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SpaceWorks Engineering, Inc. (SEI)
D4Ops: Design For Operations of Future Reusable Launch Systems
SPACEWORKS ENGINEERING, INC. (SEI)
Senior Futurist:Mr. A.C. Charania
Project Engineer:Mr. Jon G. Wallace
Technical Fellow:Dr. John R. Olds
NASA KENNEDY SPACE CENTER (KSC)
System Engineer: Mr. Edgar Zapata
IAC-04-V.2.0855th International Astronautical Congress04-08 October 2004, Vancouver, Canada
Introduction
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Space Shuttle Facilities at NASA Kennedy Space Center (KSC)
Orbiter Processing Facility (OPF)
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Turnaround Processing Activities
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Imagination and Reality in the OPF
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Overview
Quantify Shuttle Lessons Learned
New Operational Approaches
New Launch Architectures
Near, Mid, and Far Term
Systems Modeling
Metrics Assessment
The application of novel, not yet studied, but extr emely viable and promising options for an entirely operable reusable launch system design is now feasible based on advances in operations analysis, integrating tools, models, and in understanding design margin and sub-system operational characteristics.
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Motivation
D4Ops (Design for Operations) was a nine-month study effort that was conducted by SpaceWorks Engineering, Inc. (SEI) under sponsorship of the NASA Kennedy Space Center Systems Engineering Office. D4Ops was a ground operations-focused study designed to quantitatively determine the potential benefits of several proposed new D4Ops approaches to space vehicle configuration and operations. The study aimed to determine the key compromises and trade-offs between weight, cost, operations, and safety when implementing new D4Ops approaches.
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Finding New Approaches
The study leveraged findings from NASA’s Root Cause Analysis (RCA) project that is continuing to document driving maintenance tasks on the STS orbiter. Using the RCA database as an anchor point, the present study developed a list of several proposed D4Ops Approaches that have a potential to positively influence the operational figures-of-merit used to evaluate next-generation space vehicle designs. Typical “D4Ops Approaches” include: reducing overall parts count, integrating functions across subsystems, eliminating hypergolic propellants, reducing numbers of tanks and fluids, etc.
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Application of Approaches
To provide relevancy, three different space vehicle contexts were used as a backdrop to the analyses conducted in the study: Orbital Space Plane (OSP), TSTO RLV, and a new, advanced RLV concept designed for streamlined operations. These contexts were chosen based on NASA’s current Integrated Space Transportation Plan (ISTP). The goal is to compare but not replicate previous analyses.
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Process
SEI used its multi-disciplinary conceptual design environment comprised of in-house and government/industry standard computational design tools to evaluate each contextand determine the positive and negative impacts on weights, costs, performance, ops, reliability, etc. that result from the application of the proposed D4Ops Approaches. Baseline configurations using a state-of-practice design philosophy were first created. The numerical results were calibrated to design information available from ongoing studies at NASA and in industry -- not to be competitive, but to ensure the results are relevant. Once a satisfactory baseline was established, sensitivities were conducted on each of the D4Ops Approaches taken individually. In addition, a single roll-up of all applicable D4Ops Approaches was analyzed for each context.
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Selection of Best Approaches
Using multi-attribute decision making methods, the candidate D4Ops Approaches were assessed and ranked based on quantitative benefits to several key figures-of-merit. The study drew conclusions and prioritized the most promising D4Ops Approaches across the three contexts in terms of their potential to positively impact ground operations costs and cycle times without detrimentally affecting weight, non-recurring cost, or vehicle safety. The study concluded in January 2004. The results and the associated D4Ops rankings will be made available to current space vehicle design teams to be used as a decision-support resource for ongoing activities.
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Overall Ranking of Technology Portfolios: Probabilistic @ 80% Certainty
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
No Tech
Tech A
Tech B
Tech C
Tech D
Tech E
Tech B+C
Tech B+D
Tech C+D
Tech C+E
Tech D+E
Tech C+D+E
Overall Evaluation Criterion (OEC)Based upon multiple metrics which are aggregated an d ranked using decision making methods such as
TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) for a particular weighting scen ario
Cost and Safety Focus
Geometry and Operations Focus
Broad Average of Scenarios
Tech
nolo
gy P
ortfo
lios
(fea
sibl
e te
chno
logy
com
bina
tions
tha
t mee
t fun
ding
con
stra
ints
)
-1.2%
0.0%
0.1%
8.7%
-0.4%
5.2%
0.7%
1.5%
2.5%
5.1%
9.3%
17.2%
-1.1%
0.0%
-0.8%
3.7%
-0.5%
4.8%
0.6%
1.4%
2.3%
1.5%
5.2%
10.3%
-5.0% 0.0% 5.0% 10.0% 15.0% 20.0%
1: Reduce Parts
2: Reduce Engines
3: All Electric
4: No Hypergols
5: No Hypergols/Cryogens
6: Uniform TPS
7: Robust TPS
8: P-IVHM
9: Less Aeroshell
10: Common Prop./Power
11: Common Prop./Power/ECLSS
12: Roll-Up
Des
ign
Ap
proa
ch
% Difference from State of Practice (SOP)
Gross Liftoff Weight (with CES)
Dry Weight
6.6%
2.6%
-0.3%
14.0%
2.0%
0.9%
5.7%
6.2%
10.3%
8.4%
17.0%
55.1%
2.2%
1.1%
-1.2%
19.7%
2.7%
1.5%
3.6%
3.4%
3.5%
10.0%
18.6%
36.0%
-10.0% 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0%
1: Reduce Parts
2: Reduce Engines
3: All Electric
4: No Hypergols
5: No Hypergols/Cryogens
6: Uniform TPS
7: Robust TPS
8: P-IVHM
9: Less Aeroshell
10: Common Prop./Power
11: Common Prop./Power/ECLSS
12: Roll-Up
Des
ign
Ap
pro
ach
% Difference from State of Practice (SOP)
TFU Cost
DDT&E Cost
6.6%
2.6%
-0.3%
14.0%
2.0%
0.9%
5.7%
6.2%
10.3%
8.4%
17.0%
55.1%
2.2%
1.1%
-1.2%
19.7%
2.7%
1.5%
3.6%
3.4%
3.5%
10.0%
18.6%
36.0%
-10.0% 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0%
1: Reduce Parts
2: Reduce Engines
3: All Electric
4: No Hypergols
5: No Hypergols/Cryogens
6: Uniform TPS
7: Robust TPS
8: P-IVHM
9: Less Aeroshell
10: Common Prop./Power
11: Common Prop./Power/ECLSS
12: Roll-Up
Des
ign
Ap
pro
ach
% Difference from State of Practice (SOP)
TFU Cost
DDT&E Cost
-8.3%
-6.9%
-8.5%
-3.6%
-8.7%
-16.3%
-10.4%
5.1%
-16.6%
-18.8%
-14.9%
-45.7%
-8.1%
-5.8%
-7.1%
-16.2%
-21.8%
-13.6%
-8.8%
-14.3%
-14.6%
-21.4%
-16.9%
-46.4%
-6.7%
-6.0%
-7.4%
-17.6%
-20.3%
-13.4%
-9.1%
-11.8%
-14.9%
-13.9%
-10.9%
-41.5%
-50.0% -40.0% -30.0% -20.0% -10.0% 0.0% 10.0%
1: Reduce Parts
2: Reduce Engines
3: All Electric
4: No Hypergols
5: No Hypergols/Cryogens
6: Uniform TPS
7: Robust TPS
8: P-IVHM
9: Less Aeroshell
10: Common Prop./Power
11: Common Prop./Power/ECLSS
12: Roll-Up
Des
ign
App
roac
h
% Difference from State of Practice (SOP)
Total Cycle Time
Variable Costs per Flight ($M)
Total FAC/GSE (nonannualized) ($M)
Total Cycle Time
Variable Costs per Flight ($M)
Total FAC/GSE (nonannualized) ($M)
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Overview of D4Ops Project
Phase I: Development of D4Ops Approaches
Phase II: D4Ops Approaches in Context
I
II
A
B
C
D
Derivation & Supporting (Contributing) Analyses of Operational Effectiveness (OE) Attributes
New Vehicle System Design Options Definition
Quality Function Deployment (QFD) Prioritization Process
Review of Approaches
E
F
G
Context 1: Near Term Orbital Space Plane (OSP)
Context 2: Mid Term Rocket TSTO
Context 3: Far Term TBD
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Use of Quality Function Deployment (QFD) to Select D4Ops Approaches
No Relationship [0]
Weak relationship [1]
Medium relationship [3]
Strong Relationship [9]
Legend [numerical value]
OPERATIONAL EFFECTIVENESS (OE) ATTRIBUTES[A through H]
CUSTOMER REQUIREMENTS
TECHNICAL REQUIREMENTS
OPERATIONAL APPROACHES[1-52]
CU
ST
OM
ER
IMP
OR
TA
NC
E
10
4
9
7
8
10
9
4
A. VEHICLE FLIGHT PRODUCTIVITY MISSION FLEXIBILITY
B. LAUNCH AVAILABILITY/INHERENT RELIABILITY
C. GROUND SUPPORT EQUIPMENT (GSE)/FACILITY INTENSITY
D. SUPPORT SERVICES INTENSITY
E. OPS PLANNING & MANAGEMENT SUPPORT
F. MATERIALS/LOGISTICS INTENSITY
G. FLIGHT & GROUND
H. SAFETY/IN-FLIGHT RELIABILITY
TECHNICAL PRIORITIES
1. R
educ
e pa
rts
coun
t…
2. P
lace
oxi
dize
r ta
nks
in a
ft…
3. P
lace
bot
h ox
idiz
er A
ND
fuel
tank
s in
aft…
4. U
se e
xter
nal p
aylo
ad c
onta
iner
s,,,
5. In
clud
e se
lf-fe
rry
and
pow
er la
ndin
g,,,
6. C
reat
e sy
mm
etric
al la
yout
,,,
7. In
clud
e im
prov
ed a
cces
s to
veh
icle
are
as,,,
8. F
ly r
etur
n tr
ajec
tory
inve
rted
,,,
9. D
esig
n fo
r no
cen
ter
engi
ne p
lace
men
t,,,
10. R
educ
e nu
mbe
r of
flig
ht e
lem
ents
,,,
QUALITATIVE ASSESSMENT OF IMPORTANCEARRIVED AT THROUGH CONSENSUS
Note: Sample data is shown for the above case.
OE WEIGHTINGS(INTEGER SCALE OF 1-10)
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Basis of Selected D4Ops Strategies
Reduce parts count using highly reliable parts (vs. less reliability in the parts and higher need for redundancy as in Shuttle)
Use common fluids and tanks for Main Propulsion System, OMS, RCS, Power and Thermal Management (heat loads, cooling, warming, avionics, and ECLSS)
Use common fluids AND tanks for Main Propulsion System, OMS, RCS and Power
Eliminate external aeroshell and closed compartments, Integrate structural/ aerodynamics systems and safety systems (Haz Gas and Purge, Vent and Drain-PVD) as single system, lean designs resulting in reduced or eliminated fluid systems.
Reduce TPS moldline penetration and repair/replacement (self-healing TPS including self-healing seals)
Uniform, exactly identical and interchangeable TPS parts for high percentages of vehicle surfaces
Simpler, all-electric power and actuation system (use EMAs/EHAs at load and use high storage density batteries in place of fuel cells and APU’s, replace plumbing with wiring)
Incorporate Propulsion-focused IVHM
Eliminate hypergols AND cryogenic ACS propellants in favor of "green" non-cryogenic ACS propellants
Eliminate all hypergols in favor of LOX/LH2 propellant combination for ACS
Reduce engine count (use larger, fewer engines for main/OMS/RCS, i.e. Eliminate need for separate OMS engines by using throttled MPS on-orbit)
Selected Design Approach
Liquid Prop/Power/Thermal Mgmnt
(36.1% Max Contribution)
INTEGRATE ACROSS PROPULSION, PWR & THERMAL MGMNT FUNCTIONS
Unplanned Work Content
(24% Max Contribution)
INCREASE OVERALL SYSTEMS RELIABILITY
Liquid Propulsion/Power Mgmnt
(25.4% Max Contribution)
Liquid Propulsion/Structures, Mechanisms & Veh Handling
(48.2% Max Contribution )
Thermal Management Work Content (10.7% Max Contribution)
Power Management Work Content
(10.9% Max Contribution)
Liquid Propulsion Work Content
(14.5% Max Contribution)
Work Content Potential Reduction Through Use of
D4Ops Strategy(Total RCA Direct Work
Contribution)
INTEGRATE ACROSS PROPULSION & POWER FUNCTIONS
INTEGRATE ACROSS PROPULSION & AIRFRAME
IMPROVE PASSIVE THERMAL MANAGEMENT
INTEGRATE POWER MANAGEMENT FUNCTIONS
INTEGRATE PROPULSION SYSTEMS
Design4Ops Strategy
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D4Ops Generic Set of Design Approaches
BaselineState-Of-Practice (SOP)O: SOP
Reduce tank redundancy, reduce engine redundancy, eliminate redundant fuel cells while increasing individual component reliability to maintain overall end-to-end failure rates.
