AIAA Responsive Space April 22, 2004 Highly Operable Propulsion System Approaches and Propulsion Technologies for Operationally Responsive Space Systems Russell Joyner Discipline Chief - Space Systems and Mission Analysis Performance Systems Analysis & Integration

6/4/022 Presentation Outline Introduction Responsive Space, Historically Speaking “Spirally Develop” with A Focus Ground Rules for Study: Responsive Small Launch Vehicle Analysis Process Results – TSTO RSLV “Spiral 0-1” TSTO RSLV “Spiral 0-1” – Geometry Comparison “Spiral Development” from TSTO RSLV to HTO-RSLV Horizontal Take-Off (HTO) RSLV Concept Trades HTO RSLV Concept Comparison to Legacy Systems Boil Off Issues for Cryogenics - Impact of Integrated Thermal Management Unit (ITMU) Summary Of Observations

6/4/023 Introduction AFSPC /02; Operationally Responsive Spacelift (ORS) and Prompt Global Strike Mission Needs Statement Decomposition “.. capability to rapidly put spacecraft into orbit” “.. maneuver spacecraft to any point in earth-centered space” “.. logistically support them on orbit or return them to earth” “.. strike globally and rapidly high value difficult to defeat targets in a single or multi-theater environment” Operationally Responsive Spacelift Needs Architectures that Support an Over-arching Vision That Can Evolve “Spiral Development”, Merging of Technical Capability and Budget Realities A “Spiral Development” Approach for ORS Needs A Roadmap that Includes the ‘Present” and “the Possible..Technologies on the Shelf or at High Readiness” An Approach for Creating the “Roadmap” from an “Operationally Responsive” Propulsion and Propellants Point of View Evolve to Higher Responsiveness By “Spiraling in” Upgrades to Propulsion, Propellants, Propellant Management, and “Dispersed Launch” Capability

AIAA Responsive Space Responsive Space, Historically Speaking Use of Cryogenics for Propellants Was Successful Because of Focused Process and Mission Images Courtesy: Strategic Missile Website Titan I Jupiter Thor Time to Launch <20-minutes Total Propellant Loading in 15-minutes After Launch Commit Was Issued ~220,000 lbs. ~105,000 lbs. ~110,000 lbs.

AIAA Responsive Space mm Cannon Sidewinder AAM Pilot APG-65 Radar Original F-16 was designed for an important, but limited role as only an air-to-air fighter aircraft But Evolved to Be More Multi- Mission Capable Data: ONE Team Payload & Sensors Presentation Jan 2002 “Spirally Develop” With A Focus Visionary (But Focused) Approach Needed Early to Meet Full Operational Responsiveness Needs + A Responsive Small Launch Vehicle Could “Spirally” Evolve Into a Highly Responsive Launch Architecture A Total Systems Architecture Vision Is Needed A Horizontal Take-off Type RSLV Carrier? ? Images Courtesy: Space Exploration Technologies Inc., aviation-history.com,Boeing WEBSITES,

AIAA Responsive Space Ground Rules for Study: Responsive Small Launch Vehicle (RSLV) Notional Two Stage To Orbit (TSTO) RSLV As Baseline Concept (e.g. Similar to Current TSTO Approaches Coming On-line) Orbit Notional Mission: 1,700 pounds to 100/28.5 LOX/Kerosene Propulsion and Propellant as Baseline –Boost and Upper Stage Performance Per Optimum ISP Nozzle Area Ratio and Max Diameter Per Stage Diameter, O/F, and 2 Combustion Chamber Designs Low Pressure, < 500 Psia; Higher Pressure, Psia –Pressure Fed for < 500, Gas Generator and Expander Cycles for Start With LOX/Methane and 98% Hydrogen Peroxide(HTP)/Solid Fuel Hybrid Evaluated for Upper Stages and Booster Propulsion –Take LOX Operability As “workable” Per Historical Systems and Current Experience Look at Methane (T boil (K) 112)... versus (T boil (K) 90 for LOX) –+15 Seconds ISP increase over Kerosene, O/F 3.5 versus 2.7 Gives Average Bulk Density Difference ~20% Which Trades With Lower Required Propellant Fraction Look at HTP/Solid Hybrid To See How The Performance Differences Vary So System Cost Attributes Could be Investigated Look At General Thermal Storage Impact for “Sized” Vehicle Propellant Loads Evaluate Carriage of “Sized” Systems for Higher Responsiveness Level 2 Spiral

AIAA Responsive Space Analysis Process Start With Concepts Based on “Available Hardware”, Investigate “Spiral Development Elements” Define Notional TSTO (2-stage) Responsive Small Launch Vehicles: LOX/Kerosene Propellants Fly-off with POST (Trajectory Code) to 100nm/28.5 Nominal Mission, “Re-size” to Meet 1,700 pound Payload (Performance for Systems Flying 1,000 to Higher, Polar Orbits Evaluate Alternative Engines/Propellants As “Spiral Evolutions” to Base Notional Concept PROPULSION PERFORMANCE FLIGHT PERFORMANCE ANALYSIS (POST) MISSION- CONCEPT DEFINITION MASS PROPERTIES (Sizing) SUMMARIZE RESULTS AND VALIDATE WITH DATA BASE DEFINE ALTERNATIVES FOR HIGHER RESPONSIVENESS

AIAA Responsive Space Results – TSTO RSLV “Spiral 0-1”

