Session
Frank J. Redd Student Competition
Location
Utah State University, Logan, UT
Abstract
Attitude determination for small satellites is a vital aspect of spacecraft operations. Earth Horizon Sensor(s) (EHS) are one of many sensors used in on-orbit attitude estimation. A conventional EHS captures infrared images of the Earth’s horizon and estimates the nadir vector in the spacecraft body frame, using the Earth’s curvature and prior knowledge of the spacecraft’s orbit. However, the design and test of new sensors increase mission cost and development time, while some spacecraft may not be able to accommodate such dedicated sensors. Therefore, it is beneficial if existing onboard optical sensors could be repurposed as effective EHS. The Space Flight Laboratory has previously designed and launched the NorSat-2 spacecraft, equipped with the Miniature Vehicle Inspection Camera (mVIC) for antenna deployment inspection. This paper proposes a generalized nadir vector estimation methodology using simulation images from an optical sensor such as the mVIC, which was not originally designed as an EHS. Nadir vector estimation accuracy with software-generated sensor images is discussed and demonstrates the viability of the mVIC to be used as an EHS.
Attitude Determination with Self-Inspection Cameras Repurposed as Earth Horizon Sensors
Utah State University, Logan, UT
Attitude determination for small satellites is a vital aspect of spacecraft operations. Earth Horizon Sensor(s) (EHS) are one of many sensors used in on-orbit attitude estimation. A conventional EHS captures infrared images of the Earth’s horizon and estimates the nadir vector in the spacecraft body frame, using the Earth’s curvature and prior knowledge of the spacecraft’s orbit. However, the design and test of new sensors increase mission cost and development time, while some spacecraft may not be able to accommodate such dedicated sensors. Therefore, it is beneficial if existing onboard optical sensors could be repurposed as effective EHS. The Space Flight Laboratory has previously designed and launched the NorSat-2 spacecraft, equipped with the Miniature Vehicle Inspection Camera (mVIC) for antenna deployment inspection. This paper proposes a generalized nadir vector estimation methodology using simulation images from an optical sensor such as the mVIC, which was not originally designed as an EHS. Nadir vector estimation accuracy with software-generated sensor images is discussed and demonstrates the viability of the mVIC to be used as an EHS.