Reduce Overall Parts Count1: Reduce Parts
Use fewer OMS and RCS thrusters (less redundancy), but increase the reliability of the thrusters to maintain current end-to-end failure rates.
Reduce Engine Count2: Reduce Engines
Use all-battery power system. Eliminate fuel cells (note APUs and hydraulic systems already eliminated in SOP baseline)
All Electric (batteries instead of fuel cells and APUs and eliminate hydraulics)
3: All Electric
Use LOX/LH2 ACS thrustersEliminate Hypergolic ACS4: No Hypergols
Use H2O2/Ethanol thrustersEliminate Hypergolic and Cryogenic ACS5: No Hypergols/Cryogens
Use uniform thickness and density TPS tiles of common shape to maximum extent practical. Thickness governed by max thickness location.
Uniform TPS tiles and blankets (shape and thickness)6: Uniform TPS
Reduce TPS weight due to fewer access locations, but increase TPS acreage weights for self-healing sealant and coatings for improved damage tolerance and water resistance.
Reduce TPS Penetrations (Access locations and cutouts) and Repair/Replacement Actions (e.g. Self-healing TPS)
7: Robust TPS
Add Avionics weight for new controllers, sensors, and wiring to support P-IVHMPropulsion-focused IVHM System8: P-IVHM
Reduce structural skin weight by using open trusswork aft of cabin on leeward side. Add additional aeroheating protection to internal tankage and components for entry protection. Combine fill and drain functions.
Eliminate Aeroshell and Closed Compartments. Integrate structural and plumbing functions.
9: Less Aeroshell
Use LOX/LH2 ACS and combined with fuel cell tanks.Use Common Fluids and Tanks for Propulsion and Power10: Common Prop./Power
Use N2 pressurant for propulsion (eliminate He) and combine with ECLSS, use LOX/LH2 ACS and combine with fuel cells. (Note ECLSS water tanks already integrated with fuel cells in SOP baseline).
Use Common Fluids and Tanks for Propulsion, Power, and ECLSS (thermal)
11: Common Prop./Power/ECLSS
Reduce tank redundancy and tank counts, use common LOX/LH2 fluids for propulsion and ECLSS (for O2). Use N2 for ECLSS and pressurization. Reduce OMS engines and thrusters. Use all batteries rather than fuel cells. Improve TPS robustness/maintenance and eliminate TPS penetrations as practical. Use uniform thickness TPS tiles of common size where practical Add propulsion-focused IVHM. Eliminate leeward skin panel structures aft of crew cabin to eliminate closed spaces. Combine plumbing fill/drain functions. Combine tankage between propulsion and ECLSS.
All Applicable D4Ops Approaches (for OSP context use: 1-4, 6-9, 11). Assume 4 and 11 preclude approach 5. Also assume that approach 11 supercedes approach 10.
12: Roll-Up
Context 1 ImplementationD4Ops ApproachNumber / Short Name
D4Ops Approach Full Name
Root Cause Analysis Database
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Overview of Root Cause Analysis (RCA) Project
From a Technical Standpoint…- What drives the timelines? Operations- We must understand the direct operations…system discipline by discipline- Resultant metrics are lbs and people per year to space and number of successful flights between
catastrophic failure
What drives total recurring cost? Infrastructure- We must understand the interactions of the infrastructure functions with the direct operations and the drivers
of infrastructure functions- Resultant metric is ultimately $$ per year to operate the total system
Analysis of the STS design to understand technical drivers, the design root causes of Operations and Infrastructure
Analysis focuses on fundamental design causes of direct work- STS-81 is one of eight typical flows of detailed processing data to be analyzed- 7-8 flight-per-year launch rate (1996-1997)- As-Run Task Durations- Follow-on detailed systems analysis can drive to detailed design causes and technology shortfalls
Source: Vehicle Systems Research and Technology Project, Root Cause Analysis Subproject, NASA Kennedy Space Center (KSC), March 24, 2003
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Specifics of Root Cause Analysis (RCA) Project
Project initiated under SLI Program 3/2002- Analysis Formulation: Why does it cost so much to operate the Shuttle system? Why Does it Take So Long
to Process the Shuttle?
Release 1 (SLI AWG, Aug 2002) :- An Overview of Shuttle Budget & Infrastructure Functions- STS OPF Turnaround Work Content Analysis
Release 2 (NGLT Quarterly, Mar 2003):- STS Flight Element Assembly, Vehicle Integration & Launch work content analysis with update to
Turnaround work content- Access Database with Cause and Need framework for Engineering comment/review
Primary products- Release 1 CD-ROM- Release 2 (complete set on CD-ROM to be delivered in April 2003 through KSC Systems Engineering
Office):STS Design Root Cause Knowledge Capture System (MS Access Database)Cause Report (Word/*pdf)Summary Data Set (PowerPoint)
Source: Vehicle Systems Research and Technology Project, Root Cause Analysis Subproject, NASA Kennedy Space Center (KSC), March 24, 2003
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Overview of RCA Database Sources
Data in RCA DB includes components for STS-81 flight from last time sent into space- If components assembled but not sent into space then not included for that flight
Originates from historical KSC processing data- “CAPSS Analysis Data Query" exported data from RCA Access database file named "STS Root
Cause.mdb" and dated Pre-Release 2 (March 2003)
Ultimate source of data is database from United Space Alliance (USA)- Data exported from ARTEMIS database- STS processing data source (IOS/GPSS) formatted in (*.csv) Excel files- STS-81 actual work content hours loaded into Root Cause Analysis (RCA) Access database - Consists of scheduled data (not real tracking data or shop floor data)- Sources pulled from 7-8 flight-per-year work pace (1997 time frame)- Data initially cleaned and organized into Function Breakouts and Design Disciplines by NASA KSC- Data only for FBS 1.0, 2.0, 3.0, 4.0, 5.0, and 6.0 (FBS 2.0 and 5.0 have most complete data)- Source: Carey McCleskey, NASA Kennedy Space Center (KSC)
Portions of RCA DB contain data from STS-79 flights- SRBs for STS-79 moved to STS-81- Work hours related to SRBs preparation and de-stacking for STS-79 included in original data set
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Functional Breakdown System (FBS) Nomenclature
Source: Vehicle Systems Research and Technology Project, Root Cause Analysis Subproject, NASA Kennedy Space Center (KSC), March 24, 2003
Insufficient Data
Some Useful Data Available for Analysis
Indicates inclusion in RCA DB
TRANSPORTATION SYSTEM OPS
PLANNING & MGMTCONCEPT-UNIQUE
LOGISTICS
CONNECTING COMMUNITY
INFRASTRUCTURE & SUPPORT SERVICES
OPERATIONS & INFRASTRUCTURE
FBS
FLIGHT ELEMENT ASSEMBLY
LAUNCH VEHICLE INTEGRATION
FLIGHT ELEMENT TURNAROUND
LANDING & RECOVERY
LAUNCH
TRAFFIC/FLIGHT CONTROL
OFFLINE PAYLOAD PROCESSING
VEHICLE DEPOT MAINTENANCE
ELEMENT RECEIPT & ACCEPTANCE
SPACEPORT SUPPPORTSERVICES
1.0 2.0 3.0 4.0 5.0
6.0 7.0 8.0 9.0 10.0
11.0 12.0
13.0
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Overview of Space Shuttle Flight STS-81
Shuttle Atlantis (OV-104) from KSC Pad 39-B (39)
81st Shuttle Mission, 18th Flight OV-104, 5th Mir docking, 16th Night Launch, 34th KSC Landing
Mission- STS-81 was the fifth of nine planned missions to Mir and the second one involving an exchange of U.S.
astronauts- Atlantis carried the SPACEHAB double module providing additional middeck locker space for secondary
experiments.- STS-81 involved the transfer of approximately 5,975 pounds of logistics to and from the Mir, the largest
transfer of items to date. During the docked phase, 1,400 pounds of water, 1,137.7 pounds of U.S. science equipment, 2,206.1 pounds of Russian logistics along with 268.2 pounds of miscellaneous material were transferred to Mir. Returning to Earth aboard Atlantis was 1,256.6 pounds of U.S. science material, 891.8 pounds of Russian logistics and 214.6 pounds of miscellaneous material.
Hardware- SRB: BI-082, SRM: 360T054A(Left),360T054B(Right), ET: ET-83, MLP : MLP-2 - SSME-1: SN-2041 (Block I), SSME-2: SN-2034 (Phase II), SSME-3: SN-2042 (Block I)
Payload- Mir-Docking/5, SpaceHab-DM, SAREX-II, KIDSAT, TVIS, Biorack, CREAM, OSVS, MSX
Source: NASA Kennedy Space Center Science, Technology and Engineering page: http://science.ksc.nasa.gov/shuttle/missions/sts-81/mission-sts-81.html
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STS-81 Processing Schedule Overview
The SRB set used for the STS-81 flight (BI-082) was the set that was destacked for STS-79 which flew a different set (BI-083)
OPF-3 - 9/26/96, VAB - 12/05/96, PAD - 12/10/96, TCDT - 12/17/96
Launch- January 12, 1997, 4:27:23 a.m. EST. Liftoff occurred on time following smooth countdown.
Landing- January 22, 1997, 9:22:44 a.m. EST, Runway 33, Kennedy Space Center, Fla. Rollout distance: 9,350 feet
(2,850 meters). Rollout time: one minute, nine seconds. Mission duration: 10 days, four hours, 55 minutes, 21 seconds. Landed on revolution 160, on the second KSC opportunity for the day.
Source: NASA Kennedy Space Center Science, Technology and Engineering page: http://science.ksc.nasa.gov/shuttle/missions/sts-81/mission-sts-81.html
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STS-79 Processing Schedule Overview
STS-79 was previous flight of OV-104 (Atlantis) before STS-81
Flow A: OPF - 4/15/96, VAB - 6/24/96, PAD - 7/01/96
Flow B: (after rollback due to Hurricane Bertha and SRB problem) VAB - 7/10/96, OPF - 8/03/96, VAB - 8/13/96, PAD - 8/20/96, TCDT - 8/27/96
Flow C: (after rollback due to Hurricane Fran) VAB - 9/04/96, PAD - 9/05/96, L-2 - 9/14/96
Launch- Sept. 16, 1996, 4:54:49 a.m. EDT
Landing- Sept. 26, 1996, 8:13:15 a.m. EDT
Source: NASA Kennedy Space Center Science, Technology and Engineering page: http://science.ksc.nasa.gov/shuttle/missions/sts-79/mission-sts-79.html
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STS-79 Detailed Launch De-Stack
On July 1, 1996, Atlantis was rolled out from the VAB to Pad 39A
On Tuesday, July 8, 1996, Mission managers decided to roll back Atlantis from Pad LC-39A to the VAB due to the projected storm track of Hurricane Bertha
- Earlier in the week a rollback was also being considered in the event repairs will be needed to the Shuttle Solid Rocket Boosters (SRB) following the discovery of hot gas penetration of rubber insulation on the boosters for shuttle flight STS-78.
On Monday, July 15, 1996, NASA managers decided to destack and replace Atlantis' Solid Rocket Boosters (SRB) with a new set of boosters
- Technicians disassembling the motors of Space Shuttle mission STS-78 observed that hot gases had seeped into J-joints in the field joints of the motors. An investigation into the seepage identified the most probable cause was the use of a new adhesive and cleaning fluid. These elements were changed in order to comply with new Environmental Protection Agency regulations which reduce ozone depleting substances. The STS-79 booster set included the same adhesive so a new SRB stack built using the older adhesive will be used until the problem can be further analyzed.
