Book contents
- Frontmatter
- Contents
- Preface
- Acknowledgements
- List of acronyms and abbreviations
- PART I Engineering issues specific to entry probes, landers or penetrators
- PART II Previous atmosphere/surface vehicles and their payloads
- 15 Destructive impact probes
- 16 Atmospheric entry probes
- 17 Pod landers
- 18 Legged landers
- 19 Payload delivery penetrators
- 20 Small body surface missions
- PART III Case studies
- Appendix Some key parameters for bodies in the Solar System
- Bibliography
- References
- Index
18 - Legged landers
Published online by Cambridge University Press: 12 August 2009
- Frontmatter
- Contents
- Preface
- Acknowledgements
- List of acronyms and abbreviations
- PART I Engineering issues specific to entry probes, landers or penetrators
- PART II Previous atmosphere/surface vehicles and their payloads
- 15 Destructive impact probes
- 16 Atmospheric entry probes
- 17 Pod landers
- 18 Legged landers
- 19 Payload delivery penetrators
- 20 Small body surface missions
- PART III Case studies
- Appendix Some key parameters for bodies in the Solar System
- Bibliography
- References
- Index
Summary
These landers use a system of legs to cushion the landing and provide a stable platform for surface operations. With the exception of the Venera landers and the forthcoming Mars Science Laboratory (MSL) rover, all legged landers have three or four legs with footpads, and retro-thrusters perform final braking before landing. This was not required for the Veneras, whose terminal velocity at the surface was low enough (~8 m s− 1) such that the landing gear alone was able to provide sufficient damping. The landing gear was toroidal and we thus consider it as effectively a single ‘leg’. Mars Science Laboratory is due to make use of the rover's wheels as landing gear. A key feature of legged landers is that they must be the right way up for landing – beyond some tolerable limit such landers would topple over and fail. This attitude control must be performed during descent, usually by thrusters. Only for sufficiently thick atmospheres, such as that of Venus, can aerodynamic stabilisation be used.
Beyond those described here, future possible legged landers include robotic and crewed lunar landers from the US, robotic lunar landers from China and Japan, and a Mars sample-return mission.
Surveyor landers
The Surveyor landers performed soft landings on the Moon, largely as reconnaissance of the surface for the later Apollo landings. For more details see the Case Study, Chapter 21 (Figure 18.1).
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- Chapter
- Information
- Planetary Landers and Entry Probes , pp. 199 - 237Publisher: Cambridge University PressPrint publication year: 2007