THEMIS Critical Design Review Reaction Control Subsystem Mike McCullough mmccullough@swales.com 301.902.4533 THEMIS CDR 6/16/04

RCS Agenda RCS Specification Compliance RFA Status AEROJET Organization RCS Contract Chronology Production Schedule Overview Subsystem Overview Analysis Subsystem Verification Subsystem Safety Features THEMIS CDR 6/16/04

Specification Compliance Most specifications are met or exceeded Specifications that are compliant are shown with an “X” Items where the testing surpasses the requirements are shown with an “S” Some items are now out of date due to system evolution and re-pressurization upgrade Items highlighted in yellow Represent areas where compliance issues exist with the original specification Most are relatively minor and have been discussed and agreed to with Aerojet Where Aerojet will meet a revised spec are shown with an “R” THEMIS CDR 6/16/04

Specification Compliance Matrix THEMIS CDR 6/16/04

Specification Compliance Matrix THEMIS CDR 6/16/04

Specification Compliance Matrix THEMIS CDR 6/16/04

Specification Compliance Matrix THEMIS CDR 6/16/04

Specification Compliance Matrix THEMIS CDR 6/16/04

RCS CDR Peer Review RFA Status ID Action Requested Reason/Justification Requested By/ Org Assigned To Date Due Comment / Status RFA 1 There is currently a disconnect between the perceived requirement for total System external leak rate and the proposed method of verification. The following actions are requested to resolve the conflict: 1. Perform a worst-case analysis assuming that all welds have an external leak rate equal to the capability of the Snoop detection method (1 x 10E-4 sccs) to determine if the resulting loss of pressure is acceptable. If the answer is affirmative, then the proposed verification method is conservative and acceptable. 2. If the above answer is negative, then the proposed verification method must be changed to a more sensitive technique, such as: a)       bag the entire assembly and perform a total helium mass spectrometer measurement b)       perform helium mass spectrometer measurements for each of the individual welds c)       evacuate the inside of the system and measure the internal leak rate when the external environment is surrounded by helium d)       other? The current system leak requirement is not being properly validated by the proposed test method. If a worst-case system leakage analysis (assuming all welds leak at the Snoop detection capability limit) produces acceptable pressure losses for the Project, then the Project total system leak requirement should be revised to the higher allowable leak rate. If the pressure loss is unacceptable, then a new verification method must be proposed.   Mike Leeds & Marc Kaylor Swales Aerojet 5/28/04 6/11/04 - Aerojet has a tent test capability now and will be using this for system leak check. The tent will provide a 10e-6 capability. 5/14/04 - Sent to Swales the External Leak Test Process Instructions THEMIS CDR 6/16/04

RCS CDR Peer Review RFA Status Re-evaluate case of trapped gas between pyro and check valves after proof testing by: 1)               Check Range Requirement for minimum energy allowed in pressurized systems 2)               Examine possibility of adding latch-valve or solenoid valve to replace check valve. 3)               Add service valve to relieve pressure In general, flying with proof pressure is unacceptable with respect to EWR 127-1 requirements Chuck Zakrzwski NASA/GSFC Aerojet 5/28/04 6/11/04 If check valve is used, the trapped GN2 will be evacuated. A trade study has reduced candidate check valves to 3 vendors. A solenoid valve may be instituted to mitigate range safety risk. 5/19/04 Swales was notified that Aerojet was investigating adding a service valve in the dead zone. This will facilitate evacuating the zone after leak tests and allow for testing the check valve. RFA 3 Swales to define a reasonable worst case condition for thruster operation ·                     Number of pulses ·                     Number of preheated starts ·                     Propellant through put Aerojet will provide a minimum recommended start temperature for non-emergency starts Self evident Olwen Morgan Aerojet Swales Aerojet 6/11/04 Cold Bias - 250F start Temp. 2 elements 60 min., 1 element not recommended. 110F start, 2 elements 20 min., 1 element 50 min. 5/19/04: Conservative estimates from Swales provide. # of Pulses - 60K - 146K Preheated Starts: 365 Propellant Throughput: 18Kg/Thruster RFA 4 Need to prove that the system will handle worst case water hammer for opening the latch valve (analysis or test) or else preclude water hammer by design (bypass bleed-in leg or properly sized cavitating Venturi, etc.) Current system has a potential for water hammer condition from a latch valve opening (even if the lines are filled during loading) that is unknown and must be determined within the component capabilities. Mike Leeds Swales - West   6/11/04 Analyses shows that there is adequate design pressure capability to withstand surge and waterhammer flow after opening the latch valve. THEMIS CDR 6/16/04

