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Orion Optical Navigation Progress Toward Exploration Mission 1Optical navigation of human spacecraft was proposed on Gemini and implemented successfully on Apollo as a means of autonomously operating the vehicle in the event of lost communication with controllers on Earth. The Orion emergency return system utilizing optical navigation has matured in design over the last several years, and is currently undergoing the final implementation and test phase in preparation for Exploration Mission 1 (EM-1) in 2019. The software development is past its Critical Design Review, and is progressing through test and certification for human rating. The filter architecture uses a square-root-free UDU covariance factorization. Linear Covariance Analysis (LinCov) was used to analyze the measurement models and the measurement error models on a representative EM-1 trajectory. The Orion EM-1 flight camera was calibrated at the Johnson Space Center (JSC) electro-optics lab. To permanently stake the focal length of the camera a 500 mm focal length refractive collimator was used. Two Engineering Design Unit (EDU) cameras and an EDU star tracker were used for a live-sky test in Denver. In-space imagery with high-fidelity truth metadata is rare so these live-sky tests provide one of the closest real-world analogs to operational use. A hardware-in-the-loop test rig was developed in the Johnson Space Center Electro-Optics Lab to exercise the OpNav system prior to integrated testing on the Orion vehicle. The software is verified with synthetic images. Several hundred off-nominal images are also used to analyze robustness and fault detection in the software. These include effects such as stray light, excess radiation damage, and specular reflections, and are used to help verify the tuning parameters chosen for the algorithms such as earth atmosphere bias, minimum pixel intensity, and star detection thresholds.
Document ID
20180000595
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Holt, Greg N.
(NASA Johnson Space Center Houston, TX, United States)
D'Souza, Christopher N.
(NASA Johnson Space Center Houston, TX, United States)
Saley, David
(NASA Johnson Space Center Houston, TX, United States)
Date Acquired
January 17, 2018
Publication Date
January 8, 2018
Subject Category
Space Communications, Spacecraft Communications, Command And Tracking
Optics
Report/Patent Number
JSC-E-DAA-TN49589
Meeting Information
Meeting: American Institute of Aeronautics and Astronautics (AIAA) Spaceflight Mechanics Conference
Location: Kissimmee, FL
Country: United States
Start Date: January 8, 2018
End Date: January 12, 2018
Sponsors: American Inst. of Aeronautics and Astronautics
Funding Number(s)
WBS: WBS 747797.06.13.15.99.10
Distribution Limits
Public
Copyright
Public Use Permitted.
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