On Friday, August 2, 1996, Atlantis was demated from the original set of SRB's and transported to the OPF bay no. 3 at about 2 AM Saturday. STS-79's original SRBs are scheduled to be used on mission STS-81 after they are destacked, cleaned, inspected and restacked.
- On Thursday, August 8, 1996, STS-79's external tank was demated from STS-79's original set of SRBs. A new set of SRB's had already been stacked and destacking of the original SRB was expected to begin on the following Monday.
Source: NASA Kennedy Space Center Science, Technology and Engineering page: http://science.ksc.nasa.gov/shuttle/missions/sts-79/mission-sts-79.html
STS-81 Launch
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Source: NASA Kennedy Space Center Science, Technology and Engineering page: http://science.ksc.nasa.gov/shuttle/missions/sts-81/images/images.html
Shuttle Atlantis (OV-104) from KSC Pad 39-B81st Shuttle Mission, 18 th Flight OV-104, 5 th Mir docking, 16 th Night Launch, 34 th KSC Landing OPF-3 - 9/26/96, VAB - 12/05/96, PAD - 12/10/96, Launc h – 01/12/97
STS-81 Orbit and Landing
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Source: NASA Kennedy Space Center Science, Technology and Engineering page: http://science.ksc.nasa.gov/shuttle/missions/sts-81/images/images.html
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OPF Flow Time (Calendar-Days)
0
40
80
120
160
200
240
280
320
360
999388918986948381797775746971636865626151555452464942484037383132343027
Days
STS-Flow
File: TA Days.xlsTab: OPF (CD's)
Raw Data Source: DRD-1.1.7.c STS Turnaround Workday Comparison Plan
Dec 14, 1999
0
10
20
30
40
50
60
70
80
90
939589858380777269676859615754474944403531333026
Launch Pad Integrated SSV Flow (Calendar-Days per Flow)
Days
STS-Flow
File: TA Days.xls
Tab: PAD CD's
Raw Data Source: DRD-1.1.7.c STS Turnaround Workday Comparison Plan
Date: Dec 14, 1999
(From Initial Arrival at Launch Pad to Launch)
STS OPF and VAB Processing History
Source: NASA Kennedy Space Center Presentation, “Spaceport Systems Processing Model: Introduction to Space Shuttle Processing, February 4, 2000
Current NASA KSC flight rate analysis models use 80 Calendar Days for OPF Flow
Current NASA KSC flight rate analysis models use 7 Calendar Days for VAB Integrated Flow
Current NASA KSC flight rate analysis models use 28 Calendar Days for Pad Flow Duration
STS-79Flow A- OPF - 4/15/96- VAB - 6/24/96- PAD - 7/01/96Flow B- VAB - 7/10/96- OPF - 8/03/96- VAB - 8/13/96- PAD - 8/20/96Flow C- VAB - 9/04/96- PAD - 9/05/96- L-2 - 9/14/96
STS-81- OPF-3 - 9/26/96- VAB - 12/05/96- PAD - 12/10/96
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Breakdown of Work Content Data in RCA DB
3,8371,6136901,5344.0
9,8376,91402,9235.0
1,115626224676.0
1,999
386
901
0
Number of Content Hours after STS-79 Destack on 07/15/1996 and before
STS-79 Landing
37,134
4,874
23,075
32
Number of Content Hours after STS-79 Landing
7,315
2,391
0
0
Number of Content Hours before STS-79 Destack on
07/15/1996
23,9762.0
7,6513.0
46,448TOTAL
321.0
Total Work Content HoursFBS
By FBS
Source: “CAPSS Analysis Data Query" exported data from RCA Access database file named "STS Root Cause.mdb" and dated Pre-Release 2 (March 2003)
April 4, 1996First Rollout
July 15, 1996SRB Destack
September 26, 1996Landing
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Illustration of Breakdown of Work Content Data in RCA DB
Source: “CAPSS Analysis Data Query" exported data from RCA Access database file named "STS Root Cause.mdb" and dated Pre-Release 2 (March 2003)
0 5,000 10,000 15,000 20,000 25,000 30,000
1.0
2.0
3.0
4.0
5.0
6.0
FB
S
Work Content Hours
Number of Content Hours before STS-79 Destack on07/15/1996
Number of Content Hours after STS-79 Destack on07/15/1996 and before STS-79 Landing on 09/26/96
Number of Content Hours after STS-79 Landing on09/26/96
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Question of Overlapping STS-79 Data with STS-81 Data in RCA DB
Sources- “CAPSS Analysis Data Query" exported data from RCA Access database file named "STS Root
Cause.mdb" and dated Pre-Release 2 (March 2003)- Work Content Matrices, Carey McCleskey, NASA KSC, (April 21 2003)
Turnaround Data_0318036.xls (FBS 2.0), Assembly Data_031903.xls (FBS 3.0)Veh Integ Data_031703.xls (FBS 4.0), Launch Data_031903.xls (FBS 5.0)
RCA database has work items dating from March 7, 1996 to Jan. 30, 1997.- This time period overlaps two Atlantis flights- There are natural questions of cleaning up the data to accurately reflect one flight
Database and initial KSC summary results use data for STS-79, even before STS-79 lift-off on Sept. 26, 1996 (all the way back to March 7, 1996) and used to represent processing results for STS-81
- The amount of content hours after STS-79 de-stack on 07/15/1996 and before STS-79 Landing on 09/26/96 could be used to account for any work on the SRB de-stack once the problem was known. Some of these hours could be legitimately applied to STS-81.
- Such previous data, from March 7, 1996 to Sept. 14, 1997 (two days before STS-79 liftoff), actually accounts for 8,873 hours out of 46,458 (~19%)
- FBS 2.0 work content matrix summary does book-keep these separately, other FBS (3.0, 4.0, and 5.0) work content matrices still add disparate data for STS-79 and STS-81 processing together
- Issue of whether this time actually belongs to STS- 81 or STS-79 since the RCA DB keeps data under the STS-81 account
- Generally the database tracks pieces used in the sp ecific launch in question
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Conclusions from FBS 2.0 (Turnaround) Level 2 Analysis
GSE System is one of the largest drivers for FBS 2.0 Turnaround (over 20% of total hours)- GSE has a small number of Activities that require large amount of work content hours- TPS and STR Systems have less of such a “top-heavy” set of Activities- Of top 6 Activities in FBS 2.0, 4 deal with GSE System purge/filter inspections
Most of top TPS System activities deal with tile processing- 74% of all TPS system hours from two SubFunctions- “TPS Moldline Penetration & Aerosurface Hingeline Seal Servicing” (46% of TPS System hours)- “Repair or Replacement of Thermal Protection Systems (TPS) Hardware” (28% of TPS System hours)
For STR System, window servicing is a large factor- Out of approximately 70 distinct Activities, 10 (~14%) account for over 43.0% of work content hours (and all
these hours originate from activities associated with window servicing)- 826 out of a total of 1,878 STR System hours (43.0%) deal with window servicing- Specifically Activity Descriptions (ADs) dealing with “WINDOW 5,6,7,8 R/R” and “ORB WINDOW POLISH”
Context 1
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Design Summary
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Top-Level Assumptions
Use of SEI developed methods and tools for design- Consultation of previous NASA JSC reference OSP work- Use of standard Weight Breakdown Structure (WBS)- Less reliance on heavy avionics sizing as performed in NASA JSC OSP reference work
Goal is to compare but not replicate previous analy ses- Use similar type near-term architecture to examine the impact of various operational approaches
Expert-defined parameter changes to model inputs (k-factors) reflect the impact of any design approach
Scope of activity did not include analysis of Evolv ed Expendable Launch Vehicle (EELV) booster and/or i ntegration issues
Initial development consisted of Outer Mold Line (OML) development in CAD and subsystem packaging
End-to-end subsystem failure rates stayed the same whenever parts were being reduced- Assumed additional weight and cost complexity generated in order to maintain the current end-to-end failure rate
Concerned about comparisons of design approaches with State-of-Practice (SOP) design- Initial development of a baseline Context 1 design
When cost complexity changed, generally both DDT&E and TFU costs affected
Weights, Cost, and Safety, and Economics disciplines coupled in a spreadsheet-based meta model known as a ROSETTA models
Use of AATe version 1.0c for this analysis
Simple Life-Cycle Cost Model developed- Assumed static flight rates- Assumed minimum number of 2 vehicles acquired in program- IOC: 2009, Program End: 2025, DDT&E of 3 years starting in 2004, Vehicle production of 2 years starting in 2007, Facilities development of 4 years starting in
2004- Expendable booster costs not included in Life Cycle Cost estimates
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Schematic of D4Ops Project Approach
Brainstorm Design Options Set
Initial Set: Veh SysDesign Options
RankOptions to Develop
~12 D4Ops ApproachesFinal Set: D4Ops Approaches
Contributing Attributes (CA)
System Design Options
RCA Database
Operatio nal Appr oach
Reduce parts count using highly
reliable parts (vs. less reliability in
the parts and higher need for
redundancy as in
Shuttle).
Place oxidizer tanks in aft
vehicle location to minimize fill
pumping
requirements
P lace both oxidizer AN D fuel
tanks in aft vehicle location
(toriod solution) to reduce feedlines and standardize
fill/drain locations
Use external payload
container s to allow off- line
payload
integration
Include self-ferry
and power landing to reduce delays associated w ith
non-K SC landing
C reate
symmetrical layout of main
engines (spaced
for maintainability)
Reduce part s coun t using high ly reli able part s ( vs. less rel iabilit y in the par ts and higher need fo r r ed undancy as
in S huttl e) . x Pl ace o xidizer tanks in aft v eh icle location to mi nimize fi ll pum ping r equirem en ts x Pl ace b oth oxi dizer AND f uel tanks in af t vehicle
locati on (t oriod sol ution) to r educe feedli nes and standard ize fill /drain locations x Use external payload contai ners to allo w off -line pay load
int eg ration x In cl ude sel f-f err y and power landing to redu ce d el ays associat ed with non -KSC l an ding x Create symmet rical layo ut of m ain engines (spaced for
maint ainabilit y) x
Vehicle System DesignCompatibility
Operational Effectiveness Attributes with weightings
Singly and in combination,12 approach combinations
Baseline Context 1: Orbital Space Plane (OSP)
Derivation & Supporting (Contributing) Analyses of Operational Effectiveness (OE) Attributes
New Vehicle System Design Options Definition
Baseline Context
Goal / DRM
Without new ops approaches
New Ops Contexts
With new ops approaches12 variants = 12 combinations
Pareto Ranking of New Ops Approaches to Baseline
Baseline + 12 D4Ops approach combinations
5,000, 000
5,250, 000
5,500, 000
5,750, 000
6,000, 000
6,250, 000
No
Te
ch
Tech
A
Tech
B
Te
ch C
Te
ch D
Tech
E
Tech
B+
C
Tech
B+
D
Te
ch C
+D
Tech
C+E
Tech
D+E
Te
ch C
+D
+E
Gro
ss W
eig
ht [l
bm]
Pro bab ilis tic @ 8 0% Con fiden ceDet erministic
Te chnology Port fo lio
Figures of Merit (FOMs)
FOM Weightings
Note: Similar process for other contexts (Mid-term-Context 2 and Far-term-Context 3)
Provided by NASA KSC
Legend
Supporting Filters andData Mining
STS BudgetdB
Development of OE Attributes
(~10)
Quality Function Deployment (QFD)
Veh icle
Conf ig uratio nVehicle
Conf ig uratio nVehicle
Conf ig uratio n
CA No. Contributi ng Analys is (CA) [ Des ign Discipline fr om RCA Database] Weighti ng
Reduce parts count us ing
highly r el iable
parts (vs. less rel iabi l ity in the
parts and higher need for
redundancy as in Shuttle).
