September 2011
Rich Northrop The University of Chicago
1

Crest Weight Profile
Revised 7.19.2011 RN
Science Channel w/top Veto
Side,inside,& bottom veto w/supports
Gondola structure
Electronics
Solar panels
Batteries & controller
Thermal control
Flight rigging
376 (actual) x 8 channels
370
795
270
188
198
125
110
CSBF - above pin
CSBF - below pin
Antenna boom
Rotator
Ballast
Crush pad
Total estimated Science/Gondola Instrument
647
675
12
177
500 (TBD)
0 (TBD)
Total estimated weight
3008
370
795
270
188
198
125
110
5064 lbs. (2297 kg)
647
675
12
177
500
0
7075 lbs. (3209 kg)
2

3

4

Rev.A 9.5.11 RN
Crest Flight Rigging Components
Roundsling (SpanSet RCE 240) 21,200 lb.
Vertical rated capacity & 5:1 design factor
Crosby Sling Shakle (S-253) 17,500 lb.
rated capacity & 5:1 design factor
Crosby Swivel Hoist Ring (HR-125)
8,000 lb. rated capacity & 5:1 design factor
5

Rule: For multiple-cable suspensions, each cable must have an ultimate strength greater than five times the weight of the payload divided by the sine of the angle that the cable makes with horizontal in a normal flight configuration. Cable terminations, cable attachments, and gondola structural members must be capable of withstanding the load described above.
Total suspended load = 6,088 lbs. x 5 divided by sine 60 degrees = 35,150 lbs.
6

Gondola Design - Suspension Loading
Rule: A load 10 times the weight of the payload applied vertically at the suspension point.
Fixed Point
60 deg.
10 G Body Load
Total suspended load = 6,088 lbs. x 10 = 60,880 lbs.
60,880 lbs. divided by 4 = 15,220 lbs. @ 60 deg.
7

3/8 – 16 Grade 8 Bolts - 10 total
Stress area = .0775 sq. in. each
Vertical load (each corner) = 35,150 lbs.
Bolt shear =
35,150 lbs. / .0775 (10 bolts) =
45,355 psi < 90,000 Ultimate shear
8

Rule: A load five times the weight of the payload applied at the suspension point and
45 degrees to the vertical. This load factor must be accounted for in the direction perpendicular to the gondola’s short side, perpendicular to the gondola’s long side, and in the direction of the major rigid support member at the top of the gondola structure. If flexible cable suspension systems are used, they must be able to withstand uneven loading caused by cable buckling.
5 G Weight of gondola
45 deg.
Fixed Corner
Fixed Corner
Fixed Corner
Total suspended load = 6,088 lbs. x 5 = 30,440 lbs.
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10

New slides added on Dec. 8, 2011 for teleconference
11

Image 61
LongColumnT2
Loading reference only
12

Primary Gondola
13

Image 26
CornerChannelAngle
Image 17
CenterBeam
Image 14
CenterBeamAngle
14

15