System Design Review ArcJet Thruster P 17101 October

System Design Review Arc-Jet Thruster P 17101 October 6, 2016

Team Members Phil Linden ME / Communications Matt Giuffre ME / EDGE Manager David Yin ME / Engineer James Gandek EE / Project Manager Anthony Higgins EE / Engineer Dylan Bruce ME / Purchasing http: //edge. rit. edu/edge/P 17101/public/Home 2

Agenda 1. Problem Definition 2. Risk Management (Updated) 3. Functional Decomposition 4. Concept Development 5. System Architecture 6. Feasibility 7. Phase 3 Plan 8. Q/A Session 3

Problem Definition • The P 17101 team will design and test an electrothermal propulsion system to meet the requirements of a hypothetical satellite mission designed by RIT Space Exploration (SPEX). SPEX sat, a geostationary communications satellite, requires a thruster to perform orbital station-keeping over a 10 year mission lifespan. 4

Risk Assessment (Updated) 5

Risk Assessment (Updated) 6

Functional Decomposition 7

Concept Development Concept 1: Resistojet Strengths: • Safer (no HV risk, lower temperatures) • Simple electrical design Weaknesses: • Lesser performance potential • Difficult mechanical design of heating element Concept 2: Arcjet Strengths: • Greater performance potential • Simple mechanical design Weaknesses: • Increased safety risks (HV, higher temperatures) • Difficult electrical design of arc generator 8

Concept Development (cont’d) Close enough for further research 9

System Architecture • 10

Expanded System Architecture 11

Expanded System Architecture Electrical Sub-System Propellant Feed Sub-System 12

Expanded System Architecture Engine Sub-System Propellant Sub. System Electrical Sub-System 13

Feasibility – Cost *If judged to be suitable based on HT calculations Not total project cost. As material cost was a driving selection factor, the critical material purchases are shown here. Things not included that may need to be purchased include sensors, test stand material, microcontroller, electronic components, and a power supply. 14

Feasibility – Power • PSPICE Model of H. V. output from 8 stage voltage multiplier • Input 40 VAC-PP output: 400 VDC 15

Feasibility – Power Paschen’s Law Estimated Space ~ 2 mm, Pressure at <190 mm. Hg 16

Feasibility – Nozzle Design Inputs: Inlet flow: 15 mg/s Environmental pressure: 1% atm Heat transferred: 800 W Thruster Design Utility (TDU) A simple performance calculator is also being developed to reduce dependency on fluid simulations. https: //github. com/runphilrun/TDU 17

Feasibility – Testing & Propellants Testing Altitude chamber • Owned by RIT and available for student use • Typically run at ~0. 6 atm for the ETA's testing, capable of going lower (testing needed to see min pressure) • Not often used by other groups • Allowed to install electrical pass-throughs if none exist (fan currently present) • Test stand will be required to fit within chamber • Test stand will likely require mechanism to increase measured force, e. g. a lever Propellants • • • Performance increases as molecular weight decreases Breakdown voltage will be significant driver in selection (Paschen’s Law) Using flight proven propellants as baseline, excluding toxic compounds like Hydrazine (N 2 H 4) and Ammonia (NH 3) Common & inert gases like Argon (Ar), Nitrogen (N 2), and Helium (He) have decent performance and low safety risks More investigation required to down select 18

Phase 3 Plan 19

Q/A Session Questions Comments Feedback 20