Balloon, Mark 2 - "Hackathon HAB"
Overview
The High Altitude Balloon (HAB) Mk1 project is a collaboration between three Cornell Clubs:
The goal of the project is to engage in a Hackathon day to build a HAB launch vehicle and payload, and on the following day, launch, track, and recover the balloon payload. In doing so, we hope to give Cornell students some exposure to HAM radio as well as supplement their Cornell education with some additional hands-on engineering experience.
We plan to launch a latex weather balloon with a Raspberry Pi and camera payload, transmit images back to ground using SSTV, and track the balloon using APRS. To cover a broad array of interests, we will offer several sub projects such as antenna builds and the various balloon subsystems.
Timeline
12/31 - Survey Sent Out
01/05 - Project Green Light
01/24 - IEEE, CRITERS, CARC Joint Meeting (5PM)
01/27 - HAM Licensing (
TCARA)
Build/Launch Day still TBD
Action Items (Due 1/24)
A confirmed build/launch date
An alternative launch date if weather doesn't cooperate. Cold's fine, driving in dangerous conditions is not.
A confirmed list of participants
A finalized list of sub-projects
A list of parts for each of those sub projects and at least 50% of the list should be ordered or at least have a firm plan for sourcing those parts for build day.
A mapping of participants to projects (or at least a 1-2-3 ranking of what project they'd like to work on)
A list of people committed to taking the HAM licensing exam (again, licenses are NOT required, just icing on the cake). That way we can organize rides and such to 92 Brown Road on 1/27.
Liaisons
Name | Affiliation |
Jon | CARC |
Hannah | CRITERS |
Udit | IEEE |
Issues
Burst altitude forecast models exist for some documented, but more expensive balloons.
Purchase more expensive “well documented” balloon ($70ish) or less predictable one ($25ish)?
More expensive balloons offer higher altitude missions. They also require more lifting gas (and expense) and the payload will land farther away. The proposed balloon has a targeted burst at 12,000-15,000 feet if we wish the payload to land within a reasonable driving distance (60-100 miles).
Do we want to buy offset attenuators and/or inexpensive radios to use with the Yagi antennas?
Project Plan
HAB Mk1 (Priority One)
Launch Vehicle | Latex Weather Balloon | Latex Weather Balloon + H2 |
Payload | APRS, SSTV, Pi Camera | Ursus Minimus, SSTV, Raspberry Pi, Radio |
Payload container | CAD design, 3D print?, styrofoam? | |
Max Payoad Weight | 730g | |
Flight Time | 45-90 min | |
Cutdown A | Nichrome + Accelerant | |
Cutdown B | Balloon Failure | |
Recovery | Parachute? Streamer? | |
Tracking | APRS, Beacon | |
Deliverables - HAB Mk1 (Priority One)
Setup payload for a high altitude balloon based on a Raspberry Pi.
Payload uses APRS and CW (Morse Code) for post-flight retrieval.
Payload transmit SSTV (Slow Scan TV Images) in flight.
Raspberry Pi Camera module to store images on SD card for retrieval after recovery.
Payload is packaged in a lightweight insulating container.
Payload designed for nichrome cut-down mechanism with balloon burst as a backup.
Onboard microcontroller (or Raspberry Pi) drives the nichrome cutdown mechanism.
Cutdown is time based, and also potentially distance based, to limit distance from launch.
CARC will provide the APRS/CW beacon.
Budget - HAB Mk1 (Priority One)
Payload Weight Budget
Item | Weight (grams) |
Raspberry Pi | 50 |
Camera Module | 3 |
Easy Digi | 20 |
Radio | 220 |
Batteries - (3) AA | 45 |
Microcontroller board | 20 |
Payload container | 100 |
Ursus Minimus | 12 |
Parachute | 68 |
Cutdown mechanism | 20 |
Total (730 max) | 656 |
Payload notes
SSTV Receiver (Priority One)
Deliverables - SSTV Receiver (Priority One)
A receiver capable of rendering received SSTV images and storing them.
Optionally upload these images to a live web presence during the flight.
We can use
MMSSTV on Windows to receive images.
Budget - SSTV Receiver (Priority One)
Balloon APRS tracking/Recovery (Priority One)
Deliverables - Balloon APRS tracking/Recovery (Priority One)
Vehicles equipped with APRS tracking radios and laptops/mapping.
Budget - Balloon APRS tracking/Recovery (Priority One)
Item | Estimated Cost |
APRS Tracking setup - radio, laptop, etc | CARC members |
Yagi Build (Priority Two)
Deliverables - Yagi Build (Priority Two)
Yagi antennas for use in payload recovery.
We'll also need
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Budget - Yagi Build (Priority Two)
Item | Estimated Cost |
BNC connector hardware | $20 |
Antenna elements | Donated |
Antenna body | Donated |
Offset Attenuator Build (Priority Two)
Real time mission web presence (Priority Three)
Deliverables - Real time mission web presence (Priority Three)
Web presence with real-time data collection.
APRS data (aprs.fi links?)
Chase vehicles
SSTV images
Other content?
Budget - Real time mission web presence (Priority Three)
Item | Estimated Cost |
Web server | Donated by KC2WAC |
Trajectory / Burst / Landing forecast (Priority Three)
Finds best resources available for forecasting balloon trajectory.
Provides recommendation to launch team for initial balloon volume / free lift, based on predictions, to produce a reasonable flight.
Potentially integrates with real time mission web presence.
Doppler Build (Priority Three)
As we mount more balloon missions, it would be beneficial to have a fixed doppler station for DF purposes. That way, even with only one mobile bearing we might be able to triangulate. This will also be a useful addition to foxhunts.
There are several kits for building DF dopplers, the most popular of which seems to be the PicoDopp. Other doppler kits are approximately the same cost and complexity, so the total parts bill would be approximately $200.
We can install a 2m and 70cm doppler array on the roof of Barton and put it on the internet for remote usage.
Budget - Doppler Build (Priority Three)
Item | Estimated Cost |
PicoDopp Kit | $169 |
Antenna hardware | $50 |
Total | $219 |