Place oxidizer tanks in aft
vehicle location to minimize fi ll
pumping requirements
P lace both ox idizer A ND fuel
tanks in aft
vehicle location (toriod solution)
to reduce feedlines and
standardize fil l /drain locations
1 2 3
A TUNNE L AD APTER/EC L LINE MOD 0 0 0 0B F/M/A CLEAN ING 0 0 0 0C OME TRICKLE PU RGE MO NITORIN G (O MS) 0 0 0 0D RCS THR USTER D ESICC ANT INSPEC TION (O MS ) 0 0 0 0E TOTAL CO MPR ESSED A IR OUTA GE TO R &R PIPE (E.G .&G. O UTAG E) 0 0 0 0F COM,ECL,EPD ,IN S,MEQ ,OE L PR OCE SSING/H ISTORIC AL P WR DO WN PR OCES SING 0 0 0 0G MO NITOR ORBITER PURG E AIR (PVD ) 0 0 0 0H WINDO W R/R 0 0 0 0I ORB W IN DO W POLISH 0 0 0 0J TILE PR OCE SSING : TPS Moldl ine Penetration & Aer osurface Hingel ine Seal Serv ic ing, Repair or Replacement of Thermal Protection Sys tems (TPS) Hardware0 0 0 0K TPS POS T FLT INSPE CTION 0 0 0 0
Given:Design for Ops Methods
NASA JSC Initial OSP
Roll-up Ops Context
From 12 approaches, all
viable approaches in combination
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Sample Design Structure Matrix (DSM) of Context Assessment Process
Feed Forward LinksA: Wing Exposed Planform Area [ft2]
Total Exposed Wingspan (less fuselage width)Total Tail Planform Area [ft2]Nose Structural Surface Area [ft2]Midbody Surface Area (less cabin) [ft2]Base Area [ft2]ACC Leading Edges Length (total)AETB-8 Wetted Area [ft2]AFRSI Wetted Area [ft2]
B: Total Vehicle Length [ft]Total Vehicle Height-w/o landing gear down [ft]Total Vehicle Width [ft]Total Vehicle Wetted Area [ft2]
C: Total Vehicle Length [ft]Total Vehicle Height-w/o landing gear down [ft]Total Vehicle Width [ft]
D: Dry Weights [lbs] from 14 categoriesE: Total Propellant Weight [lbs]
Total Number of OMS EnginesF: Total Development Cost [$B]G: DDT&E Cost [$B]
TFU Cost [$B]H: Vehicle ReliabilityI: Recurring Operations Cost per Year [$M]
Recurring Operations Cost per Flight [$M/Flight]GSE Operations Cost [$M]Turnaround Time [days]Vehicle Reliability
A CB
D E
F
H
G
I
Safety[GTSafety-II]
Weights and Sizing[MERs]
Cost[NAFCOM 99]
DESIGN ASSUMPTIONS
CAD[Solid Edge]
Operations[AATe]
Economics[CABAM_A]
Vehicle Summary
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D4Ops Context 1: Design Approach 0 (State-of-Practice) (1)
External View Internal Packaging View
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D4Ops Context 1: Design Approach 0 (State-of-Practice) (2)
Top View View on Delta-V Heavy EELV Booster
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D4Ops Context 1 Scale Comparison
JSC OSP Baseline42.6 Klbs
44 ft.----
41 ft.
0 feet
100 feet
200 feet
VARIANT TYPEDRY WEIGHT
LengthHeight (w/o wheels down)
Width
SEI D4Ops Context 1 SOP39.2 Klbs46.03 ft.9.24 ft.
28.23 ft.
0 meters
30.48 meters
60.96 meters
STS (Orbiter)173 Klbs184.2 ft.76.6 ft.78.1 ft.
Apollo CM, SM, and LM12.2 Klbs
10.9 ft. (CM)12.8 ft. (CM)12.8 ft. (CM)
Delta IV-Heavy185 Klbs
236 ft.49 ft.16 ft.
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Context 1 Comparison of NASA JSC OSP Baseline with SEI State-of-Practice (SOP)
Dry Weight
Insertion Weight (without Crew Escape System)
NASA JSC Baseline
Weight [lbs]
42,644
46,643
Item
39,218
48,016
SEI Design Approach 0 (State-of-Practice)
Weight [lbs]
NASA JSC analysis assumed 27,000 lb entry weight for vehicle with insertion weight (i.e. release from booster and discard of Crew Escape System or CES) equal to that plus 3,999 lb of assumed propellant, therefore, actual NASA JSC insertion weight (from the WBS) is more, therefore NASA JSC OSP baseline is too low on NTO/MMH propellant for desired missionSEI estimates for Power and Electrical Conversion and Distribution (ECD) are generally lower than the JSC reference
45,948
53,202
SEI Design Approach 12 (Roll-up)
Weight [lbs]
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Context 1 Three View: Design Approach 0 (State-of-Practice)
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Context 1: D4Ops Design Approaches to Be Added
1. Reduce Overall Parts Count
2. Reduce Engine Count
3. All Electric (batteries instead of fuel cells and APUs and eliminate hydraulics)
4. Eliminate Hypergolic ACS
5. Eliminate Hypergolic and Cryogenic ACS
6. Uniform TPS tiles and blankets (shape and thickness)
7. Reduce TPS Penetrations (Access locations and cutouts) and Repair/Replacement Actions (e.g. Self-healing TPS)
8. Propulsion-focused IVHM System9. Eliminate Aeroshell and Closed Compartments. Integrate structural and plumbing functions.
10. Use Common Fluids and Tanks for Propulsion and Power
11. Use Common Fluids and Tanks for Propulsion, Power, and ECLSS (thermal)
D4Ops approaches (No. 1-11) to be applied to baseline OSP in key functions/subsystems areas as shown
BASELINE OSP
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D4Ops Context 1: Design Approach 12 (Roll-up)
External View Internal Packaging View
OMS Engine (x1)
OMS Propellant Tank: LOX
Aft RCS Thrusters (x8)
Nose RCS Thrusters (x8)
Docking System/Hatch
Parachute Recovery System
OMS Propellant Tank: LH2
Batteries (x4)
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Context 1 Three View: Design Approach 12 (Roll-Up)
Note: Emergency Escape Rocket and Adapter Not Shown
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Context 1 Tank/Propulsion Comparison: State-of-Practice (SOP) versus Approach Rollup
NTO NTO MMH MMH
GHE GHE
LOX LOX LH2 LH2
H2O H2O GN2 GN2 GN2 GN2
Design Approach 0: State-of-Practice (SOP)
GN2 LOX LH2 H2O
Design Approach 12: Roll-up
SCORECARD
Number of Oxidizer Tanks
Number of Fuel Tanks
Number of Pressurant Tanks (GN2)
Number of LH2 Tanks: Fuel Cells
Number of LOX Tanks: Fuel Cells
Number of H20 Tanks
Number of GN2 Tanks for Cabin Gas
TOTAL NUMBER OF TANKS
Number of Nose RCS Thrusters
Number of Aft RCS Thrusters
Number of OMS Engines
2
2
2
2
2
2
4
16
14
24
6
SCORECARD
Number of Oxidizer Tanks
Number of Fuel Tanks
Number of Pressurant Tanks (GN2)
Number of LH2 Tanks: Fuel Cells
Number of LOX Tanks: Fuel Cells
Number of H20 Tanks
Number of GN2 Tanks for Cabin Gas
TOTAL NUMBER OF TANKS
Number of Nose RCS Thrusters
Number of Aft RCS Thrusters
Number of OMS Engines
1
1
1
0
0
1
0
4
8
8
1
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D4Ops Context 1: Design Approach Comparison-SOP versus Approach 12 (Roll-up)
BEFORE D4Ops: Context 1 Baseline
BEFORE D4Ops: Context 1 Baseline
SCORECARD
Number of Oxidizer Tanks
Number of Fuel Tanks
Number of Pressurant Tanks (GN2)
Number of LH2 Tanks: Fuel Cells
Number of LOX Tanks: Fuel Cells
Number of H20 Tanks
Number of GN2 Tanks for Cabin Gas
TOTAL NUMBER OF TANKS
Number of Nose RCS Thrusters
Number of Aft RCS Thrusters
Number of OMS Engines
2
2
2
2
2
2
4
16
14
24
6
SCORECARD
Number of Oxidizer Tanks
Number of Fuel Tanks
Number of Pressurant Tanks (GN2)
Number of LH2 Tanks: Fuel Cells
Number of LOX Tanks: Fuel Cells
Number of H20 Tanks
Number of GN2 Tanks for Cabin Gas
TOTAL NUMBER OF TANKS
Number of Nose RCS Thrusters
Number of Aft RCS Thrusters
Number of OMS Engines
1
1
1
0
0
1
0
4
8
8
1
AFTER D4Ops: Context 1 With 11 Approaches
AFTER D4Ops: Context 1 With 11 Approaches
Analysis of Design Approaches
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D4Ops Context 1: Weight Metric Comparison to SOP
-1.2%
0.0%
0.1%
8.7%
-0.4%
5.2%
0.7%
1.5%
2.5%
5.1%
9.3%
17.2%
-1.1%
0.0%
-0.8%
3.7%
-0.5%
4.8%
0.6%
1.4%
2.3%
1.5%
5.2%
10.3%
-5.0% 0.0% 5.0% 10.0% 15.0% 20.0%
1: Reduce Parts
2: Reduce Engines
3: All Electric
4: No Hypergols
5: No Hypergols/Cryogens
6: Uniform TPS
7: Robust TPS
8: P-IVHM
9: Less Aeroshell
10: Common Prop./Power
11: Common Prop./Power/ECLSS
12: Roll-Up
Des
ign
App
roac
h
% Difference from State of Practice (SOP)
Gross Liftoff Weight (with CES)
Dry Weight
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D4Ops Context 1: Non-Recurring Cost Metric Comparison to SOP
6.6%
2.6%
-0.3%
14.0%
2.0%
0.9%
5.7%
6.2%
10.3%
8.4%
17.0%
55.1%
2.2%
1.1%
-1.2%
19.7%
2.7%
1.5%
3.6%
3.4%
3.5%
10.0%
18.6%
36.0%
-10.0% 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0%
1: Reduce Parts
2: Reduce Engines
3: All Electric
4: No Hypergols
5: No Hypergols/Cryogens
6: Uniform TPS
7: Robust TPS
8: P-IVHM
9: Less Aeroshell
10: Common Prop./Power
11: Common Prop./Power/ECLSS
12: Roll-Up
Des
ign
App
roac
h
% Difference from State of Practice (SOP)
TFU Cost
DDT&E Cost
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D4Ops Context 1: Operations Metric Comparison to SOP
-8.3%
-6.9%
-8.5%
-3.6%
-8.7%
-16.3%
-10.4%
5.1%
-16.6%
-18.8%
-14.9%
-45.7%
-8.1%
-5.8%
-7.1%
-16.2%
-21.8%
-13.6%
-8.8%
-14.3%
-14.6%
-21.4%
-16.9%
-46.4%
-6.7%
-6.0%
-7.4%
-17.6%
-20.3%
-13.4%
-9.1%
-11.8%
-14.9%
-13.9%
-10.9%
-41.5%
-50.0% -40.0% -30.0% -20.0% -10.0% 0.0% 10.0%
1: Reduce Parts
2: Reduce Engines
3: All Electric
4: No Hypergols
5: No Hypergols/Cryogens
6: Uniform TPS
7: Robust TPS
8: P-IVHM
9: Less Aeroshell
10: Common Prop./Power
11: Common Prop./Power/ECLSS
12: Roll-Up
Des
ign
App
roac
h
% Difference from State of Practice (SOP)
Total Cycle Time
Variable Costs per Flight ($M)
Total FAC/GSE (nonannualized) ($M)
All Approaches Combined Have the Greatest Impact Upon Operations Metrics
All Approaches Combined Have the Greatest Impact Upon Operations Metrics
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D4Ops Context 1: Life Cycle Cost Comparison
$-
$1,000
$2,000
$3,000
$4,000
$5,000
$6,000
O: S
OP
1: R
educ
e P
arts
2: R
educ
e E
ngin
es
3: A
ll E
lect
ric
4: N
o H
yper
gols
5: N
o H
yper
gols
/Cry
ogen
s
6: U
nifo
rm T
PS
7: R
obus
t TP
S
8: P
-IV
HM
9: L
ess
Aer
oshe
ll
10: C
omm
on P
rop.
/Pow
er
11: C
omm
onP
rop.
