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5 Thermal Control Technology of Lunar Lander
The lunar dust is a special issue for thermal control of the lunar lander, which will
degrade heat rejection system performance seriously even only little amount of dust
accumulated on thermal radiators [2–4]. There is no effective cleaning technique now
to remove lunar dust from radiator surface because of its fine grain size and static
electric effect by sunlight on lunar surface [5]. It is difficult to precisely predict the
orientation of the lunar lander before landing because of lunar terrain at landing site.
The tilt and rotation of the lunar lander will affect the input of external heat flux and
the performance of thermal control devices such as heat pipes, so the adaptability of
thermal control subsystem shall be high.
Because the mission profile is complicated with harsh environment and lot of
uncertainties, the thermal control subsystem should take different philosophy, solutions and ground test methods from other kinds of spacecraft on the basis of mature
thermal control devices and technology to satisfy the requirements. In this chapter,
design constraints, philosophy and solutions, typical technologies, and ground test
methods of thermal control are described briefly.
5.2 Current Status of Thermal Control Technology
The Apollo program of the United States and Lunokhod of the Soviet Union had
successfully implemented lunar soft-landing and operation on lunar surface, while
lots of thermal control technologies were developed. Compared with passive thermal
control technologies, active thermal control technologies such as variable conductance device, fluid circulation loop, water sublimator heat sink, lunar dust prevention
were paid more attention recently because of extreme thermal environment in lunar
daytime and night for the lunar lander in different countries [6–9].
In the design of thermal control of the lunar landers in different countries, the
philosophy was the same. In order to minimize the influence of external environment
change on the temperature of structure and instruments, the internal of lunar probe
were insulated from external by insulator between main body and outer components
and multilayer insulation blankets on surface [6, 9]. Thermal radiators should be
oriented toward proper direction to dissipate excessive heat of working instruments
to space, and minimize the lunar surface radiation flux and lunar albedo flux by
conducting or transferring through heat pipes or fluid loops [8].
In order to solve the thermal control challenges to survive on the Moon for longterm the lunar lander or lunar base, many efforts were taken in different countries
to developing “heat switch” techniques such as variable conductance devices and
fluid loop devices [9]. Variable conductance devices include VCHP, Loop Heat
Pipes (LHPs), Capillary Pumped two-phase fluid Loops, mechanically Pumped twophase fluid Loops, mechanically Pumped single-phase fluid Loops and etc., while the
mechanically Pumped single-phase fluid Loops are suitable for short-term manned
the lunar landers. Considering for the temperature differences between the internal
and external parts, as well as crews’ safety, the thermal design of the lunar lander
is usually divided into internal systems and external systems and there is the heat
5 Thermal Control Technology of Lunar Lander
The lunar dust is a special issue for thermal control of the lunar lander, which will
degrade heat rejection system performance seriously even only little amount of dust
accumulated on thermal radiators [2–4]. There is no effective cleaning technique now
to remove lunar dust from radiator surface because of its fine grain size and static
electric effect by sunlight on lunar surface [5]. It is difficult to precisely predict the
orientation of the lunar lander before landing because of lunar terrain at landing site.
The tilt and rotation of the lunar lander will affect the input of external heat flux and
the performance of thermal control devices such as heat pipes, so the adaptability of
thermal control subsystem shall be high.
Because the mission profile is complicated with harsh environment and lot of
uncertainties, the thermal control subsystem should take different philosophy, solutions and ground test methods from other kinds of spacecraft on the basis of mature
thermal control devices and technology to satisfy the requirements. In this chapter,
design constraints, philosophy and solutions, typical technologies, and ground test
methods of thermal control are described briefly.
5.2 Current Status of Thermal Control Technology
The Apollo program of the United States and Lunokhod of the Soviet Union had
successfully implemented lunar soft-landing and operation on lunar surface, while
lots of thermal control technologies were developed. Compared with passive thermal
control technologies, active thermal control technologies such as variable conductance device, fluid circulation loop, water sublimator heat sink, lunar dust prevention
were paid more attention recently because of extreme thermal environment in lunar
daytime and night for the lunar lander in different countries [6–9].
In the design of thermal control of the lunar landers in different countries, the
philosophy was the same. In order to minimize the influence of external environment
change on the temperature of structure and instruments, the internal of lunar probe
were insulated from external by insulator between main body and outer components
and multilayer insulation blankets on surface [6, 9]. Thermal radiators should be
oriented toward proper direction to dissipate excessive heat of working instruments
to space, and minimize the lunar surface radiation flux and lunar albedo flux by
conducting or transferring through heat pipes or fluid loops [8].
In order to solve the thermal control challenges to survive on the Moon for longterm the lunar lander or lunar base, many efforts were taken in different countries
to developing “heat switch” techniques such as variable conductance devices and
fluid loop devices [9]. Variable conductance devices include VCHP, Loop Heat
Pipes (LHPs), Capillary Pumped two-phase fluid Loops, mechanically Pumped twophase fluid Loops, mechanically Pumped single-phase fluid Loops and etc., while the
mechanically Pumped single-phase fluid Loops are suitable for short-term manned
the lunar landers. Considering for the temperature differences between the internal
and external parts, as well as crews’ safety, the thermal design of the lunar lander
is usually divided into internal systems and external systems and there is the heat