SpaceWorks Engineering, Inc. (SEI) · - Upperstage engines shutoff after transonic flight regime (Mach ~2) - RBCC engines operate in ramjet mode from Mach 2.5 to Mach 5.5 - Scram-rocket

Engineering Today, Enabling TomorrowSpaceWorks Engineering, Inc. (SEI)www.sei.aero

World Space Congress – 200210-19 Oct 2002/Houston, Texas

Page 1

SpaceWorks Engineering, Inc. (SEI)

IAC-02-S.5.02

Xcalibur: 3rd Gen TSTO RLV with HEDM Upperstage

Director of Hypersonics:Dr. John E. Bradford

President / CEO:Dr. John R. Olds

Senior Futurist:Mr. A.C. Charania

October 2002

AboutSpaceWorks Engineering, Inc. (SEI) is a small aerospace engineering and consulting company located in metro Atlanta. The firm specializes in providing timely and unbiased analysis of advanced space concepts ranging from space launch vehicles to deep space missions.

Our practice areas include:- Space Systems Analysis- Technology Prioritization- Financial Engineering- Future Market Assessment- Policy and Media Consultation

SpaceWorks Engineering, Inc. (SEI)www.sei.aero


Page 2

Engineering Today, Enabling Tomorrow

Image sources:Space Systems Design Lab (SSDL) / Georgia Institute of Technology, SAIC, NASA Kennedy Space Center, NASA Marshall Space Flight Center, Media Fusion, Boeing



Page 3


Including:- 2nd, 3rd, and 4th generation single-stage and two-stage Reusable Launch Vehicle (RLV) designs (rocket, airbreather, combined-cycle)- Human Exploration and Development of Space (HEDS) infrastructures including Space Solar Power (SSP)- Launch assist systems- In-space transfer vehicles and upper stages and orbital maneuvering vehicles- Lunar and Mars transfer vehicles and landers for human exploration missions- In-space transportation nodes and propellant depots- Interstellar missions

Concepts and Architectures



Page 4


From Vision to Concept

Including:- Engineering design and analysis- New concept design- Independent concept assessment- Full, life cycle analysis- Programmatic and technical analysis

Illustrations of the Future



Page 5


Including:- Storyboards- Technical concept illustrations (marker and pastel of various rendering qualities in B&W and color)- 2-D line engineering drawings with technical layouts and dimensions- 3-D engineering CAD models of concept designs- High-resolution computer graphics imaging (renders) - Concept / architecture summary datasheets and single page handouts / flyers

Study Motivation

STAGING TYPE

LA

UN

CH

TY

PE

Single-Stage-To-Orbit[SSTO]

Two-Stage-To-Orbit[TSTO]

Vertical Take-Off

[VTO]

Horizontal Take-Off

[HTO]

Langley Research Center (LaRC)Marshall Space Flight Center (MSFC)

Ames Research Center (ARC)Marshall Space Flight Center (MSFC)

Request from NASA - MSFC to perform Exploratory Concept Investigation of anRBCC-powered Vertical Takeoff TSTO RLV:- Little explored region of the RBCC design space- Study objective is to determine whether an attractive configuration might exist here

Why?

Candidate RBCC Configurations:

Motivation

Glenn Research Center (GRC)

VTO TSTO Configuration Issues

Lower wing size and wing weight requirementsLower undercarriage weight (assuming some propellant dump for abort landing)Lower bending/bounce normal loads on takeoff

Increased lift-off thrust (T/W = 1.15)Decision: Augment RBCC ejector thrust with exposed upperstage engines at lift-offResults in smaller RBCC thrusters, increased bypass ratio and low inlet starting Mach number

Increased vertical loadsDecision: LH2 tank forward, LOX/HC tanks aftResulting aft c.g. may lead to trim issues

In-line thrust vector required for trim at liftoffDecision: Side mounted, symmetric RBCC engine modules vs. underslug lifting bodyResults in less forebody compression and lower scramjet thrust at high MachOvercome with heavy use of scram-rocket mode above Mach 5Internal and aft upper stage location allows thrust through c.g. or gimbal control

