Balloon Launch Recap

Friday, August 16^th: The Night Before the Launch.

This night consisted of fixing the capsule and checking that the Arduino returned the right coordinates across the walkie-talkie.  Little known fact; we designed and built the parachute mechanism that night, without any testing or much planning.  After several hours we finished everything at 2:20 AM and went to bed

Saturday, August 17^th: The Launch and Recovery

Waking up at 3:30 AM, I felt more tired than before I went asleep.  We packed the truck and were leaving at 4:10 AM.  It was a much shorter trip than last launch, taking 90 minutes to drive there.  Arriving at Perrydale high school in Perrydale Oregon, the launch site was better than could be expected.  The only hazards were the track lighting which surrounded the field.  Given that our nozzle lift was much higher than last time, these lights weren’t going to be a problem.  Since we arrived early in the morning, the wind had not yet picked up.  The skies were clear, and it seemed like the launch would go well.  Rolling out the tarp, Lee started on the balloon while I organized the payload.  For what seemed like an eternity I stood around and watched Lee fill the balloon because assembling wasn’t going to take a long time.  I had gone through the motions of assembling the capsule the night before, so I waited until 25 minutes before launch to start assembling.  The main reason we did this was to give the GoPro as much in flight battery life as possible.  On our previous launch the GoPro batteries died before the balloon even popped.  Furthermore, we added a battery stick which connected to the GoPro’s mini USB in order to prevent total power failure.

This is where the fun began.  In reassembling the foam interior I ran across some interference with the walkie talkie.  Additionally, the Arduino was not sending back the right coordinates.  It took us around 10 minutes to realize the batter powering the Arduino was creating an electric field which messed up our transmission.  Hacking away at the foam I oriented the battery lines farther from the GPS.  Once this was finished, the transmissions which were irregularly spaced started to send as coded.  As a side note, we probably should have done much more exhaustive testing and cleaned up the code for the Arduino, but we didn’t.  All seemed well and we began taping the rest of the capsule.  Right before we started taping my phone in place the walkie talkie lost power.  They had been almost fully charged the night before, so we were very confused as to why this happened.  Switching batteries between the walkie talkies, we reassembled the capsule while charging the other battery.  At this point, Lee and I just wanted to launch the balloon, problems and all.  Although this took place in less than half an hour, the stress from problematic electronics and a diminishing launch window was immense.  We eventually fixed everything and let it go.

It was a relief to let go of the balloon, considering that if everything but the GPS on my phone failed, we would still be fine.  I then predicted that the walkie talkie would run out of power in 90 minutes.  It lasted 20 minutes.  You could say that the constant use of a walkie talkie on Hi-band consumes quite a bit of power.  We probably should have done more math regarding its duty cycle.  However, with the loss of our primary form of communication/location, my cell phone had not yet died.  We actually managed to send back photos from my phone during the trip.

 

Compared to our launch last year recovery was easy.  The nozzle lift was much higher than the previous balloon, limiting the balloon’s overall time in the air.  It landed in a field bordered by thick trees and a road.  We were very glad that it landed where it did, considering the amount of local tree farms.  Unfortunately, the GoPro was turned off when we found it.  The capsule was slightly damaged, but landed properly nonetheless.  Using a program found online, Lee managed to reclaim most of the footage that was damaged in the landing.  If you look closely, right before the camera hits the ground the video starts to become grainy.  Although we were disappointed that the footage of the capsule hitting the earth was lost, I was glad nothing was permanently damaged.

 

Despite the failure of the GPS recovery system, we consider the launch to be a great success, and we were able to capture some amazing footage. Our video can be seen at: https://www.youtube.com/watch?v=W-lo2QAYHZQ

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Tracking Device Progress

Once again, it's been a while since I've made a new post (seriously, it's becoming cliche). But that doesn't mean we haven't been working hard at our project. In fact, we've made some serious progress on the Arduino based tracking device. After realizing we had a major oversight concerning radio communication, we decided to change our methods from serial communication to DTMF (Dual Tone, Multiple Frequency) communication. Don't know what DTMF is? You know the sound you hear when you push a number on your telephone? It's that. The tones you hear through your phone are actually a combination of two frequencies. Each number on the phone corresponds to a unique combination of two of a set of frequencies. When the telephone station (or whatever it's called) receives these tones, it recognizes the combined frequencies as a set of numbers, and takes action accordingly. What exactly does this have to do with our project? Well, because audio signals transmit over radio much better than binary signals, we've decided to use dual frequency signals to communicate the latitude, longitude, and altitude values. We have an IC (integrated circuit) that will take in binary data and convert it to these tones, so we can easily plug output of this chip into the mic of a radio, and plug the speaker of the other radio into a computer to interpret the signals.