Aerojet's THEMIS Team THEMIS CDR 6/16/04

Contract History THEMIS CDR 6/16/04

Top Level Schedule THEMIS CDR 6/16/04

RCS Overview Two Stage Blow-down System Monopropellant Hydrazine Propellant Load: 48 kg Helium Pressurant: 54 g Three Segments Pressurant System MEOP of 1760 psi @ 104ºF Carleton COPV P/N Propellant Management Assembly MEOP of 400 psi @ 121ºF Ardé I-718 Propellant Tanks Rocket Engine Assembly Manifold MEOP of 650 psi @ 121ºF Four MR 111C 4.4N Thrusters Thermostatically Controlled Heaters All Welded Construction Complete Assembly By Aerojet THEMIS CDR 6/16/04

Prepress System Increases Fuel Load Blow-Down Curve – Pyro Valve Actuation THEMIS CDR 6/16/04

RCS Layout Pyro Valve 1832-243 (Repressurization Subsystem) Fill/Drain Valve 1831-180 (Repressurization Subsystem) REA T1 REA A2 Tube, 35613-123 Tube, 35613-124 Tube, 35613-121 Tube, 35613-109 THEMIS CDR 6/16/04

RCS Layout Pyro-Actuated Valve Service Valve, SV4 Tank 1 Tank 2 REA T1 Tube 35613-101 Filter, F2 F0D10802-01 REA A1 Tube, 35613-106 2 Places Latch Valve, LV2 35614-501 Latch Valve, LV1 THEMIS CDR 6/16/04

RCS Layout View into X-Y Plane directed along +Z-axis -Y +X Tube, 35613-118 (Cross-over line from outlet of Latch Valve, LV2 to outlet of LV1) Propellant Filter, F2 REA T2 REA T1 REA A1 Tank 2 +X Tank 1 Latch Valve, LV1 Latch Valve, LV2 REA A2 Propellant Filter, F1 View into X-Y Plane directed along +Z-axis -Bottom Deck Omitted for Clarity THEMIS CDR 6/16/04

Thermal Modeling Overview Aerojet performed extensive thermal modeling of the RCS subsystem 7 Thermal Control Zones Both Propellant Tanks Thruster A1 Thruster A2 Thruster T1 Thruster T2 Fuel Lines & Plumbing Zone 1 Fuel Lines & Plumbing Zone 2 Thermostats: Elmwood 3200 Series 50oF - 70oF Primary Setpoints Series Redundant in All Zones 41oF - 61oF Secondary Setpoints Series Redundant on N2H4 tanks only Boundary conditions supplied by Swales to Aerojet Swales verifies Aerojet thermal analysis, correlates results and folds into overall bus thermal model THEMIS CDR 6/16/04

Thermal Summary REAs Have Adequate Thermal Margin in Hot & Cold Environments Current Design Exceeds 2 Watt Power Usage Target Swales and Aerojet refining thermal interfaces to reduce heater power both at the component and system level. May be reduced THEMIS CDR 6/16/04

Plume Impingement Analysis Status Nearfield/Farfield Plume Axial Thruster Plume Analysis is Complete Tangential Thruster Plume Analysis Awaiting More Information Need spacecraft boom geometric definition (Not included in ICD or STEP files) Axial Thruster Plume Impingement Analysis Evaluated Plume Impingement from Axial Thrusters 1 & 2 on Separation Ring Analyses Shows Plume Impingement Forces are Extremely Small THEMIS CDR 6/16/04

Basic Parameters and Analysis Assumptions Basic analysis parameters and assumptions Propellant mass: 24 kg each tank (total 48 kg) Two tanks for four MR-111C thrusters Propellant tank internal volume: 1556 in3 each tank Propellant: high purity hydrazine Propellant ullage volume charged to 210 psia at 62 °F thus, MEOP is 400 psi @ max temperature of 120 °F Pressurant gas: GN2 Pressurant tank internal volume: 140 in3 GN2 fill pressure: 1630 psi @ 62 °F One pressurant tank for two propellant tanks Propellant line elasticity modulus: 212 GPa Hydrazine bulk modulus: 2.19 GPa THEMIS CDR 6/16/04

Performance Analysis Completed to Date Re-pressurization system Pressure drop analysis Surge and Water Hammer Pressure analysis Check valve leakage analysis Performance analysis includes thruster performance THEMIS CDR 6/16/04