AIAA Responsive Space TSTO RSLV “Spiral 0-1” – Geometry Comparison 64 ft 75 ft 58 ft Payload(lb)1,7001,700 1,7002,3001,700 GLOW(lb)64k144k52k68k72k Empty(lb)3.7k18k4.7k4.2k11k Objective: Achieve Greater Responsiveness with “Core” and Evolve Via “Spiral Development” to be Fully Responsive With Technology Insertion via Upgraded Stage Propulsion and ITMU Usage Images Courtesy: Strategic Missile Website Design the “Spiral Development” Elemental Steps In At the Beginning To Avoid Encroachment On Objective: Responsiveness

6/4/0210 Level 1 “Spiral” Level 0 “Spiral” Level 2 “Spiral” Options High Pressure All LOX/Kerosene High Pressure LOX/Kerosene Boost LOX/Methane U/S High Pressure Hybrid Boost or S/O LOX/Methane U/S Horizontal T/O & Hybrid Boost or S/O LOX/Methane U/S “Spiral Development” from TSTO RSLV to HTO-RSLV

AIAA Responsive Space Horizontal Take-Off (HTO) RSLV Concept Trades 163,000 lb Other A/C TOGW(lb) For Comparison C-17585,000 B-1B477,000

6/4/0212 USAF/General Dynamics B-58 “Hustler” TOGW(lb)163,000Payload(lb) < 40,000 Empty(lb)56,000Mach cruise 2.2 Sref (ft^2)1,550Length(ft) 97, b_span 56 ft Runway Field Length< 7,900 ft, T/W ~0.3 TOGW(lb)160,000Payload(lb) <70,000(LEO 3,000) Empty(lb)74,000Mach max 3.5 Sref(ft^2)1,600Length(ft) < 100, b_span 65 ft Runway Field Length< 5,500 ft, T/W ~0.5 HTO RSLV Concept Comparison to Legacy Systems

AIAA Responsive Space Boil Off Issues for Cryogenics - Impact of Integrated Thermal Management Unit (ITMU) Images Courtesy: NASA GRC NASA/GRC Has TMS/ZBO Designs Evolving To Higher Tech Readiness

AIAA Responsive Space Summary of Observations Responsive Spacelift Must Be Approached With A Careful “Spiral Development” Approach –A RSLV system must also keep trading off how the system meets affordable cost criteria, obtains high reliability and low maintenance, and has the performance to deliver a wide range of payload that could go as low as 100 pounds or as high as 12,000 pounds to LEO Most likely not done by a single launch vehicle design due to the affordability trade-offs but by some combination of stages that builds off the base design without compromising the “Demonstrated Responsiveness” To Meet Global Reach and Rapid Spacelift Mission Needs, Systems Must Respond in Minutes Like Current Military Aircraft The Goal Should be; “Spirally Develop” Systems Using Evolved Propulsion Technologies With A Strong Focus on Operability Within a Military Mission Environment (e.g. F119, RL10) –Evolve them to formulate a reliable, Operationally Responsive Spacelift and on-orbit architecture –Evolve in innovative use of air-breathing propulsion, employment of soft-cryogenic fuels and oxidizers, low cost hybrid motors, and an integrated vehicle-engine health management system to create higher levels of operational responsiveness An “Operationally Responsive Propulsion” Roadmap can be Created Using This Approach to Support Evolving Responsive Spacelift And Systems Needs for the Military Forces of the United States of America

AIAA Responsive Space BACKUPS

AIAA Responsive Space Possible “Sweet-spot” Evolved HTO

AIAA Responsive Space Process and Physics Driven Cost

AIAA Responsive Space Klb Methane Expander Engine Concept LEGEND PressurePSIA TemperatureDeg R Mass Flow RateLbm/Sec Flange, Orifice, Main Turbine Inlet Main Turbine Exit Total Area Ratio 70 : 1 Vacuum Thrust 22,000 lbf Vacuum Isp sec CH4 In Turbine bypass=0.8 lb/s O2 In OFC FSV OIV FIV Regen Area Ratio 10 : 1 Radiation-cooled skirt Regen section

AIAA Responsive Space ~20Klb Thrust CH4/O2 Systems Integration RL10 CH4 History Leverage current RL10 hardware - O2 turbo pump and fuel turbo pump - Fuel and oxidizer inlet valves - Main fuel and main oxidizer valves - Thrust control valve - Cool down valves - Pneumatic control approach Minimum modifications to existing injector Use existing 40Klb test chamber Insert new TCA technology Regeneratively or radiatively cooled nozzle 20Klb Methane Expander Engine Concept Attributes Alter Gear Ratio Between Fuel and Oxidizer Pumps Low Risk CH 4 Expander Demo Indicates Previous Risk Reduction

AIAA Responsive Space The Symbiotic Hybrid As Part Of an RLV Key Features: No Additional Turbomachinery Low Risk Pressurization Flow Uses LOX tank pressurant from vehicle main engines Affordability Thrust Augmentation Modular development Benign environments Low complexity Low cost fuel canisters Expendable Hybrid Fuel Canister (Pc ~ 1000 psia) Vehicle Interface Pressurant flow from main engines

AIAA Responsive Space 2004 Notional HRC Characteristics For Hybrid Motor Simplified HRC characteristics derived from HPDP program (P&W team member) Leverage HPDP Technology Fixed Nozzle ‘Baseline’ Low Cost Monolithic Graphite Case

AIAA Responsive Space 2004 Firebolt/HAST Hybrid Propulsion System First Production Hybrid with Flight Maturity--Demonstrated Throttling Capability Hybrids have gone to production and flight status before……..