/Pow
er/E
CLS
S
12: R
oll-U
p
Design Approach
DD
T&
E a
nd T
FU
Cos
t [F
Y20
03$M
]
$-
$50
$100
$150
$200
$250
$300
$350
LCC
/Flig
ht [F
Y20
03$M
/Flig
ht]
DDT&E Cost
TFU Cost
Cost Per Flight [$M/Flight] at 4 Flights/Year
Cost Per Flight [$M/Flight] at 16 Flights/Year
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D4Ops Context 1 State-of-Practice (SOP): Initial Program Cost
Cost includes DDT&E, acquisition of 4 flight articl es, 2 non-flying test beds, facilities development, operations (at $1.23B/year), and EELV launch (at $375M/launch but not including EELV crew-rating qualification cost)
Cumulative Total Costs (w/expendable boosters)
Expendable Booster Costs
Operations Costs
Acquisition Costs: Airframe
Non-Recurring Costs
Total Cumulative Life Cycle Cost Up to Fifth Year o f Flight =
$23.6B [FY2003]
$-
$5,000
$10,000
$15,000
$20,000
$25,000
$30,000
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013
Program Year
Cos
t [$M
, FY
2003
]
Initial Operating Capability (IOC)@ 6 Flights Per Year
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D4Ops Context 1: Cumulative Life Cycle Cost Comparison to SOP (State-of-Practice)
-30%
-25%
-20%
-15%
-10%
-5%
0%
5%
10%
15%
20%
25%
30%
35%
2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025
Program Year
% D
iffer
ence
In C
umul
ativ
e Li
fe C
ycle
Cos
t (LC
C)
Fr
om S
tate
-of-
Pra
ctic
e (S
OP
)
CROSSING HORIZONTAL AXIS INDICATES POINT AT WHICH L CC BECOMES LESS THAN LCC OF STATE-OF-PRACTICE (SOP) CA SE
1: Reduce Parts
2: Reduce Engines
3: All Electric
4: No Hypergols
5: No Hypergols/Cryogens
6: Uniform TPS
7: Robust TPS
8: P-IVHM
9: Less Aeroshell
10: Common Prop./Power
11: Common Prop./Power/ECLSS
12: Roll-Up
Design Approach
DISTANCE FROM HORIZONTAL AXIS INDICATES HOW MUCH LOWER OR HIGHER LCC IS VERSUS LCC OF STATE-OF-PRACTICE (SOP) CASE
Initial Operating Capability (IOC), 16 Flights Per Year
Facility Development
DDT&E Acq.
AS THE LIFE CYCLE PROGRESSES, HIGHER INITIAL FIXED COSTS (DDT&E, ACQUISITION) ARE MORE THAN OFFSET BY REDUCED OPERATIONAL COSTS (FACI LITIES AND RECURRING)
AS THE LIFE CYCLE PROGRESSES, HIGHER INITIAL FIXED COSTS (DDT&E, ACQUISITION) ARE MORE THAN OFFSET BY REDUCED OPERATIONAL COSTS (FACI LITIES AND RECURRING)
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D4Ops Context 1: Ranking of Design Approaches
Life Cycle Costs
Cycle Time
Weight
Even across 9 FOMS
Orientation of Weighting Scenarios For Figures of Merit (FOMs)
10
Median of Rank Across 10 different
Weighting Scenarios
=
NOTE: LARGER OEC SCORE IS BETTER
Overall Evaluation Criterion (OEC): Relative Closeness to Ideal Solution, Based upon multiple metrics which are aggregated and ranked using decision making methods such as TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) for a particular weighting scenario
0.434
0.434
0.458
0.388
0.540
0.510
0.445
0.418
0.491
0.523
0.409
0.582
0.854
0.827
0.838
0.488
0.875
0.594
0.814
0.773
0.740
0.673
0.430
0.163
0.039
0.034
0.055
0.327
0.404
0.212
0.093
0.166
0.252
0.227
0.140
0.965
0.079
0.061
0.103
0.178
0.545
0.315
0.095
0.203
0.279
0.515
0.260
0.937
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
1: Reduce Parts
2: Reduce Engines
3: All Electric
4: No Hypergols
5: No Hypergols/Cryogens
6: Uniform TPS
7: Robust TPS
8: P-IVHM
9: Less Aeroshell
10: Common Prop./Power
11: Common Prop./Power/ECLSS
12: Roll-Up
Des
ign
Ap
pro
ach
10
12
8
11
2
4
6
7
5
3
9
1
The Rank Indicates the Importance of theApproach Towards Meeting the Goals
The Rank Indicates the Importance of theApproach Towards Meeting the Goals
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Summary
With ops cost / turn-time improvements the fleet si ze acquired might be reduced for any given flight r ate (a major cost in LCC)
The OSP as a presumed architecture and by consideri ng here only one element of a broader architecture, likely limits the improvements that would be gained vs. an end-to-end system design incorporating the D4Ops approaches. This will be studied further in Context 3.
Approach 12 (Roll-up) is the best across all weighting scenarios- In terms of Life Cycle Costs (LCC), Cycle Time, Loss of Vehicle (LOV) Reliability, GSE cost, variable cost per flight, total number of tanks- Worst amongst all approaches when considering lowest weight or lowest DDT&E cost
Approach 5 (No Hypergols/Cryogens) is second best across all weighting scenarios- Very positive when looking at considering lowest weight (from slight increase in ISP and increase in propellant densities)- Second best when comparing Life Cycle Costs (LCC) or Cycle Time
Approach 10 (Common/Fluids/Tanks for Power/Propulsion) is third best across all weighting scenarios- Not as good in terms of lowest cycle time as Approach 12 (Roll-up)- Very positive when looking at considering lowest weight- Approach 11 (that also integrates ECLSS) has higher costs, weights than Approach 10
Just reducing parts counts or number of engines may be necessary but not sufficient for best approach- Beneficial mainly by reducing weight- Reduction of items is important but so is what is being reduced or replaced- Uniform TPS or uniform fluid types were beneficial to metrics- Robust TPS not as much weight increase as compared to other approaches
Generally, specific integration of parts (i.e tanks) with easier to handle fluids embedded in the best approaches
As the life cycle progresses, higher initial fixed costs (DDT&E, acquisition) are more than offset by r educed operational costs (facilities and recurring) to reduce total Life Cyc le Cost (LCC)
Further refinement of modeling process can be developed- More refined justification for certain k-factor effects
Context 2
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Design Summary
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Top-Level Assumptions
Use of SEI developed methods and tools for design- Consultation of current NASA NGLT Architecture 1 TSTO work- Use of standard Weight Breakdown Structure (WBS)
Goal is to compare but not replicate previous analy ses- Use similar type mid-term architecture to examine the impact of various operational approaches
Expert-defined parameter changes to model inputs (k-factors) reflect the impact of any design approach
Scope of activity did not include analysis of alter native main propellants for Booster stage or Orbite r stage
Initial development consisted of Outer Mold Line (OML) development in CAD and subsystem packaging
End-to-end subsystem failure rates stayed the same whenever parts were reduced- Assumed additional weight and cost complexity generated in order to maintain the current end-to-end failure rate
Concerned about comparisons of design approaches with State-of-Practice (SOP) design- Initial development of a baseline Context 2 design
When cost complexity changed, generally both DDT&E and TFU costs affected
Weights, Cost, and Safety, and Economics disciplines coupled in a spreadsheet-based meta model known as a ROSETTA models
Use of AATe version 1.0d for this analysis
Simple Life-Cycle Cost Model developed- Booster/orbiter rocket engine is new development, mostly sunk DDT&E for booster fly back engines- Assumed static flight rates of 5 flights per year- Assumed minimum number of 3 vehicles (orbiter and booster) acquired in program- IOC: 2015, Program End: 2035, DDT&E of 4 years starting in 2009, Vehicle production of 3 years starting in 2012, Facilities development of 5 years starting in
2010- Additional vehicles purchased due to LOV probability- DDT&E cost includes system test hardware (STH), STH is 130% of flight unit, 30% contingency, 10% fee, 20% program support
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Plan for Context 2
E Context 2: Mid Term Two Stage To Orbit (TSTO)
Final Set: D4Ops Approaches (1-11)
Operatio nal Appr oach
Reduce parts count us ing highly
rel iable parts (vs. less rel iabil i ty in
the parts and higher need for
redundancy as in
Shuttle).
Place ox idizer tanks in aft
vehic le location to minimize fi ll
pumping
requirements
P lace both ox idizer AN D fuel
tanks in aft vehic le location
(toriod solution) to reduce feedl ines and s tandardize
fi l l/drain locations
Use external pay load
container s to al low off- line
pay load
integration
Include self-ferry
and power landing to reduce delays assoc iated w ith
non-K SC landing
C reate
symmetrical layout of main
engines (spaced
for maintainabi l i ty)
Reduce part s coun t using high ly reli able part s ( vs. less rel iabilit y in the par ts and higher need fo r r ed undancy as
in S huttl e) . x Pl ace o xidizer tanks in aft v eh icle location to mi nimize fi ll pum ping r equirem en ts x Pl ace b oth oxi dizer AND fuel tanks in af t vehicle
locati on (t oriod sol ution) to r educe feedli nes and standard ize fill /drain locations x Use external payload contai ners to allo w off -line pay load
int eg ration x In cl ude sel f-f err y and power landing to redu ce d el ays associat ed with non -KSC l an ding x Create symmet rical layo ut of m ain engines (spaced for
maint ainabilit y) x
Vehicle System DesignCompatibility
State-of-Practice
Goal / DRM
Ranking of New Ops Approaches
5,0 0 0, 00 0
5,2 5 0, 00 0
5,5 0 0, 00 0
5,7 5 0, 00 0
6,0 0 0, 00 0
6,2 5 0, 00 0
No
Te
ch
Tech
A
Tech
B
Te
ch C
Te
ch D
Tech
E
Tech
B+
C
Tech
B+
D
Te
ch C
+D
Tech
C+E
Tech
D+E
Te
ch C
+D
+E
Gro
ss W
eig
ht [l
bm]
Pro bab ilis tic @ 8 0% Con fiden ceDet erministic
Te chnology Port fo lio
Figures of Merit (FOMs)
FOM Weightings
New Ops Contexts
NASA NGLTArchitecture 1
Roll-up Ops Context
Without new ops approaches With new ops approaches10 variants = 10 combinations
From 10 approaches, all
viable approaches in combination (approach 12)
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Design Structure Matrix (DSM) for TSTO Context Analysis
Feed Forward LinksA: External Geometry of “as-drawn” vehicle elementsB: External Geometry of “as-drawn” vehicle elementsC: Tables of longitudinal aerodynamic coefficientsD: Booster Mass Ratio (guess)
Orbiter Mass Ratio (guess)E: Booster Gross Weight [lbs]
Orbiter Gross Weight [lbs]Booster Total Vacuum Thrust [lbs]Orbiter Total Vacuum Thrust [lbs]Booster Total Engine Exit Area [ft2]Orbiter Total Engine Exit Area [ft2]Booster Sref [ft2]Orbiter Sref [ft2]
F: Booster Gross Weight [lbs]Orbiter Gross Weight [lbs]Booster Total Propellant Consumed [lbs]Orbiter Total Propellant Consumed [lbs]
Feedback LinksG: Calculated Booster Mass Ratio
Calculated Orbiter Mass Ratio
C
Converger(DOT)
Weights andSizing
(MERs)
Trajectory[POST]
MR ScriptDISCIPLINE[Tool Name]
E
G
D
ACAD
[Solid Edge]
Aerodynamics[APAS]
B
F
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Vehicle Closure Process in ModelCenter© Collaborative Design Environment
Vehicle Summary
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D4Ops Context 2: Design Approach 0 (State-of-Practice)Booster Geometry and Packaging
External View Internal Packaging View
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D4Ops Context 2: Design Approach 0 (State-of-Practice)Orbiter Geometry and Packaging
External View Internal Packaging View
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Context 2 Three View: Design Approach 0 (State-of-Practice)Booster
4,290,683 lbsGross Weight
472,856 lbsDry Weight
7Main Engine Count
RS-84Main Engine Type
Design Specifications
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Context 2 Three View: Design Approach 0 (State-of-Practice)Orbiter
984,643 lbsGross Weight
184,737 lbsDry Weight
4Main Engine Count
RLXMain Engine Type
Design Specifications
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D4Ops Context 2: Design Approach 12 (Roll-up)Geometry and Packaging
Booster Stage Orbiter Stage
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Context 2 Three View: Design Approach 12 (Roll-up)Booster
4,226,200 lbsGross Weight
466,199 lbsDry Weight
5Main Engine Count
RS-84Main Engine Type
Design Specifications
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Context 2 Three View: Design Approach 12 (Roll-up)Orbiter
968,743 lbsGross Weight
183,309 lbsDry Weight
3Main Engine Count
RLXMain Engine Type
Design Specifications
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D4Ops Context 2 Scale Comparison
0 feet
100 feet
200 feet
VARIANT TYPEDRY WEIGHT
LengthHeight (w/o wheels down)
Width
SEI D4Ops Context 2 SOP658 Klbs
164 ft.45 ft.104 ft.