‘NISA’ FEA Model Integration of All Lines With a Compliant Support Structure CENTER SUPPORT SPRINGS FUEL TANK MASS COMPLIANT DECK Ongoing Analysis THEMIS CDR 6/16/04

Qualification Testing Hydrazine Tank Qualification Testing THEMIS CDR 6/16/04

THEMIS System Final Assembly Flow Install Tank #1 onto Flight structure verify tube endpoint locations with mating tubes secure & torque Install service valve & thermal spacers verify tube endpoint location with mating tube secure & torque Install Tank #2 onto Flight structure verify tube endpoint locations with mating tubes secure & torque Install Re-pressurization manifold and brackets onto Flight structure verify tube endpoint locations with mating tubes secure & torque Install REA manifold and bracket.Secure corner panel to handling fixture (3) places. Verify tube endpoint location with mating fitting secure & torque Verify torque of all components and manifold standoff locations Orbital weld (9) places THEMIS System closeout welds THEMIS CDR 6/16/04

THEMIS System Final Assembly Flow, Con’t Visual & X-RAY inspect orbital welds (9) places Proof/Leak test (9) closeout welds Penetrant Inspect (9) closeout welds. Use poly film sheet blanket to protect adjacent hardware Finish final placement of propellant line heaters and thermal tape overlap Complete electrical fabrication per wiring diagram Verify electrical fabrication.Check each THEMIS component continuity & IR. Heat & cool thermostats heater to verify circuits REA, Latch & Service Valves functional/leak checks Verify Thrust alignment and position of REAS to THEMIS structure datum A, B, & D Remove all GSE, measure THEMIS System weight with handling fixture subtract handling fixture weight. Replace all protective GSE THEMIS CDR 6/16/04

Safety/Quality/Reliability System Level Features System Is All Welded Design 100% Radiographic Dye Penetrant and Bubble Leak Tested Proof Test to 1.5 MEOP of Each Section Periodic Leak Checks Accomplished for Thruster and Latch Valve Seats ¼” x 0.028 Tubing with Cajon Fittings Burst Pressure > 15,000 psi (20,000 psi pre-installation) Material Compatibility in Accordance With RD-WSTF-0002 MSFC-HDBK-527 AIAA SP-084-1999 MAPTIS, Marshall Space Flight Center Materials List Leak Checking Methods are Under Investigation Snoop Threshold of 1x10-4 Does Not Meet Mission Requirement Heritage of Leak Check Method Indicates Better Resolution THEMIS CDR 6/16/04

Safety/Quality/Reliability Pressurant System Carleton PTD P/N 7149, Developed for the ST-5 Program COPV Is Classified Fracture Critical In Accordance With Carleton PTD Damage Control Plan 5412 Liner: 6061-T6 Aluminum Per AMS QQ-250/11 Fluid Port Boss: Bimetallic 6061-T6 Aluminum To 304L CRES Overwrap: 791 ksi PBO Fiber MOP: 2240 Psig At 104°F Proof Pressure: 3360 psig Min. Burst Pressure: 4480 psig Design, Manufacture, and Qualification Of COPV is IAW ANSI/AIAA S-081-2000 Operational Cycle Life: 8 MEOP Pressure Cycles From 0 To 2240 psig And 6 Proof Cycles From 0 To 3360 psig THEMIS CDR 6/16/04

Safety/Quality/Reliability Pressurant System – Cont’d Paine Pressure Transducer P/N 213-76-450-01 0-2000 psi Range Proof 4000 psi Conax N/C Pyro Valve P/N 1832-241 MOP 9400 psi Actuated by NSI EED with a Booster Carleton PTD P/N 7149, Developed for the ST-5 Program Qualified IAW Carleton QTP 1337 Carleton Qualification Test Report 5286 Conax High Pressure Service Valve 1700 psi MEOP, 6800 psi design burst Requirement for Check Valve is Currently Under Investigation THEMIS CDR 6/16/04

Safety/Quality/Reliability Propellant Feed Assembly ValveTech Latch Valve P/N 35614-301 Proof Pressure 1000 psi Burst Pressure 2400 psi Vacco Filter P/N F0D10802-01 Proof Pressure 600 psi Burst Pressure 800 psi Vacco Fill/ Drain Valves P/N V1E10572-01 Burst Pressure 2000 psi Arde Propellant Tank P/N D4899 Inconel I-718 to Meet Magnetics Cleanliness THEMIS CDR 6/16/04

