AUGMENTATION OF AN IMAGING CONSTELLATION WITH THE HYPERSPECTRAL MICROSATELLITE 'OKEV'

摘要

The OKEV microsatellite is a student project to design a scientific mission, which useshyperspectral wide field imaging in exploring marine and coastal environments. In order tobetter utilize the hyperspectral instrument it was suggested to place OKEV in orbit with anexisting 'On - going' constellation of Earth remote sensing satellites. OKEV would be placedas part of the AM-Train formation, in a circular sun synchronous Earth repeating orbit.OKEV satellite design guidelines included: using trade studies to iterate spacecraft designsand components; and selecting COTS equipment whenever possible while injecting advancedtechnologies.OKEV satellite presents an aluminum structure composed of prism and pyramid parts andis stabilized about all three axes using an integrated momentum biased system with someacquisition modes. The satellite employs cold-gas reaction thrusters for maneuvers and hasredundant on-board computers for command and data handling. Thermal control is providedby a combination of passive methods. Communications (mission and telemetry) with groundstation use innovative S-bands link. Electrical power, provided by body-mounted solar cellsand batteries, exceeds 63 W averages including more than 15% margin. OKEV designaccommodates mean mission duration of 5 years.The OKEV payload is a remote sensor of the Earth and the Earth’s atmosphere operatedin the hyperspectral mode – WFIS (Wide Field Imaging Spectrometer). The satellite totalmass is less than 85 kg including 20 kg of WFIS mass.