Unique Support Structure USS 02 Mechanical Design

1
Unique Support Structure (USS) - 02 Mechanical
Design

• Ross A. Harold
• Lockheed Martin Space Operations

2
USS-02 Requirements

• Integrate the AMS-02 Experiment to Shuttle and
  Station per Program Requirements Document and
  Project Management Plan for the AMS Payload
  Integration Hardware (PIH) (JSC-27296 /
  LMSEAT-31947)
• Interface with the AMS-02 Experiment Components
  per the AMS-02 Experiment/PIH Interfaces
  (JSC-29095)

3
USS-02 Requirements

• Structural requirements per AMS Structural
  Verification Plan (SVP) JSC 28792
• Corrosion Control Plan developed with Rajib
  Dasgupta of LM/Materials
• Interface with Space Shuttle per the Space
  Shuttle Core ICD (NSTS-21000-IDD-ISS)
• Interface with ISS per the Attached Payload
  Interface Requirements Document (SSP57003)

4
USS-02 Requirements

• Protect payload safety critical components from
  Micro Meteoroid and Orbital Debris (MMOD) per
  SSP57003

5
USS-02 Design Features

• All aluminum alloy primary structure
• Riveted box beam and joint construction
• Comprised of 4 bolted separable subassemblies
• Friction Stir Welded (FSW) closed section beams

6
USS-02 Design Features

• The VC is an integral, load carrying part of the
  structure
• Experiment components are bolted directly to the
  USS-02/VC
• "Generic" hole pattern allows for experiment
  integration flexibility

7
AMS-02 Experiment Interfaces

• Transition Radiation Detector (TRD) Upper Time
  of Flight (TOF)
• 4 dedicated interfaces to Upper VC Joints.
• Brackets mounted to VC joints then TOF and TRD
  mounted to joints.
• Thermally isolating shims between bracket and VC
  joint.
• Silicon Tracker (Tracker)
• 8 dedicated interfaces to VC Conical Flange near
  Inner Cylinder

8
AMS-02 Experiment Interfaces

• Anticoincidence Counter (ACC)
• 32 dedicated interfaces to the VC Conical Flange
  near inner Cylinder
• Lower Time of Flight (TOF)
• 4 dedicated interfaces to the Lower VC Joint
• 4 dedicated interfaces to the Lower USS
  centerbody joints
• Ring Imaging Cherenkov Counter (RICH)
• 8 dedicated interfaces to Lower USS box beams

9
AMS-02 Experiment Interfaces

• Electromagnetic Calorimeter (ECAL)
• 4 dedicated interfaces to Lower USS centerbody
  joints
• Electronic Crates Thermal Control System (TCS)
  Radiators
• 6 interfaces to the USS-02 generic hole pattern
  on the Upper Lower Trunnion Bridge Beams, and
  Lower VC Joint

10
AMS-02 Experiment Interfaces

• Cryomagnet Avionics Box (CAB)
• 2 interfaces to the USS-02 generic hole pattern
  on the Upper Upper Trunnion Bridge Beams
• Tracker Thermal Control System (TTCS)
• Interfaces with Lower Trunnion Bridge Beams
• TRD Gas Supply (UGBS)
• 2 interfaces to the Upper Lower Trunnion Bridge
  Beams

11
AMS-02 Experiment Interfaces

• Cryomagnet Discharge System
• 8 interfaces to both of the Y Sill Joints
• Cryomagnet Uninterruptible Power Source (UPS)
• 2 crates mounted to the -X, Y Upper VC Joint
• Cryomagnet Warm Helium Crate
• Mounted to the -X, Y Lower Trunnion Bridge Beam

12
Shuttle Interfaces

• 4 Sill Trunnions
• 2 Primary, orbiter coordinates Xo 1155.53
• 2 Secondary, orbiter coordinates Xo 1234.20
• 1 Keel Trunnion
• Orbiter coordinates Xo 1167.33
• Offset from primary trunnions 11.80" in Xo
• 4 Scuff Plates

13
Shuttle Interfaces

• Remotely Operated Electrical Umbilical (ROEU)
  Payload Disconnect Assembly (PDA)
• PDA centerline orbiter coordinates Xo 1100.47
• Wire harness clamp mounted facing outboard (Yo
  69.20)
• Flight Releasable Grapple Fixture (FRGF)

14
ISS Interfaces

• Payload Attach System (PAS)
• Guide Pins
• Unloadable/Releasable Capture Bar
• Scuff Plates
• Umbilical Mechanism Assembly (UMA)
• EVA Contingency Release Bolts
• EVA Contingency Release Capture Bar Handle
• Berthing Cues System (BCS) Camera

15
ISS Interfaces

• EVA Interface Panel EVA Connectors
• Power Video Grapple Fixture (PVGF)

16
USS-02 Structural Design

• Materials
• Trunnions and Shear Pins made from Custom 455
  H1000 Stainless Steel
• All joints are machined from aluminum alloy plate
  7050-T7451 (8" thick maximum)
• Lower USS-02 Sill Tubes, Centerbody Tubes, and
  Keel Tubes are made from the same lot of extruded
  aluminum alloy 7075-T74511 4" x 4" box beams as
  used on AMS-01.

17
USS-02 Structural Design

• Materials
• Diagonal Tubes made from 6061-T6 Extruded
  Aluminum alloy round tube
• Custom made Eccentric Bushings made from Aluminum
  Bronze
• All bolts, washers, and inserts are A-286
  Stainless Steel Alloy
• Shims made from Aluminum Alloy or Stainless Steel
  laminated shim stock

18
USS-02 Structural Design

• Materials
• Thermal isolating shims made from G-10 glass
  fiber laminated epoxy sheet (non-structural
  interfaces) or titanium sheet (structural
  interfaces).
• Rivets are NAS1398 series Monel or aluminum alloy.

19
USS-02 Structural Design

• Materials
• Self-aligning, self-lubricating, rod-end bearings
  are per MIL-B-81935 except
• Body 15-5PH, heat treated to condition H1025,
  passivated
• Ball 13-8Mo per AMS5629 with PTFE liner
• Race 17-4PH Stainless Steel

20
USS-02 Structural Design

• Trunnion Bridge Beams are Friction Stir Welded
  (FSW) box beams.
• Made from 7050-T0 plate
• Machined into two c-channel profiles
• FSW c-channels together to form a closed section
  box beam
• Post weld heat treated to the 7050-T73 condition
• FSW Process developed by Dan Rybicki JSC's ES
  Division

21
USS-02 Structural Design

• USS will be assembled upside down on the Assembly
  Fixture
• The Assembly Fixture replicates the interfaces of
  the Orbiter, VC and Experiment.
• Laser Tracker system will be used to maintain
  /- .010 precision to all interfaces.