for emergency situations are design ..... a locally exponential atmosphere, ...... are made of stainless steel and aluminum. The total mass of plumbing, valves.
Project
SPARC
Instructor: Virginia
Team
Organization
Dr. A. K. Jakubowski
Polytechnic
Institute May,
Team
Orbital
University
1990
Leader:
Tyler
Mechanics
Eric
and State
Evans
/ Aerodynamics
Hammer
(group
Troy
Hetrick
leader)
Ray Poff AimEe Thornton Roni
Winkler
Propulsion Theodore
Systems
Bugtong
(group
leader)
Steve Davenport Brett Flanders
Vehicle
Structures, Stuart
Aerobrake,
and Crew
Deitrick
(group
Support
Systems
leader)
Tyler Evans Jason Lachowicz Hank Susan Steve
Massey
Document Susan
Lee
MacDowell
Editors
MacDowell
Steve
Graphics
Massey
Editors
Theodore Bugtong Jason Lachowicz Hank Aim6e
Lee Thornton i
Abstract
Future
United
States'
Geosynchronous possible GEO
space
facilities
Operations
Support
mode
of transfer
between
to LEO,
the Earth's
atmosphere
vehicle,
which
aerobrake
reduces
is added
the amount
requirements.
This increase report
transfer
crew
Project
SPARC,
and
cargo
Center,
in low Earth
of propulsive
is an aerobraking change
not exceed
between-the
vehicle.
in velocity
the amount
Space
Station
and
Reusable
When
GeoShack.
saved
during
from of the
vehicle
An
propellant the aeropass.
vehicle
consists
a
One
for the mission. increases
The
SPARC
(GEO).
traveling
mass
of an aerobraking
Craft.
and
the velocity
required
of propellant
(LEO)
orbit
reduce
but the additional
and development
Aeroassisted
orbit
in geosynchronous
can be used to aerodynamically
the design
a SPace-based
Station
or GeoShack,
for this purpose,
must
addresses
a Space
the two orbits
to the vehicle
The- following
include
that
is referred
will to as
of a removable
45'
diameter aerobrake, two modified Pratt & Whitney Advanced with a liquid oxygen/liquid hydrogen propellant, a removable
Expander Engines (I_p = 487 see) crew module with a maximum
capacity
a maximum
28,000
of five, Ibm.
and
The
angle-of-attack
aerobrake, due
protection
system.
maximum
propellant
advantages aerobrake
standard
sized
payload
a rigid,
to a 73" Maximum
rake dry
of SPARC include and crew module.
ellipsoidally angle,
mass
requirement
is its
bays
and
providing blunted
is covered
of the vehicle 79,753
Ibm
at
capability
to
meet
elliptical with
without an
payload
oxidizer mission
cone,
a flexible to
payload
capacity
provides
lift
multi-layer is 20,535
fuel
changes,
ratio and
its
at zero thermal
Ibm, of
of
and 6/1.
the Key
removable
o.°
111
I_IN_NT_kLLY
PRECEDING
PAGE BLANK
NOT
F|LMED
SPARC
V
i6_..,.._...._1__
_
PRECEDING
PAGE
BLANK
NOT
FILMED
Nomenclature
ABS
quilted
alumino
ACS
atmospheric
&/A"
engine
AEE
advanced
AFE
aeroassisted
CADAM
Computer-Graphic
Co
borosilicate
control
fabric
system
exit area-to-critical expander
area
ratio
engine
flight
experiment Augmented
CL
drag coefficient lift coefficient
Cm
moment
Cma
slope
DOF
degree
E(1)
longitudinal
E(2) EMU
transverse extravehicular
mobility
EVA
extravehicular
activity
F.S.