0 meters
30.48 meters
60.96 meters
STS (orbiter)173 Klbs184.2 ft.76.6 ft.78.1 ft.
Delta IV-Heavy185 Klbs
236 ft.49 ft.16 ft.
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Context 2 Tank/Propulsion Comparison: State-of-Practice (SOP) versus Approach RollupBooster Stage
LOX RP-1 LOX C2H6O
GHe GHe
LOX C2H6O JP-8 JP-8
GHe GHe GHe GHe GHe GHe
Design Approach 0: State-of-Practice (SOP)
LOX RP-1 LOX C2H6O
Design Approach 12: Roll-up
SCORECARD
Number of Main Oxidizer Tanks
Number of Main Fuel Tanks
Number of Pressurant Tanks (GHe)
Number of JP-8 Tanks: Flyback
Number of Coolant Tanks (Freon)
Number of RCS Oxidizer Tanks
Number of RCS Fuel Tanks
TOTAL NUMBER OF TANKS
Number of Main Engines (RS-84)
Number of Nose RCS Thrusters
Number of Aft RCS Thrusters
Number of OMS Engines
1
1
8
2
2
2
2
18
7
14
12
0
SCORECARD
Number of Oxidizer Tanks
Number of Fuel Tanks
Number of Pressurant Tanks (GN2)
Number of JP-8 Tanks: Flyback
Number of Coolant Tanks (H2O)
Number of RCS Oxidizer Tanks
Number of RCS Fuel Tanks
TOTAL NUMBER OF TANKS
Main Engines (RS-84)
Number of Nose RCS Thrusters
Number of Aft RCS Thrusters
Number of OMS Engines
1
1
4
1
1
1
1
10
5
8
8
0
Freon Freon
GHe GHe
GHe GHe JP-8 H2O
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Context 2 Tank/Propulsion Comparison: State-of-Practice (SOP) versus Approach RollupOrbiter Stage
LOX LH2 LOX C2H6O
GHe GHe
LOX C2H6O GHe GHe
GHe GHe GHe GHe LOX LH2
Design Approach 0: State-of-Practice (SOP)
LOX LH2
Design Approach 12: Roll-up
SCORECARD
Number of Main Oxidizer Tanks
Number of Main Fuel Tanks
Number of Pressurant Tanks (GHe)
Number of Freon Tanks: Equipment Cooling
Number of RCS Oxidizer Tanks
Number of RCS Fuel Tanks
Number of Fuel Cell LOX Tanks
Number of Fuel Cell LH2 Tanks
Number of Turboalternator Reactant Tanks
Number of Water Tanks
TOTAL NUMBER OF TANKS
Number of Nose RCS Thrusters
Number of Aft RCS Thrusters
Number of OMS Engines
Number of Main Engines
1
1
8
2
2
2
3
3
2
1
25
14
12
2
4
LOX LH2 LOX LH2 Freon Freon H2O GH2
GO2
SCORECARD
Number of Main Oxidizer Tanks
Number of Main Fuel Tanks
Number of Pressurant Tanks (GHe)
Number of Freon Tanks: Equipment Cooling
Number of RCS Oxidizer Tanks
Number of RCS Fuel Tanks
Number of Fuel Cell LOX Tanks
Number of Fuel Cell LH2 Tanks
Number of Turboalternator Reactant Tanks
Number of Water Tanks
TOTAL NUMBER OF TANKS
Number of Nose RCS Thrusters
Number of Aft RCS Thrusters
Number of OMS Engines
Number of Main Engines
1
1
0
0
0
0
0
0
0
1
3
8
8
0
3
H2O
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Context 2 Booster Stage: D4Ops Design Approaches to Be Added
1. Reduce Overall Parts Count
2. Reduce Engine Count
5. Eliminate Cryogenic ACS
6. Uniform TPS tiles and blankets (shape and thickness)
7. Reduce TPS Penetrations (Access locations and cutouts) and Repair/Replacement Actions (e.g. Self-healing TPS)
8. Advanced P-IVHM System9. Eliminate Aeroshell and Closed Compartments. Integrate structural and plumbing functions.
10. Use Common Fluids and Tanks for Propulsion and Power
11. Use Common Fluids and Tanks for Propulsion, Power, and ECLSS (thermal)
D4Ops approaches to be applied to baseline TSTO in key functions/subsystems areas as shown
BASELINE TSTOBOOSTER
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Context 2 Orbiter Stage: D4Ops Design Approaches to Be Added
1. Reduce Overall Parts Count
2. Reduce Engine Count
3. All Electric (batteries instead of fuel cells and APUs)
5. Eliminate Cryogenic ACS
6. Uniform TPS tiles and blankets (shape and thickness)
7. Reduce TPS Penetrations (Access locations and cutouts) and Repair/Replacement Actions (e.g. Self-healing TPS)
8. Advanced P-IVHM System 9. Eliminate Aeroshell and Closed Compartments. Integrate structural and plumbing functions.
10. Use Common Fluids and Tanks for Propulsion and Power
11. Use Common Fluids and Tanks for Propulsion, Power, and ECLSS (thermal)
D4Ops approaches to be applied to baseline TSTO in key functions/subsystems areas as shown
BASELINE TSTOORBITER
Analysis of Design Approaches
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D4Ops Context 2: Weight Metric Comparison to SOP
-4.35%
-2.58%
-1.65%
0.00%
0.02%
26.46%
5.03%
1.10%
-4.52%
1.66%
1.30%
21.29%
-4.15%
-2.39%
-1.64%
0.00%
0.02%
24.83%
4.73%
1.00%
-4.13%
1.27%
0.94%
19.32%
-10.00% -5.00% 0.00% 5.00% 10.00% 15.00% 20.00% 25.00% 30.00%
1: Reduce Parts
2: Reduce Engines
3: All Electric
4: No Hypergols
5: No Hypergols/Cryogens
6: Uniform TPS
7: Robust TPS
8: P-IVHM
9: Less Aeroshell
10: Common Prop./Power
11: Common Prop./Power/ECLSS
12: Roll-Up
Des
ign
App
roac
h
% Difference from State of Practice (SOP)
Gross Liftoff Weight
Dry Weight
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D4Ops Context 2: Non-Recurring Cost Metric Comparison to SOP
-0.2%
-1.1%
-1.4%
0.0%
2.0%
13.1%
11.6%
5.2%
4.4%
3.6%
5.7%
65.1%
-7.3%
-5.4%
-1.5%
0.0%
2.2%
15.4%
8.1%
1.7%
-1.7%
2.0%
3.2%
24.3%
-20.0% -10.0% 0.0% 10.0% 20.0% 30.0% 40.0% 50.0% 60.0% 70.0%
1: Reduce Parts
2: Reduce Engines
3: All Electric
4: No Hypergols
5: No Hypergols/Cryogens
6: Uniform TPS
7: Robust TPS
8: P-IVHM
9: Less Aeroshell
10: Common Prop./Power
11: Common Prop./Power/ECLSS
12: Roll-Up
Des
ign
App
roac
h
% Difference from State of Practice (SOP)
Vehicle Acquisition Cost
DDT&E Cost
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D4Ops Context 2: Operations Metric Comparison to SOP
-5.9%
-1.4%
-2.8%
0.0%
1.6%
8.2%
-8.5%
-17.0%
-17.0%
-16.1%
-2.1%
-33.3%
-10.8%
-3.4%
-5.8%
0.0%
3.3%
-2.7%
-8.0%
-16.8%
-13.3%
-26.2%
-25.6%
-38.9%
-7.6%
-4.9%
-8.1%
0.0%
4.7%
-4.7%
-10.3%
-16.2%
-17.1%
-21.1%
-10.3%
-30.1%
-50.0% -40.0% -30.0% -20.0% -10.0% 0.0% 10.0% 20.0%
1: Reduce Parts
2: Reduce Engines
3: All Electric
4: No Hypergols
5: No Hypergols/Cryogens
6: Uniform TPS
7: Robust TPS
8: P-IVHM
9: Less Aeroshell
10: Common Prop./Power
11: Common Prop./Power/ECLSS
12: Roll-Up
Des
ign
App
roac
h
% Difference from State of Practice (SOP)
Total Cycle Time (days)
Variable Costs per Flight ($M)
Total FAC/GSE (nonannualized) ($M)
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D4Ops Context 2 State-of-Practice (SOP): Initial Program Cost
Cost includes DDT&E, acquisition of 3 flight articl es (booster and orbiter), facilities development, and operations (at $2.19B/year)
Operations Costs
Acquisition Costs
Non-Recurring Costs
Total Cumulative Life Cycle Cost Up to Fifth Year of Flight =
$76.4B [FY2003]Initial Operating Capability (IOC)@ 5 Flights Per Year
$-
$2,000
$4,000
$6,000
$8,000
$10,000
$12,000
$14,000
$16,000
$18,000
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Program Year
Co
st [
$M, F
Y20
03]
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AS THE LIFE CYCLE PROGRESSES, HIGHER INITIAL FIXED COSTS (DDT&E, ACQUISITION) ARE MORE THAN OFFSET BY REDUCED OPERATIONAL COSTS (FACI LITIES AND RECURRING)
-10%
-5%
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
50%
55%
60%
65%
70%
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035
Program Year
% D
iffer
ence
In C
umul
ativ
e Li
fe C
ycle
Cos
t (LC
C)
Fr
om S
tate
-of-
Pra
ctic
e (S
OP
)
D4Ops Context 2: Cumulative Life Cycle Cost Comparison to SOP
1: Reduce Parts
2: Reduce Engines
3: All Electric
4: No Hypergols
5: No Hypergols/Cryogens
6: Uniform TPS
7: Robust TPS
8: P-IVHM
9: Less Aeroshell
10: Common Prop./Power
11: Common Prop./Power/ECLSS
12: Roll-Up
Design Approach
DISTANCE FROM HORIZONTAL AXIS INDICATES HOW MUCH LOWER OR HIGHER LCC IS VERSUS LCC OF STATE-OF-PRACTICE (SOP) CASE
CROSSING HORIZONTAL AXIS INDICATES POINT AT WHICH L CC BECOMES LESS THAN LCC OF STATE-OF-PRACTICE (SOP) CA SE
Initial Operating Capability (IOC), 5 Flights Per Y ear
Facility Development
DDT&E Acq.
