# A Brazilian Space Launch System for the Small Satellite Market
## 2 Methodology and Launch Vehicle Configuration
### Cost Analysis  
Recently, [PERSON] and colleagues [15] proposed a new methodology in which the development and manufacturing costs are inferred for each equipment element individually of the proposed launcher configuration (sub-system level) as opposed to the system-level approach which forms the basis of the TRANSCOST model [16]. Cost assessment, applied to launch vehicle concepts, should help to rank the cost-effective solutions proposed in this study. Considering we rely on system level data, we chose the TRANSCOST model for the space launch system cost analysis. TRANSCOST's launch systems cost database is rather comprehensive and had been updated from 1960 to 2009.  
In the TRANSCOST model, cost unit is based on Work-Year (WYr), therefore, not linked to a specific currency, independent from inflation and fluctuation of the exchange rate for a given country.  
Work-Year cost is defined as the total company annual budget, subcontracts excluded, divided by the number of productive full-time employees. The cost of one Work-Year, as suggested by the reference, is a measurement of direct cost labour, fees, and many other related parameters. As for Brazil, the space industry is comprised of very few small enterprises, but the aeronautic industry is well established, considering that Brazil has the third largest airplane producer in the world (EMBRAER). Based on the country's aeronautic sector, we estimated a reference value of 378,000 BRL, or about 102,000 USD (as for January 2019) for the cost of one Work-Year in Brazil.  
The TRANSCOST model is organized in three cost areas, i.e., launch system development cost, vehicle fabrication cost, and ground and flight operation costs. These costs were derived based, mostly, on the mass of a given system or subsystem. The reference data base was collected from 1960 to 2009, from US, European and Japanese space systems.  
Cost estimation relationships (CER), for development and fabrication, are based on:  
1. mass of engine or stage, \(m^{b}\);
2. system-specific cost-to-mass sensitivity factor \(b\);
3. technical development status factor, \(f_{1}\);
4. technical quality factor, \(f_{2}\);
5. team experience factor, \(f_{3}\);
6. cost reduction factor for series production, \(f_{4}\).  
The regression factors, \(f_{1}\), \(f_{2}\), and \(f_{3}\) were introduced into the TRANSCOST model to bring cost predictions, which are mass-based, to the reference data of engine and stage development costs from actual projects within \(\pm 15\) to 20% accuracy. Technical development status factor is related to the necessary effort to develop a given space system. Higher factor values, 1.3 to 1.4, are used for first generation system development. If just minor modifications to the existing system are needed, \(f_{1}\) should be within 0.4 to 0.6. Factor values within 0.7 to 1.2, should be used, accordingly for moderate levels of system development effort, as proposed by the model [16]. Technical quality factor (\(f_{2}\)) is directed related to the level of reliability required for the liquid rocket engine, varying from 0.6 to about 1.8 depending on the number of qualification firings. If the system is space qualified, the reference value is one. Team experience factor (\(f_{3}\)) varies from 0.7 to 1.4. The lower limit refers to a team with superior experience in similar projects, while higher values are used when the team has little experience in similar projects. For a given level of experience, between these limits, the factor has to be set accordingly [16]. Parameter \(f_{4}\) is used to refine vehicle fabrication cost estimations based on learning factors from system series production. For most systems, learning factor varies from 0.25 to 1.0. Lower mass systems and high annual production rates decrease the value of the learning factor. Reference [16] has a chart to help infer the value of this parameter.