a group of objects that cross the orbit of Earth but have an orbital period less than one year. 2020 PN1 is now a backup target, with other potential targets noted should the mission need to launch in 2026 or 2027.
Targets for the test were selected based on a series of principles. These include avoiding objects considered a risk before or after an impact, with an orbital inclination less than five degrees, relatively high magnitudes for viewing and multiple observation opportunities, potential science value and launch windows between 2025-2027.