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D4Ops Context 2: TOPSIS Ranking of Design Approaches
Life Cycle Costs
Cycle Time
Weight
Even across 9 FOMS
Orientation of Weighting Scenarios For Figures of Merit (FOMs)
10
Median of Rank Across 10 different
Weighting Scenarios
=
NOTE: LARGER OEC SCORE IS BETTER
0.623
0.566
0.582
0.522
0.489
0.369
0.537
0.685
0.689
0.753
0.634
0.501
0.946
0.911
0.892
0.840
0.836
0.053
0.689
0.817
0.959
0.805
0.813
0.194
0.355
0.279
0.369
0.141
0.042
0.270
0.430
0.600
0.626
0.742
0.430
0.955
0.743
0.538
0.579
0.394
0.281
0.061
0.294
0.720
0.673
0.964
0.906
0.353
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
1: Reduce Parts
2: Reduce Engines
3: All Electric
4: No Hypergols
5: No Hypergols/Cryogens
6: Uniform TPS
7: Robust TPS
8: P-IVHM
9: Less Aeroshell
10: Common Prop./Power
11: Common Prop./Power/ECLSS
12: Roll-Up
Des
ign
Ap
pro
ach
OEC Score: Relative Closeness to Ideal Solution, , Based upon multiple metrics which are aggregated and ranked using decision making methods such as TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) for a particular weighting scenario
4
7
6
9
11
12
8
3
2
1
5
10
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Summary
Context 2 TSTO required a more refined performance closure process, resulting in re-flown/re-sized veh icle for each approach
It was initially assumed that Approach 12 (Roll-up) would fare well, however due to high costs and wei ght, operational benefits (including lowest cycle time amongst all approaches ) were overshadowed
Approach 10 (Common/Fluids/Tanks for Power/Propulsion) is the best when considering all weighting scenarios- The best in terms of Life Cycle Costs (LCC) and Even Weighting
Approach 9 (Less Aeroshell) is second best across all weighting scenarios- Very positive when looking at lowest weight- Second best when comparing using an even weighting- Taking off aeroshell made a substantial difference in vehicle closure, resulting in reduced weight
Approach 8 (P-IVHM) is third best across all weighting scenarios- Good ranking across multiple metrics, not near the top in any one weighting scenario
Approach 6 (Uniform TPS) is worst approach due to weight penalty
As the life cycle progresses, higher initial fixed costs (DDT&E, acquisition) are more than offset by r educed operational costs (facilities and recurring) to reduce total Life Cyc le Cost (LCC), however required almost entire progr am life for Approach 12 tobeat baseline
Further refinement of modeling process can be developed- More refined justification for certain k-factor effects
Context 3
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Design Summary
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D4Ops Process for Context 3
The final contexts in which a set of D4Ops design approaches were evaluated were a pair of advanced, far-term architectures.
For the purposes of this study “far-term” was taken to mean a vehicle whose IOC was around 2020. Discussion between study participants, the authors and personnel at NASA KSC, led to changes in the implementation of the D4Ops process for Contexts 3a and 3b.
Unlike Contexts 1 and 2, 3a and 3b would not be based on any particular existing design study.
Instead of developing a baseline Context and then applying D4Ops design approaches one by one as done previously, Contexts 3a and 3b would incorporate D4Ops thinking from the beginning.
Modifications to the initial list of eleven D4Ops design approaches should be made before proceeding to the far-term context analysis.
The authors reviewed the list of ideas conceived during the initial D4Ops brainstorming session and reviewed operational design recommendations published by the Space Propulsion Synergy Team (SPST).
Several new D4Ops approaches were subsequently added to the original eleven, while some of the existing approaches were combined.
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Top-Level Assumptions
Use of SEI developed methods and tools for design- Consultation of past and current rocket-powered SSTO design concepts- Use of standard Weight Breakdown Structure (WBS) with appropriate modifications
Goal is to incorporate D4Ops guidelines from start to finish in the context of a far-term SSTO vehicle
Expert-defined parameter changes to model inputs (k-factors) reflect the impact of any design approach
Initial development consisted of Outer Mold Line (OML) development in CAD and subsystem packaging
End-to-end subsystem failure rates stayed the same whenever parts were reduced- Assumed additional weight and cost complexity generated in order to maintain the current end-to-end failure rate
When cost complexity changed, generally both DDT&E and TFU costs affected
Weights, Cost, and Safety, and Economics disciplines coupled in a spreadsheet-based meta model known as a ROSETTA models
Use of AATe version 1.0d for this analysis
Simple Life-Cycle Cost Model developed- Main rocket engine is new development- Assumed static flight rates of 10 flights per year- Assumed minimum number of 1 vehicles (orbiter and booster) acquired in program- IOC: 2020, Program End: 2039, DDT&E of 4 years starting in 2013, Vehicle production of 3 years starting in 2017, Facilities
development of 5 years starting in 2015- Additional vehicles purchased due to LOV probability
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> Lessons learned >
Plan for Context 3
E Context 3a and 3b: Far Term Single Stage To Orbit (SSTO)
Expanded Set: D4Ops Guidelines
Operatio nal Appr oach
Reduce parts count us ing highly
rel iable parts (vs. less rel iabil i ty in
the parts and higher need for
redundancy as in
Shuttle).
Place ox idizer tanks in aft
vehic le location to minimize fi ll
pumping
requirements
P lace both ox idizer AN D fuel
tanks in aft vehic le location
(toriod solution) to reduce feedl ines and s tandardize
fi l l/drain locations
Use external pay load
container s to al low off- line
pay load
integration
Include self-ferry
and power landing to reduce delays assoc iated w ith
non-K SC landing
C reate
symmetrical layout of main
engines (spaced
for maintainabi l i ty)
Reduce part s coun t using high ly reli able part s ( vs. less rel iabilit y in the par ts and higher need fo r r ed undancy as
in S huttl e) . x Pl ace o xidizer tanks in aft v eh icle location to mi nimize fi ll pum ping r equirem en ts x Pl ace b oth oxi dizer AND fuel tanks in af t vehicle
locati on (t oriod sol ution) to r educe feedli nes and standard ize fill /drain locations x Use external payload contai ners to allo w off -line pay load
int eg ration x In cl ude sel f-f err y and power landing to redu ce d el ays associat ed with non -KSC l an ding x Create symmet rical layo ut of m ain engines (spaced for
maint ainabilit y) x
Vehicle System DesignCompatibility
Context 3a
Goal / DRM
Context 3b
Previous SSTOVehicle Studies
Metrics Comparison
5,0 0 0, 00 0
5,2 5 0, 00 0
5,5 0 0, 00 0
5,7 5 0, 00 0
6,0 0 0, 00 0
6,2 5 0, 00 0
No
Te
ch
Tech
A
Tech
B
Te
ch C
Te
ch D
Tech
E
Tech
B+
C
Tech
B+
D
Te
ch C
+D
Tech
C+E
Tech
D+E
Te
ch C
+D
+E
Gro
ss W
eig
ht [l
bm]
Pro bab ilis tic @ 8 0% Con fiden ceDet erministic
Te chnology Port fo lio
With expanded ops approaches With expanded ops approaches.Expand modularity concept to
included palletized main propellants.
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D4Ops Context 3 Expanded Design Guidelines (1)
Locate propellant tankage and subsystems on pallet modulesIncorporate Modular Design ApproachCONFIGURATION
If applicable, position LOX tank in aft end of fuselage in order to shorten or eliminate feedlinesPlace LOX Tank Aft
Minimize windward TPS penetrations by re-entering atmosphere invertedFly Return Trajectory Inverted
Use Non-toxic / Benign Propellants for OMS / RCS
Reduce RCS Thruster Count
Avoid Using Center Engine
Design Accessible Propulsion System
Reduce Likelihood of Gas / Liquid Leakage
Reduce Main Engine Count
Utilize MPS with Improved Design Life
Design Guideline
Main propulsion system should have improved design life compared with SSME in terms of duration and number of startsPROPULSION
Reduce system complexity by reducing number of main engines (while increasing individual engine reliability)
Design connector and distribution systems to minimize risk of gas or liquid propellant leakage
Propulsion system components should be arranged to facilitate support and maintenance
Avoid multi-engine designs in which a main engine is positioned in the center of a group of engines (poor access for engine maintenance)
Reduce system complexity by employing fewer RCS thrusters than STS baseline (while simultaneously increasing the reliability of individual units)
Avoid chemicals such at hydrazine, MMH, and NTO to improve supportability and maintainability
Description
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D4Ops Context 3 Expanded Design Guidelines (2)
Include propulsion-focused IVHM system to improve ground checkout, safety, and maintainabilityIncorporate P-IVHM
Where possible, combine propellant tankage and hardware for OMS and RCS to improve supportability and maintainabilityIntegrate OMS / RCS Tankage and Hardware
Use high energy density storage batteries where possible in place of fuel cells to reduce complexityReduce / Eliminate Fuel Cells
Design for minimal TPS penetration locations on vehicle. Use robust TPS design where penetrations are requiredReduce TPS Penetration Points
Use EMA / EHA systems for landing gear, aerosurface actuation, etc.Eliminate Hydraulic SystemsMECHANICAL
Design systems, tankage, and feedlines such that common fluids can be used for propulsion, power, and thermal management functions. Reduce number of unique fluids on vehicle to improve maintainability and supportability
Use Common Fluids for Propulsion, Power, and Thermal Management
INTEGRATION
Reduce Flight to Ground Interfaces
Eliminate Closed Compartments
Use Selectively-Uniform TPS Layout
Use Left / Right Symmetric TPS
Design Guideline
Design mirrored TPS such that left and right TPS layouts are symmetric for a large percentage of the surface areaSTRUCTURES
Increase maintainability and supportability of TPS by using uniform (common shape/thickness) tiles or blankets on selected surfaces
Remove aeroshell in selected areas to eliminate closed compartments and improve maintainability and supportability
Design systems such that number of flight to ground interfaces is reduced compared with STS baselineINTERFACES
Description
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Design Structure Matrix (DSM) for Context 3 Analysis
Feed Forward LinksA: External Geometry of “as-drawn” vehicle elementsB: External Geometry of “as-drawn” vehicle elementsC: Tables of longitudinal aerodynamic coefficientsD: Mixture Ratio Schedule (function of time)E: Gross Weight [lbs]
Total Vacuum Thrust [lbs]Total Engine Exit Area [ft2]Sref [ft2]
F: Mass Ratio (simulation output)Overall Vehicle Mixture Ratio (simulation output)
Feedback LinksG: Calculated Vehicle Gross WeightH: Mass Ratio (guess)
Overall Vehicle Mixture Ratio (guess)
C
Optmizer[OptWorksAutoGA]
Weights andSizing
[MERs]
Trajectory[POST]
ConvergerDISCIPLINE[Tool Name]
F
D
ACAD
[Solid Edge]
Aerodynamics[APAS]
B
E
G
H
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Vehicle Closure Process in ModelCenter© Collaborative Design Environment
Vehicle Summary
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Preliminary D4Ops Context 3a: Geometry and Packaging
External View Internal Packaging View
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Preliminary D4Ops Context 3a: Three-view
1,317,749 lbsGross Weight
153,007 lbsDry Weight
2Main Engine Count
ACRE-92Main Engine Type
Design Specifications
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Preliminary D4Ops Context 3b: Geometry and Packaging
External View Internal Packaging View
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Preliminary D4Ops Context 3b: Three-view
780,344 lbsGross Weight
81,617 lbsDry Weight
2Main Engine Count
ACRE-92Main Engine Type
Design Specifications
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D4Ops Context 3a Scale Comparison
0 feet
100 feet
200 feet
VARIANT TYPEDRY WEIGHT
LengthHeight (w/o wheels down)
Width
SEI D4Ops Context 3a153 Klbs
159 ft.27 ft.92 ft.
0 meters
30.48 meters
60.96 meters
STS (Orbiter)173 Klbs184.2 ft.76.6 ft.78.1 ft.
SEI D4Ops Context 3b81 Klbs118 ft.18 ft.68 ft.
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D4Ops Context 3a: Design Approaches to Be Added
Reduce Overall Parts Count
Reduce Engine Count
Selectively Uniform TPS tiles and blankets (shape and thickness)
Reduce TPS Penetrations (Access locations and cutouts) and Repair/Replacement Actions (e.g. Self-healing TPS)
Advanced P-IVHM System
Eliminate Closed Compartments (remove aft aeroshell). Integrate structural and plumbing functions.
Place LOX Tank(s) Aft
Use Common Fluids and Tanks for Propulsion and ECLSS (thermal)
D4Ops approaches applied to SSTO in key functions/subsystems areas as shown
Use Modular Approach
Utilize MPS with Improved Design Life
Use Accessible Propulsion System
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D4Ops Context 3b: Design Approaches to Be Added
Reduce Overall Parts Count
Reduce Engine Count
Selectively Uniform TPS tiles and blankets (shape and thickness)
Advanced P-IVHM System
Eliminate Closed Compartments (no aeroshell). Integrate structural and plumbing functions.