factor
ZruO) Fru(2)
longitudinal
Design
coefficient
of moment
coefficient
with
Young's Young's
unit
of safety ultimate
strength
GEO
geosynchronous
guidance, navigation, and control global positioning system altitude
IRU
earth
heavy lift launch inertial reference specific
strength orbit
vehicle unit
impulse
L/D
lift-to-drag
(L/D).o .iao
analytically determined impact theory
ratio lift-to-drag
(L/D)_
maximum
LEO
experimentally determined low earth orbit
n_
mass
m/(C:)
ballistic
MLI
multi-layer
MMV
manned National
NCRP
lift-to-drag
flow
NOTS
Naval
Q-felt
silica
of attack
Modulus
GNC
HLLV
to angle
Modulus
G12
h
respect
of freedom
transverse ultimate shear modulus
GPS
& Manufacturing
ratio,
based
on newtonian
ratio lift-to-drag
ratio
rate
coefficient insulation maneuvering unit Council on Radiation Ordinance fiber
convective
felt
Test blanket
stagnation
Protection
Station insulation point
heating
rate
vii
_l_
, _
PRECEDING
PAGE
_,._,,, "' _"""
NOT
FILMED
maximum
convective
stagnation
R
aerobrake
base
radius
Ra RCS
apogee reaction
RN
stagnation
Rp RTV
perigee
4111n_
plane
radius control
nose
radius
radius
room temperature vulcanized shuttle derived vehicle
SPARC
SPace-based
S_f
aerobrake
SSAM S_
Static Structural Analysis aerobrake surface area
t
thickness
T_2 TOF
ultimate
TPS
thermal
V
velocity oxidizer-to-fuel
Aeroassisted reference
shear
Reusable
for Microcomputers
strength
time of flight protection
aerobrake change
system ratio
rake angle in velocity
emissitivity Eb
aerobrake
bluntnose
Eeo_
aerobrake aerobrake
cone cone
ellipticity half angle
in xy-plane
0_
aerobrake
cone
half
in xz-plane
P
density skirt
circular
0_
-g
aerobrake flight
°°J
VIII
path
angle
Craft
area
absorptivity AV
heating
system
point
SDV-3R
WJWf
point
ellipticity
angle
arc angle
rate
Table
Project Abstract SPARC
Contents
SPARC Team Organization ....................................... ......................................................... ..........................................................
Nomenclature Table
of
v
....................................................
of Contents
i iii vii
..................................................
ix
List
of Tables
.....................................................
xi
List
of Figures
....................................................
xii
Chapter
Chapter
.............................................. 1 Introduction 1.1 Project Background ......................................... 1.2 Mission Scenario ...........................................
2 SPARC 2.1 Vehicle
Configuration Design
2.2 Configuration 2.3 Stability
......................................
Evolution Selection
Analysis
..................................... .......................................
..........................................
2.4 Center of Gravity Analysis 2.5 Mass Moments of Inertia
Chapter
3 Trajectory 3.1 Introduction 3.2 Orbital
Chapter
Analysis ....................................... ..............................................
Mechanics
.........................................
3 3 5 7 9 21 21 22 25 27 27
3.4 Time of Flight ............................................ 3.5 Atmospheric Pass ..........................................
29
4 The Aerobrake ........................................... 4.1 Introduction ..............................................
41
4.2 Geometry 4.3 Structure
43
4.4 Thermal Chapter
................................... ....................................
1
5 Propulsion 5.1 Introduction
and Aerodynamics .................................. and Materials ...................................... Protection
System
...................................
Systems ....................................... ..............................................
5.2 Propellant ............................................... 5.3 Main Engines ............................................ 5.4 Engine Mount ............................................
31
43 43 46 51 53 53 54 57
5.5 Selection of Fuel Tank Shape ................................. 5.6 Main Propellant Tanks ...................................... 5.7 Auxiliary Tanks ...........................................
59
5.8 Insulation
65
5.9 Propellant
............................................... Lines
...........................................
63 65 65
ix
Chapter
6 Structures 6.1 Introduction 6.2 Materials 6.3 Main
6.4 Structural 6.6 Tank
Structure
83 83
.........................................
Accommodation Support
81
.......................................
Analysis
6.7 Docking Chapter
81
................................................
Truss
6.5 Payload
79
.............................................. ..............................................
90
.....................................
92
.............................................
97
................................................
........................................... 7 Crew Module 7.1 Introduction .............................................
103
7.2 Cabin
105 105
Environment
105
........................................
7.3 Atmospheric Control System ................................. 7.4 Interior Design ........................................... 7.5 Extravehicular 7.6 Crew Module 7.7 Pressure
110
Activity ..................................... Hull Structure .................................
Shell
111
...........................................
111
7.8 Insulation
..............................................
115
7.9 Radiation
..............................................
115
Chapter
8 Navigation, 8.1 Guidance,
Communication, Navigation,
& Power
Control
(GNC)
8.2 Communications
and Data Processing
8.3 Electrical
System
Chapter
9 Cost 9.1 Cost
Power
Analysis Analysis
10 Design 10.1
References Appendices
Summary
Summary
...........................
