Author Archives: Devinhenson

Launch Recap and Thoughts

Wow, Sunday was an eventful and satisfying day. For the most part, every aspect of the launch could not have been more perfect. While it is still fresh in my mind, I wanted to take a minute and recap in fuller detail the timeline of our day. If you have any questions regarding specifics of the flight or our project, leave them in the comments and one of my students or I will try to answer it for you.

10:20am – I arrived at campus (our launch site) to begin setting up. WLTX news was already there! One of my students was already there and he helped me bring all the equipment to the launch site.



11:15am – All equipment and materials are laid out and we begin filling the balloon. Other students simultaneously are working on getting GPS gyro-bowl installed in payload and initializing GoPro camera. We were extremely fortunate our 125 cu ft helium tank ran out of helium exactly when we hit our required lifting force of 7.5 lbs.


11:39am – Liftoff. Everything went perfectly without a hitch.


11:50am – We pack up launch site and head towards predicted landing site outside of Sumter, SC. The balloon tracks very well, and heads north for a bit before turning sharply east.

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12:19pm – We lose contact (as expected) with the payload as the balloon surpasses 20,000 feet (max operating altitude for SPOT GPS).

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1:42pm – We get our first GPS hit from Sumter a few miles away. We get three in succession right around each other as the balloon descends.


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1:54pm – Touchdown. The payload comes to rest in a storage facility. Fortunately, the gates were open for customers and we were able to drive in and retrieve our payload.


We immediately get the footage out and view it on our laptop. Success!!


Later that evening, two different news agencies ran a clip about our project.


I’d say 95% of the project could not have gone more perfect. We had lots of good publicity after the launch, and I’ve had many students contact me from other classes asking to participate if we did another launch. Future launches will be relatively inexpensive since the costly equipment has already been purchased and is reusable.

The one rather big disappointment of our launch was the Arduino microprocessor we spent many hours perfecting for some reason did not record any data.  I suspect it was not an issue with cold temps, as the card was readable post-recovery and it still had data on it from previous testing. My best guess is that while loading the payload with the GoPro, GPS, etc. we may have bumped the device and unplugged or loosened a wire, causing the Arduino to not record properly. Lesson learned — next time we will test the Arduino immediately before launch, and put it in a protective case. I think a pencil case would work well. The impact of this failure means we do not have precise temperature, pressure, or altitude readings for our launch. However, we do have lat/long recordings of our payload which closely followed the predicted path. Also, based off of time calculations our project was extremely consistent with dozens of other HAB launches which all reached 100,000+ feet altitude.

I hope to do this process again soon, where we can hopefully now think more about the sensors and data retrieval instead of the “wow factor” of the HD video and do some good math modeling with our results. Some other sensors we may consider next time include GPS tracker (ours worked great, but hey – why not have a backup system), accelerometer, magneto (measures Earth’s magnetic forces — helps determine which way you’re facing NSEW), temperature (inside and outside the box), pressure, altitude, and humidity. An ambitious project that is currently above my level of expertise that I think would also be fun is to make a HAM radio repeater where you can use the balloon’s high altitude to send radio signals for many many miles.

One other small hiccup which obviously did not affect us too bad was that I think our GoPro Backpac was faulty. We charged it for many hours before launch but it did not read that it was taking a charge. We’ll send it back to GoPro for an exchange. Even so, we were easily able to record through the balloon burst. We were simply not able to record all the way back to earth but that was no big deal.

To close out this project I am currently working on taking our latitude/longitude data from the GPS, matching it with the predicted altitudes from our software projections to build a somewhat accurate .kml file that can be viewed on Google Earth.

Thanks everyone for their support during this project, and again — one more thanks to the Midlands Technical College Foundation for generously supporting our entire mission. Without them we would have been sending up a polaroid camera in a grocery bag, attached to a party balloon instead of the high quality equipment we were able to use!

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HAB Launch Video

After many hours of editing, here is the shorter version of the highlights of today’s events. I definitely have a lot more to say about the project and how it went, but for tonight — enjoy! 

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What a day!

This morning’s launch could not have gone more perfect. Great weather and no hiccups as far as setting up the payload or filling the balloon with helium. Tracking went perfect as well and came down very close to our predicted landing spot.

Many more pictures and HD video will be coming soon after I’ve had time to process it, but here is a little appetizer:


Just after take-off


 100,000 feet altitude – over 3x higher than commercial airliner



Beautiful picture

Stay tuned for HD video — coming soon!

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Launch Day!

The car is loaded up and I’m about to drive to the launch site. The weather is beautiful and the skies are crystal clear. Final tweaks were made this weekend to the payload and parachute. Also, this past Friday we got the helium tank and rigged up a regulator valve that (hopefully) will help us fill the balloon.

