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Upper Stage Weekly Summary 3/3 – 3/9/2008. Talked to Joe about simulation Joe said that the Δ v’s seemed high but reasonable Joe suggested running simulations to find what parameters might be sensitive Found that thruster selection, mainly Isp, and navigational error cause most deviation.
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Upper Stage Weekly Summary3/3 – 3/9/2008 • Talked to Joe about simulation • Joe said that the Δv’s seemed high but reasonable • Joe suggested running simulations to find what parameters might be sensitive • Found that thruster selection, mainly Isp, and navigational error cause most deviation
Thruster selection • Looked at Hydrazine thrusters. Model CHT 1 by EADS Astrium. 1N thrust, 211s Isp, mass of 0.29kg • Looked at cold gas thrusters. Model 58E142 by Moog. Uses nitrogen as propellent. 0.12N thrust, 70s Isp, uses 10W of power. • Also looked at Marotta cold gas thruster. 0.445N thrust, using 0.4W of power, and mass of 50g. Ibit=44mNs(unsure what an Ibit is)
Refinement • Once the navigation system is selected, navigation error can be used to refine the fuel requirements • Found Δv requirements for mission duration (30 days) less than 15.2 m/s • Suggest using the Marotta thruster. Lower power requirements, lower mass, reasonable thrust. Find the definition of Ibit to find Isp • Looking at how many thrusters needed on satellite