d on Node 1
serves as a primary docking port
for the Space Shuttle.
The U.S. Lab Module Destiny provides research
and habitation accommodations. Node 2 is to the
left; the truss is mounted atop the U.S. Lab; Node
1, Unity, is to the right; Node 3 and the Cupola are
below and to the right.

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A
rchitecture
D
esign
e
volution
Standoff
Module Design and Layout
Module Architecture
Early Concepts
Module Architecture Racks
with Four Structural Standoffs
Why does the ISS look the way it does ?
The design evolved over more than a decade. The modularity and size of the U.S.,
Japanese, and European elements were dictated by the use of the Space Shuttle as the
primary launch vehicle and by the requirement to make system components
maintainable and replaceable over a lifetime of many years.
When the Russians joined the program in 1993, their architecture was based
largely on the Mir and Salyut stations they had built earlier. Russian space vehicle
design philosophy has always emphasized automated operation and remote control.
The design of the interior of the U.S., European, and Japanese elements was dictated
by four specific principles: modularity, maintainability, reconfigurability, and accessibility.
Interior modular hardware racks and utilities could be replaced as needs or age dictated.
Racks could be swung away from the pressure hull of the module in case a meteoritic
puncture necessitated a repair. Crew preferences dictated that module
interiors be arranged with distinct floors, ceilings, and walls.
Architecture Design Evolution
1979Modules with
connecting tunnels.
1982Common
modules.
1986Habitation Module,
Laboratory Module
(Hab, Lab), spherical
Nodes, and tunnels.
,
1988Boeing
Phase C/D Nodes,
Logistics Module,
and 45-ft Hab,
Lab.
1992Freedom, Nodes,
Airlock, Logistics Module,
and 27-ft Hab, Lab.
Loft concept.
Modular outfitting.
Standard racks
(2 sizes).

Standard rack
(1 size).
Access to module
pressure shell.
Access to utility runs
in standoffs.
Intravehicular EMU access.
1980Horizontal
layout.
1980Horizontal
layout.
1980Vertical layout.
1986Central core.
1986Central beam.
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F
unctionAl
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Argo
B
lock

24
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


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S
ervice
M
odule

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The SM under construction at Khrunichev State
Research and Production Space Center in Moscow.
Leroy Chiao exercises in the SM.
R -3
Probe/Drogue Docking
System and Aft (Service
Module) Axial Docking Port
1
Airflow Vent
2
Body Mass Measurement
Device
3
Camera
4
Caution and Warning Panel,
Clock, and Monitors
5
Communications Panel
6
Condensate Water
Processor
7
Crew Sleep Compartment
8
Forward Docking Port
(to FGB)
9
Fuses
10 Galley Table
11 Integrated Control Panel
12 Lighting Control Panels
13 Maintenance Box
14 Nadir Docking Port
15 Navigation Sighting
Station
16 Night-Lights
17 Power Distribution Panel
18 Recessed Cavity & Valve
Panel
19 Smoke Detector
20 Solid Fuel Oxygen
Generators (SFOG)
21 Toru Rendezvous Control
Station
22 Toru Seat
23 Treadmill & Vibration
Isolation System
24 Vela Ergometer
25 Ventilation Screen
26 Vozdukh Control Panel
27 Waste Management
Compartment
28 Zenith Docking Port
29 Soyuz and Progress
Docking Port
1
Air Ducts
2
Communications Panel
3
Caution and Warning
Systems Panel
4
Contaminant Filters
5
Contingency Transfer (Water)
Container Bag
6
Contingency Transfer (Water)
Container Connections
7
Dust Collectors
8
Electrical Outlet
9
Flex Airduct Container
10 Fuse
11 Fuse Panels (behind
close-outs)
12 Gas Analyzer
13 Gas Mask
14 Handrail
15 Hatch Protection
16 Instrument Containers
17 Docking Port to PMA
18 Laptop Outlets
19 Lighting Panel
20 Lights
21 Nadir Docking Port
22 Onboard Documentation
23 Onboard Network Receptacle
Outlets
24 Pole and Hook
25 Portable Fans
26 Removable Fire Extinguisher
27 Power Outlet
28 Pressurized Valve Unit
29 Caution and Warning Panel
30 Smoke Detector
31 TV Outlet
32 Wipes/Filters


PMA NODE

FGB
1
1
PMA
Androgynous
Peripheral Docking
System and
Forward Axial
Docking Port
Primary
Propulsion
System
Propellant
Tanks
Micrometeorite
Protection
Nadir Docking
Port
Kurs Rendezvous
Antenna
Thermal
Control
Radiator
Attitude
Control
Engines
Attitude Control
Engines


Service
Progress
Module
FGB
Soyuz
To U.S. and
International
Modules
Research
Module
{

