An Approach Guidance Method Using a Single Onboard Optical Measurement

An Approach Guidance Method Using a Single Onboard Optical Measurement PDF Author: Harold A. Hamer
Publisher:
ISBN:
Category : Approach guidance
Languages : en
Pages : 92

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Book Description
An empirical method has been developed for onboard guidance within the sphere of influence of a celestial body. For guidance maneuvers made at a relatively large distance from the body, only one preselected measurement from a star to the body is required. Although the method is designed to control the magnitude of the periapsis radius (or entry angle), the periapsis position and velocity automatically remain close to the nominal values. For lunar approach, error analysis with an assumed one-sigma error of 10 seconds of arc in the optical angular measurements and a one-sigma velocity-cutoff error of 0.2 m/sec has shown that perilune radius can be controlled to a one-sigma accuracy of from 7 to 13 km, depending on the time the approach guidance is performed.

An Approach Guidance Method Using a Single Onboard Optical Measurement

An Approach Guidance Method Using a Single Onboard Optical Measurement PDF Author: Harold A. Hamer
Publisher:
ISBN:
Category : Approach guidance
Languages : en
Pages : 92

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Book Description
An empirical method has been developed for onboard guidance within the sphere of influence of a celestial body. For guidance maneuvers made at a relatively large distance from the body, only one preselected measurement from a star to the body is required. Although the method is designed to control the magnitude of the periapsis radius (or entry angle), the periapsis position and velocity automatically remain close to the nominal values. For lunar approach, error analysis with an assumed one-sigma error of 10 seconds of arc in the optical angular measurements and a one-sigma velocity-cutoff error of 0.2 m/sec has shown that perilune radius can be controlled to a one-sigma accuracy of from 7 to 13 km, depending on the time the approach guidance is performed.

Midcourse and Approach Guidance Requirements for Simplified Onboard Control of Moon-to-earth Trajectories

Midcourse and Approach Guidance Requirements for Simplified Onboard Control of Moon-to-earth Trajectories PDF Author: Harold A. Hamer
Publisher:
ISBN:
Category : Inertial navigation (Aeronautics)
Languages : en
Pages : 68

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NASA Technical Note

NASA Technical Note PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 418

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Fixed-angle Translunar Guidance Procedures Using Onboard Optical Measurements

Fixed-angle Translunar Guidance Procedures Using Onboard Optical Measurements PDF Author: Harold A. Hamer
Publisher:
ISBN:
Category : Optical measurements
Languages : en
Pages : 50

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Book Description
Onboard procedures requiring only simple calculations have been developed for midcourse and approach guidance for translunar trajectories. For midcourse guidance the procedure relies solely on an optical range measurement. The approach-guidance procedure requires a star-to-body measurement and may require a range measurement, depending on the distance to the moon. For both procedures the velocity-correction vector is applied in a fixed inertial direction. In the approach-guidance procedure either one or two guidance maneuvers are applied, depending on the accuracy desired and tile distance to the moon. An error analysis showed that perilune radius can be controlled to a onesigma accuracy of about 30 km.

Monthly Catalog of United States Government Publications, Cumulative Index

Monthly Catalog of United States Government Publications, Cumulative Index PDF Author: United States. Superintendent of Documents
Publisher:
ISBN:
Category : United States
Languages : en
Pages : 1348

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Monthly Catalogue, United States Public Documents

Monthly Catalogue, United States Public Documents PDF Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1730

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Monthly Catalog of United States Government Publications

Monthly Catalog of United States Government Publications PDF Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1386

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Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 232

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Simplified Interplanetary Guidance Procedures Using Onboard Optical Measurements

Simplified Interplanetary Guidance Procedures Using Onboard Optical Measurements PDF Author: Harold A. Hamer
Publisher:
ISBN:
Category : Space trajectories
Languages : en
Pages : 36

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Cumulative Title Index to United States Public Documents, 1789-1976

Cumulative Title Index to United States Public Documents, 1789-1976 PDF Author: Sandra K. Faull
Publisher: Arlington, Va. : United States Historical Documents Institute
ISBN:
Category : Reference
Languages : en
Pages : 608

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