### Abstract

Language | English |
---|---|

Pages | 183-185 |

Number of pages | 2 |

Journal | Journal of Guidance, Control and Dynamics |

Volume | 26 |

Issue number | 1 |

Publication status | Published - 2003 |

### Fingerprint

### Keywords

- mars
- space travel
- guidance systems
- orbitsl gravity
- astronautical engineering

### Cite this

*Journal of Guidance, Control and Dynamics*,

*26*(1), 183-185.

}

*Journal of Guidance, Control and Dynamics*, vol. 26, no. 1, pp. 183-185.

**Gravity-turn descent from low circular orbit conditions.** / McInnes, C.R.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Gravity-turn descent from low circular orbit conditions

AU - McInnes, C.R.

PY - 2003

Y1 - 2003

N2 - GRAVITY-TURN descent to the surface of a planetary or small solar system body has been investigated for many years and, indeed, has been used for both lunar and Mars descent vehicles. Such a descent proŽ le requires that the vehicle thrust vector is oriented opposite to the instantaneous velocity vector along the entire descent trajectory. This requirement can be achieved with knowledge of the vehicle velocity vector from an inertial measurement unit and an attitude control system that can maintain the thrust vector antiparallel to the instantaneous velocity vector.1 For pure gravity-turndescent, the steering law is, therefore, relatively easy to implement in practice, although the descent may be modiŽ ed at the terminal phase for surface hazard avoidance. An important beneŽfit of gravity-turn descent is that the landing is assured to be vertical, and the steering law is close to fuel optimum.

AB - GRAVITY-TURN descent to the surface of a planetary or small solar system body has been investigated for many years and, indeed, has been used for both lunar and Mars descent vehicles. Such a descent proŽ le requires that the vehicle thrust vector is oriented opposite to the instantaneous velocity vector along the entire descent trajectory. This requirement can be achieved with knowledge of the vehicle velocity vector from an inertial measurement unit and an attitude control system that can maintain the thrust vector antiparallel to the instantaneous velocity vector.1 For pure gravity-turndescent, the steering law is, therefore, relatively easy to implement in practice, although the descent may be modiŽ ed at the terminal phase for surface hazard avoidance. An important beneŽfit of gravity-turn descent is that the landing is assured to be vertical, and the steering law is close to fuel optimum.

KW - mars

KW - space travel

KW - guidance systems

KW - orbitsl gravity

KW - astronautical engineering

UR - http://pdf.aiaa.org/jaPreview/JGCD/2003/PVJAIMP5033.pdf

M3 - Article

VL - 26

SP - 183

EP - 185

JO - Journal of Guidance, Control and Dynamics

T2 - Journal of Guidance, Control and Dynamics

JF - Journal of Guidance, Control and Dynamics

SN - 0731-5090

IS - 1

ER -