Avoid closed compartment for any internally tanked LH2Decision: LOX/HEDM HC for upperstage propellantsIncreased bulk density helps internal packagingPerformance of HEDM is adequate, but staging Mach needs to be high to reduce orbiter ? VCross feed of upperstage propellants from booster tanks during boost reduces orbiter size

VTO Advantages over HTO:

Configuration Adjustments:

Xcalibur Concept Overview

Xcalibur

- 3rd Generation (first flight 2025) Reusable Launch Vehicle (RLV) developed at SEI- Fully reusable, Two-Stage-To-Orbit (TSTO) system- Vertical Takeoff, Horizontal Landing (VTHL)- Capable of delivering 20 Klbs. to Low-Earth-Orbit (LEO)- Upperstage is carried inside of booster- Rocket-Based Combined Cycle (RBCC) main propulsion booster- Advanced all-rocket upperstage engines- LOX/LH2 propellants for RBCC engines, HEDM for upperstage rockets- Autonomous, unpiloted flight- Powered supersonic flyback for booster- Advanced systems engineering tools and processes used for conceptual design

- Take-off from Kennedy Space Center (KSC) with engines from both stages ignited- Thrust-to-Weight (T/W vehicle) = 1.15, % thrust from upperstage at take-off = 15%- Upperstage engines shutoff after transonic flight regime (Mach ~2)- RBCC engines operate in ramjet mode from Mach 2.5 to Mach 5.5- Scram-rocket mode from Mach 5.5 to staging point at Mach ~15.5- Booster returns to KSC under ramjet power with Mach 3 cruise- Upperstage injects into 30x100 nmi. at 28.5o; circularizes to 100 nmi.- Delivery of 20 Klbs. payload- Upperstage performs deorbit burn, reenters, and returns to KSC

Concept Overview:

Mission Overview:

Xcalibur Integrated Booster and Upperstage

Xcalibur Staging

Xcalibur Upperstage on orbit



Page 14

Key Vehicle Technologies

(4) RBCC enginesSHARP TPS leading edges (nose, cowl, wings, and tail)Ti-Al hot-structure (wings and tail)Combination of integral/non-integral Gr-Ep tanks (nbp H2 )Non-integral Al-Li Oxidizer tanksAFRSI/TUFI TPS tiles (fuselage)Gaseous H2/O2 RCS (no OMS capability)

(3) High-energy density matter (HEDM) propellant enginesNon-integral Gr-Ep cylindrical/spherical tanksACC TPS (nose)AFRSI/TUFI TPS tiles (fuselage)Middle HEDM engine used as OMS engine for circularization and deorbitTotal OMS ∆V of 450 ft/s

Integrated Vehicle Health Monitoring (IVHM) systemsEMA’s (no hydraulics)Advanced avionics

Booster Stage Specific

Upperstage Stage Specific

Entire Vehicle



Page 15

4 Oxygen-Hydrogen Ejector-Scramrocket (ESR) Engines- 3 operating modes

1) Air-Augmented Rocket (Mach 0 to 2.5)2) Ramjet (Mach 2.5 to 5.5)3) Scram-Rocket (Mach 5.5 +)

- Two-ramp external compression systemInitial 6.5o conical rampTransitions to 15o 2-D ramp

- Shock-On-Lip condition at Mach 12- Cowl height of 3.5 feet- Bypass ratio (ms/mp) of 1.5- Rocket thrusters

Pc = 2,500 psiExpansion Ratio = 5Mixture Ratio = 6.5

- Variable geometry inlet with mechanical choke in combustor, inlet starts at Mach 2.5- Estimated engine length = 35 feet- T/W|e = 30 (uninstalled)- Engine sized by varying rocket thruster flowrate and flowpath geometry to meet required

total vehicle takeoff T/W of 1.15

Booster Propulsion System



Page 16

Upperstage Propulsion System

3 Staged-Combustion cycle liquid rocket engines

HEDM strained-ring hydrocarbon (AFRL-1, Quadricyclane derived) and LOX propellants

Multiple restart capable

Engine Specifications:- O/F = 2.5- Pc = 3,000 psia- Area Ratio = 25 / 100 with extendible skirt- Isp,vac = 338.5 / 360.2 sec.- Estimated Weight = 789 lbm.- T/W)e = 73.0 SLS

