### Abstract

Satellite retrieval following failure of an upper stage may require expending the unused propellants by firing the engine. If the satellite is already in a Shuttle-accessible orbit, then the thrust must be controlled such that the changes in orbital elements (primarily semi-major axis, eccentricity, and inclination) are minimized. This paper develops a set of blended extremal controls that minimizes changes in semi-major axis and eccentricity; under the assumption of a spherical gravity field, in-plane thrusting results in zero inclination change. The method requires the solution of a nonlinear programming problem, using as optimization variables the engine ignition time and a set of weighting factors to blend the contributions of the extremal controls. Three example cases for typical engine capabilities indicate that acceptable solutions are possible, with reasonable requirements on thrust steering.

Original language | English (US) |
---|---|

Pages (from-to) | 1631-1638 |

Number of pages | 8 |

Journal | Advances in the Astronautical Sciences |

Volume | 105 II |

State | Published - Dec 1 2000 |

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### All Science Journal Classification (ASJC) codes

- Aerospace Engineering
- Space and Planetary Science

### Cite this

*Advances in the Astronautical Sciences*,

*105 II*, 1631-1638.

}

*Advances in the Astronautical Sciences*, vol. 105 II, pp. 1631-1638.

**Control laws for minimum orbital changes -the satellite retrieval problem.** / Cichan, Timothy; Melton, Robert G.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Control laws for minimum orbital changes -the satellite retrieval problem

AU - Cichan, Timothy

AU - Melton, Robert G.

PY - 2000/12/1

Y1 - 2000/12/1

N2 - Satellite retrieval following failure of an upper stage may require expending the unused propellants by firing the engine. If the satellite is already in a Shuttle-accessible orbit, then the thrust must be controlled such that the changes in orbital elements (primarily semi-major axis, eccentricity, and inclination) are minimized. This paper develops a set of blended extremal controls that minimizes changes in semi-major axis and eccentricity; under the assumption of a spherical gravity field, in-plane thrusting results in zero inclination change. The method requires the solution of a nonlinear programming problem, using as optimization variables the engine ignition time and a set of weighting factors to blend the contributions of the extremal controls. Three example cases for typical engine capabilities indicate that acceptable solutions are possible, with reasonable requirements on thrust steering.

AB - Satellite retrieval following failure of an upper stage may require expending the unused propellants by firing the engine. If the satellite is already in a Shuttle-accessible orbit, then the thrust must be controlled such that the changes in orbital elements (primarily semi-major axis, eccentricity, and inclination) are minimized. This paper develops a set of blended extremal controls that minimizes changes in semi-major axis and eccentricity; under the assumption of a spherical gravity field, in-plane thrusting results in zero inclination change. The method requires the solution of a nonlinear programming problem, using as optimization variables the engine ignition time and a set of weighting factors to blend the contributions of the extremal controls. Three example cases for typical engine capabilities indicate that acceptable solutions are possible, with reasonable requirements on thrust steering.

UR - http://www.scopus.com/inward/record.url?scp=0040566795&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0040566795&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0040566795

VL - 105 II

SP - 1631

EP - 1638

JO - Advances in the Astronautical Sciences

JF - Advances in the Astronautical Sciences

SN - 1081-6003

ER -