TOAST: Thermal Optimization And Scientific Testing
PURPOSE
As independent researchers start launching more frequent Low Earth orbit tests on scientific balloons with chemicals sensitive to extreme temperatures, can a low power active heating system replace conventional insulation as a more compact and precise alternative for experiments in a near space environment?
During 2024 our team was researching potential projects involving medication when we noticed that certain chemicals or medication required room temperature environments to remain potent. After noticing that insulation was taking too much room in our cube, we decided to pivot from testing medication, to finding alternatives to insulation.
During scientific balloon missions to test medication and how cosmic radiation could affect it, we noticed that temperatures could drop to -65°C which could spoil chemicals. These temperatures are extreme enough that a medication deemed essential by the World Health Organization such as Tropicamide which is used during eye surgery would be rendered unusable. Though some medications such as Tropicamide can survive high temperatures, once a liquid is frozen, the drug may be unevenly distributed after thawing or chemically changed. This makes isolating variables such as radiation and how it affects different chemicals difficult to observe.
Still, conventional insulation such as those employed by NASA on spacecraft tend to occupy a considerable amount of space relative to the limited area available during scientific balloon missions, especially after factoring in electronics for gathering data. Additionally, the potential manufacturing of innovative pharmaceuticals in space which utilize microgravity is growing in interest. This means scientific balloon experiments involving cosmic radiation's effect on medication are increasing which may result in researchers encountering difficulty in finding suitable insulation for certain medications. Though active heating is already being utilized, it was difficult to find a commercially available, low power, and compact system which was a realistic alternative to insulation for individual scientific balloon mission experiments.
The experiment seeks if the TOAST (Thermal Optimization And Scientific Testing) module which aims to be a compact, cost effective, and efficient active heating alternative to conventional insulation methods is viable. The experiment will involve comparing the performance in keeping room temperature conditions (15°C to 25°C) inside of sufficiently insulated cubes and cubes with the TOAST module while in a near space environment to simulate the preservation of chemicals.
The environment observed in scientific balloons such as the RB-10 are suitable for this experiment because of the extreme temperature fluctuations which can occur with flight through atmospheric layers and exposure to sunlight. These fluctuations range between -65°C to 65°C and are the same parameters which are dangerous to certain medications (Especially liquid based ones which freeze). Moreover, the size, power, and other restraints which are usually present in scientific balloons ensure that the TOAST module fits the required parameters to realistically act as an insulation alternative.
The internal temperature of the cubes will be tracked with thermistors to compare the performance of the TOAST module and conventional insulation when preserving chemicals. Temperature is crucial for evaluating the precision and effectiveness of the TOAST module and insulation. Additionally, the cost, power, and size of the TOAST module will be tracked to ensure that it is a more compact, economical, and effective solution when compared to insulation. The size and cost of the insulation will also be logged for the same reason. Lastly, flight data such as acceleration and altitude will be recorded so we can better visualize at what rate the temperature changes in the balloon during descent and ascent in order to fine tune our active heating system for the future.
The experiment will be conducted along the duration of the RB-10 scientific balloon mission until the balloon finishes its final descent. A TOAST cube with heating, data tracking, and with minimal insulation will be launched. A second TOAST cube but with a small FPV camera run periodically (Chosen because of compact size and not being used for actual data) will help determine if electronics which emit significant amounts of passive heat will help improve TOASTs heating ability, while justifying that the space taken up by TOAST's microcontroller and PCB as it can be utilized by other electronics which may appear in experiments. Lastly, a cube with an optimal amount of multi layered insulation along with temperature sensors and data tracking electronics will be launched to act as a control to compare TOASTs performance to conventional insulation.
