Part 2 - High-Altitude Balloon Launch Test
Each group needs:
- One payload completely built and ready to launch. Please refer to the Payload Manual Guide as needed.
- At least one copy of the Payload Manual Guide for the Engineer(s) and Computer Scientist(s) to refer to for directions and guidance building and programming, as well as for other roles to gain an overall idea of the goal for the project.
To share with the entire class:
- Materials to complete a high-altitude balloon launch. In total, this may cost upwards of $1000–$2000. The main components include:
- 2 tanks of Helium ($250–400/tank, each should hold at least 200 cubic ft of helium)
- Compressed gas regulator with hose for filling the balloon ($50, make sure regulator fits the valve on the tank)
- 72-inch parachute ($50–100)
- High-strength (>10lb. strength) string/cord (e.g., kite string, paracord, etc.) to attach payloads to each other and to balloon
- A tracking device that logs GPS location and altitude data during flight and transmits that data back to participants in real-time ($50–500 depending on what is used, see below)
- (Highly recommended) Backup GPS device such as a SPOT GPS transmitter ($200–300 each including the cost of monthly subscription to access satellite network)
- (Optional) Action camera(s) such as a GoPro ($200–400 each)
- Miscellaneous items:
- Large wrench to tighten regulator to helium tank
- Additional string/cord to hold balloon down prior to launch (i.e., safety line),
- Digital fish scale to measure balloon’s free lift
- Zip ties
- Electrical tape
- Duct tape
- Latex gloves
- A means to attach the string/cord to the payload items. You may wish to build a payload harness with nylon or polyester webbing/straps, or perhaps attach string to the corners of the payload and tie down with duct tape. Securing metal swivels or rings to the top and bottom of the box (or harness) allows for easy attachment of the payload to the payload train. You might have to experiment a little bit to find the best method of attachment for your specific payload box.
- Space to set up, fill, and release balloon, preferably outdoors on a calm morning
NOTE: For the live tracking device, there are multiple approaches one could use. One approach is to simply purchase a device that provides real-time tracking and data transmission via a satellite network, like the Iridium network. This can be rather expensive ($200–500) and often requires a monthly or annual satellite subscription. There are also companies that sell high-quality, ready-to-go tracking devices specifically for ballooning (e.g., https://stratostar.com/), although these can be much more expensive. A cheaper option could be the $300 flight computer from High Altitude Science (https://www.highaltitudescience.com/products/eagle-flight-computer). Many of these purchases are one-time purchases to get started and equipment can be reused for future launches.
Teachers who are more tech-savvy may wish to construct their own devices using an Arduino or Raspberry Pi and track the balloon via Ham radio (see https://www.overlookhorizon.com/how-to-launch-weather-balloons/tracking-systems/ or https://www.sparkfun.com/tutorials/185). This can be a significantly cheaper option (<$100), but of course requires some knowledge of electronics, circuits, and Ham radios. The simplest approach is to just track the payload with a SPOT GPS transmitter (see above). However, these types of GPS transmitters update less frequently (every ~5 minutes), often do not operate above ~18,300 m (60,000 ft) above sea level, and do not generally include altitude data. In testing these balloon launches, this curriculum used equipment previously purchased using grant funds from a company called StratoStar. Helium tanks are an additional expense. For teachers in the state of Wyoming, launches and helium are provided by Wyoming NASA Space Grant free of charge and teachers can apply for grants to purchase additional supplies and equipment through our office as well if needed. Teachers in other states may be able to partner with the Space Grant office in their state, with universities engaged in launching weather balloons, or apply for grants to get started in ballooning.
Additional resources for purchasing ballooning equipment: