Transcript X-43 Mishap Investigation Board Status Report

X-43A Flights 2 and 3 Overview
Luat T. Nguyen
NASA Langley Research Center
Aerospace Control and Guidance Systems Committee Meeting
Salt Lake City, Utah
March 3, 2005
Background
Air-Breathing Launch Systems Are More Efficient
Air-Breathing Systems Possess Significantly Higher Propulsive Efficiency
Hydrogen Fuel
Hydrocarbon Fuels
Turbojets
Rocket
Rocket Based Combined Cycle
Specific
Impulse
Turbine Based Combined Cycle
Ramjets
Scramjets
Turbojets
Ramjets
Scramjets
Rockets
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MACH NUMBER
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2
Goals/Objectives of
Hyper-X Program
GOALS: Demonstrate, validate and advance the technology, experimental techniques,
and computational methods and tools for design and performance predictions of a
hypersonic aircraft powered with an airframe-integrated, scramjet engine.
FLIGHT OBJECTIVES:
- Three flights: two @ Mach 7 and one Mach 10
- Methods verification
- Scaling confirmation
Primary Metric: Accelerate
TECHNOLOGY
OBJECTIVES:
- Vehicle design & risk
reduction
- Flight validation of
design methods
- Design method
enhancement
- Hyper-X Phase 2 and
beyond
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Comparison of
Ground
&
Flight Data
Wind Tunnel-toWind Tunnel
Comparison
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X-43 Vehicle Geometry
148"
60"
Length: 12'4" (3.7 meters)
Width: 5'0" (1.5 meters)
Height:: 2'2" (0.6 meters)
Weight: 3000 lb max
19"
26"
30"
144"
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Approach and Methodology
X-43 Vehicle 1
Controller
Rudder
H2O
Fads PPTs
N2
Actuator
Battery
Wing
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SiH4
H2
FMU
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Approach and Methodology
Hyper-X Research Vehicle Key Mission Events
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B-52 and X-43 Ground Track
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X-43 Mach 7 Flight 1 Trajectory
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First Flight Mishap
June 2, 2001
• Nominal flight to launch point
• Drop of booster stack and ignition at 5 seconds after drop
nominal
• At ~13 seconds after drop booster departed controlled
flight -- right fin broke off, followed, within one second, by
left fin and rudder
• Wing broke off at 15 seconds
• Booster data stream lost at 21 seconds
• At 48.5 seconds, FTS initiated by Navy Range Safety Officer
while booster was within cleared corridor – no hazard to
civilians on ground or air crews
• X-43 data stream lost at 77.5 seconds
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Mishap Description
ORIG_F1.avi
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MIB Findings
• Modeling deficiencies causing over-prediction
of autopilot stability margins
– Fin Actuation System
– Aerodynamics
– Mass/Geometry Characteristics
• Over-prediction of fin actuator torque margin
– Misprediction of aerodynamic hinge moments
• Other areas for improvement
– Validation/Cross Checking/Reviews
– Documentation
– Workforce
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X-43A RTF Risk Reduction
Major Actions
Launch Vehicle
•
•
Higher fidelity models
–
Aerodynamics
–
Actuators
–
Structures
–
Autopilot
Actuator upgrade for
greater torque
capability
•
Lower loads
trajectory: booster
propellant off-load
•
Autopilot
trades/optimization
•
Independent
simulation
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Stage Separation
Research Vehicle
•
Higher fidelity models
•
Increased AOA for
flameout robustness
and greater thrust
Control law
refinements for
robustness
•
Upgraded engine
control logic for
unstart robustness
Independent
simulation
•
Adapter fluid systems
improvements
•
Redesign of wing
control horns
•
Aircraft-in-the-loop
timing tests
•
Independent
simulation
•
Higher fidelity models
•
Additional separation
mechanism testing
•
•
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RTF Aerodynamic
Database Enhancement
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X-43A Flight #1 Profile vs. Pegasus
X-43A Flt. #1
2000
1600
q 1200
psf
6/01
Mishap
800
Pegasus
400
0
0
1
2
3
4
5
6
7
8
9
Mach
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Booster Modification
• Approximately 3,345 lbs of propellant removed
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Propellant Off-Load
Halfway through Machining
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Machining Completed
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X-43A Flight Profiles vs. Pegasus
X-43A Flt. #1
2000
1600
X-43A Flt. #2
q 1200
psf
6/01
Mishap
800
Pegasus
400
0
0
1
2
3
4
5
6
7
8
9
Mach
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Fin Actuation System Upgrade
Electronic Control Unit (ECU)
• Objective:
Actuator
To increase the FAS hinge torque
capability from 1850 ft-lbs to 3000+ ft-lbs
• Modifications:
–
–
–
–
–
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Add second motor in torque summing arrangement
Fabricate new gears to handle higher loads
