In order to meet the specifications detailed for CubeSats and meet the mission goal of accessibility for EQUiSat, we are paying close attention developing robust construction methods and procedures.
A key feature of the structure system is the “mono-block” chassis. This design provides maximal specific strength and minimal geometric tolerance stack-up. The simplicity of the overall design provides an architecture to maximize internal capacity and allow freedom in modifying the structure for project needs.
- Robust, integrated fasteners for mounting of 1-2 PCBs
- External mounting holes on crossbars for solar panel and LED panel attachment
- All major features 8.5mm min. thickness
- Milled from a single piece of 6061 Aluminum stock
- Used only a basic 3 axis CNC mill
- Structure and tolerance to conform to CubeSat specification
The second iteration of the chassis is now in development. Considerations for the revised design include:
- Further reducing weight by using thinner cross beams
- Increasing the number of internal fastening points for components
- Alterations in the precise mounting locations of the necessary printed circuit boards
The flash side of the satellite is being designed for optimal thermal transfer away from the LEDs and to the chassis. A render of the flash side arrangement can be seen above; the assembly drawing is at right. To accomplish the required thermal transfer, the SST-90s will be used with the preexisting ‘starboard’ option, as described in the LEDs page and detailed in the Resources. These starboards are mounted to the backside of the outermost PCB. The entire assembly, including deployment posts for the antenna will then be filled with thermally conductive epoxy. Using the bolts at the panel corners, the entire assembly will be bolted to the mono-block chassis with a sufficient inset to meet the outer profile of CubeSat specifications.
Thermal conduction away from the LED flash panel is very important to:
- Preserve the optimal visibility from the panel
- Equalize the temperature gradient across the satellite
The ideal epoxy or coating to use for component potting is currently under evaluation.
In accordance with our mission goal of accessibility and DIY Philosophy, below are links to the drawings of EquiSat currently in use by the team. Full instructions will be included as the design is finalized. For additional information in the interim, please email us here.
Additional files will be posted as they become available or are updated.
Currently, the following components will be included in the satellite. Note, this list is a work in progress and therefore incomplete and not yet finalized.
|Power||PCB 1||Board mount for the side arrays of Solar Panels||3|
|Power||PCB 2||Board mount for the top and bottom arrays of Solar Panels||2|
|Power||Flash Batteries||A pack of lithium iron phosphate batteries is in testing for use on the satellite to power the LED array||4 (2s2p)|
|Power||Electronics Batteries||A set of lithium ion batteries to power the radio and PIC||4 (2s2p)|
|Electronics||PCB 3||Board mount for internal circuitry and electrical components||1|
|Electronics||PIC Microcontroller||Microcontroller as satellite CPU||4|
|Flash||PCB 4||Board for mounting LEDs||1|
|Flash||PCB 5||Board for mounting flash side assembly||1|
|Flash||Luminus SST-90 LED||High power 5600K 2000lm LED||15-20|
|Attitude Determination||Thermopile Sensor||A thermopile sensor on each side of the cube will be used to assess orientation||6|
|Attitude Control||Magnet 1||This magnet will sit perpendicular to the flash side of the satellite||1|
|Attitude Control||Magnet 2||These magnets will complete the triad within the satellite||2|
|Radio||Radio Transmitter||An XDL Micro transmitter will provide health data and location via the 435MHz band||1|
|Radio||Antenna||Superalloy dipole antenna||1|
|Radio||Deployment Posts||Machined posts will be used to wrap and subsequently deploy the antenna in orbit||3-4|
|Chassis||Monoblock||The solid Al 6061 chassis provides the body of EquiSat and fastening points for all components||1|
|*all fields subject to change|