CubeSat Subsystems

We're building all of OreSat from scratch. For the record, this is a terrible idea. There are plenty of amazing commercial-off-the-shelf CubeSat kits and components out there. But they're not open source, they're a tad bit expensive, and we're an educational group that likes to DIY it anyway. Here are our subsystems: fly them as is, use them as a reference design, or hack them up to make them better! We look forward to seeing what you do with the OreSat bus.

First, you might want to see our OreSat System Block Diagram to see how everything fits together. Then see our subsystems listed below.

Open Source CubeSat Workshop 2021

Several of our student + Andrew presented at the Open Source CubeSat Workshop 2021 and gave great overview of our mechanical, electrical, and software and firmware of our OreSat bus. See below the awesome presentations!


Hayden and Marvin give a tour of OreSat's mechanical systems, including structure, thermal management, and deployable antennas.


David gives an overview of OreSat's solar, battery, bus and backplane, cards, and power domain system. 


Andrew gives a quick overview of onboard software and firmware.

OreSat bus subsystems

1U, 2U, and 3U Structures

The OreSat bus system uses 4 anodized Aluminum frames  bolted together to make a robust, lightweight, and vaguely inexpensive CubeSat structure that can be scaled from 1U to 3U. OreSat structure is compliant to the CubeSat Developer's Specification v13 and later.

STATUS: 1U in orbit! 2U in process, 1.5U and 3U in CAD/3D prints only.

Source: OreSat OnShape

Solar modules

Each 1U face of the OreSat structure can have a single solar module. That's 4 boards for a 1U, and up to 12 for a 3U. Each module has two 30% efficient GaAs solar cells,  a built-in custom maximum power point tracker, and full telemetry. We get about 2 watts/module in full sun.

STATUS: v5.3 in Orbit! Works!

Source: oresat-solar

Battery Cards

Each battery card has two independent battery packs on it. Each pack is 2 Lithium Ion 18650 cells in series, so a card gives us a capacity of 7.2 V (nominal)  at 5.2 Ah = 37 Wh. Our battery cards also have fuel gauging, current and voltage monitoring, and carry the inhibit and battery disconnect switches.

Status: v3 in Orbit! Works!

Source: oresat-batteries

C3 onboard computer

ARM Cortex M4 on board computer, 16 GB eMMC memory, rad hard watchdog timer, deployment circuits, UHF transceiver radio, L band receiver, and OreSat Power Domain controller... all on one board.

Status: v5 In Orbit! Works! Working on v6.

Source: oresat-c3 

Backplane CAD

Data, Power, and RFBackplane

The backplane connects all of the OreSat cards together with power, data, and RF signals. The backplane is located on the inner wall of the -X side of the structure.

Status:  v2 1U in Orbit! Works!

Source: oresat-backplane

Deployable tri-band turnstile antenna

These are the turnstile antennas that will be used on the OreSat0. The tri-band, four element, deployable turnstile antenna provides omnidirectional, circularly polarized antennas for OreSat0's UHF downlink radio, our L band uplink radio, and the GPS receiver. 

Status:  v2 in Orbit! Works!

Source: oresat-structure

End Cap CAD

+/- Z End Caps

The End Caps are boards that fit on the very outer surface of the + Z and - Z sides of the satellite (top and bottom). They protect the end cards, and usually have the magnetometers on them.

Status:  In Orbit! Works!

Source: oresat-endcaps

+/- Z End Cards

The End Cards are the top and bottom most card slots. They're important, and different, because they hold any deployable antennas and   connect both the the solar modules and the end caps to the backplane.

Status:  In Orbit! Works!

Source: oresat-end-cards

Attitude Determination System (ADS)

Star Tracker

This card has a ON Semi AR0134 camera that takes images of stars. The unique pattern of the stars let us figure out which way the satellite is pointing, using the openstartracker star tracking software.

Status:  In orbit, not yet activated!

Source: oresat-star-tracker and oresat-star-tracker-software

Attitude Control System Card


The magnetomers measure the Earth's magnetic field. If we know where OreSat is, we can tell which way it's pointing. 2x Memsic HMC3883A magnetometers are on each End Cap, and they're read by the uC on the ACS Card.

Status:   In orbit, not yet activated!

Source: oresat-adcs-hardware

Attitude Control System Card


The Inertial Measurement Unit is a Bosch BMM180 that has 3 accelerometers and 3 gyroscopes to measure the satellite's movement. In orbit, the accelerometers just measure zero (!); we just use the gyroscopes to measure our spin rate. The IMU is on the  ACS Card.

Status:   In orbit, not yet activated!

Source: oresat-adcs-hardware


Our software defined radio GPS receiver is a space-based GPS receiver based on collecting raw IQ data from the Maxim MAX2771 SDR GPS IC.

Status:   In orbit, not yet activated!

Source: oresat-gps-hardware and oresat-gps-software

Attitude Control System (ACS)

Reaction Wheels

We use 4 reaction wheels to precisely control which way OreSat is pointed. We have 4 custom boards that control each of the motors.

Status:  Prototyped, awaiting firmware

Source: oresat-adcs-hardware


We can point OreSat by pushing against the Earth's magnetic field using our 3 magnetorquers.

Status:  Prototyped

Source: oresat-structure and oresat-adcs-hardware

OreSat Live mission

(Please see our OreSat Live mission page for an overview!)

Helical antenna

The helical or high gain antenna is the spiral, single-pronged antenna on the +Z face of the satellite. It's the narrow-beam, high-data-rate antenna the satellite uses for transmitting video.

Status: Prototypes only

Source: oresat-structure

Attitude Control System Card


This is our long distance WiFi system: a Atheros AR9271 IC along with a Qorvo power amp.

Status: Breadboard prototypes only

Source: oresat-dxwifi-hardware and oresat-dxwifi-software

OreSat Live Camera + Lens

We use a schmidt-Cassegrain "lens" along with a high resolution USB camera to capture high resolution images of you!

Status: First prototypes, engineering unit lens

Source: oresat-structure

Cirrus Flux Cam mission

(Please see our CFC mission page for an overview)

Cirrus Flux Camera CAD

SWIR Camera System

We use multi-angle shots from a short wave infrared camera to map cirrus clouds.

Status: Prototyped, works, flown on our HASP balloon mission.

Source: oresat-structure

CFC Cards

These two card controls the CFC camera and cooler.

Status: v1 works, flown on HASP balloon mission.

Source: oresat-cfc-hardware

Image Processing

We use multi-angle shots from a short wave infrared camera to map cirrus clouds.

Status: Discussions only

Source: TBD

Distributed Computational Resources

ST STM32F091 (Cortex M0)

We have a dozen or so small microcontrollers around OreSat that run ChibiOS, communicate using the CAN bus, and do all of the small housekeeping and telemetry tasks you'd expect. Some of the more demanding subsystems, like the C3 card,  use a Cortex M4 microcontroller.

Status: See subsystems

Source: oresat-proto-card

Cortex M Firmware:
ChibiOS + C

We use the ChibiOS NIL real time operating system (RTOS) on our Cortex M microcontrollers, and use C to write our firmware. All with open source tools, of course!

Status: See subsystems

Source: oresat-firmware

Octavo OSD335x-SM
(Cortex A8)

We have a few large processors running Linux that do the heavy lifting, including image processing. These are the same processors used on the PocketBeagle open source single board computer. 

Status: See subsytems

Source: oresat-star-tracker

Linux in Space

We run Debian Linux on our Cortex A8 processors!

Status: See subsystems

Source: oresat-linux