Transcript Boiler Plate - Center for Astrophysics and Space Astronomy

Aug.19, 1999
George T. Roach
Integration Mission Design Center
NASA- GSFC
Code 543
Greenbelt, MD. 20771
301-286-2213
FAX 301-286-0343
E-Mail- [email protected]
Overview
• See if the dual spacecraft MAXIM configuration can be accommodated on a
single U.S. launch vehicle.
• Present a trade study comparing launch vehicles
• Present a concept that can meet mission requirements:
- Launch and orbit configuration
* Payload Instruments placements
* Structural mass summary
Spacecraft Mechanical Overview
• The baseline will be 2 Mission Unique Spacecraft ( MUS):
- Use of commercial parts and subsystems
- Accommodate the Detector Instruments and Optic Instruments
- Provide accommodations for a dual wing fixed solar array panels (total area= 6 meters ^2),
for the detector spacecraft.
- Provide accommodations for a fixed semi ring solar array panels (total area= 7 meters ^2),
for the optic spacecraft.
- The Optics spacecraft will interface to the Delta IV 5m dia. X 19.8 m long/ 17362 PAF
- The core structure will be made-up of aluminum honeycomb panels, aluminum truss, fittings,
brackets, diagonals and stringers.
Note- Due to the time element in preparing this presentation, I baseline aluminum material, however
due to the thermal sensitivity the structure material most likely would be composite. This would increase
cost and fabrication complexity, but would decrease mass. In either case, this is do-able in the design.
Launch Vehicle Trade Study
Based on Performance to C3 = 0; Mass = 4100kg;
Volume = 3.25 dia X 14.5 m
Access Mode Candidates

No Foreign Launch Vehicles Investigated (Space Policy-buy American)

Delta II and III do not meet C3 performance requirements

Delta IV:
 S,M, M+(4,2 &5,2 config.) do not meet C3 performance requirements
 M+ (5,4) config. meets C3 performance requirements but does not meet fairing volume envelope
 Heavy meets C3 performance requirements and fairing volume envelope

Atlas V:
 Core and core plus 2 strap-on do not meet C3 performance requirements
 Core plus 4 or 5 strap-on meet C3 performance requirements but does not meet fairing volume
envelop for the 5m short or medium PLF
 Heavy meets C3 performance requirements and fairing volume envelope

Lockheed Martin studying (via a KSC task) whether the stretched version of the medium PLF (5.4 m dia.X
26.5 m) can be used on the medium EELV launch vehicles (Results expected in a couple of months)

