Advancing Operationally Responsive Space Systems with Propulsion Technologies

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

2. 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

3. Introduction • AFSPC 001-01/02; 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

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

5. “Spirally Develop” With A FocusVisionary (But Focused) Approach Needed Early to Meet Full Operational Responsiveness Needs Sidewinder AAM Pilot APG-65 Radar 20mm Cannon Sidewinder AAM • 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 • 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,

6. 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, 750-900 Psia • Pressure Fed for < 500, Gas Generator and Expander Cycles for 750-900 • 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 (Tboil (K) 112) ... versus (Tboil (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

7. MISSION-CONCEPT DEFINITION PROPULSION PERFORMANCE MASS PROPERTIES (Sizing) FLIGHT PERFORMANCE ANALYSIS (POST) DEFINE ALTERNATIVES FOR HIGHER RESPONSIVENESS 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 SUMMARIZE RESULTS AND VALIDATE WITH DATA BASE

8. Results – TSTO RSLV “Spiral 0-1”

9. TSTO RSLV “Spiral 0-1” – Geometry Comparison • 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 75 ft 58 ft 64 ft 58 ft 58 ft Design the “Spiral Development” Elemental Steps In At the Beginning To Avoid Encroachment On Objective: Responsiveness Payload(lb) 1,700 1,700 1,700 2,300 1,700 GLOW(lb) 64k 144k 52k 68k 72k Empty(lb) 3.7k 18k 4.7k 4.2k 11k

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

11. 163,000 lb Horizontal Take-Off (HTO) RSLV Concept Trades Other A/C TOGW(lb) For Comparison C-17 585,000 B-1B 477,000

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

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

14. 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

15. BACKUPS

16. Possible “Sweet-spot” Evolved HTO

17. Process and Physics Driven Cost

18. LEGEND Pressure PSIA Temperature Deg R Mass Flow Rate Lbm/Sec Flange, Orifice , 20Klb Methane Expander Engine Concept CH4 In O2 In 25 43 200 175 13.8 48.4 FIV OIV Total Area Ratio Main Turbine Inlet FSV 990 591 70 : 1 880 800 742 OFC 179 Regen Area Ratio 1549 13.0 13.0 48.4 216 10 : 1 13.8 Vacuum Thrust Main Turbine Exit 591 22,000 lbf 742 500 Vacuum Isp Regen section 13.0 6244 1010 353.2 sec 62.3 800 13.8 Turbine bypass=0.8 lb/s Radiation-cooled skirt

19. 20Klb Methane Expander Engine Concept Attributes Indicates Previous Risk Reduction 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 Alter Gear Ratio Between Fuel and Oxidizer Pumps Regeneratively or radiativelycooled nozzle ~20Klb ThrustCH4/O2Systems Integration RL10 CH4 History Minimum modifications to existing injector Use existing 40Klb test chamber Insert new TCA technology Low Risk CH4 Expander Demo

20. Pressurant flow from main engines Vehicle Interface Expendable Hybrid Fuel Canister (Pc ~ 1000 psia) 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 AugmentationModular development Benign environments Low complexity Low cost fuel canisters

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

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