Design Analysis Tools



Page 18

Xcalibur Engineering Analysis and Design Toolset

SCORES-IILiquid Rocket Propulsion

S/HABP + TCAT-IIAeroheating

CABAMEconomics

GT-Safety IISafety

AATeOperations

Excel Spreadsheet using discretized range equationsFlyback Simulation

SCCREAMRBCC Propulsion

APAS, S/HABPAerodynamics

POST (3-DOF, untrimmed)Ascent Trajectory

NAFCOM Cost Estimating Relationships (CERs)Cost

Excel Spreadsheet with Mass Estimating Relationships (MERs)Mass Properties

SDRC-IDEAS, CANVASCAD

Tool, Model, SimulationDiscipline

Vehicle Performance Toolsets

Economic Closure Toolsets

Wrapped in Phoenix Integration’s Analysis Server© tool with server location at SEI



Page 19

Air-Breathing Propulsion Performance Prediction

SCCREAM v.6- Written in C++ with executable versions for the PC, SGI, and Mac OS X- Performance prediction for ramjet, scramjet, and RBCC engines- RBCC thruster analysis based on SCORES-II capabilities- Executes in ‘batch’ mode predicting performance at 100’s of flight conditions (Mach number, Altitude, and throttle

setting)- Automatically generates formatted POST deck of thrust, thrust coefficient, and Isp for each engine mode- Total execution time on order of 5 minutes- Features new rapid aftbody nozzle performance prediction model:

Series of RSE’s used to predict static pressure ratios at 5 x/L locations on aftbody for supersonic flight (Mach 2.5-15)User can specify initial and final nozzle expansion angles, as well as combustor-to-nozzle length (h/L) ratioSCCREAM 1-D combustor model provides combustor exit/nozzle entrance flow conditionsChi-Square fitting algorithm then used to reconstruct complete aftbody pressure distribution from 5 x/L pressure ratiosDistribution can then be integrated to obtain axial force, normal force and pitching momentEnables quick and accurate aftbody shape optimization

Tool is wrapped for use in ModelCenter© collaborative design environment



Page 20

Aeroheating Analysis

Thermal Calculations Analysis Tool (TCAT)-II- TPS selection and sizing tool- Written in C++ with PC, Max OS X, and SGI executables available- Solves 1-D unsteady heat transfer equation

Adiabatic backface boundary conditionOuter boundary condition has conductive, convective, and radiative terms

- Integrated material properties database from NASA AmesContains over 75 different material types (metals, alloys, blankets, foam, composites)Thermal conductivity and specific heat contained as function of temperature

- User can assign any number of TPS stackup candidates that TCAT-II will select from- Tool will size out user-selected layer for each stackup to meet a backface temperature requirement- Utilizes geometry model and convective heat rates from APAS- User provides trajectory flight path information (time, altitude, Mach number, etc.)- Convective heat rates at each time step can be either directly specified or an interpolation feature can be selected.

Interpolation feature allows for updates to trajectory path without need for regeneration of APAS results (in-the-loop TPS sizing)

- Includes ‘heat exchanger’ active-TPS override option- Outputs contain total TPS weight, acreage, unit weights, volumes, and thickness by stackup type and geometry

component model- Future capabilities:

Isothermal backface conditionMulti-layer stackup optimization



Page 21

Economic Analysis

Cost and Business Analysis Module (CABAM)- MS-Excel spreadsheet-based model that attempts to model both the demand and supply for space transportation

services in the future- Capability to model both multi-stage reusable and expendable concepts with/without cargo and crew containers

with/without expendable boosters- Demand takes the form of market assumptions (both near term and far-term) and the supply comes from user-defined

vehicles that are placed into the model- Inputs from other disciplinary models (cost, operations) to generate Life-Cycle-Cost (LCC) and economic metrics- One of the major assumptions inherent in CABAM is that the project is modeled as a commercial endeavor with the

possibility to model the effects of government contribution, tax-breaks, loan guarantees, etc. - Operation includes a multi-step process:

User defines a particular program that consists of a certain set of economic and schedule assumptionsThe performance, cost, production, and operational properties of the vehicle are then definedUser can then manipulate the price charged per market to maximize (or meet) a desired financial return