Change housing material from aluminum to stainless steel
Add two additional batteries
Redesign the power and pre-driver boards in the ECU
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Stage Separation Aerodynamics
•
Independent time accurate, N-S CFD w/ coupled
3DOF trajectory simulation performed by CFD
Research Corp. as part of RTF risk reduction
•
Results indicate excellent agreement with NASA
SepSim tool and CFD results
•
Coupled time accurate simulation predicts clean,
controlled separation (no re-contact) trajectory
Ejector
Piston
Force
Tail
Surface
Deflection
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Scramjet Unstart Prevention:
Durascram
•
Unstart occurs when pressure from combustion causes isolator shock
train to propagate forward into the inlet causing massive flow spillage
•
Actively controlling fuel flow via isolator pressure feedback (Durascram)
to enhance unstart robustness
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Flight Simulations
Primary
Boost
Separation
Research Flight
NRTSim (Orbital)
SepSim (Langley)
RVSim (Dryden)
•
Full Stack sim up to
separation
•
6+6 DOF sim of LV & RV
during separation
•
RV flight from post separation
to splash
•
Pegasus heritage
•
Built on MSC/ADAMS code
•
Dryden sim environment
•
LV analysis, autopilot
design, trajectory analysis
•
Sep analysis, sensitivity
studies, collision detection
•
RV analysis, autopilot design,
sensitivity studies
Drop-to-Splash (Dryden)
Back-Up
•
•
•
•
Full mission simulation
NRTSim + StepSim + RVSim
Manual linking of sims
Validation of individual sim phases/integrated flight
LVSim-D (Dryden)
Post 2 Sep (Langley)
•
Independent LV sim
•
6+6 DOF sep simulation
•
Dryden sim environment
•
Built on POST2 code
•
Independent LV analysis
•
Independent Sep analysis
End-to-End Sim (Langley)
•
•
Full mission simulation
NRTSim + SepSim + RVSim
•
•
Single user interface, automated linking/integration
Validation of Drop-to-Splash & individual sims
X-43A Flight 2
March 27, 2004
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hyper-x_second_flight .avi
Flight Objectives Met:
High Quality Vehicle and Engine Data Obtained –
Provides Basis for Extensive Analysis and Research
Thrust predicted to ~3%
Mach 7 Flight
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Mach 7 Thermal Results
Comparison with Flight Data
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X-43 Free Flight
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Flight 3 / Flight 2 Boost Comparison
Alpha Comparisons

Mach Comparisons
M
Time, sec
Time, sec
Engine Cowl Heating
Engine CowlParameter
Heating Parameter
Comparisons
Comparisons
Dynamic Pressure Comparisons
q
Heating
Parameter
(lb/ft2)
(Btu/ft2sec)
Time, sec
Time, sec
Flight 3 Hardware Configuration
Fillet Assembly
- Localized Reinforcement
- Revised Attachment Method
- Upgraded Pegasus TPS
- Additional structural composite plies
FAS
- Dual Motors
- Gear train
- Electronics/Batteries
- Through-bolted actuator mount
Wing Assembly
- Standard Pegasus
- Upgraded LE TPS
- Additional themocouples on the right side
Bulkhead Mounted Avionics
- HXLV Specific
Ballast Assembly
- Adjusted for Mach 10 trajectory
NOZZLE
- Upgraded TPS
AFT Skirt Assembly
- Aluminum
- Upgraded TPS on Fins LE
- Standard Pegasus Fins
Orion 50S Rocket Motor
X-43
- Upgraded Pegasus TPS
- No propellant offload
- Upgraded LE TPS
Ballast/Avionics Module
- Aluminum
Hyper-X Adapter
- Strengthened panels, GN2 mod
- Aluminum
X-43A Mission Details
Flight 3 versus Flight 2
MACH 9.6
(3 sec)
NONE
110,000 ft
-0.5g’s
(3 sec)
2.5g’s
X-43A/Booster Separation
at M=9.7, h=109k feet
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X-43A Flight #3 Data
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X-43A Demonstrated Propulsive Efficiency
Required for Future Launch Systems
Safe, Flexible, Affordable
Airframe Integrated
Turbojets
X-43 scaled
I sp
Ramjets
Scramjets
Rockets
0
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MACH NUMBER
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X-43 2004 Flight Summary
•
All program objectives were met
–
A wealth of high quality flight data substantiates
hypersonic vehicle and engine design tools and scaling
methodologies
+ Stability and control, aerodynamics, boundary layer transition,
vehicle structure, TPS, and internal environment performed
as predicted
–
Proved in flight that an airframe-integrated scramjet
works well - engine performance was very close to
preflight predictions
+ X-43 accelerated at Mach 6.83
+ X-43 cruised at Mach 9.68, the design condition
•
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–
Proved that non-symmetrical high q/high Mach stage separation is very doable,
leading the way to future safe staged launch systems
–
Paved the way for future systems
Why were we successful?
–
Exceptional teamwork across multiple government and industry organizations
–
Thorough understanding of what we wanted to do and how we were doing it from an
integrated systems perspective
–
Rigorous processes for design, development, testing, and checking
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