1. Relator: Prof. R. Barboni
Co-relators: Ing. G. Perrotta
Ing. M. de Benedetti
Study and structural analysis of a
new configuration for a
micro/nano/picosatellite dispenser
for the Vega launcher
Università degli Studi di Roma
"La Sapienza"
Engineering
Astronautic & Aerospace Engineering Department
Student: Stefano Coltellacci

2. Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci
Summary
Trade off
Results & Conclusions
Classical and FEM Structural Analysis
Search for adequate configurations
System Analysis

3. Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci
Trade off between small satellite dispensers of common use
on various launch systems
Dispenser for Globalstar
spacecrafts on DELTA II
Dispenser for GRACE spacecrafts
on Rockot
Dispenser IKAR for
Globalstar spacecraft on
Soyuz TM/Fregat
Dispenser JAWSAT on Minotaur
Dispenser ASAP 5 on Ariane 5

4. System Analysis
 Preliminary cost-effectiveness
analysis
 Typical payload
hosted
Dual Launch Configuration
(SYLDA5 on Ariane 5-like)
 Payload
envelope analysis
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

5. 3,2 m
3,1 m
0,6 m
2,3 m
Definition of the Dual
Launch System
Picosatellites inside
P-POD
Nanosatellites
Microsatellites
Different vertical levels for
different kind of payloads
Minisat
1.0 m
1.0 m
0.6 m
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

6. Configurations, trade off
Two final configurations
Al-built boxed
structure reinforced
with column
JAWSAT-like Al-built
ISOGRID structure
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

7. Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci
Configuration 1
Al-built boxed structure reinforced with
CFRP column (filament winding
technique)

8. Configuration 2
Al-built boxed structure reinforced with
CFRP column (filament winding
technique) filled with Rohacell WF 51
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

9. Configuration 3
Al-built boxed structure reinforced with CFRP
sandwich column with Rohacell WF 51 core
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

10. Configuration 4
Al-built boxed structure reinforced with
CFRP column (ISOGRID technique)
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

11. Configuration 5
JAWSAT-like Al-built ISOGRID structure
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

12. Weight of the dispenser structure(W)
Heritage (HER)
Flexibility of project (FP)
Capability to host a large variety of
payloads (CVP)
Ability to maximize payload weight (MPW)
Availability of cots parts (COTS)
Simplicity of project (SP)
Parameters for comparison
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

13. Comparison of various configurations
W MPW CVP FP HER COTS SP
Configuration [1] 46Kg +++ ++ + ++++ ++++ ++++
Configuration [2] 54.5Kg +++ +++ +++ +++ ++++ +++
Configuration [3] 50.5Kg +++ +++ ++++ +++ ++++ +++
Configuration [4] 44.5Kg +++ ++ - + - -
Configuration [5] 75 Kg ++ ++++ - + - -
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

14. Configuration 3 winner
External boxed structure
material: Al 7075-T651
CFRP sandwich column with
Rohacell WF 51 foam core and
7-plies CFRP skins, Hexcell
AS4C 10K
Adapter with 26-plies sym
CFRP laminate, Hexcell AS4C
10K
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

15. Classical structural analysis
Wrinkling critical load
Eulerian critical load
Hand calculations of critical buckling load and
comparison with inertial load in the launch
environment
Simplified approach on the most
critical structural element: the
sandwich column
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

16. Launch Environment
d p z cP m m n
P=103.88 KN
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

17. Eulerian critical load
Wrinkling critical load
2
2
4
572
607.644
cr
cr
cr
cr
EI
P
L
P KN
P
MPa
A
2 4 22
2
11 12 66 222 2 2 2
21
2 2
548
515.85
c
wr
f f c
wr
wr
E aa a
D m D D D
t a b m b m t t
MPa
P KN
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci
Compliance with Launch environment

18. FEM Structural Analysis
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

19. Nastran FEM Model
4053 DoF
1020 Elements
891 Nodes
CQUAD4 and CTRIA3
Elements
18 elements CONM2
spacecrafts simulating
connected to the main
structure with RBE2
elements
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

20. Static Analysis for 1g lateral
accelerations and 10g longitudinals
(SOL 101)
Max Von Mises Stress
15.5 MPa@Nd 255
(Al-boxed structure)
Von Mises Stress
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

21. Interlaminar Analysis for shear stress
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

22. Ply
(Shear stress)@node
[Mpa] Ply
(Shear stress)@node
[Mpa]
1 13.6@Nd420 14 9.82@Nd1
2 13.5@Nd419 15 13.1@Nd419
3 11.3@Nd428 16 13.4@Nd420
4 11.1@Nd418 17 12.8@Nd420
5 13.6@Nd420 18 12.8@Nd420
6 13.4@Nd419 19 7.93@Nd434
7 7.9@Nd434 20 7.94@Nd434
8 7.9@Nd434 21 13@Nd419
9 13@Nd419 22 13.3@Nd420
10 13@Nd419 23 10.8@Nd418
11 13.5@Nd420 24 11.1@Nd418
12 13.2@Nd419 25 12.9@Nd419
13 8.77@Nd1 26 13.2@Nd420
Adapter
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci
Interlaminar Analysis for shear stress

