# First Earth-Imaging CubeSat with Harmonic Diffractive Lens
## 2 A CubeSX-HSE Nanosatellite-Based Remote Sensing Platform
### Nanosatellite Design
#### 2.1.2 Hardware Configuration  
CubeSX-HSE is a small satellite made up of three 10 \(\times\) 10 \(\times\) 10 cm cubic units on a single aluminum alloy frame. One unit contains a set of flywheels for the satellite spatial orientation, the second unit houses circuit boards for the satellite control, and the third unit is entirely dedicated to the payload, in our case a diffractive-lens-based remote sensing camera.  
The OrbiCraft-Pro platform was designed for the manual assembly of its electronic and mechanical components into a CubeSat nanosatellite [23]. The Pro modification represents an assembled and manufacturer-approved platform version that has passed a complete set of qualification tests. It has a three-axis orientation and stabilization system and gallium arsenide photoelectric transducers, and it can be integrated with a custom payload. Included are printed circuit boards linked together with PC/104 connectors, where each board implements one or several satellite functions; the platform also includes cables, solar cells, and power supply elements [24].  
The main unit contains three connected components: the main stack of electronic circuit boards, a mounting frame, and solar panels, as shown in Figure 1a.  
The electronics are designed to be modular, and the position of modules in the satellite card cage can be varied. Various modules connected to the PC/104 bus can be installed into the vertical stack cage; these include an orientation and stabilization system controller, various payload boards, and other modules, as shown in Figure 1b. Each system is connected to the CAN2.0B-based internal satellite network operating at 1 Mbit/s. A high-level UniCAN 2.0 protocol runs on top of the CAN2.0B protocol stack to ensure reliable and convenient telemetry and command reception/transmission. The satellite cabling utilizes extensible PC/104 connections, including connections to the service board and side-face devices such as solar panels. The service board is connected to the satellite communication system and the battery charging interface, and it has a multiplexed two-wire interface to test and update the firmware without the need to remove electronic boards from the assembled satellite. The solar sensors are mounted on all sides of the satellite frame and protected by dedicated side-panel windows.  
Figure 1: The 3U satellite layout based on the OrbiCraft-Pro platform [25]. OrbiCraft-Pro main unit. (**a**) The appearance of a collapsible satellite platform; (**b**) internal view of the platform; (**c**) placement of modules in the “stack” during satellite assembly.  
An easy-to-assemble, rugged satellite frame provides convenient access to the internals [24]. The satellite is separated from the launch container into its orbit with two spring pushers and duplicated circuit breakers with slots for connecting with the SXC-PSU-03 power unit. Mounted at the bottom of the satellite, the separation system has two spring-loaded switches located at the ends of a diagonal rail and may include two separating springs. During the transportation and storage, the switches are off and the battery is disconnected. When in orbit, the springs are activated, ejecting the satellite from a launch container P-POD to the outer space, closing the switches, and connecting the battery pack to the satellite power circuit.