We maintain that for most hardware production items such as for DC-RF conver ters and antenna systems, the cost of production in space will be substantially belov that on Earth due to following factors: • Less stringent operating conditions of hardware due to relaxed weight limitations • Reduced reliability requirements due to ability to replace components. • Far less testing — components need not operate both in atmosphere and in vacuun nor survive launch and landing loads. • Lower cost power on moon. As an example, space qualified hardware generally costs a minimum of 10 times tha of domestic market items of similar function and capacity. The most obviouslj erroneous cost comparison factors are represented by terms d, e, i, j, I and o of the subject study, d and o represent defective model choices as previously discussed, t is erroneous due to improper unit costing based on unit number rather than on uni power. i, j and I are subjective estimates which fail to properly account for the types o production tasks or manpower requirements needed. As an example i and./ refer to operations to prepare solar array structures and cell; respectively. Unit costs in the SPS model are about 9 and 40 $/m2 respectively We claim that construction of solar cell support mounds can be done in situ witl tractor-like equipment for less than 5e/m2 based on analogy to farming operations i.e. the factor / should properly be near .005. Similarly, in situ deposition of thin filn converters requires only about 2% of the SPS mass/unit area and by analogy witl high-speed thin film terrestrial deposition costs we estimate total costs of 440/m2 or t j factor of .011. The I factor is a measure of total crew size required to achieve uniform rates o: annual peak power increment deliverable to Earth. A “worst case” estimate can be obtained by using results from the Convair lunar derived SPS study which used t crew of 1580 to produce 10 peak GW/year, compared to about 670 for baseline SPS which would set an upper limit to I of 2.35. A more detailed examination of the Convair study in which production tasks such as conventional solar cell production manufacture and assembly of structural elements and large scale assembly were eliminated gave an I value of 1.054. Revised Cost Comparison We shall refrain from presenting a full line-by-line item revised cost comparisor equivalent to Table 1 of subject study. Before presenting our simplified results, it is worth noting that by incorporating only the model revisions regarding rectenna area a reflector aperture and properly accounting for power dependent RF hardware, bu using all of the subject study's remaining parameters, one would decrease overal LPS costs to less than half the value given in Table 1. We have chosen to group the reference SPS and LPS cost items into 6 classes as shown in our Table 2. All hardware items for the reference SPS represent vendor costs while transportation and construction/manufacturing refer to space operations only For LPS, solar blanket hardware represents in situ manufacturing costs, while othei hardware refers to vendor costs of Earth supplied items. Costs of remaining hard ware made from lunar materials and assembly have been transferred to the construe tion/manufacturing category.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==