We ran one last prediction model and it has us landing just short of Sumter, SC.

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If you are interested in tracking the balloon online, or want to see the predicted launch site in Google Earth, the predicted latitude/longitude is

Lat: 33.9331

Lon: -80.3966

*Just type the numbers straight into Google Earth.

The actual GPS tracking page for the GPS tracker in our payload is here:

Here is a Google Earth image of the predicted landing area. Hope we avoid that pond! And the trees!

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Wish us luck! Hopefully in a few hours we will have retrieved the payload, and will have some nice images and footage to share sometime tonight or tomorrow!


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Launch Day Approaching

With the build basically completed, we have set a tentative launch date (weather permitting) for 11:00am Sunday, April 13th. So far it looks like we will have decent weather — high of 84 degrees, and winds SSE at 7 mph. There is a storm front coming in the next day, so hopefully the weather will hold off for us.

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Based on the current tracking predictions, we should land in this field outside of Sumter!

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Over the last couple of days we’ve done more testing with the SPOT GPS tracker and it has worked well. If you’d like to keep up with the location of the balloon live during the launch, you can follow our balloon using this public tracking page {will be activated launch day –  Sunday April 13th}:

We are also considering making a few adjustments to the parachute design. Our chute simply has a hole in the top, so there is nothing to keep tension between the parachute and balloon during the ascent. We are researching ways to attach the parachute to the balloon that will keep the parachute taut until deployment. We’ll post an update after the launch.

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Landing Predictor Software

There are some great online resources which will use current weather data, as well as the specs of your payload (balloon size, payload weight, etc.) to predict possible landing zones of your payload. One of our students took the lead on researching landing predictor software and provided us with a likely landing zone for the payload.

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Here are some links to a few online landing predictors. It appears these predictors have been quite accurate for launches from other groups. I’ll post an update after our launch with the accuracy of our prediction.

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Launch day has been tentatively set for Sunday, April 13th. Due to everyone’s busy schedules, I wanted to have one solid workday where we could knock out the majority of the project. That day was Friday, April 4th. Everyone pitched in for a successful workday. Below are a few pictures from our workday. Note that the apparatus is now built, so the remainder of the posts will be more oriented towards the launch and the launch conditions, and hopefully some good images that we will retrieve.

One of our students working on the landing predictor models…

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A student working on the gyro-bowl GPS mechanism…

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Two students researching FAA regulations…

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Working on the parachute and overall design…

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Getting the box customized just right…

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Pressure / Temperature / Altitude Sensor

Originally we were simply going to launch the balloon with an HD camera and potentially include more scientific equipment if we did a future launch. Looking at other groups’ projects some of the electronics used seemed to be potentially more time consuming and expensive than we wanted to for this project. However, after a few of our items came in under budget I reconsidered the idea.

It turns out there is this great piece of equipment called an Arduino which is very flexible for many different projects. Arduino is a microprocessor (basically a tiny computer) that can take inputs (from humans or from sensors) and produce outputs (turn motors, operate lights, etc.). So, I purchased an Arduino Uno, a BMP-085 Pressure/Temperature/Altitude sensor, and an SD card module to record the data readings.

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For me, this might end up being the most challenging part of the project, and it was a very rewarding feeling once the sensor was working. I owe 100% of the credit for the success of the Arduino contraption to the talented Jeremy Blum. Jeremy had a great series of Arduino tutorial videos that covered everything from the absolute basics to everything we needed to know for our project.

Here are Jeremy’s Arduino tutorials. You can also find his tutorial videos on YouTube.


Hours of thinking…

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Hours of messing with code…

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Cold Weather Test

Cold weather test…

Here is a quick plot of the data value obtained by the sensor. Here the only meaningful curve is the temperature cure as the sensor went from room temp, to refrigerator, to freezer, to fireplace. Obviously the pressure and altitude stayed the same in my house.

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Temperature graph (test run)

If you want to use a similar setup to mine, I recommend: 1) Getting the temperature sensor working over SPI, then 2) getting the SD card to work, then 3) try to get the data from the temperature sensor to actually record on the SD card.

Here are the Arduino files I used for each step as a .txt file that you can copy/paste into the Arduino IDE:

  1. Testing the temperature sensor – [.txt] {outputs the surrounding temp/pressure/altitude}
  2. Testing the SD card – [.txt] {simply records “hello” over and over to the SD card}
  3. Final compilation – [.txt] {here is the final file that takes data and records to the SD card}


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GoPro Camera

One of the big improvements I anticipate ours will have over projects done 3-4 years ago is the quality of video we should receive. The relatively new GoPro series of cameras gives absolutely stunning HD video in a camera that weighs only a few ounces.

