HELSINKI — China launched what’s regarded as the world’s first geosynchronous orbit synthetic aperture radar satellite on Saturday.
A Long March 3B rocket lifted off from Xichang Satellite Launch Center in southwest China at 1:36 p.m. Eastern (1736 UTC) Aug. 12. The Land Exploration-4 01 (Ludi Tance-4 (01)) satellite successfully entered geosynchronous transfer orbit, the China Aerospace Science and Technology Corp., (CASC) announced inside an hour of liftoff.
Few details of the satellite were provided by CASC. Nonetheless the group’s “blue book” outlining plans for 2023 released in January noted the launch of a “high-orbit 20-meter [resolution] SAR satellite.”
The L-band synthetic aperture radar (SAR) satellite will provide all-day, all-weather remark of China and surrounding areas, boosting the country’s disaster prevention, reduction, and relief capabilities.
The land remark satellite series and “high-orbit SAR technology” are listed within the country’s Medium and Long Term Development Plan for Civilian Space Infrastructure (2015-2025). The plan includes establishing high and medium resolution optical and artificial aperture radar constellations for a variety of land, marine and atmospheric monitoring.
The series is separate from the China High-resolution Earth Statement System (CHEOS), which consists of Gaofen (“high resolution”) satellites. China’s Gaofen-4 satellite is a GEO optical satellite. SAR at GEO, while providing much lower resolution than satellites in low Earth orbit, can provide constant coverage and imagery despite cloud cover.
It just isn’t yet known what orbital scheme the Land Exploration-4 (01) satellite will enter. An inclined GEO orbit would produce a “figure eight” ground track over the world of intended coverage. Chinese academics from the Beijing Institute of Technology have produced a study of varied schemes, while others have published research into modified signal models for GEO SAR.
The (01) designation suggests China could launch other SAR satellites into geosynchronous orbits. The satellite was developed by the China Academy of Spacecraft Technology (CAST.)
The mission was followed early Monday by the launch of 5 automatic identification system (AIS) tracking satellites for HEAD Aerospace, which is affiliated to CASC.
A Kuaizhou-1A light-lift solid rocket lifted off from Xichang at 1:32 a.m. Eastern (0532 UTC) Aug. 14, official industry outlet China Space News reported.
The HEDE-3 A-E satellites join earlier satellites designed to acquire and transmit data for shipping and other maritime industries.
The Kuaizhou-1A was provided by Expace, a by-product from the China Aerospace Science and Industry Corp., (CASIC), a large state-owned defense contractor.
The launches were China’s thirty fifth and thirty sixth orbital missions of 2023. CASC goals to launch around 70 times this yr, while China’s business launch service providers are adding to Chinese activities.
Up to now Galactic Energy, iSpace, Space Pioneer and Landspace, in addition to state-owned business spinoffs CAS Space and Expace, have all reached orbit thus far this yr. One other, Orienspace, is targeting its first launch with the Gravity-1 solid rocket in December.