A lander for China's Mars mission is seen after a hovering-and-obstacle avoidance test at a test facility in Huailai, Hebei province, China November 14, 2019. China on Thursday successfully completed a crucial landing test in northern Hebei province ahead of a historic unmanned exploration mission to Mars next year. REUTERS/Jason Lee

A lander is hanged for a hovering-and-obstacle avoidance test for China's Mars mission at a test facility in Huailai, Hebei province, China November 14, 2019. China is on track to launch its Mars mission, Zhang Kejian, head of the China National Space Administration, said on Thursday, speaking to foreign diplomats and the media before the test. REUTERS/Jason Lee

A lander is hanged for a hovering-and-obstacle avoidance test for China's Mars mission at a test facility in Huailai, Hebei province, China November 14, 2019. The Mars lander underwent a hovering-and-obstacle avoidance test at a sprawling site in Huailai, northwest of Beijing. REUTERS/Jason Lee

A lander is hanged for a hovering-and-obstacle avoidance test for China's Mars mission at a test facility in Huailai, Hebei province, China November 14, 2019. The journey through space will take about seven months, while landing will take seven minutes, said Zhang Rongqiao, chief architect of the Mars exploration programme. REUTERS/Jason Lee

A lander for China's Mars mission is seen before a hovering-and-obstacle avoidance test at a test facility in Huailai, Hebei province, China November 14, 2019. The same Long March 5 rocket is meant to deliver the Chang'e-5 probe to the moon by the end of 2019 or early next year to bring back samples of lunar rocks. REUTERS/Jason Lee

A lander for China's Mars mission is seen before a hovering-and-obstacle avoidance test at a test facility in Huailai, Hebei province, China November 14, 2019. REUTERS/Jason Lee