1. Upper Stage Weekly Summary 3/3 – 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

2. 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)

3. 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 I bit to find Isp Looking at how many thrusters needed on satellite