If the hypothesis is supported after we compare the data between TOAST and its insulated counterpart, it would suggest that small-scale active heating systems can outperform conventional insulation in both space efficiency and thermal precision. This would allow for more internal room in experimental cubes, enabling larger or more complex experiments in space-constrained environments like the ones found in scientific balloons. Additionally, precise thermal control could improve the reliability of temperature-sensitive research, such as pharmaceutical or materials testing in near space environments. The findings could lead to accessible, more versatile, and reprogrammable experiment modules for spaceflight and open new possibilities for researchers. Currently, there is no commercially available small scale heating system which reaches the power, size, and cost requirements.
EXPERIMENT DESCRIPTION
Materials
The experiment tests the heating capability of the TOAST module, a TOAST module with a camera which radiates passive heat, and a cube with conventional multi layered insulation.
Beside the quantity of each part, the designator is also located for ease of use. Please note that each electronic was chosen to work within the RB-10 missions space and power budget. Furthermore, three of these PCB's will be manufactured from PCBWAY, and the following PCB material list includes the parts of only one PCB. The PCB will include the needed compatibility for the FPV camera used for passive electronic heat simulation and also microcontroller data pins. The control cube of multi layered insulation will also include a TOAST PCB in order to simulate a conventional experiment which may also use a PCB for its data gathering.
The PBC parts for TOAST include:
(PCB is 3.8cm x 2.6cm)
- Black Acrylic Enclosure
• Part: Keystone 236
• Manufacturer: Keystone Electronics
• Quantity: 1
• Description: Lightweight housing for electronics (MONOCHRON). Plastic shell only—no hardware included. - 0402 Surface Mount Ceramic Capacitor
• Part: 0402 Generic Cap
• Manufacturer: FTDI
• Quantity: 2 (C1, C2) - SMT Electrolytic Capacitor
• Part: EEE-HA1C100R
• Manufacturer: Panasonic
• Quantity: 2 (C3, C4) - NPN Transistor (SOT-23)
• Part: NSS40201LT1G
• Manufacturer: ON Semiconductor (now onsemi)
• Quantity: 4 (Q2, Q3, Q7, Q8) - 3.3V Voltage Regulator (Used as our heating as well)
• Part: LD33V
• Manufacturer: STMicroelectronics
• Quantity: 1 (U1) - 3-Axis Accelerometer
• Part: LIS2DHTR
• Manufacturer: STMicroelectronics
• Quantity: 1 (U2) - Analog Pressure Sensor
• Part: KP216H1416
• Manufacturer: Infineon Technologies
• Quantity: 1 - Voltage Converter (Used as our heating as well)
• Part: MAX5026EUT+T
• Manufacturer: Analog Devices
• Quantity: 1
Other Electronics or Parts Used for Insulated Cube and TOAST Cubes:
- The Cube provided by Cubes in Space (three cubes in total).
- Each cube including the insulated cube (So three cubes in total) will come with a Tiny Pico ESP-32 Microcontroller USB-C model which is 18x35mmx4mm. It includes a programmable RGB flashing light in accordance with RB-10 powered experiment requirements.
- Thermistors from DUTTY which are 2.54cm by 2.54cm.
- Actual Insulation used in space: Manufacturer: Dunmore, Double Aluminized Polyester Film, and a small amount will be needed to surround the cube, but only purchasable in large rolls.
- NiMh Battery (Passive Heating and Voltage Help), SKU: RB-Sta-04, Manufacturer #: SL-NM-0, 10.16H x 24.89W x 38.1L mm (+- 0.2 mm compliance).
- Nano FPV Camera (Passive Heating), SKU: Nano2-BL, Manufacturer: RunCam, 14mmx16mmx10mm.
- RunCam Mini FPV DVR, SKU: RUNCAM-DVR-S, Manufacturer: RunCam, 25mmx25mmx11mm.
Consumables:
A 3D printed housing to make sure each electronic part is in place will be made with Forwards AM Ultrafuse TPU 64D which comes in 750 gram spools.