Place LOX Tank(s) Aft
Use Common Fluids and Tanks for Propulsion and ECLSS (thermal)
D4Ops approaches applied to SSTO in key functions/subsystems areas as shown
Use Modular Approach
Utilize MPS with Improved Design Life
Use Accessible Propulsion System
Analysis of Design Approaches
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D4Ops Context 3a Metrics Summary
Tail Group
Body Group
Thermal Protection
Landing Gear
Main Propulsion
RCS Propulsion
Primary Power
Electrical Conversion and Distribution
EHA Systems
Avionics
Thermal / Environmental Control
Dry Weight Margin
Dry Weight
Cargo (up and down)
Residual Propellants
Reserve Propellants
Landed Weight
Entry/Landing Propellants
Entry Weight
ACS Propellants (consumed on-orbit)
Unusable Propellants
Insertion Weight
Main Engine Ascent Propellants
Gross Liftoff Weight
Weight [lbs]
4,744
76,609
16,845
3,356
22,919
782
1,200
3,233
931
1,702
730
19,957
153,007
12,000
1,246
5,869
172,122
578
172,701
1,878
5,743
180,321
1,137,428
1,317,749
Weight Item
3.1%
50.1%
11.0%
2.2%
15.0%
0.5%
0.8%
2.1%
0.6%
1.1%
0.5%
13.0%
100.0%
% of Dry Weight
System Gross Weight (lbs) 1,317,749
Vehicle LengthWingspanHeight (w/o gear down)
DIMENSIONS
159 ft92 ft27 ft
SCORECARD
Number of Main Oxidizer Tanks
Number of Main Fuel Tanks
Number of Pressurant Tanks (GHe)
Number of OMS/RCS Oxidizer Tanks
Number of OMS/RCS Fuel Tanks
Number of Coolant Tanks
Number of Fuel Cell Reactant Tanks
Number of APU Reactant Tanks
Number of Water Tanks
TOTAL NUMBER OF TANKS
Number of Main Engines
Number of Nose RCS Thrusters
Number of Aft RCS Thrusters
Number of OMS Engines
2
1
0
0
0
0
0
0
1
4
2
8
8
0
NON-RECURRING AND LIFE CYCLE COST
DDT&E Cost {$M]
Acquisition Cost [$M]
Life Cycle Cost [$M] at 7 and 67 Flights/Year
Cost Per Flight [$M/Flight] at 7 and 67 Flights/Year
SAFETY
Loss of Mission (LOM) MFBF / Reliability
Loss of Vehicle (LOV) MFBF / Reliability
Casualty Rate [per year] at 7 and 67 Flights/Year
OPERATIONS
GSE/Facility Cost: Non-Annualized Cost [$M]
Fixed Operational: Annual Operations Costs [$M]
Variable Costs per Flight [$M]
Minimum Cycle Time / Flight Capability Per Year
SUMMARY METRICS (in FY2003 unless otherwise noted)
$6,147 M
$741 M
$10,396 M / $20,776 M
$30.58 M / $15.50 M
1 in 1,673 Flights / 0.99940
1 in 3,558 Flights / 0.99972
6.20E-04 / 2.44E-03
$347.3 M
$80.1 M
$4.9 M
7.50 days / 38.3 Flights
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D4Ops Context 3b Metrics Summary
Tail Group
Body Group
Thermal Protection
Landing Gear
Main Propulsion
RCS Propulsion
Primary Power
Electrical Conversion and Distribution
EHA Systems
Avionics
Thermal / Environmental Control
Dry Weight Margin
Dry Weight
Cargo (up and down)
Residual Propellants
Reserve Propellants
Landed Weight
Entry/Landing Propellants
Entry Weight
ACS Propellants (consumed on-orbit)
Unusable Propellants
Insertion Weight
Main Engine Ascent Propellants
Gross Liftoff Weight
Weight [lbs]
2,351
36,513
9,103
1,925
13,573
667
1,200
2,674
534
1,702
730
10,646
81,617
12,000
1,057
4,047
98,721
332
99,053
6,960
3,455
109,468
670,876
780,344
Weight Item
2.9%
44.7%
11.2%
2.4%
16.6%
0.8%
1.5%
3.3%
0.7%
2.1%
0.9%
13.0%
100.0%
% of Dry Weight SCORECARD
Number of Main Oxidizer Tanks
Number of Main Fuel Tanks
Number of Pressurant Tanks (GHe)
Number of OMS/RCS Oxidizer Tanks
Number of OMS/RCS Fuel Tanks
Number of Coolant Tanks
Number of Fuel Cell Reactant Tanks
Number of APU Reactant Tanks
Number of Water Tanks
TOTAL NUMBER OF TANKS
Number of Main Engines
Number of Nose RCS Thrusters
Number of Aft RCS Thrusters
Number of OMS Engines
2
2
0
0
0
0
0
0
1
5
2
8
8
0
System Gross Weight (lbs) 780,344
Vehicle LengthWingspanHeight (w/o gear down)
DIMENSIONS
118 ft68 ft18 ft
NON-RECURRING AND LIFE CYCLE COST
DDT&E Cost {$M]
Acquisition Cost [$M]
Life Cycle Cost [$M] at 7 and 67 Flights/Year
Cost Per Flight [$M/Flight] at 7 and 67 Flights/Year
SAFETY
Loss of Mission (LOM) MFBF / Reliability
Loss of Vehicle (LOV) MFBF / Reliability
Casualty Rate [ per year] at 7 and 67 Flights/Year
OPERATIONS
GSE/Facility Cost: Non-Annualized Cost [$M]
Fixed Operational: Annual Operations Costs [$M]
Variable Costs per Flight [$M]
Minimum Cycle Time / Flight Capability Per Year
SUMMARY METRICS (in FY2003 unless otherwise noted)
$4,435 M
$559 M
$8,391 M / $18,061 M
$24.68 M / $13.48 M
1 in 1,649 Flights / 0.99939
1 in 3,502 Flights / 0.99971
5.88E-04 / 2.32E-03
$194.2 M
$63.9 M
$4.1 M
6.20 days / 43.4 Flights
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D4Ops Context 3a and 3b Comparison
Context 3 design process incorporated D4Ops philosophy from the beginning (instead of “baseline” vehicle with approaches applied later) Developed two variants of a 12,000 lb payload SSTO with rapid turnaround capability based upon D4Ops design guidelines
$7.86M$9.61MRecurring Cost per Flight (Fixed + Variable)
$24.68M$30.58MLife Cycle Cost per Flight
81,617 lbs153,007 lbsDry Weight
780,344 lbs1,317,749 lbsGross Weight
Context 3bContext 3aItem
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Summary
The objective of Context 3 was to attempt to use D4 Ops principles from the outset of a new, far-term v ehicle design.
First and foremost, the fact that old habits are hard to break was made evident early on in the Context 3 analysis. - Although the authors set out to use D4Ops from the very beginning, it was found that key early design decisions were based on past experience
and specifically performance-based reasoning. - Traditional conceptual vehicle design begins with a mission requirement such as payload to LEO or number of passengers to a moon colony.
What D4Ops process suggests is that along with this mission requirement a corresponding operational design goal should be established at the start.
- For instance, instead of simply dictating that Context 3a and 3b would be vertical take-off, horizontal landing, rocket-powered vehicles, the process should have begun with a D4Ops-derived operational goal (such as the vehicle shall have the minimum practical number of fluids and tanks).
- The combination of mission requirements and operable design requirements could then have been allowed to drive out a particular vehicle architecture and geometry.
During the brainstorming sessions that preceded the development of Context 3, the idea that modular vehicle systems might enhance operability gained support .
- What was interesting was to watch how the implementation of modular design evolved in the Context. - Early thoughts that the main propellant tanks could be designed to resemble the Space Shuttle EDO pallets were dismissed when faced with the
geometric reality of accommodating the required fluids. - When when thoughts turned to dividing the main propellant volume into smaller cylinders that could presumably be removed through an opening
in the aeroshell, the perceived operational benefits seemed to evaporate. Only when the modular approach was mated with the conformal tanks and deleted aeroshell was the anticipated result achieved.
Perhaps the greater lesson to be learned from the modularity experiment is that had the vehicle configuration and geometry not be predetermined before thoughts of D4Ops approaches were put into action, the question would not have been “How do we make modularity work on this architecture?” but rather “What architecture will enable the best implementati on of modularity?” The answer to the second question reflects the inherent characteristics of a D4Ops philosophy.
Summary
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Findings (1)
The D4Ops approaches chosen for this study had a wide variety of impacts on the system.
Application of most of these D4Ops approaches result in systems that performed better operationally (in terms of lower recurring operations cost per flight and turnaround time) at a cost of having worse performance. Application of these approaches generally resulted in systems with heavier dry and gross lift-off weights (GLOW) that required more development funding with higher flight unit acquisition costs.
While many D4Ops design features do impose performance (i.e. weight) penalties, some approaches can provide operational benefits with only slight performance penalties.
The D4Ops approaches chosen for this study were developed through a combination of qualitative and quantitative processes.
It took extensive time and effort to develop and apply the first foundations of such a D4Ops intuition. As more contexts were examined, this process became easier. As the project progressed the study group was more and more concerned about using the D4Ops design intuition that was developed from each previous Context. Thus by Context 3 this study group was readily cognizant of the impact of certain design decisions upon operational metrics of interest. For example, as the project further progressed the impact of reducing to a complete battery power storage system became apparent. Yet even at the end of the study, there was still some hesitancy in taking the D4Ops philosophy to its logical conclusion.
The portion of the RCA database used in this study, based upon Space Transportation System (STS) orbiter processing information from NASA KSC, has some data integrity issues. The work hours in the database may not be reflective of actual man hours on each task. The data should be updated to reflect both the breadth of missions (currently only includes data mainly for the STS-81 flight) and the depth of work required all throughout the organization for such a flight.
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Findings (2)
Constraints were imposed by the pre-selection of Contexts 1 and 2. The top level architecture assumptions inherent in these two contexts, OSP and TSTO RLS, precluded some approaches from being applied. Conversely, this actually may have been beneficial in order to show the discrepancy of current performance-oriented design intuition and the influence of a D4Ops-oriented approach.
Even given flexibility in choosing Context 3, it was potentially too constrained to be able to handle all of the D4Ops approaches developed from the RCA database.
It is recognized that the Context 3 RLS is an easier concept to operate given the single stage nature of the architecture. There is no implication made here that such SSTO systems are the most optimum. The SSTO option was chosen to include a vastly different context than that seen in Contexts 1 and 2.
Design discussion and data transfer issues were made easier by the co-location of both performance and operations discipline experts in the same geographic area (as performed by the authors, located at the same organization).
The conceptual level toolset is limited in its ability to model certain D4Ops design approaches.
Reducing the number of fluids carried on a RLS is beneficial to its operability.
Given the extensive nature of some of the D4Ops approaches on nearer term Contexts 1 and 2, it is speculated that adding such approaches to the current Space Shuttle orbiter would be very difficult and potentially vastly expensive.
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Recommendations
The results of this study should be used to integrate the D4Ops design intuition philosophy into the current conceptual design process. This could include education of the performance-oriented discipline experts of the impact of their design assumptions on operational FOMs.
Better modeling capability should be developed to handle different operational approaches than those currently used on the Space Shuttle. There may be a need to examine the entire operational flow process for these contexts (from landing to launch) to better account for the impact of D4Ops approaches.
Future analyses using the D4Ops philosophy should examine contexts from the same time frame for more accurate comparison of D4Ops approaches.
Additional D4Ops approaches can be developed using similar methods of brainstorming and prioritization as described in this study.
The RCA needs to be updated with additional data gathering and mining.
There may be a potential to examine a more revolutionary use of the D4Ops philosophy in the design process. There may be some follow-on activity from this project that could examine how the execution of the operations discipline could be moved forward in the design process, feeding some portion of the performance closure loop. In this scenario, the operations discipline could actually help determine vehicle level characteristics such as the geometry including the outer mold line (OML).
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Summary
The D4Ops project has developed a generic set of relevant operational approaches based upon past historical knowledge of STS operations
The D4Ops project can be a pathway pointing to features that future designs will need to consider to meet operational goals
Context 3 may be the most important context in terms of acting as showcase of the general D4Ops philosophy starting immediately from the initial design stage
- Context 3 also benefits from lessons learned in applying approaches in Context 1 and 2
Generally adding D4Ops approaches do indeed increase system weights, yet substantial benefits in the operational metrics can result
- A trade-off emerges many times with choosing a heavier but more operationally viable system- For instance, Context 1 results indicate that weight growth of 17% arises when multiple approaches are incorporated, resulting in a
reduction of operational metrics (cost and turnaround time) by more than 40%
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