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
9 - Power systems
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
A sobering thought experiment is to contemplate a world without electricity. Not only is electricity exploited as a convenient means of delivering mechanical or thermal energy to remote locations, but electricity is vital in information transmission and in sensing and control. Although the first planetary missions contemplated involved launching to the Moon a vehicle containing flash powder with which it would optically announce its arrival, and some early spacecraft used clockwork timers to sequence operations, every mission actually flown has been electrically powered.
In this chapter we first consider the overall requirements on the probe's power system, and how these requirements favour the various means adopted to meet them. The power supply and storage possibilities are then discussed, with particular reference to planetary probes. A general reference for power considerations is the book by Angrist (1982).
It is instructive to consider the electrical power requirements of various household devices to place spacecraft requirements in context. A modern PC may consume perhaps 200 W; a laptop perhaps an order of magnitude less. The Viking lander ran on 90 W. The Huygens probe's batteries supplied around 300 W for about 5 hours. The Sojourner rover had a solar array that delivered a mere 15 W.
System requirements
The total energy requirement of a mission (i.e. its integrated power requirement) is the most fundamental parameter for designing the power system.
- Type
- Chapter
- Information
- Planetary Landers and Entry Probes , pp. 94 - 104Publisher: Cambridge University PressPrint publication year: 2007