MW12

1
Observatory Configuration
Telescope
The observatory is ?4m tall and has a mass of
?865kg
Solar Panel Shield
Outer Shell
Solar Panel
Spacecraft Shield
Spacecraft Bus

Star Trackers and
Inertial Reference Units
Low Gain Antennae
High Gain Antenna
2
Observatory Cutaway
The observatory is ?4m tall and has a mass of
?865kg
Telescope
Outer Shell
Cryostat Aperture Door
Solar Panel
Multiple Instrument Chamber
Solar Panel Shield
Cryostat Vacuum Shell
Helium Tank
CTA Support Truss
Spacecraft Shield
Nitrogen Tank
Star Tracker and IRU
Spacecraft Bus
Battery
High Gain Antenna
3
Cryogenic Telescope AssemblyCompleted At Ball
Aerospace
4
SIRTF Family Portrait
IRS
MIPS
IRAC
5
SIRTF Telescope Installation
6
Completed Cryostat
7
Primary Mirror Prior to Integration Into Chamber
8
SIRTF Flight Primary Mirror Exceeds Cold Figure
Requirements
Mirror meets spec on rms surface figure(0.067µm
rms compared to 0.075µm) over the entire clear
aperture
9
Warm Launch Architecture in Solar Orbit Leads to
Lower Mass, More Efficient Cryogenic
SystemSIRTF Projected Lifetime is 5 yr with 350
liters of LHeISO achieved 2.5 yr with 2100
liters
Warm Launch Architecture
10
Heat Flow Map and Steady StateTemps for Nominal
Parameters
1 mW
12.8 W
Solar Panel 340K
Solar Panel Shield 115K
330 mW
Outer Shell 35K
Instrument Power
6 mW
84 mW
12.0 W
28 mW
2.0 mW
11 mW
Vapor Cooling
Upper Spacecraft
at .275 mg/s
2.5 mW
4.5 mW
Shield 118K
25 mW
17 mW
283 mW
0.9 W
2.9 W
2.6 W
Spacecraft 273K
11
Spacecraft Assembly atLockheed Martin
LGA Hats Couplers
RWA 3
CCU
Magnetic Current Sensors
12
Building Up the SpacecraftAttitude Reference
Bench