There was no question that we would purchase a GoPro, but there was some flexibility in which model we bought. Because of our generous budget, this was the one area we splurged and got the top of the line GoPro Hero3+ Black. In addition to having stellar quality video, it also has helpful features for testing purposes like a WiFi remote, and the ability to use your smartphone to control the GoPro via WiFi and even see what it is recording.

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Here were our minimal requirements:

  • The battery had to last at least up to the balloon burst, and preferably for the whole trip. Minimum we need 2.5 hrs, preferably 3 hrs record time.
  • We purchased a 64gb SD card. Make sure it is a high quality class 10 card from a reputable dealer. This should be more than sufficient recording space.
  • We also want to use the mode that will record HD video while periodically taking an HD picture every 60 seconds.

The default battery doesn’t last super long, so we purchased a GoPro Backpac which is a battery extender which increases battery life. Note: the Bacpac doesn’t exactly double the battery life but gets fairly close. Also, you don’t need  the LCD backpack — just this regular Bacpac.

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One of our students took responsibility for finding the appropriate GoPro settings that will achieve our goals and maximize video quality. We settled on 720p video settings at a 60fps recording rate. During testing we obtained right at 3 hours record time. This number may decrease a little in the cold upper atmosphere, but should still be more than sufficient.

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GPS – Global Positioning System

When the HAB returns to earth, we will need to retrieve the payload which is only possible with high quality tracking equipment.

We found a wide variety of different approaches in regards to payload tracking. Some used microprocessors equipped with GPS modules, some used old cellphones that would send a text message with it’s current latitude/longitude, and some used retail GPS systems.

I would say the most commonly used were the SPOT GPS trackers. They are easy to use, with no technical knowledge required. Many hikers use them since they do not rely on spotty cell coverage. You can also track the SPOT’s movements via Google Maps or their own custom tracking page. Here is our custom tracking page SPOT let us set up that we will distribute to people who want to follow our launch online.


While many groups use the SPOT Messenger, we will be using the newly released SPOT Trace. It is promoted as a theft-alert GPS tracker that you would attach to a boat, ATV, or car – but it’s small size will work perfectly for our uses. Testing was successful as it tracked our students as they did a test run to the convenience store.


One downside to the SPOT GPS trackers is that they must be facing skywards so that it can communicate with satellites overhead. If a box tips over during landing, theoretically the SPOT could face sideways (or even downwards), not be able to transmit its GPS coordinates, and we’d lose the payload.

So… we came up with this neat idea to take a “gyro-bowl” that parents use so that their toddler won’t spill his Cheerio’s and integrate it with the SPOT Trace so that the SPOT always faces upwards! In the world of HABs, this is probably the only part of our project where we devised something not yet done before (that I’ve seen). All in all I think it turned out pretty great.

Here is our student who constructed the gyro-bowl/SPOT contraption.

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Another challenge was somehow placing this apparatus in the box since it has a rounded bottom. We suspended the device inside the box by attaching string to the handles of the gyro-bowl and tying them together outside the box.




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Styrofoam Box

Luckily one of our students was able to get us a perfect styrofoam box that was roughly 12″x 14″x14″. The box we found was for transporting medicine between hospitals or doctor offices. It provided plenty of insulation for the cold external temperature and plenty of space for our electronics, yet was light enough to not add substantial weight.

Since the box was so thick, we removed some of the styrofoam from the inside and top to lessen the weight. Holes were cut inside the box for the GoPro camera, as well as hole for the parachute cords. Here is one of our students hollowing out some unnecessary styrofoam. Just FYI, for future reference — do this outside. Even though we put down plastic sheets, I’m sure our cleaning crew was not happy with us after we left.

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A high quality parachute is necessary to safely bring the payload back to earth. The parachute should have a high enough drag coefficient to regulate the falling payload’s terminal velocity, but low enough where the apparatus doesn’t travel a longer distance than necessary.

Using this chart, we decided on a 42″ Spherachute. This company seems to be a reputable company that many HAB and rocket enthusiasts use. The product arrived quickly and they had great customer service.

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To connect the box with the chute and balloon, we are going to use braided paracord. We read that one group was able to minimize twisting of the box using braided cord.

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Balloon and Helium

Over the next few posts, we will go through the detailed specifics of each area of our project. The first thing we’ll go over is the balloon and lifting gas we used.

By far the two most common lifting gases used in HABs are helium and hydrogen. Hydrogen is cheaper and has better lift, but unfortunately it is quite flammable. We found that the vast majority of HAB groups use helium since it is an inert gas and therefore is safer to handle.

