D. Rosenberg, A. Goldberg, M. Keidar, N. Kalderon, C.Friedman, I. Gur, Y. Ron, G. Kushnir, L. Ben-Yishay, I.Beigelman, I. Baskin, P. Bruk
Dr. Fred Ortenberg, Dr. David Mishne
Microsatellite “INSPECTOR” was designed in order to observe the International Space Station (ISS) with high resolution imagery both in the visible and the IR wavelengths during ISS lifetime. The system is operating independently from the Station. It is also capable of observing docked spacecraft, support EVA operations and environmental monitoring. The detection task would be aided by detailed, on-demand images of any region of vehicle’s exterior. The satellite is able to maneuver in the vicinity of ISS, and perform automatic, image-based navigation.
The satellite will be ferried on board the space station using existing platforms and will be launched from the ISS airlock. It will then enter a yearlong mission to observe the ISS from multiple orbits. The satellite is capable of imaging both in the visible and the IR wavelengths with live video option. It communicates directly with the ISS, however in a case of a critical failure in the ISS it has the ability to communicate with a ground station as well.
Satellite-inspector design guidelines included: using trade-off studies to iterate spacecraft designs and components, and selecting COTS equipment whenever possible while injecting advanced technologies. A strong emphasis was given to maintaining weight and cost budgets during the design of the satellite.
The INSPECTOR satellite is based on aluminium structure of rectangular parallelepiped form. The microsatellite weight is 35 kg and its dimensions are 600x600x600 [mm]. The payload CCD cameras maximal resolutions at the distance between ISS and Inspector about 100cm are 1cm and 11cm in visible and IR respectively. The redundant attitude sensor set includes a 3-axis magnetometer, a star tracker and a block of fibre optic gyros (FOG). The attitude actuators include an integrated momentum biased system and magneto torques. The satellite pointing capability is about 0.5º.
The satellite employs six hydrazine reaction thrusters designed by RAFAEL for manoeuvres and has redundant on-board computers for command and data handling. Thermal control is provided by a combination of passive methods. Communications (mission and telemetry) with ground station use innovative S-bands link. Electrical power, provided by body-mounted Silicon solar cells and Li-Ion batteries, exceeds 68 W averages. The satellite design accommodates mean mission duration about one year. For launch, the Russian relatively low cost, high performance and reliable launchers will be chosen. The overview of Inspector mission, the details of microsatellite design and simulations of satellite performance are presented in Students Project Final Report and Report on 55thInternational Astronautical Congress, October 2004, Vancouver, BC. IAC-54-W.03.5
Figures below present isometric views of the satellite: