Hawkeye Mechanical Design Snapshot Compiled March 10th, 2016

Overall Mechanical Requirements House the optics Connect the instrument to rails and spacecraft Fit within overall length of payload. Position CCDs and get their heat out Provide a shutter for dark frames Support the Finder Scope assembly Maintain a light tight package around sensors Support the circuit boards Implement materials and finish for thermal control Distribute heat by creating thermal paths Meet weight budget

Optical Design Concept – 8 Arrays

Mechanical Design Concept Science Apertures Finderscope Aperture Solenoids for shutter Shutter Vane Interface to CubeSat Circuit Cards Debug Port

Payload Illustration Within Rails Without Rails

Payload Length Payload length is at 4.200 inches or 106.68 mm A protrusion of 0.150 inches or 3.8 mm is needed for finderscope board. This protrusion will lie within the SIR bracket.

Payload to Platform Interface 16x Rail Attachment (4 per rail) 4x End Plate attachment

Interface to Platform Endplate Location of four attachment holes on Endplate. We will provide four M2 threaded holes. Holes not symmetric. Will need to know final orientation. 1 2 3 4

Interface to Platform Rails Total of 16 attachment points to Platform rails. We will provide 16 threaded M2 holes. Eight holes per each of two End Caps.

Payload to Platform Interface Based on the configuration of the Payload it was determined that directly mounting to the Platform rails was the best option. Mounting locations based on solid models provided by Clyde Space. Areas requiring clearance such as protruding screw heads on the SIR mounting brackets have been noted. Clyde Space requires a 1 mm clearance between Payload and Platform structure for vibration purposes.

Interference Clearance Clearance of 3.5 mm for four stack termination screws will be provided to clear screw head height of 2.5mm. This screw is located on the Clyde Space mounting bracket.

Interface Issues to Address Space and location of cable routing needs to be determined. Due to the non symmetric mounting holes on the End Panel and SIR Mounting Bracket, orientation of those pieces will need to be communicated so we can place our attachment points. The location of the sun sensor will have to be determined so we can design for it. It was mentioned that a smaller sensor might be used.

CCD Parts Stack, Top to Bottom CCD Stack Assembly CCD Parts Stack, Top to Bottom Lightshield * CCD Pedestal CCD Board * Held in by two 2-56 flat head Phillips screws using two threaded swages.

“Finderscope” Assembly Field Of View RG 830 Filter Lens Elements Micron 752x480 Pixel CMOS Sensor

Circuit Card Configuration Motherboard Picozed Board CCD Board Finderscope sensor Analog Board Interface Board

Circuit Board Placement Circuit boards will be attached directly to the housing or to each other by way of threaded stand offs and threaded swages Board spacing was based on connector spacing and board proximity to mechanical components and payload edges. Space is very limited.

Thermal Considerations Heat sinking rails will be used on the Analog and Mother board. Heat sinking will be needed to dissipate heat from four CCDs. Additional heat sinking will be required on the PicoZed board due to heat produced by Zynq processor. We plan to create a heat sinking surface on main housing that contacts processor.

Materials and Finish The majority of parts will be made of standard Aluminum 6061-T6. The optic barrels will be made of Stainless Steel due to the lower expansion properties. Exterior surfaces will be gold plated to take advantage of the thermal properties. These include the end pieces and cover plates.

Payload Weight Breakdown qty lbs. Total lbs lbs Kg   Shutter Solenoids 2 0.049 0.098 Solenoid Bracket 1 0.014 Vane 0.0118 Arm 0.0026 Brackets 0.0067 0.0134 Fasteners (ss) 8 0.0024 0.0192 0.159 0.072121 Optics Scrambler Wedge 0.0079 0.0632 Filter 2 0.0039 0.0312 Lens 1 0.00194 0.01552 Lens 2 0.0013 0.0104 Lens 3 0.00167 0.01336 Barrel (ss) 0.0156 0.1248 Adjustment sq 0.00174 0.01392 0.2724 0.123558 CCD Assy ccds 4 0.0119 0.0476 Pedestal 0.0073 0.0292 Lightshield 0.0057 0.0228 0.05895 0.0996 0.045178 Boards Pico Zed 0.139 Board CCD 0.066 Board Analog 0.125 Board Interface 0.044 Board Mother 0.099 0.473 0.214549 Enclosure Side cover Long 0.038 0.076 Side cover Short 0.05 Sides ends 0.104 0.208 Top Baffle 0.03 Housing 0.41 Baffles 0.005 0.02 Filter Housing 0.08 0.874 0.396439 Finderscope ccd 0.0078 Board 0.0022 Lenses 0.0322 0.014606 TOTALS: 1.910 0.866 Payload Weight Breakdown Weight chart is divided into subassemblies and component groups. Current total weight estimate is 0.866 Kg The majority of weight changes will occur in the Enclosure components.

Weight Budget Currently the estimated weight of payload is 0.866 kg. Most of the weight is concentrated in the mechanical structures. Total payload weight will be controlled here. Circuit Board weights will need to be revisited after prototype boards are made. Numbers not expected to change too much. Weight of following should not change since design is determined. Shutter Assembly Optical Assembly CCD array assembly (Includes lightshields and pedestals) Finderscope

Instrument fits within CubeSat Envelope