Boeing studying (via a KSC task) whether the heavy fairing (5 m dia. X 19.8 m) can be used on the medium
EELV launch vehicles (Results expected in a couple of months)
Launch Vehicle Performance
Vehicle
Capacit yt o GTO ( kg)
1
P/L W eight to C3=0 ( kg)
Comments
Del ta II/7920
Del ta II/7925
1300
1869
910
1308.3
Esti mated (70% of GTO)
Esti mated (70% of GTO)
Del ta III/6 GEMs
Del ta III/9 GEMs
2690
3810
1883
2667
Esti mated (70% of GTO)
Esti mated (70% of GTO)
2180
3900
5300
4350
6120
14200
1526
2730
3849
2786
4159
9306
Esti mated (70% of GTO)
Esti mated (70% of GTO)
(C3 = 0.3)
(C3 = 0.3)
(C3 = 0.3)
(C3 = 0.3)
Atlas V (MLV-A Government)
5380
3465
Atlas V Core (MLV-G Comercial)
4100
2698
P/L weig ht may be based on 5m short PLF
Core + 2 Strap-ons
6000
4149
P/L weig ht may be based on 5m short PLF
Core + 4 Strap-ons
7600
5278
P/L weig ht may be based on 5m short PLF
Core + 5 Strap-ons
8200
12485
5649
8040
P/L weig ht may be based on 5m short PLF
Del ta IV S
Del ta IV M
Del ta IV M+ (4,2)
Del ta IV M+ (5,2)
Del ta IV M+ (5,4)
Del ta IV H
Baselined 8/18/99
Atlas V Heavy
1
2
= Val ue fr om ISIR Report or Boeing/LMA g ener ated information
= Going to 5 m medium PLF, expected performance degr adation between 59.3 to 66.6 kg
2
2
2
2
LAUNCH VEHICLE
For this study the Delta IV/5m/19.8m was baseline
Launch vehicle will:
• Meet lift-off (mass) requirements +20%
(actually approx.. 50%, as of 8/19 AM)
• Meets volume requirements
Delta IV (H) 5m diameter x 19.8m long
Baffling
Payload
Spacecraft
Detector Spacecraft
(2.2m)
16.4 m
Launch Fairing Removed
15.5 m
LAUNCH
CONFIGURATION
Optics Instruments
(10m)
Optic Spacecraft Systems
(2.2m)
Detector Spacecraft
Solar Array
(7 m^2, projected area)
ORBIT CONFIGURATION
Optic Spacecraft
OPTIC SPACECRAFT (DIFFERENT VIEWS)
Different views
of the Optic spacecraft
Spacecraft subSystem
This view the spacecraft subsystems removed
OPTIC SPACECRAFT (ON ORBIT)
Propulsion Tanks
(4)
Solar Array
This is the far end away from
the detector spacecraft
This is the viewing end toward
the detector spacecraft
Note- The X-Ray Interferometer
has been removed form clarity
Walter Telescope
Aspect Interferometer
OPTIC Instrument
with support structure
X-Ray Interferometer
Range lasers (4)
OPTIC Instrument
(rotated)
Walter Telescope Electronics
Aspect Interferometer
OPTIC INSTRUMENT
Payload
DETECTOR SPACECRAFT
Fixed
Solar Array
(6m^2 shown)
Stowed
Orbit
Spacecraft
Spacecraft Subsystems are mounted in
this volume
Range Sensors and Baffle
Detector / CCD/ QC Cryogenics
and Baffle
DETECTOR PAYLOAD
INSTRUMENTS
Detector Baffle
Range Sensors Baffle
Detector / CCD/ QC Cryogenics
Payload Volume
Range Sensors
Enlarged View of Baffle
DETECTOR SPACECRAFT
TOP LEVEL SPACECRAFT BUS MASS SUMMARY
Mass(kg)/per
unit
Structure
Structure (Optics SC) :
Cylinder (3m dia, x 10m long)
Misc Attachment, Cylinder
Stiffening Structure (Cylinder / Detector S/C)
Thrust Tube
Gusset (8)
Misc Attachment, Thrust Tube/Gussets
Structure (Detector SC) :
Core Structure - Detector S/C
Misc Attachment
Interface Truss Structure
906.6
554.0
110.8
143.0
58.0
34.0
6.8
145.2
40.0
10.0
95.2
Total Mass(kg)
1051.7
TOP LEVEL SPACECRAFT BUS MASS SUMMARY
Mass(kg)/per
unit
737.5
Structure (composite)
Structure (Optics SC) :
Cylinder (3m dia, x 10m long)
Misc Attachment, Cylinder
Stiffening Structure (Cylinder / Detector S/C)
Thrust Tube
Gusset (8)
Misc Attachment, Thrust Tube/Gussets
Structure (Detector SC) :
Core Structure - Detector S/C
Misc Attachment
Interface Truss Structure
Total Mass(kg)
638.3
365.6
110.8
94.4
38.3
22.4
6.8
99.2
26.4
10
62.8
Amendment 8/20/99
SYSTEM LEVEL MASS
SUMMARY
(preliminary)
Amendment 8/20/99
Conclusions:
• Mechanically this mission is feasible:
- As of this phase of the study the dual spacecraft configuration can be accommodated
on a single launch vehicle.
* Using the Delta IV, DIV-H 5 m diameter x 19.8 m long fairing
* Meets the minimum 20% mass margin
* Meets the volume margin
• Launching two spacecraft always lower the frequencies due to the two separations, however with
the extra mass margins you can increase the structural integrity of the structure by
adding structural members and increasing cross sectional areas.
• The separation system between the Optic spacecraft and Detector spacecraft has yet to be worked out.
This is not a trivial matter, I’m not aware of a 3 m + diameter marman ring at this time.
Note- According with the Titan IV folks, anything that fit's inside this fairing the PAF can handle
with reference to C.G. locations.