Ex-Alta 3
The Experimental Albertan #3 Satellite
The Experimental Albertan #3 (Ex-Alta 3) is part of the CubeSats Initiative in Canada for STEM (CUBICS). CUBICS is an initiative from the Canadian Space Agency (CSA), designed to provide post-secondary institutions the opportunity to develop a CubeSat. Like its predecessors Ex-Alta 1 and Ex-Alta 2, Ex-Alta 3 will fly a digital fluxgate magnetometer (DFGM) to measure magnetic fields in the Earth’s ionosphere; as well as carry the next generation of AlbertaSat’s multi-spectral imager, Iris, to characterize ice and snow coverage. Ex-Alta 3 is expected to launch into a high inclination sun synchronous orbit in 2026.
Mission Objectives
- Support the training and development of highly qualified personnel by providing students with the opportunity to design, build and operate satellites as well as support the development of open-source designs
- Characterize ice, snow, and glacial regions within Canada, using our open-source, student designed imager
- Characterize DC and AC magnetic fields at low earth orbit altitudes using a Digital Fluxgate Magnetometer (DFGM)
- Allow students to gain experience with amateur radio through satellite communications. Learn more about AlbertaSat’s amateur radio initiatives here.
How Ex-Alta 3 Will Use and Support Amateur Radio
Amateur radio serves a critical role on Ex-Alta 3, as all communications with the spacecraft once it is in space will be sent in the amateur radio band frequencies.
Ex-Alta 3 will result in an end-to-end communications system between the spacecraft and AlbertaSat’s two amateur radio ground stations (learn more about our facilities here), developed and maintained by our volunteers. All of Ex-Alta 3’s volunteer operators will be trained and licensed in the amateur radio bands, in partnership with our local amateur radio organization, the Northern Alberta Radio Club (NARC). To date, over fifty AlbertaSat members have been licensed to operate in the amateur radio bands, and remain engaged with the amateur radio community through field events, operations, and promotion of amateur radio in outreach.
This communications systems will utilize software defined radio in the amateur UHF and amateur S-Band frequencies. Two-way UHF communication will be used primarily for Telemetry, Tracking, and Command (TT&C), while S-Band communications will be for downlink only, receiving larger data packages from the two active payloads on the satellite. Ex-Alta 3 will transmit AX.25 beacons every 30 seconds, which can be received by any amateur radio operator — more information will be released upon Ex-Alta 3’s deployment.
Part of this communication system includes the development of a novel, miniaturized dual-band patch antenna using meta-materials, and a technology demonstration of the design on a CubeSat platform. Such open source designs increase accessibility to improve both amateur radio and small satellite technology.
Ex-Alta 3 Preliminary Communications System Parameters
Last Updated: May 2024
Note these parameters are subject to change before the launch of Ex-Alta 3. Final parameters and detailed instructions on Ex-Alta 3 operations will be shared closer to launch.
Parameter | UHF Band | S-Band |
|---|---|---|
Center Frequency (MHz) | 435-438* | 2 400 – 2 450* |
Output Power (dBW) | 3.0 | 0 |
Data Rate (kbps) | 19.2 | 10 000 |
Antenna Beamwidth (deg) | 180 | |
Antenna Gain (dB) | 2.5 | 2.5 |
Pointing Loss (dB) | -6.0 | |
Line Loss (dB) | -2.0 | -0.4 |
Noise Temperature (K) | 253 | |
Orbit Altitude (km) | 600** | 600** |
*Pending IARU frequency coordination
**Pending launch opportunity
Ex-Alta 3 Subsystem Technical Specifications
Last updated: June 2, 2024
Ex-Alta 3 will be flying a COTS ADCS integrated system, featuring 3-axis control via reaction wheels and magnetorquers.
Ex-Alta 3 will feature an in-house, open-source dual-band (UHF and S-Band) patch antenna, dubbed the Hermes Antenna Array. One COTS UHF transceiver will be used for telemetry and telecommand, and one COTS S-Band transmitter will be used for payload downlink. Software-defined radio (SDR) will be used.
Major Dimensions (excluding deployables): 117.570 mm x 115.681 mm x 372.100 mm
Estimated mass: 4.18 kg
Ex-Alta 3 will fly a COTS power distribution system (electronic power system, or EPS), alongside AlbertaSat’s in-house Hyperion solar panels. Ex-Alta 3 will have 3 body mounted solar panels, along with deployable solar panels along the port and starboard faces–generating approximately 5.80 W per orbit.
Ex-Alta 3’s flight software will be written in the Rust programming language. Flight software will be responsible for the the Launch and Early Operations Procedures (LEOP), execution and scheduling of commands, and transport and storage of payload and system-wide telemetry data. Each subsystem will be commanded using a unique and individual subsystem handler, which interfaces with Ex-Alta 3’s main On-Board Computer (OBC).
Ex-Alta 3 will fly a COTS On-Board Computer (OBC), integrated into the remainder of the bus via the in-house Daedalus OBC Daughterboard design. Daedalus will also host a COTS GPS module for positional data, as well as a MOSFET burnwire system to release deployable components.
Iris: The Iris multispectral imager will image in visible and near-infrared bands (VNIR), as well as short-wave infrared bands (SWIR) to capture scientifically valuable data regarding ice and snow coverage. Iris is an in-house design and includes two optical paths and a housing, which interfaces to COTS sensor modules. The entire Iris payload fits within 1U.
Digital Fluxgate Magnetometer (DFGM): The DFGM was developed by the Space Physics Lab at the University of Alberta to characterize the magnetic field in Earth’s ionosphere. The DFGM sensor is boom-mounted using an in-house boom design with elbow and shoulder hinges, and deploys to 60 cm to reduce noise in data measured.
Corner Cube Retroreflector: An array of corner cube retroreflectors will be mounted to the anti-ram face of Ex-Alta 3, providing the ability to laser range the satellite and provide highly-accurate positional data. These measurements are complementary to the DFGM and will allow us to map magnetic field activity to specific regions and altitudes, as well as characterize the altitude decay of a 3U CubeSat with high precision.