Additionally: Silicon Wires, 10cm cable required for powered missions as specified in technical requirements, M2 screws and bolts, M2 heat set threaded inserts, solder wire, solder paste, coloured stickers for marking objects, plastic containers for storage, double sided tape, super glue, sharpie for labeling, bubble wrap, styrofoam, and Isopropyl alcohol.
Preflight Procedures
The experimental setup consists of three payload cubes: one using the TOAST (Thermal Optimization And Scientific Testing) active heating module, one TOAST unit with passive heat-emitting electronics (camera), and one control cube insulated with conventional multilayer insulation. All cubes are equipped with thermistors and microcontrollers to monitor and log internal temperature in real time throughout the RB-10 balloon flight. The payload cubes will also be labeled to prevent mistakes. Each cube will come assembled, and can easily be opened for inspection. A notch in the front of the cube with the required 10cm cable for powered experiments will be included for each cube.
Observations and measurements will focus on how effectively each cube maintains internal temperatures between 15°C and 25°C as the balloon experiences temperature fluctuations ranging from -65°C to 65°C. Additional sensors will collect flight data (altitude, acceleration) to correlate external conditions with internal performance. Power consumption and internal space usage will be logged to assess the space-efficiency of TOAST versus insulation.
For the first TOAST active heating module, a 3D printed housing made of Forwards AM Ultrafuse TPU 64D will be set up by inserting the electronics such as the TOAST PCB and Tiny Pico ESP-32 microcontroller in place. The housing has specific frames designed for each part, and coloured stickers corresponding to each electronic will be placed on the printed housing to ensure the correct electronics are put in place. Furthermore, the technical diagram can act as a reference to verify the correct electronics are in place. Once the electronics are set in place inside of the housing, use the indicated mounting holes and provided screws to secure the electronics. Labeled stickers referencing the technical diagram will direct electronic placement for thermistors, wiring, and soldering locations. The proper tools and safety procedures must be used, furthermore, check if the Tiny Pico ESP-32 is working and running the correct software for tracking data by powering it with a USBC to A cable. If the LED lights are flashing, the microcontroller is in working order and it will be powered and working during launch. To ensure that the experiment is easily accessible to be inspected before launch, make sure to label the orientation of the cube with labeled stickers and corresponding electronics. Electronics and structural integrity will be confirmed through power-on tests and shake tests to meet payload safety and operational requirements. The module will go through a check list inspection which includes mission requirements rules and powered experiment requirement rules. An additional electronics test which will run the cube on idle for a duration of 17 hours (replicating ascent and descent time of a scientific balloon) will be done to ensure that the electronics will last the duration of the flight.
For the second TOAST active heating module cube which has passive heat emitting electronics (camera), repeat the same steps as the first cube but during electronics assembly include the: RunCam Mini FPV DVR, battery, FPV Camera, and the additional wires and mounting materials which are included. The same electronics and structural test will need to be conducted, and labeling for the additional parts is required.
Lastly, the insulated cube will replicate the same steps as the first TOAST module, but the active heating systems will not be activated (Please ensure Tiny Pico is running the correct software as indicated) and the Double Aluminized Polyester Film Insulation must be cut with scissors and using a ruler. Please measure the correct sizing needed for each side of the cube and use the payload cube dimensions diagram to check your work. After, using glue as an adhesive, attach the film to each side of the cube or use the inner part of the 3D printed housing. Lastly, cut out a small notch in the film located in the front of the cube in order to string the required cables through. Ensure that the glue only attaches to the housing or cube sides to make inspection and opening the cube easy.
Use a checklist referencing payload cube dimensions, RB-10 Mission requirements, and RB-10 Powered Mission Requirements to ensure the following of proper guidelines. Label, organize, and log used consumables and electronics to ensure that nothing is missing.
During shipping, bubble wrap will surround all payload cubes, and some bubble wrap will be used inside cube internals inside empty spaces to ensure the cubes are internally protected. Furthermore, styrofoam will also encapsulate the bottom of the shipping box to maintain rigidity and prevent cubes from shifting.
