Author: Harold A. Hamer
Publisher:
ISBN:
Category : Approach guidance
Languages : en
Pages : 92
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
Author: Harold A. Hamer
Publisher:
ISBN:
Category : Approach guidance
Languages : en
Pages : 92
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.
Publisher:
ISBN:
Category : Approach guidance
Languages : en
Pages : 92
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
Author: Harold A. Hamer
Publisher:
ISBN:
Category : Inertial navigation (Aeronautics)
Languages : en
Pages : 68
Book Description
Publisher:
ISBN:
Category : Inertial navigation (Aeronautics)
Languages : en
Pages : 68
Book Description
NASA Technical Note
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 418
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 418
Book Description
Fixed-angle Translunar Guidance Procedures Using Onboard Optical Measurements
Author: Harold A. Hamer
Publisher:
ISBN:
Category : Optical measurements
Languages : en
Pages : 50
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.
Publisher:
ISBN:
Category : Optical measurements
Languages : en
Pages : 50
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
Author: United States. Superintendent of Documents
Publisher:
ISBN:
Category : United States
Languages : en
Pages : 1348
Book Description
Publisher:
ISBN:
Category : United States
Languages : en
Pages : 1348
Book Description
Monthly Catalogue, United States Public Documents
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1730
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1730
Book Description
Monthly Catalog of United States Government Publications
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1386
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1386
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 232
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 232
Book Description
Simplified Interplanetary Guidance Procedures Using Onboard Optical Measurements
Author: Harold A. Hamer
Publisher:
ISBN:
Category : Space trajectories
Languages : en
Pages : 36
Book Description
Publisher:
ISBN:
Category : Space trajectories
Languages : en
Pages : 36
Book Description
Cumulative Title Index to United States Public Documents, 1789-1976
Author: Sandra K. Faull
Publisher: Arlington, Va. : United States Historical Documents Institute
ISBN:
Category : Reference
Languages : en
Pages : 608
Book Description
Publisher: Arlington, Va. : United States Historical Documents Institute
ISBN:
Category : Reference
Languages : en
Pages : 608
Book Description