23. CFRP Sandwich
column
Ply
(Shear stress)@node
[Mpa]
1 3.72@Nd15
2 3.76@Nd15
3 3.41@Nd46407
4 3.59@Nd46319
5 3.62@Nd15
6 3.66@Nd15
7 4.7@Nd15
(CORE)
8 0.0482@Nd111
9 7.02@Nd11332
10 10.6@Nd14050
11 10.6@Nd14050
12 10@Nd14050
13 9.69@Nd14050
14 11.2@Nd14050
15 11.2@Nd14050
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci
Interlaminar Analysis for shear stress

24. Hoffman Failure Indices
Element Fail. Th. Ply Failure Index
481 HOFFMAN 18 0,0153
482 HOFFMAN 9 0,0157
483 HOFFMAN 25 0,0128
485 HOFFMAN 10 0,0093
486 HOFFMAN 19 0,0163
487 HOFFMAN 8 0,0175
493 HOFFMAN 9 0,0166
494 HOFFMAN 9 0,0124
494 HOFFMAN 10 0,0124
496 HOFFMAN 19 0,0124
496 HOFFMAN 20 0,0124
Element Fail. Th. Ply Failure Index
2446 HOFFMAN 15 0,0158
3211 HOFFMAN 15 0,0154
3212 HOFFMAN 15 0,0157
3227 HOFFMAN 15 0,0103
3268 HOFFMAN 2 0,0115
3289 HOFFMAN 14 0,0182
3290 HOFFMAN 1 0,0143
3317 HOFFMAN 15 0,0229
3337 HOFFMAN 1 0,0108
3379 HOFFMAN 15 0,0174
3380 HOFFMAN 15 0,0167
CFRP Sandwich columnAdapter
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

25. Modal analysis (SOL 101)
First 100 vibrational modes
determination and compliance
verification with launcher vibrational
modes
Modal participation Mass Factors
determinations to verify the “real
weight” of each vibrational mode
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

26. Most significant vibrational modes
Mode Frequency (Hz) Direction
1 18,731 Tx,Rx,Ry
2 18,731 Ty,Rx,Ry
3 21,223 Rz
29 74,18916 Ty
30 74,19931 Tx
48 94,29205 Ty
49 94,29256 Tx
93 178,3847 Tz
Compliance with VEGA launcher:
1° lateral mode> 15 Hz
1° longitudinal mode> 35 Hz
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

27. Buckling Analysis (SOL 105)
First eigenvalue for
Buckling made a critial
buckling load of 713.1 KN
Critical stress 671 Mpa (as
previded in hand
calculations)
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

28. Sinusoidal vibrations analysis
(SOL 108)
Mode Frequency (Hz) Direction Stress [Mpa]
1 18,731 Tx,Rx,Ry 63.8@Nd421x18Hz
2 18,731 Ty,Rx,Ry 172@Nd421x19Hz
3 21,223 Rz 33.2@Nd421x20Hz
17.3@Nd421x21Hz
29 74,18916 Ty 49.3@Nd7646x73Hz
30 74,19931 Tx 324@Nd7646x74Hz
48 94,29205 Ty 40.3@Nd35x93Hz
49 94,29256 Tx 373@Nd200x94Hz
33.4@Nd33368x95Hz
Von Mises Stress
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

29. Most stressed nodes analysis
Displacements
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

30. Von Mises Stress
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci
Most stressed nodes analysis

31. Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci
94 Hz structure “breathing” mode
…we have a problem!

32. Waiver to limitate displacements
CFRP ribs inside the sandwich column in the most
displaced locations
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci
CFRP ribs inside the sandwich column in the most
displaced locations

33. Most stressed nodes analysis, waiver
Displacements
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci
More acceptable values

34. Von Mises Stress
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci
Most stressed nodes analysis, waiver
More acceptable values

35. Random analysis (SOL 111)
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

36. Analisi RMS
RMS Analysis Tx NASTRAN output
Total Displacements [m] 6.84E-5m@Nd8494
Von Mises Stress[Mpa] 0.39Mpa@Nd8648
Total accelerations [g] 24.9g@Nd622
RMS Analysis Ty NASTRAN output
Total Displacements [m] 7.26E-5m@Nd6888
Von Mises Stress[Mpa] 0.41Mpa@Nd227
Total accelerations [g] 26.9g@Nd532
RMS Analysis Tz NASTRAN output
Total Displacements [m] 2.08E-5m@Nd1980
Von Mises Stress[Mpa] 0.42Mpa@Nd460
Total accelerations [g] 15.1g@Nd395
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

37. PSD determination as a payload input (MSC RANDOM)
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci

38. GRMS Y value GRMS Z value
Microsatellite 2.577GRMS@Nd655 5.751GRMS@Nd655
Nanosatellite “low” 3.095GRMS@Nd669 7.43GRMS@Nd669
Nanosatellite “high” 3.59GRMS@Nd664 7.806GRMS@Nd664
P-POD 5.577GRMS@Nd670 7.982GRMS@Nd670
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci
PSD determination as a payload input (MSC RANDOM)

39. Results & Conclusions
The mechanical model verified the first
compliance of structural I/F requirements in the
launch environment for the VEGA launcher
Next steps, structural tests on a sandwich column
to update the FEM model for a non-linear analysis
After a long tradeoff, this study proposes a
simple structure for a dispenser realized with
COTS materials
Study and structural analysis of a new configuration for a micro/nano/picosatellite dispenser for the Vega launcher
Stefano Coltellacci