.................................
B Mass
Appendix
C DRAG
Appendix
D Propellant
121 122 125 127
.......................................
131 133 135 145
.................................................... A Stability
121
127
.....................................................
Appendix
119
.......................................
..............................................
Appendix
..................
..........................
...........................................
9.2 On Orbit Assembly Chapter
Systems
....................................
& Assembly
Equations
Moments
.................................
of Inertia
Program Analysis
i
107
.............................
................................... Program
...........................
147 148 149 155
w
List of Tables
Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table Table
2.1 Vehicle Mass Summary ...................................... 3.1 Flight Summary ........................................... 3.2 Multiple Aeropass Scenarios ...................................
20 28 30
3.3 Analytic Perigee Solution Summary .............................. 3.4 Critical Values ............................................ 4.1 Aerobrake Characteristics ..................................... 4.2 Aerobrake Shell and TPS Mass Summary .........................
33 40
5.1 Propellant Calculations ....................................... 5.2 Characteristics of Vehicle Engine Candidates
53
5.3 Modified AEE Characteristics 5.4 Tank Characteristics for Tank
.......................
..................................
5.7 Thruster Characteristics 5.8 RCS Mass Summary 6.1 Material 6.2 Propellant 7.1 Mass 7.2 ACS
Properties Tank
Summary
......................
.................................
......................................
75 82
................................ Storage
Tanks
97
.....................
Mass Summary ....................................... 7.3 Volumetric Allocations ...................................... 7.4 Crew Module Mass Summary ................................. 8.1 GNC Summary ........................................... 8.2 Communications and 8.3 Power Requirements
Data
Processing
62 64 75
.........................................
of Atmospheric
54
70
........................................
Characteristics
50
56
Shape Selection .........................................
5.5 Tank Characteristics 5.6 Propellant Line Characteristics
44
Summary
106 107 110 114 121
....................
.......................................
122 122
8.4 Power System ............................................ 9.1 SPARC Cost Analysis ......................................
123
9.2 SPARC
Component
129
10.1
Parameter
Design
Useable Summary
Lifetime
...........................
.................................
128 134
xi
List
Figure
2.1 SPARC 2.2 SPARC
of Figures
Configuration
........................................
8
Configuration
........................................
8
Configuration ........................................ 2.3 SPARC I ........................................... 2.4 Configuration
8 10
2.5 Configuration 2.6 Configuration
11 ........................................... HI ..........................................
11 13
IV
14
Figure
2.7 Configuration 2.8 Configuration
Figure
2.9 Final
Figure
2.10
Final
Configuration
Front
Figure
2.11
Final
Configuration
Side View
Figure
2.12
Payload
Figure Figure
2.13 2.14
C,, versus Allowable
Figure
2.15
Center
Figure Figure
3.1 Flight 3.2 2-Pass
Summary Senario
........................................... ............................................
27 29
Figure
3.3 3-Pass
Senario
............................................
29
Figure Figure
3.4 Relative 3.5 Flowchart
Figure
3.6 Perigee
Figure
3.7 Total
Figure
3.8 Velocity
versus
Figure
3.9 Altitude
versus
Figure
3.10
Deceleration
Figure
3.11
Heating
Figure
3.12
Total
Figure
3.13
Velocity
versus
Time
(6,000-Ibm
Mission)
Figure
3.14
Altitude
versus
Time
(6,000-Ibm
Mission)
Figure
3.15
Deceleration
Figure Figure
3.16 Heating 4.1 Aerobrake
Figure
4.2 Quilted
Multilayer
Figure
5.1 Engine
Performance
Figure
5.2 Engine
Actuation
Figure
5.3 Shape 5.4 Shape
Factor
- Oxidizer
Factor
- Fuel Tank
5.5 Shape 5.6 Shape
Factor
- Fuel Tanks
Factor
- Oxidizer
Figure Figure Figure Figure Figure Figure
Figure Figure Figure Figure Figure
xii
..........................................
V ...........................................
Configuration
Top
View
.................................
View
Configurations
14 16
................................
17
.....................................
ct ............................................. Center of Gravity Envelope
of Gravity
15
...............................
History
19 23 23
..........................
and Engine
Mount
Angle
.................