- The model takes a corporate finance mentality as far as economic modeling- Various input financial ratios and rates (debt-to-equity, discount rates, etc.) are need for calculation of financial metrics- The long-term market forecasts are based upon the Commercial Space Transportation Study (CSTS) from the early

1990s- Both full fidelity and lower fidelity (CABAM_A, CABAM_Abbreviated) versions available



Page 22

Conceptual Design Processes Within ModelCenter© Collaborative Design Environment

Performance Closure Process

Economic Closure Process

Design/System Engineering Toolkits

- A suite of packages developed by SEI to expand current capabilities of Phoenix Integration’s ModelCenter© collaborative design environment

- Each tool is implemented as a Java-based component that is hosted on Analysis Server© - Available from SEI as single-user or site license

- Features 8 non-gradient based optimizers- Genetic Algorithm and AutoGA- Simulated Annealing and AutoSA- Compass Search- Grid Search- Random Walk- Random Search

- Can handle discrete and continuous variables- User sets convergence requirements, maximum iterations, solution fidelity (e.g. number of bits, step size)

- Features 4 tools to enable and analyze uncertainty problems- Statistical Monte Carlo driver- Discrete Probability with Optimal Matching Distributions (DPOMD)- Design of Experiments and Response Surface Equation (RSE) Generator- Sensitivity Analysis

Overview:

OptWorks:

ProbWorks:

Baseline Concept Results

Xcalibur Booster 3-View

Dry wgt = 162.1 Klb

Gross wgt = 1.002 Mlb

Payload = 20,000 lb

Ox wgt/Fuel wgt = 4.34

Mass Ratio = 3.376

Payload bay (in upper stage)

LH2 tank

LOX tanks

RBCC engines (2 each side)

Rocketengines (3)

HC tank

181.7 ft

69.8 ft

Xcalibur Upperstage 3-View

Dry wgt = 24.3 Klb

Gross wgt = 103.7 Klb

Payload = 20,000 lb

LOX wgt/HC wgt = 2.5

Mass Ratio = 2.16

Payload bay 10 ft wide x 20 ft long

LOX tanks

19.3 ft

Rocketengines (3)

HC tanks

42.4 ft

stowed

deployed

Xcalibur Booster CAD Models



Page 28

Booster Weight Breakdown Summary

1,001,500Gross Lift-Off Weight (GLOW)

704,880Ascent Propellants

296,620Staging Weight

9,010RCS, Unusable, and Reserve Propellants

21,840Flyback Propellants

103,710Payload Carried

162,060Dry Weight

10,470Subsystems

46,710MPS + RCS

5,630Landing Gear

19,610TPS

79,640Body, Wings, and Tails

Value [lbs]WBS Item

Xcalibur Upperstage CAD Models



Page 30

Upperstage Weight Breakdown Summary

103,710Gross Lift-Off Weight (GLOW)

55,640Ascent Propellants

48,070Insertion Weight

3,730RCS, Unusable, and Reserve Propellants

20,000Payload Carried

24,340Dry Weight

5,250Subsystems

4,300MPS + RCS

1,555Landing Gear

2,290TPS

10,945Body, Wings, and Tails

Value [lbs]WBS Item



Page 31

Ascent Trajectory Results

Altitude and Mach Number versus Time Thrust and Acceleration versus Time

0

50,000

100,000

150,000

200,000

250,000

300,000

0 100 200 300 400 500

Time (seconds)

Altit

ude

(ft)

0.0

5.0

10.0

15.0

20.0

25.0

30.0

Mach Num

ber

AltitudeMach Number

0

340,000

680,000

1,020,000

1,360,000

1,700,000

0 50 100 150 200 250 300 350

Time (seconds)

Thru

st (l

bs)

0.0

1.0

2.0

3.0

4.0

5.0

Acceleration (G's)

ThrustG's



Page 32

APAS Aerodynamics Model of Booster

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0.16

0.18

0 2 4 6 8 10 12 14 16Mach Number

Dra

g C

oef

fici

ent

(Cd

)