}
Multi-Purpose
Laboratory
{

1
2
3
6
7
8
9
10
11
12
13
15
16
23
19
20
20
22
24
26
27
29
5
32
31
1
14
25
30
16
28
30
23
18
4
21
17
Forward FGB
Docking Port
Luch
Satellite
Antenna
Zenith Docking Port
Kurs Rendezvous
Antenna
Maneuvering
Reboost Engines
(2,300 kgf each)
Igla
Rendezvous
Antenna
Attitude
Control Engines
(6 clusters,
32 engines,
14 kgf each)
2
3
4
5
5
6
8
9
10
11
13
15
16
17
20
21
22
23
24
25
27
28
14
1
7
19
12
26
29
18
Functional Cargo Block (FGB)
Zarya (Sunrise) and Russian Research Modules
NASA/Khrunichev Production Center
The FGB was the first element of the International Space Station, built in Russia under
a U.S. contract. During the early stages of ISS assembly, the FGB was self-contained,
providing power, communications, and attitude control functions. The FGB module
is now used primarily for storage and propulsion. The FGB was based on the modules
of Mir. The Russian Multipurpose Modules planned for the ISS will be based on the
FGB-2, a spare developed as a backup to the FGB. The Russian Research Module may
be based on the FGB design.
Length
12,990 m (42.6 ft)
Maximum diameter
4.1 m (13.5 ft)
Mass
24,968 kg (55,045 lb)
Pressurized volume
71.5 m
3
(2,525 ft
3
)
Solar array span
24.4 m (80 ft)
Array surface area
28 m
2
(301 ft
2
)
Power supply (avg.)
3 kW
Propellant mass
3,800 kg (8,377 lb)
Launch date
Nov. 20, 1998, on a
Proton rocket
The Service Module was the first fully Russian contribution to the ISS. The Module
provided the Stations early living quarters, life-support system, electrical power
distribution, data processing system, flight control system, and propulsion system.
Its communications system still enables remote command capabilities from
ground flight controllers. Although some of these systems were subse-
quently supplemented or replaced by later U.S. systems, the Service
Module remains the structural and functional center of the Russian
segment of the International Space Station.
Service Module (SM)
Zvezda (Star)
S.P. Korolev Rocket and Space Corporation Energia
(RSC Energia)
Length
13.1 m (43 ft)
Diameter
4.2 m (13.5 ft)
Wingspan
29.7 m (97.5 ft)
Weight
24,604 kg (54,242 lb)
Launch date
July 11, 2000,
on a Proton rocket
Attitude control
32 engines
Orbital maneuvering
2 engines

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N
odes

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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P
ressurized
M
atiNg
a
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26
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Nodes 2 and 3 have
locations for 8 racks.
Placement of 4
racks in Node 1.
Node 1 shown
shortly after
deployment in orbit.
PMA 2 is to the left.
Node 1 is shown with the Russian
segment FGB to the right (aft), the
U.S. Lab to the left (fore), the U.S.
Airlock at the bottom (starboard),
and PMA 3 at the top (port).
Radial Common Berthing
Mechanism and Hatch (4 places,
with 50-in hatch width)
Axial Common Berthing Mechanism
and Hatch (2, one on each end)

Interior of Node 1 deck
(port and aft shown).
Radial Hatches
Axial
Hatches
Interior of Node 1 (ceiling, port,
and forward endcone shown).
Standard
Rack Bays
Interior view of Node 1.
PMA structure shows
a series of offset
aluminum cylinders.
Androgynous Docking
Port for FGB, Space
Shuttle, and CEV
(30-in hatch width)
PMA 2 on the forward berthing
ring of Node 1.
Nodes
Node 1 (Unity), Node 2, Node 3
NASA/Boeing, Alcatel Alenia Space
Nodes are U.S. modules that connect the elements of the ISS. Node
1, called Unity,
was the first U.S.-built element of the ISS that was launched, and it connects the U.S.
and Russian segments of the ISS.
Node
2 will connect the U.S., European, and Japanese laboratories. Node 3, still
in development, will provide additional habitation functions, including hygiene and
sleeping compartments. Nodes
2 and 3 are slightly longer than Node 1.
Length of
Node 1
Node 2, 3
5.5 m (18 ft)
6.1 m (21 ft)
Width (diameter)
4.3 m (14 ft)
Mass of
Node 1
Node 2
Node 3
11,895 kg (26,225 lb)
13,508 kg (29,781 lb)
TBD
Exterior
Aluminum cylindrical
sections, 2 endcones
Number of racks for
Node 1
Node 23

4
8
Node 1 launch date
Dec. 1998, ISS-2A,
STS-88
NODE 1s
six ports provide berthing connections
to the Z
1
Truss, U.S. Lab Module, Airlock,
Node
3
, and the PMAs. The Multi-Purpose
Logistics Module (MPLM) logistics carriers are
berthed at Node
1
during some Shuttle visits.
NODE 2
is a utility hub, providing air, electrical
power, water, and other systems essential to
support life on
the ISS. It distributes
resources from the truss structure
and the U.S. Laboratory to the ESA
Columbus Lab and Japanese JEM lab.
NODE 3
will be attached to the nadir (Earth-
facing) r