Responsive Access Small Cargo Affordable Launch (RASCAL ...

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the second stage was chosen over solid propellant for a number of reasons. First, the hybrid engines offer a higher performance than solids due to the higher Isp that hybrids provide. A second reason hybrids were chosen over solids was that hybrids have the ability to shutdown if an anomaly in the firing of the engine is detected. This shutdown ability is not available in solid motors which could pose a danger to the manned first stage if a catastrophic failure were to occur soon after separation. The final stage was chosen to be solid for packaging as well as the cost considerations. These stages insert the payload directly into a 270 nautical mile circular orbit at a sun synchronous inclination of 98 degrees. Figure 4: RASCAL Total Mission Profile. The RASCAL design is intended to launch a 250 lb payload into a 270 nautical mile circular orbit at a sun synchronous inclination of 98 degrees. The design goal is to also launch 400 lbs of payload into a 270 nautical mile, 28.5 degree inclination low earth orbit. Both of these mission profiles will be simulated with the RASCAL design being set for the more constraining mission. The secondary mission (the one which is not the 6
driving constraint) will then be flown with the same design with the resulting payload exceeding the RASCAL design requirements. Design Methodology: The purpose of this project is to compare the published RASCAL numbers with those computed using a design methodology currently used in the Space System Design Laboratory at The Georgia Institute of Technology. To accomplish the RASCAL baseline design was analyzed in the following design structure matrix (DSM) (Figure 5). The DSM is a method of graphically interpreting the way that different contributing analyses (design disciplines) interact to create a design. This DSM is very similar to most launch vehicle designs. There is a strong iteration loop between the propulsion design, trajectory, and weights and sizing. This iteration loop does the major convergence of the vehicle. A smaller feedback occurs between aeroheating and weights and sizing (TPS weight). This is a smaller feedback since there are not radical departures in TPS design between similar trajectories. There is no feedback to the aerodynamics from the trajectory contributing analysis as one would expect. This is because the aerodynamic coefficients are non-dimensional and scale with the vehicle. This design methodology is used for the RASCAL design. Due to the complexity of the design some contributing analyses are broken down into the two main constituents of the design (the first stage and the upper stage) to get converged solutions. These converged solutions are then recombined and reconverged in the contributing analysis before continuing through the DSM. This method of simplifying the problem was mainly used in the trajectory contributing analysis. It was too difficult of a problem to run the entire trajectory from an initial guess so the first and upper stages were run independently matched at the separation point. Once this is achieved the two solutions are combined into one trajectory analysis with the solutions to the separate problems given as initial guesses to the combined problem. These “better guesses” allow the entire vehicle to be optimized and then closed in the main iteration loop. 7
Page 1 and 2: Responsive Access Small Cargo Affor
Page 3 and 4: List of Figures: Figure 1: Launch C
Page 5 and 6: Abstract: RASCAL is a Defense Depar
Page 7 and 8: Introduction: Due to the uncertaint
Page 9 and 10: This stage will then propel the veh
Page 11: stages which continue on to orbit.
Page 15 and 16: Once the geometry is defined it mus
Page 17 and 18: Coefficient of Drag 0.6 0.5 0.4 0.3
Page 19 and 20: These characteristics were then ana
Page 21 and 22: To analyze the effect of MIPCC an A
Page 23 and 24: 14. The new Isp of the MIPCC engine
Page 25 and 26: combination selected the overall we
Page 27 and 28: Table 5: POST Trajectory Constraint
Page 29 and 30: Thrust (lbs) 120000 100000 80000 60
Page 31 and 32: Gross Gross Weight Dry Dry Weight W
Page 33 and 34: Temperature (F) 1400 1300 1200 1100
Page 35 and 36: Operations: Number 1st Stages 5 Num
Page 37 and 38: Cost Estimation: The cost estimatio
Page 39 and 40: As this figure depicts the DDT&E fo
Page 41 and 42: profile of the cost charts is due t
Page 43 and 44: Each of these alternatives will be
Page 45 and 46: 1+2+3 1+3 4th Stage MMC 1st Lox Hyb
Page 47 and 48: The design alternatives were costed
Page 49 and 50: GT RASCAL: From this alternative an
Page 51 and 52: As this figure shows the GT RASCAL
Page 53 and 54: used in the GT RASCAL design is in
Page 55 and 56: Figure 39: GT RASCAL Mission Profil
Page 57 and 58: When the final cost numbers of the
Page 59 and 60: References: 1. Cyr, Kelley, “US L

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