Finding helium is tougher than you’d think. The large tanks from party stores cost a fortune (~$200) to rent, plus require a $150+ deposit to make sure you don’t take their tank. And, I was not aware that there was recently a nationwide helium shortage and that helium is now regulated by the government. From what I understand helium is a non-renewable resource, and since it is lighter than air once it escapes and rises into the atmosphere it is gone forever. Fortunately we were able to rent a 120 cu. ft. helium tank at Airgas for about $90. We will also attempt to rent it through our college which will save us the safety deposit.

It is recommended to have enough helium to generate 1.5x lift compared to the weight of the payload. Doing some quick math and the chart here we find:

120 cu. ft. of helium is equivalent to 7.5 lbs of lift, and 7.5/1.5 = 5 lb max payload

So we are going to try to stay below 5 lbs including: balloon, parachute, box with equipment. This sounds reasonable compared to other’s projects.

Make sure you buy a high quality weather balloon from a reputable dealer. We bought a 600g weather balloon from Amazon.

Here are some super helpful videos on preparing and filling a HAB:

Here are a couple of more helpful links related to filling a HAB:

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Where to Start

We began our project scouring online for similar projects that other schools or individuals have done. We found a range of successful and unsuccessful attempts, but more importantly we are starting to see some common resources that many used throughout their project. Even though all had different specific designs, most had basically the same common setup:

  • A weather balloon large enough to lift their payload.
  • A box or apparatus of some kind to hold equipment.
  • A camera that can record pictures and/or HD video.
  • A parachute to safely return the payload to earth.
  • A GPS system to locate the payload once it lands.

We will go through each of these design elements in detail throughout in future posts. For now, below is a list of links we are currently using of other people’s projects that is proving very useful in helping us decide what materials or equipment to use.

Based off of what we found from other similar experiments, here is a quick rundown of what we will have to deal with during our project:

– Most balloons ascend to an altitude of approximately 80,000-110,000 feet. As the altitude increases, the pressure decreases, which in turn increases the volume of the balloon until it bursts. Once the balloon bursts it will return to earth safely using an on board parachute.

– Temperatures are an issue for the electronics inside the payload since temps can get to -50 degrees F or less. Some element of our design will have to keep our electronics warm.

– GPS signals do not transmit as high as our balloon will travel, so we will lose contact with the balloon for some time. Also, most GPS receivers need to face skyward to work which may be problematic. Without a GPS signal we will lose the payload.

– Helium is expensive, so the weight must be kept as minimal as possible to minimize the amount of helium needed. Hydrogen is less expensive and has better lift, but it is recommended to avoid hydrogen since it is a flammable gas. Helium is an inert gas that is much safer.

– We discovered that unmanned weather balloons require notice ahead of time to the FAA (Federal Aviation Administration) in the USA. We will need to contact them before launch day to notify them of our project.

Finally, after all our research we were able to determine about how much we wanted to spend for our project so we submitted a project proposal and were approved. Below is the final tally of our various materials and expenses. You can find details on each of these in future posts.

600g Weather balloon $54.99
GoPro HD camera – Black $399.00
GoPro HD camera – extended battery pack $49.99
Parachute – 42” + shipping $38.00+$7
SPOT GPS Trace + Service West Marine / $99.99+100
MicroSD card – 64gb video storage $48.69
Helium tank rental Airgas National Welders $90
Styrofoam box Donated free
Hand Warmers (to keep equipment from freezing) Donated free
Miscellaneous rope, tape, connectors, etc. Lowes/Radio Shack $50
Arduino, pressure sensor, datalogger $80
T-shirts $175
Pizza, drinks, etc. for launch day Papa John’s $80
TOTAL: $1300
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Project HAB is a go!

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A few years ago I stumbled across a video of a guy and his son launching an iPhone into space and capturing pretty neat video as the iPhone ascended into near-space. As a math instructor, I thought this would be a great project for a Differential Equations class. With the ever evolving improvement of technology, I also thought a more recent launch may provide better quality images and video than from three or four years ago. This current spring of 2014, everything is finally converging together to make this project happen.

First, I have a small DE class this semester (about 11 guys) many of whom I had previously for other calculus classes. And second, we were able to get generous funding from the Midlands Technical College Foundation to purchase all of the necessary equipment.

With funding secure and a capable team to develop the apparatus, we are now ready to research, design, and launch this weather balloon into space. If we can successfully recover the payload, hopefully we will have some very nice images and HD video from 100,000+ feet above the earth (approx. 19 miles!) in a band of the atmosphere often called ‘near-space’.

We hope you will keep up with our progress on this site. If you are starting a HAB group at your school, feel free to ask any questions about our project!

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