Safety/Quality/Reliability Propellant Feed Assembly Arde Propellant Tank P/N D4899 Inconel I-718 to Meet Magnetics Cleanliness MIL-STD-1522 and EWR 127-1 Compliant Path 2A Leak Before Burst Radiographic Inspection Post Proof Test Per NAS-1514 Class 1 for Welds and QA10177 for Membrane Special Level Fluorescent Penetrant Inspection Sensitivity at 0.030” at 90/95% Probability of Detection/Confidence Level Certification of Inspectors by Boeing Valid through November 2005 Stress Analysis and Fracture Analysis per ANSI/AIAA S-080 Sections 4.2.5 and 4.2.6 Analysis Report Ardé EG10399, N/C Being Updated for 48kg Propellant Load DVT and Qualification Testing Being Conducted by Arde to Meet THEMIS Mission Requirements THEMIS CDR 6/16/04

Safety/Quality/Reliability Rocket Engine Assemblies Rocket Engine Assembly Manifold MEOP = 400 psia + 250 psia, Latch Valve Reverse Cracking Pressure Proof Test to 1.5 x 650 psia Thrusters – Aerojet MR 111C Nominal 4.4 N Thrust Mission Average Specific Impulse Estimated 215 s Dual Coil – Dual Seat Valve with Integral Filter Proof Test 1500 psi Design Burst Pressure 2650 psia THEMIS CDR 6/16/04

RCS Hazards Personnel Exposure to Hydrazine Propellant is Toxic, Flammable and Known Carcinogen Material Incompatibility with Propellant Hydrazine Will React Catalytically With a Variety of Materials Structural Failure of Propulsion System Components Tanks, Tube Supports, Tube Runs, Components Fatigue Failure of Propellant or Pressurant Tank Highly Stressed Components, Limited Cycle Life Inadvertent Actuation of Thruster or Pyro Valves, Valve Leakage Release of Hydrazine Plume Constituents (H2, N2 and NH3) at elevated temperature Over Pressurization of Propellant Management Assembly Failure of Thermal Control System Elements Potential to Drive System Pressure Outside Design Limits THEMIS CDR 6/16/04

Safety Inhibits – Propellant Flow Three Mechanical Inhibits to Prevent Propellant Leakage / Inadvertent Commanding Dual Coil / Dual Seat Thruster Valves (2 Inhibits) Thruster Enable Plug Permits Individual Testing of Valve Seats Latch Valve Closed Immediately Following Propellant Loading (1 Inhibit) “Wet to the Seat” to Prevent Surge Pressure Rise Upon Opening LV Minimal Propellant Volume in Manifold and No Driving Force through Thrusters with Latch Valve Closed Three Electrical Inhibits Thruster Drive Circuit Grounded until Fairing Separation Enable Command Processed through Bus Avionics Unit Communications Card (Special Command) Thruster Commands Processed through Bus Avionics Unit Processor Card and Power Module Inhibits are Independent and Verifiable THEMIS CDR 6/16/04

Safety Inhibits – Repress Mechanical Inhibits to Prevent Inadvertent / or Uncommanded Over Pressurization of the RCS NSI Actuated Pyro Technic Valve (2 Inhibits) Inlet and Outlet Port Must Both Be Punctured No credible failure mechanism for both to fail Failure causes inadvertent pressurization but not catastrophic failure Three Electrical Inhibits Pyro Drive Circuit Grounded until Fairing Separation Enable Command Processed through Bus Avionics Unit Communications Card (Special Command) Pyro Fire Command Processed through Bus Avionics Unit Processor Card and Power Module Inhibits are Independent and Verifiable THEMIS CDR 6/16/04

Safety Inhibits – Over Temperature A “Stuck” Heater on the Propellant Tank Has Been Identified as a Failure that can Lead To Catastrophic Failure Propellant Tank Heaters can cause over pressure due to the “piston” effect of heated propellant – The Hazard does not come from chemical energy release Propellant Tanks are Thermally Isolated for reduced Power Consumption Three Inhibits For Propellant Tank Heaters Series Redundant Thermostats (2 Inhibits) Limit Checking Task In BAU to Monitor Tank Temperatures and Disable Propellant Tank Heater Service Upon Reaching 121ºF (1 Inhibit) THEMIS CDR 6/16/04

Safety - RCS GSE GSE for RCS is limited to a pressure panel Designed, Fabricated and Tested IAW EWR 127-1 Redundant Relief Valves limit pressurization level to MEOP Pressure Panel used for functional demonstration of RCS Propellant Load Equipment and GSE is TBD Anticipate using KSC Propellant Loading Services Introductory Meeting set for late Summer THEMIS CDR 6/16/04