Author: Harold A. Hamer
Publisher:
ISBN:
Category : Navigation (Astronautics)
Languages : en
Pages : 90
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.
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
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.
A Selected Listing of NASA Scientific and Technical Reports
Author: United States. National Aeronautics and Space Administration. Scientific and Technical Information Division
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 470
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 470
Book Description
Monthly Catalog of United States Government Publications
Author: United States. Superintendent of Documents
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1320
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1320
Book Description
NASA Scientific and Technical Reports
Author: United States. National Aeronautics and Space Administration Scientific and Technical Information Division
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 478
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 478
Book Description
NASA Technical Note
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 418
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 418
Book Description
Monthly Catalog, United States Public Documents
Author: United States. Superintendent of Documents
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1716
Book Description
February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1716
Book Description
February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 256
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 256
Book Description