Long March 4B launched with Ziyuan-3-2 on atop

Today at 03:17 GMT Chinese launch vehicle Long March 4B lifted to orbit high resolution imaging satellite Ziyuan-3-2 along with two additional spacecrafts-two commercial Argentinian NuSat-1 & NuSat-2 imaging satellites. 

Launch was planned and performed from Taiyuan Satellite Launch Center’s LC9 launch platform. Rocket was launched punctually at 03:17 GMT with three spacecrafts under payload fairing: Chinese remote sensing satellite Ziyuan-3-2 operated jointly by China (Center for Earth Operation and Digital Earth-CEODE) and Brazil (INPE-Instituto Nacional de Pesquisas Espaciais – National Institute of Space Research) and two commercial imaging satellites owned by Argentinian company Satellogic S.A.: NuSat-1 and NuSat-2 . These two small spacecrafts will be first two satellites of the Aleph constellation which will provide real time imaging services for customers around the globe.

Ziyuan-3-2 is second remote sensing satellite from Ziyuan-3 series; first was launched in 2012 and is operated by State Bureau of Surveying and Mapping. These satellites are designed and manufactured by China's Academy of Space Technology using modified ZY-2 satellite bus with three onboard high resolution cameras made by Changchun Institute of Optics, Fine Machinery and Physics as main payload. Satellite is based on two modules with imaging equipment installed in the front and not covered with any fairing. Inside service module engineers decided to install power generation unit, control unit, temperature control system, propulsion control unit, data processing unit and avionics are stored. Payload module includes sensors, Data Transmission System and data recording computer. Main payload consists of one camera able to take images with 2.5 m resolution and two operating in 4 m resolution. In spite of three imaging devices, satellite is equipped with  infrared multispectral spectrometer able to operate in resolution of 6 m. Main objectives of 5 years satellite's mission are urban planning, resource monitoring and disaster management. Ziyuan-3-2 weighs 2630 kg and is stabilized with 3 axis stabilizing system. It is powered by two deployable solar arrays with 6 m wingspan. Satellite will cover with range of its imaging devices area between 84° north and 84° south latitude from 505.984 km SSO orbit with a 97.421°.

NuSat-1 and NuSat-2 are imaging satellites built and designed by Satellogic S.A. company from Argentina. Company objective is creating Aleph constellation with 300 small satellites which will be able to provide low cost imaging service in real time for various commercial customers with 5 minute revisit time. Each satellite weighs 37 kg and their dimensions are 40 cm × 43 cm × 75 cm. Both satellites are equipped with U/V linear transponder provided by AMSAT-LU to offer services to the HAM community. Satellites are capable to downlink/uplink using U/V transponder (2 W of power) with uplink of 435.935 MHz to 435.965 MHz and a downlink of 145.965 MHz to 145.935 MHz frequencies. NuSats are also equipped with CW beacon operating at 145.900 MHz. Satellites will operate from  500 km SSO orbit with inclination at 97.5°.

Long March 4B remains in service since 1999. It was designed by China Academy of Launch Vehicle Technology for LEO and SSO missions with possibility of lifting up to 4200 kg of payload (for LEO, for SSO it is 2800 kg). It consists three stages fueled with N2O4/UDMH; rocket is long for 45.8 m with diameter at 3.35 m and weighs 249200 kg.