Geometry ......................................... ............................................... Altitude
Heat
vs. Conic
versus
Time Time Time
versus
Rate Heat
Perigee
......................
35
........................
36
(20,000-1bm
mission)
........................
36
(20,000-Ibm
Time Time
versus
Mission)
35
mission)
versus
Mission)
(20,000-Ibm
(6,000-Ibm
Time
Rate versus Structure
........................
(20,000-Ibm Time
versus
30 32
Altitude
(20,000-Ibm
24
....................
Mission) Mission)
(6,000-Ibm
...................
...................... ....................... ........................
Mission)
.....................
Time (6,000-Ibm Mission) ........................................
TPS
Concept
....................
...............................
(Front) (Back)
Tank
38 38 39 39 40 45
58
.......................................... (Front)
37
48 56
........................................ Tank
37
............................
60
............................... ..............................
(Profile/Bottom)
60
.....................
........................ 5.7 Shape Factor - Fuel Tank (Profile/Bottom) Tank and Cross Section .............................. 5.8 Propellant
61 61 62 66
Figure 5.9 Heat Flux versus# of InsulationLayers .......................... Figure 5.10 Engine Schematic ......................................... Figure 5.11 PropellantLines .......................................... Figure 5.12 Oxygen Line Location ...................................... Figure 5.13 Hydorgen Line Location .................................... Figure 5.14 ReactionControl System .................................... Figure 5.15 ReactionControl SystemSchematic ............................ Figure 6.1 TrussSupportStructure(Top View) ............................. Figure 6.2a Location of SectionViews ................................... Figure 6.2b SectionViews A Through D ................................. Figure 6.2c SecitonViews E Through H ................................. Figure 6.3 Typical 5-MemberJoiner .................................... Figure 6.4 PayloadStructure .......................................... Figure 6.5a Oxygen Main Tank Support .................................. Figure 6.5b Oxygen Auxiliary Tank Support ............................... Figure 6.6a HydrogenMain Tank Support ................................ Figure 6.6b HydrogenAuxiliary Tank Support ............................. Figure 6.7 Docking (Side View) ....................................... Figure 6.8 Docking (Top View) ....................................... Figure 6.9 Docking (RearView) ...................................... Figure 7.1 Atmospheric Control SystemSchematic ......................... Figure 7.2 Crew Module Interior Floor Plan .............................. Figure 7.3 Crew Module 3-D Wire Frame ............................... Figure 7.4 SupportBracket .......................................... Figure 7.5 Crew Module CrossSection .................................
67 68 71 72 72 74 77 85 86 87 88 89 91 93 94 95 96 99 100 102 108 109 112 113 116
xiii
Chapter
1
Introduction 1.1Project
Background
1.2 Mission
Scenario
1.1 Project
Background
In the near future, will
serve
as
servicing, on
the
the United
and a home Space
proposed
States
a laboratory
and
tools)
The
Geosynchronous
well
as serve
will place
advanced
for the astronauts
Station,
that extra
for
and
travel
supplies
be stored
between satellite
Operations
as a way-station will be a repair
station
to the Earth's
surface
vehicle
transport
the Space
Station
an orbital
transfer
1.2 Mission 1.2.1
a great
to assist
atmosphere
in orbital can
the amount
propellant
saved
of
an
during
aerodynamic
stability.
Three
thermal
Mission mission
is transfer only, Space orbit.
and
is limited it is
equipment,
this purpose
eliminating
the GeoShack,
the need
and
of the following Aeroassisted
as
Furthermore,
it is necessary
the
for them
that
return
report:
Reusable
a space-
supplies
to
the design
of
Craft)
when
on the use
traveling
A V required
for the mission.
the
from
velocity An
of the planetary
GEO
to LEO,
of the
aerobrake
vehicle, must
in turn, increases the propellant this increase must not exceed
the thus
be added
requirements. the amount of
in the first place. vehicle
atmospheric
include
pass
and
becomes
of the entire down
the vehicle.
scenarios
have
been
is a round-trip
of a 20,000-Ibm
Station.
focused
the the
necessary
vehicle,
excessive
heating
rate
that
difficulties
encountered
in
to design
an aerobrake
that
be aerodynamically
stable,
and
would
be
maintaining will
provide
create
enough
Requirements
The first the
has been
Specifically,
adding mass, which to be economical,
It therefore slow
and research
reduce
aerobraked
protection
to sufficiently
GeoShack.
from
and
is expensive,
life support
or elsewhere.
