ABSTRACT
A •ssion surface power system on the Moon has the possibility of producing 40 kilowatts of electric power, which can supply about eight houses on Earth (NASA 2009). Figure 4.1 shows NASA’s conceptual design of a •ssion surface power system (NASA 2010). Figure 4.2 shows a front view of a •ssion surface power system construction that is based on the NASA design (Coulter 2010). Figure 4.3 shows the LNPR. In addition, Figure 4.4 shows the
CONTENTS
4.1 Introduction ..................................................................................................33 4.2 Method ..........................................................................................................38 4.3 Calculation ....................................................................................................40 4.4 Results ...........................................................................................................43 4.5 Conclusions ...................................................................................................44 References ............................................................................................................... 49
simpli•ed con•guration of the LNPR. The event Ÿow of an accidental cooling loop failure (ACLF) is shown in Figure 4.5. The cooling matter is the regolith, which is lunar highland soil. Table 4.1 shows a comparison of lunar highland soil and Earth soil (Prado 2009). The temperature of the Moon is changed by the Sun’s angle of the solar light to the exposed lunar surface. The effective heat sink temperature is examined for the horizontal and vertical radiator located at the lunar equator (Ewert 1993), which is in Figure 4.6. The heat transfer of the cooling is done by the radiation on the Moon. The surface temperature rises up to equilibrium with incoming solar radiation because there is no atmosphere and the surface is rock material of low conductivity and relatively low heat capacity. The Stefan-Boltzmann equation sets the numbers that govern solar radiation:
I T= εσ 4 (4.1)
where, I is the absorbed solar energy per unit area. T is the absolute surface temperature (Kelvin), ε is the emissivity, and σ is Stefan’s constant, 5.67 × 108 in metric units.
