Book contents
- Frontmatter
- Contents
- Preface
- Acknowledgements
- List of acronyms and abbreviations
- PART I Engineering issues specific to entry probes, landers or penetrators
- 1 Mission goals and system engineering
- 2 Accommodation, launch, cruise and arrival from orbit or interplanetary trajectory
- 3 Entering atmospheres
- 4 Descent through an atmosphere
- 5 Descent to an airless body
- 6 Planetary balloons, aircraft, submarines and cryobots
- 7 Arrival at a surface
- 8 Thermal control of landers and entry probes
- 9 Power systems
- 10 Communication and tracking of entry probes
- 11 Radiation environment
- 12 Surface activities: arms, drills, moles and mobility
- 13 Structures
- 14 Contamination of spacecraft and planets
- PART II Previous atmosphere/surface vehicles and their payloads
- PART III Case studies
- Appendix Some key parameters for bodies in the Solar System
- Bibliography
- References
- Index
12 - Surface activities: arms, drills, moles and mobility
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
- 1 Mission goals and system engineering
- 2 Accommodation, launch, cruise and arrival from orbit or interplanetary trajectory
- 3 Entering atmospheres
- 4 Descent through an atmosphere
- 5 Descent to an airless body
- 6 Planetary balloons, aircraft, submarines and cryobots
- 7 Arrival at a surface
- 8 Thermal control of landers and entry probes
- 9 Power systems
- 10 Communication and tracking of entry probes
- 11 Radiation environment
- 12 Surface activities: arms, drills, moles and mobility
- 13 Structures
- 14 Contamination of spacecraft and planets
- PART II Previous atmosphere/surface vehicles and their payloads
- PART III Case studies
- Appendix Some key parameters for bodies in the Solar System
- Bibliography
- References
- Index
Summary
While much can be achieved by purely passive observations and measurements of a planetary lander's immediate environment, some key science requires the landed system to interact with the surface mechanically. This may involve the acquisition of samples of material, either to be returned to Earth or delivered to instrumentation internal to the lander. Other instruments, while external, require intimate contact with target rocks – these include alpha-X-ray, X-ray fluorescence or Mössbauer spectrometers, and microscopes. Other interactions may include mechanical-properties investigations using a penetrometer, or current measurements of wheel-drive motors.
Thus a variety of mechanisms have been operated on planetary surfaces, including deployment devices and sampling arms of various types, together with drills, abrasion tools and instrumentation. Soviet/Russian landers have tended to feature simple but robust actuators, usually simple hinged arms, and often actuated by pyro or spring. These include the penetrometers on the Luna and Venera missions. Lunokhods 1 and 2 carried a cone-vane shear penetrometer that was lowered into the lunar regolith and rotated by a motor, to measure bearing strength and shear strength. The rovers made 500 and 740 such measurements, respectively, during their traverses across the lunar surface.
A more sophisticated arm was flown on the Surveyor 3, 4 and 7 lunar landers (Figure 12.1). The Surveyor soil mechanics surface sampler (SMSS) was a tubular aluminium pantograph, five segments long, with a total reach of 1.5 m.
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- Information
- Planetary Landers and Entry Probes , pp. 124 - 129Publisher: Cambridge University PressPrint publication year: 2007