Subsequently,
to and
space
will accomplish
often
which
(GEO).
Mars,
to aerodynamically
of propulsive
experienced
1.2.2
satellites
(SPace-based
transfers.
be used
by the aeropass
Disadvantages
adequate
or GeoShack,
is the subject
SPARC
deal of interest
to the vehicle for this purpose, In order for the aeromaneuver
drag
crew
vehicle
Station
orbit
(LEO)
operations
Since
lab supplies,
to the Moon,
for existing
and
operations.
the Space
orbit
satellite
Requirements
years,
reducing
Center, missions
for servicing.
This
Project
and
for
Scenario
atmospheres Earth's
needed.
vehicle:
Aerobraking
In recent
equipment
when
Earth
these
(i.e. propellant,
Support
to be returned based
the
in a low Earth
a center
in a geosynchronous
for future
the GeoShack
Station
who will perform
and equipment
on another
a Space
experiments,
third This
payload
is transfer final
specified transfer and
for a 6,000-Ibm crew
of a 28,000-Ibm
mission
for transfer
is expendable
of five payload
between
the
payload
and crew
to the GeoShack to the
and the vehicle
Space and
GeoShack will
Station of five,
return
with
no
be discarded
and
the
the second of the
return
crew to the
into a higher
3
t)t PRECEDING
PAGE
BLANK
NOT
FILMED
Chapter SPARC 2.1 Vehicle
2
Configuration Design
Evolution
2.2
Configuration
2.3
Stability
Analysis
2.4
Center
of Gravity
2.5 Mass
Selection
Moments
PRECEDING
Analysis of Inertia
PAGE BLANK
NOT
FILMED
2.1 Vehicle The
Design
first step
designs
of the design
were
Figure
Evolution
tanks, payload that surrounds
design
storage
2.1 through
module. during
requiring
less
engines
The ballute atmospheric
to accommodate
of an aerobrake
Three
space
and axial
placement
initial
of the propellant
is a non-lifting, inflatable, balloon-like entry and serves as a variable-drag
atmospheric
hangar
configuration.
2.3).
with forward-firing
bay and crew the vehicle
on demand
compact
was the selection
(Figures
2.1 is a ballute
responding
process
considered
variations.
at the
Space
Advantages Station,
include
and
no
structure device
a low mass,
on-orbit
assembly
requirement. Major disadvantages of this configuration include a high susceptibility to longitudinal if the location of the center of pressure is not carefully controlled relative to the center during
drag
through
modulation,
the
magnitude fluxes
non-uniform
"are
predicted
well
every
mission
corrections
flight
Due
2.3 illustrates
a ballute
lifting
complications,
The
capability Since
because
the use of rear
aerobrake.
aeropass.
of the reaction
bent and
the
firing
biconic has
ability
to provide of the Earth
the
heating
and
stagnation
point
contemporary, was
ruled
rear-placed these
convective convective
reusable
out. Other engines,
complications,
Figure
2.2 has a fixed
above
the
symmetric constant
(Menees,
of accessibility
configuration
to higher
thermal
instability
during
a small
variations. loading certain
aerobrake
designs lifting
variable-lift Analysis than
phases
the
design
located
guidance during
considerations.
payload
module because
change
and of its
during
corresponding
capability conical
symmetric
providing however, The
beyond
the
ballistic
conical
PRECED[tqG
"the
high
capability aerobrake
associated
payload
of
bay.
with Due
to
considerations. vehicle with
structure this
lifting
1983)
creates
aerobrake,
PAGE BLANK
a a
to compensate
aerobrake and
mounted
configuration:
aerobrake
the maneuverability
lifting
the
the biconic
that the symmetric (Menees,
that
problems
located
design
and the main
The
states
problems,
be accommodated
aerobrake
of the aeropass.
well
centrally
from
engines
aerobrake.
has shown,
biconic
to the
can
Menees
are the stability
eliminated
with side-firing
Two
with
was
increase.
