Solar Arrays and Battery Power Sources Conceptual Design for Low Earth Orbit Microsatellites

Abstract

The power system is a vital subsystem in a spacecraft. As long as the spacecraft has power, it can perform its mission. Almost all other failures can be worked out by ground operations from ground stations but a power loss is very fatal for the spacecraft. In the early years of spaceflight, the power system was also the limiting factor in any mission duration. Many studies show that solar cell power (short-circuit current and open-circuit voltage) are degraded by space environment radiation. The power system is designed such that the end of life (EOL) power is adequate for the mission’s requirements. Beginning of life (BOL) power is set by the estimate of the radiation damage over the spacecraft’s lifetime. It is well known in the literature, the radiation damage to solar cells is caused by high-energy protons from solar flares and from trapped electrons in the Van Allen belt. The purpose of this paper is to investigate the power system design trades involved in the mission analysis of a low earth orbit (LEO) satellite at an altitude of 700 km. Based on the power requirements of the payload and the constant power requirements for the remainder of the spacecraft (platform subsystems), the solar arrays and batteries for the spacecraft will be sized.