-0.20

-0.10

0.00

0.10

0.20

0.30

0.40

0 2 4 6 8 10 12 14 16

Mach Number

Lif

t C

oef

fici

ent

(Cl)

TCAT-II RLV Booster Results: Maximum Surface Temperatures and Tile Thickness(Top View)

TCAT-II RLV Booster Results: Maximum Surface Temperatures and Tile Thickness(Bottom View)



Page 35

Non-Recurring and First Vehicle Acquisition Cost Summary

Booster

DDT&E (Airframe)

DDT&E Engines (RBCC)

DDT&E Engines (Rocket)

DDT&E (All Engines)

Total DDT&E

TFU (Airframe)

TFU Per Engine (Ramjet)‡

TFU Per Engine (Rocket)‡

Acquisition Engines (Ramjet)¥

Acquisition Engines (Rocket)¥

Total Acquisition (All Engines)

Total Acquisition (First Vehicle)

Upperstage Total

$5,845 M

$1,870 M

$1,870 M

$7,715 M

$1,243 M

$299 M

$1,001 M

$1,001 M

$2,244 M

$1,922 M

$98 M

$98 M

$2,020 M

$391 M

$24 M

$62 M

$62 M

$453 M

$7,767 M

$1,968 M

$9,735 M

$1,633 M

$1,063 M

$2,696 M

† - rounded FY2002 US$, assuming a 2.1% inflation rate‡ - Per engine without learning or production rate effects¥ - For all engines with 85% learning/production rate effect percentage

Cost Item

No

n-R

ecu

rrin

g C

ost

Su

mm

ary

So

urc

e: N

AF

CO

M C

ER

s

Cost to First Vehicle$12,431 M



Page 36

Operations and Safety Summary†

Booster

OPERATIONS

AATe Input Flight Rate [Flights Per Year]

Fixed Operations Cost Per Year

Variable Operations Cost Per Flight

Propellant Cost Per Flight

Insurance Cost Per Flight

Site Fee Cost Per Flight

Total Recurring Cost Per Flight

Facilities / GSE Acquisition (one time)

Vehicle Ground Cycle Time [days]

SAFETY

Loss of Mission (LOM) [MFBF]

Loss of Vehicle (LOV) [MFBF]

Casualty Rate [Casualties Per Year]

Upperstage Total

-----

-----

-----

-----

-----

-----

-----

-----

4.03 Days

1,056 Flights

2,079 Flights

0.0176

-----

-----

-----

-----

-----

-----

-----

-----

3.46 Days

2,887 Flights

5,685 Flights

0.0211

25.1 Flights/Year

$50.30 M

$4.0 M

$0.1 M

$1.68 M

$0.50 M

$8.3 M

$450.91 M

4.03 Days

773 Flights

1,523 Flights

0.0387

† - rounded FY2002 US$, 2.1% inflation rate, flights rates going into GTSafetyII used flight rate assumptions of 25-26 flights per year. Assuming 4 passenger flights per year with 15 passengers per light, 200 ground touch personnel for booster, 150 ground touch personnel for orbiter, propellant bought for launch assumed to be 1.5 times propellant required from vehicle weight breakdown due to losses in transportation

Item

So

urc

e: A

AT

e, G

TS

afet

yII



Page 37

Economic Summary

Market Price Per lb (to meet financial return where Net Present Value = 0)

Life Cycle Cost Per lb (pre Government Contribution)

Life Cycle Cost Per lb (post Government Contribution)

Recurring Cost Per lb (operations + propellant + insurance + site fee)

Recurring Operations Cost Per lb (operations + propellant)

Weighted Average Cost of Capital (WACC) + Incentive Return

Flight Rate (Cargo + Passenger) Per Year for Above Price (fractional)

% of Flights that are Commercial

Number of Booster Units Acquired (Lifetime = 1,000 Flights)

Number of ESR RBCC Propulsion Units Acquired (Lifetime = 500 flights)

Number of Upperstage Units Acquired (Lifetime = 1,000 Flights)

Number of HEDM Propulsion Units Acquired (Lifetime = 500 Flights)

Total Life Cycle Cost (LCC) without Financing pre Government Contribution

Total Government Contribution (DDT&E, Facilities Development, 1st Vehicle)

