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.
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
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1388
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1388
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 284
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 284
Book Description
Monthly Catalog of United States Government Publications, Cumulative Index
Author: United States. Superintendent of Documents
Publisher:
ISBN:
Category : United States
Languages : en
Pages : 1408
Book Description
Publisher:
ISBN:
Category : United States
Languages : en
Pages : 1408
Book Description
NASA Technical Note
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 732
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 732
Book Description
Midcourse-guidance Procedure with Single Position Fix Obtained from Onboard Optical Measurements
Author: Harold A. Hamer
Publisher:
ISBN:
Category : Navigation (Astronautics)
Languages : en
Pages : 90
Book Description
Publisher:
ISBN:
Category : Navigation (Astronautics)
Languages : en
Pages : 90
Book Description
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.
Government Reports Announcements
Author:
Publisher:
ISBN:
Category : Research
Languages : en
Pages : 844
Book Description
Publisher:
ISBN:
Category : Research
Languages : en
Pages : 844
Book Description
Government Reports Announcements & Index
Author:
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 846
Book Description
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 846
Book Description
Applied Mechanics Reviews
Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 300
Book Description
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 300
Book Description