This page and its subpages contain thermal system designs that are particular to ArcticSat. Please refer to General Bus Design - Thermal for general thermal information. Please open the tree item for more detailed design and analysis results.
As of July 24th, we do not know for sure if radiators are needed for ArcticSat.
Figure 1: ArcticSat Thermal Functional Block Diagram
Figure 2: ArcticSat System Block Diagram
Figure 3: Thermal Control Block Diagram
Thermistors will be placed to monitor the temperatures of the
CDH computer
ADCS board
Batteries
Reaction wheel
Payload
Power board
Communications equipment
Solar arrays
Except for those on the batteries, these thermistors will only be used for telemetry and health monitoring, as none of these components will have active thermal controls. All thermistors used will be automotive grade to improve reliability and lifetime. Board-mounted thermistors will be soldered, while component-mounted ones will be bonded on. A diagram of the thermal control system, including the thermistors, heaters, and flows of data and heat can be found in Figure 3.
ArcticSat's batteries may require heating to stay alive, depending on the impacts of the short eclipses and temperature ranges expected during launch. Analysis has not yet included eclipses, and a launch provider has not yet been selected. The Datec heaters from Iris's design are included on ArcticSat as they are very low mass and volume. These 3D printed heaters were developed by Datec Coating Corporation in Ontario, and qualified on Iris. Thermistors on the battery will inform CDH of temperatures, and CDH will turn heaters on/off. The heater will be secured using thermal epoxy.
ArcticSat has an aluminum shell structure which allows for fairly low resistance heat conduction about the satellite. Two specific areas of concern for the thermal subsystem are the batteries and the payload electronics. As mentioned above, the batteries have an electric heater, but they will also generate heat while in use. Both of these attributes will cause local temperatures to fluctuate. The payload electronics must be kept at a constant, pre-calibrated temperature. Because of this, the batteries and the payload electronics are placed far apart in the bus layout.
While Iris's structure was black anodized for thermal performance, little difference was seens between black and clear anodization in analyses for ArcticSat. As such, and pending more detailed analysis, this CubeSat will use clear anodization to improve its optical visibility. The solar arrays have high surface area to volume ratio, and could quickly exceed their temperature limits while constantly being exposed to the Sun. These arrays may require highly reflective paints on the front, or radiative coatings on the back to manage temperatures properly. More detailed analysis is required to determine this.
Orbit
Iris - ISS orbit (R-MIS-0010) vs ArcticSat - SSO
We need to perform new thermal analysis due to the new orbital environment
2. Mission life time
Iris - 3 months (R-MIS-0001) vs ArcticSat - 1 year (R-ARC-MIS-007)
We might need to select new components with longer lifetime in a SSO environment
3. Payload
Iris - rock samples (R-MIS-0030) vs ArcticSat - large deployable antenna (R-ARC-MIS-001)
A different payload consists of components with different temperature requirements, and vastly different geometries, therefore different thermal components may be required to maintain payload temperatures
4. Components
Iris - Datec heaters (R-MIS-0080, R-INT-0150) vs ArcticSat - no prescribed heater
We integrated experimental Datec heaters to Iris to flight qualify them, however, that is not a necessity for ArcticSat. We could still choose to use Datec heaters if they fit our design requirements.