$5,542 / lb

$2,203 / lb

$1,629 / lb

$416 / lb

$307 / lb

15.23%

25.1 Flights / Year

40.7%

1

4

1

3

$23,243 M

$6,057 M

Economic Output Item

† - rounded FY2002 US$, 2.1% inflation rate, price charged is that to meet Weighted Average Cost of Capital (WACC) target, assuming 4 passenger flight per year (2 commercial and 2 government) charging FY2002$2M per passenger, all other flights are cargo, one price charged for all markets (commercial and government), assumes 20Klbs LEO equivalent payload with 15% payload inefficiency factor, using facilities cost and LOV for 25 flights

Lif

e C

ycle

Co

st P

er P

ou

nd

So

urc

e: C

AB

AM

_A

Value

Alternate Configurations



Page 39

Alternate Configurations

$2.045 BTFU

55Flights per year

$6.4 M / flightRecurring Cost

$7.545 BDDT&E

1:1798 [flights]Loss of Vehicle (LOV)

Commercial price

Upperstage Length

Upperstage Dry

Booster Length

Booster Dry

System GLOW

$4,576 / lb

28.4 ft

14,200 lbs

148.9 ft

98,900 lbs

570,100 lbs

• Reduced payload weight from 20K lbs to 10K lbs• Same mission to 100 nmi. LEO• Improved packaging efficiency on the upperstage• Vehicle closed for both performance and economics

• Upperstage system removed, 50% of volume retained• Booster provides 100% of takeoff thrust (T/W=1.15)• Engine T/W reduced from 30:1 to 20:1• Booster maximum Mach number of 12• Airframe structural unit weights increased

$3.89 BTotal Cost to Acquire

$1.09 BAcquisition

$2.80 BDDT&E

176,680 lbsGLOW

49,470 lbsDry Weight

104.1 ftLength

ALTERNATE PAYLOAD CONFIGURATIONBOOSTER DEMONSTRATOR VEHICLE

Summary and Conclusions

Xcalibur Study Conclusions

VTHL TSTO appears to be a feasible vehicle architecture as a 3rd Gen RLV, resulting in an ~1 Mlbs class vehicle with dry weight of only 186 Klbs for 20 Klbs to LEO.

The TSTO option eliminates the all-rocket mode RBCC engine operation, which has traditionally been an area of high uncertainty in performance and extreme vehicle sensitivity. The elimination of the all-rocket mode increases engine T/W.

The extended utilization of the scram-rocket mode drives the configuration to a more rocket-like propellant load and smaller size. The vehicle retains loiter, flyback, and abort options inherent with air-breathing propulsion system through the RBCC engines.

The high acceleration in this mode compared to a SJ then SR mode option appears to be highly beneficial.

By reducing the payload to 10 Klbs to LEO, the lower DDT&E cost from the smaller vehicle reduces the launch price and increased vehicle flight rates.

Even for fairly aggressive vehicle performance and cost assumptions, the financial hurdle is still very difficult. Lower DDT&E is required (<$5B) and significantly expanded payload markets will be necessary.

Performance

Economics



Page 42

SpaceWorks Engineering, Inc. (SEI)

Business Address:SpaceWorks Engineering, Inc. (SEI)1200 Ashwood ParkwaySuite 506Atlanta, GA 30338 U.S.A.

Phone: 770-379-8000Fax: 770-379-8001

Internet:WWW: www.sei.aeroE-mail: [email protected]

President / CEO: Dr. John R. OldsPhone: 770-379-8002E-mail: [email protected]

Director of Hypersonics: Dr. John E. BradfordPhone: 770-379-8007E-mail: [email protected]

Director of Concept Development: Mr. Matthew GrahamPhone: 770-379-8009E-mail: [email protected]

Project Engineer: Mr. Jon WallacePhone: 770-379-8008E-mail: [email protected]

Senior Futurist: Mr. A.C. CharaniaPhone: 770-379-8006E-mail: [email protected]

Contact Information

SpaceWorks Engineering, Inc. (SEI) · - Upperstage engines shutoff after transonic flight regime (Mach ~2) - RBCC engines operate in ramjet mode from Mach 2.5 to Mach 5.5 - Scram-rocket

Documents