Due to these
the
and a conical
drag
1983)
this
aerobrake
to provide
from
the
the
to be replaced
by the ballute
pane-inclination
bent
and
aerobrake.
for atmospheric
the
of this configuration
aerobrake
required
however,
to drastically
disadvantages lack
protection
the required A V. The perigee altitude must therefore compared to the larger area "drag brakes" causing both
rates...place
materials."
will have
for this configuration
surface
These
that will accommodate
enveloped
a centrally
to provide
drag
loads
heating
with
combined
heating.
for the thermal
was eliminated
also considered
a reduced
coefficient must be increased be much closer to the surface radiative
engines
was
subsequent
biconic
system
fluctuations
is the
near peak
material
control
density
ballute
the ballute
the craft is partially
this concept
the
proposed
Furthermore,
is difficult
and
heat fluxes
flexible-reusable
1983)
placement
to these
with
convective
of the material
is no existing (Menees,
turbulence
problem
and
of the capability there
during
Another
radiative
fluxes."
and
during
the aeropass.
high
In fact, heat
instability
atmosphere.
in excess
surface
Figure
directional
of the non-equilibrium
of this structure. after
and
instability of gravity
is subject
is subject possessing
NOT
to rollall the
FILMED
(-_
advantages of a symmetric The frustrum is contoured overcomes fixed An
the
conical
aerobrake, to alleviate
roll-instability lifting
advantage
possible
points.
that fire away
placement
was
was
meets
and
the
aerobrake.
options
were
the aerobrake. a side-firing
design
For these
reasons,
the
chosen.
is the side-firing
other
from
rejected
of the symmetric
lift at zero angle of attack. and the asymmetric shape
engines.
Consideration
doors in the aerobrake then retract during on the surface of the aerobrake causing
Two
or engines 2.2
design
of this configuration
failure
Figure
characteristic
aerobrake
engines that fire through doors create discontinuities
is raked at an angle to provide the high edge-heating effects
available:
Since
crew safety
engine
requirements
engines
orientation
most
was
also
aeromaneuvering, excessive thermal
that fire through is paramount,
was
effectively
chosen.
and
to
the aerobrake
this type of engine The
was
given
but these loads and
configuration
therefore
in
chosen
for
development. 2.2 Configuration 2.2.1
Structural
There
are
Design
numerous
including
propellant
requirements atmospheric
2.2.2
Initial
Two
preliminary
payload
bay crew
plane,
were
are shown meets
the (35'
and
the entire
same
plate
2.5 features and
mounted
the hydrogen x 5.4')
tanks
makes
the payload an external
to mission
SPARC
changes
configuration
to variable
scenario,
and control
vehicle
a separate
payload
a center
of gravity
of the vehicle
and
allowance
which
set of avionics
orientation
payload
volume
requirements
length,
6' radius), bay.
and
during
for
the
emergency
plane,
located
structure
utilize
the offset between
skirt
mission
which
the tanks.
tanks.
The crew
tanks
tanks
aerobrake.
The
an even
to an attachment is offset
module
mission.
from
(11'
is connected
to provide
the
situa-
are all mounted
tank
crew
the
to shield
to provide
oxygen
module
for the expendable
the offset
bay of the
is connected The
a large
to connect
an emergency
and payload of the
area, and a rectangular
it to be removed
is positioned
module,
the
rectangular
mission,
is necessary
is considered
within
one
structure
the hydrogen
surrounding
the aerobrake
between enable
bay for each
largest
truss
aerobrake
at the bottom
surrounding
2.4 features
of the
a box-like version
crew
of the structure
2.5. Figure
A 58'-diameter
The expendable
is lost. The tanks,
payload
to the truss to better
for the Figure
heating.
the vehicle
considered 2.4 and
the payload
use of the space modules
of the flexibility
For each
for stability
in Figure
engines are mounted to the truss structure thrust distribution about the x-axis. Figure
version.
to provide
adaptability
design
Configurations
from aerodynamic
tion in which
in the
accommodations,
criteria.
module
module,
components in the
which
crew
of an expendable
configurations
crew
considered
size,
is desired
Aerobrake
and they
were
tank
Furthermore,
Fixed
cylindrical
that and
the necessity
are design
aerobrake,
D
factors
as possible pass.
situations
Considerations
mass
and
as far forward
tanks,
Selection
much
In such
the necessary
x 6.5' like
a case, control
9
Figu£e2.4 Configuration
58'
10
Figure 2.5 Configuration I!
A
50' \ PAYLOAD
PLATE/ /
28,000lbs.
