China launches four Earth-observation radar satellites into orbit

China launches four Earth-observation radar satellites into orbit
by Simon Mansfield
Sydney, Australia (SPX) Dec 20, 2024

China successfully launched four Earth-observation radar satellites into space early Tuesday morning aboard a Long March 2D rocket, according to China Aerospace Science and Technology Corporation (CASC). The launch took place at 2:50 am from the Taiyuan Satellite Launch Center in Shanxi province, marking a significant step in China's expanding satellite network.

The four satellites, named PIESAT-2, were developed by the Beijing-based private company GalaxySpace. Equipped with advanced synthetic aperture radars (SAR), these satellites are capable of capturing high-resolution images under all weather conditions and during both day and night. Duan Xiao, chief designer of the satellites, explained, "Synthetic aperture radar allows for round-the-clock, all-weather monitoring of designated areas on Earth and can play important roles in many public service fields such as land resources management, natural disaster detection, and geological mapping."

This mission is notable as it involved deploying multiple satellites using a single rocket, showcasing China's growing capability in efficient satellite delivery. The Long March 2D rocket, designed by the Shanghai Academy of Spaceflight Technology, has a diameter of 3.8 meters. Its spacious interior enables omnidirectional wave transmission, facilitating effective satellite-to-ground communication. The rocket is powered by liquid propellants and can carry a payload of up to 1.3 tons into a sun-synchronous orbit at an altitude of 700 kilometers.

Despite encountering extreme weather conditions, including temperatures dropping below minus 20 degrees Celsius, the launch proceeded successfully. To mitigate the impact of low temperatures - a challenge that has long posed risks to aerospace missions - engineers applied advanced thermal insulation layers to the rocket's fairing and critical components. Warm air was continuously supplied through ground air ducts at the launch tower to maintain optimal operating conditions.

Historical precedent underscores the importance of addressing cold-weather risks. The 1986 Challenger disaster highlighted the dangers of brittle rocket components caused by freezing temperatures. Since then, technological advancements have enhanced aerospace safety, but precautions remain critical in extreme climates.

The successful deployment of the PIESAT-2 satellites represents the 553rd mission for the Long March rocket series and China's 65th launch of 2024. CASC has reported that at least eight additional PIESAT-2 satellites will be launched next year, comprising four sun-synchronous orbit X-SAR satellites and four low-angle C-SAR satellites. Once all 20 satellites are in place, the network will enable global operations, significantly improving satellite response capabilities for Earth observation.

Years of consistent Long March rocket launches have solidified the series' reputation for reliability and performance, reinforcing China's position as a major player in global space technology.