Post Flight Procedure (Analysis Plan)
After recovery of the payloads, all three cubes—TOAST, TOAST with passive heat electronics, and the insulated control—will undergo detailed post-flight inspection and analysis. Each cube will be opened and visually examined for the condition of its internal electronics, wiring, solder joints, insulation, and structural components such as thermistors and the 3D printed housing. Any physical damage, shifting of components, or signs of overheating will be recorded. The operational status of each Tiny Pico ESP-32 microcontroller will be confirmed through onboard status LEDs. Data collected throughout the flight will be retrieved via USB-C, including internal temperature logs, altitude, and acceleration, which will then be used to assess environmental exposure and performance. Power usage will be calculated based on runtime and hardware specifications, while internal volume used by components will be measured to evaluate space efficiency.
Testing will involve comparing the temperature retention of each cube by analyzing recorded sensor data, evaluating the impact of passive heat from the FPV camera in the TOAST + Camera cube. Microcontrollers will be rebooted and re-tested to ensure they remain fully functional. Data will be organized into tables tracking temperature over time, power consumption, component volume, and rates of internal vs. external temperature change. Graphs will include line charts for thermal trends, bar charts for volume and power usage, and scatter plots correlating environmental and internal temperatures. Figures will visually present internal layouts and overlay environmental data for context, all compiled into a single .pdf report.
Validation of results will involve cross-referencing data logs with the balloon's mission timeline and external flight conditions. Redundant thermistor readings will help ensure data consistency, and all sensor outputs will be recalibrated and rechecked post-flight. Depending on the outcomes, various implications may arise: if TOAST maintains stable internal temperatures with minimal power usage, it will confirm the viability of active heating as a compact alternative to insulation. If the TOAST + Camera cube performs better, it could suggest that passive heat from electronics enhances system efficiency, supporting hybrid approaches. Should the insulated cube outperform both TOAST configurations but at the cost of space, future designs may need to weigh thermal precision against internal volume constraints. In the case of inconclusive or negative results, further iterations of TOAST could involve hardware refinements or smarter thermal control algorithms. The post-flight analysis report will include a thorough documentation regarding our findings including a cost analysis and documentation regarding where to find our technical diagrams.
Communication Plan
In addition to submitting our post-flight analysis report to Cubes in Space, our findings will be shared with university rocketry teams such as the University of Waterloo rocketry team who are attempting to launch their own scientific balloon missions.
We also plan to share the findings with members interested in material science and biomedical engineering inside of Cubes in Space and university teams, especially those exploring thermally regulated enclosures or medical research in near space environments. These groups care because our TOAST module could enable more scalable, modular, and precise experimentation without needing bulky insulation, which is especially relevant for high-altitude tests and eventual orbital deployment.
The results will be communicated in the form of a formal research summary PDF, which includes all graphical data, comparative analysis, and thermal performance tables. This will be complemented by a short-form technical presentation for educational outreach and a public summary blog post on platforms like ResearchHub or GitHub Pages, to ensure accessibility and open-source availability. These formats are appropriate because they cater to both technical researchers (detailed PDF) and general interest communities (presentation and blog), helping ensure the research has both academic and real-world impact. In addition, the team would love to present and elaborate on TOAST during FlightFest 2025 in Ottawa!
Citations Used
- World Health Organization. Tropicamide. The WHO Model List of Essential Medicines, https://list.essentialmeds.org/medicines/165
- U.S. National Library of Medicine. Tropicamide Ophthalmic Solution, USP, 0.5% – Storage Instructions. DailyMed, https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=521592d1-53a1-4314-8b3f-d808f3bccfcd
- iEDU. Module Four: RB-10 Balloon Missions and Facts. Cubes in Space Educator Training Program, 2025. https://courses.iedu.world/path-player?courseid=2025-educator-training-course&unit=677b5158a2e64afa8e001be2Unit