DTMF tones of different numbers

So we have a language to communicate the data, but we also need a way to get the data. You may think it's pretty simple, just take the GPS data and plug it into this magical chip. However, we have to convert the GPS data, which is stored in "float" (a type of variable which has numbers after the decimal point), into an array of numbers, so that they can be called individually. After a long time programming, filled with frustration, we finally got it. The video you see below is the GPS data being converted to individual numbers, and then displayed sequentially as binary numbers in four bits. It's probably hard to tell what the numbers are because the LED's are so bright, but the sequence is 2,6,3,7,8,0,3,7,8,4,0,0, and then it repeats again after all the LED's go on. This means that the location in "minutes" (1/60th of a degree) is 26.3780 by 37.8400. I disregarded the degrees because the balloon's trajectory should not cover more than a degree of latitude, and if it does, we'll know which degree area it is in anyway.

Now, all that's left is to get all of the hardware ready and test the range of the radios. That's still a lot of stuff to do, and we only have under 3 weeks left. This is the part of the project where stress levels rise to a record high. I'm fairly confident we can get all of it done, but we're nowhere near where I thought we'd be at this point. What's left on the shopping list? The balloon, the helium, and any materials we need to fashion the capsule. Oh yeah, and another unexpected cost came up recently. As it turns out, the radio range of 40+ miles is only reachable in the GMRS setting. And the FCC requires you to have a license to operate the GMRS channels. And the license costs $85. Yeah. Donations, anyone?

Update

There hasn't been a blog post in a while, so I figured I'd give everyone an update. 

We've finally collected all of our electronics equipment for the tracking device. I say that with some reservations, however, after making three or four separate shipments from the same electronics site within days of each other. You tend to not realize what it is you forgot to buy until after the shipment arrives. In short, we spent a little too much on shipping than we should have. So anyway, all of the equipment is here and I've already made some tests on the GPS with the arduino, and the radios. Thankfully I have access to the electronics equipment at school: oscilloscopes, storage-scopes, meters, etc. I hope to have the tracker finished by spring break, but I have a lot of work to do. I may post a video on the Facebook page of some tests in the weeks to come. In other news, we've decided on a launch date, which will be the weekend of April 18th-21st. Why those dates? Well that's another bit of news for you. Recently, I stumbled upon something called the Global Space Balloon Challenge. It's a worldwide competition for teams to enter who are doing projects just like us. We've decided to enter it, and the launch date is between the 18th and 21st of April. We'll be competing against high school, college, and independent teams from countries all over the world!

Well that's about all I have for now. Remember, go like our Facebook page at facebook.com/nearspaceadventures for the latest news and content. 

Oh yeah, and maybe you could help us out a little and press that shiny "donate" button over there on the right side of the page. Don't worry, it's through Paypal so it's quite secure. So yeah, press the button. I dare you.

Facebook (finally)

Just a quick update to say that we are finally on Facebook! Like our page to receive updates on new blog posts and exclusive media as we endeavor to make a second successful launch. Find it all at: https://www.facebook.com/nearspaceadventures

New Developments: Microcomputing and Arduino

As you may infer from the title, we have been making some progress and some changes in our project, relating to the implementation of microcomputers, specifically an Arduino Microcomputer, to control the whole mission. What is a Microcomputer? If you guessed that it's a really small computer, then you'd be right. Basically it's a programmable computer chip that can be used to control motors, LED's, read data from sensors, and things of that sort. It will serve as the "brain" of the mission, mainly to read GPS data and send the information over radio transmission. Arduino is the brand of microcomputer which we are using, mainly because I just got one (thank's Mom and Dad), and it'll be easy to program and buy the extra hardware for it.

Arduino Uno Microprocessor

 With the decision to use this method, we have cut some cost while adding more versatility to the mission. We now have the ability to run servos and motors, log altitude and temperature data, and a wide variety of other possibilities. One idea is to perform a HALO Launch, which is a High Altitude, Low Opening launch. This basically means that we would delay the activation of the parachute until it reaches a given altitude, like 1000 feet. This has two advantages. The main advantage is that it would lower the descent time considerably and the capsule would land very close to straight underneath where the balloon popped. The other advantage is that it would be totally awesome for the capsule to reach terminal velocity as it falls, which may be 100-200 miles per hour. Then again, if the parachute failed to open upon command, we would have a serious problem on our hands. We're still thinking this whole thing through.

To sum it all up, the Arduino is going to help us considerably in making a reliable recovery and data logging system. We'll keep you posted as we prototype and test these new ideas.

Near Space 14!

Yup, that's right, we're doing it again folks. Balloon Launch v2.0, A Grand Day Out: The Sequel, Near Space 2, whatever you want to call it, we're making a second journey to the stratosphere in a weather balloon. Well, not us personally, but you get the picture. Learning from previous mistakes and implementing some better, and invariably more expensive, telemetry technology, we're planning a launch in the Spring of 2014.

Why another launch?

The main reason is simply this: You can never get anything perfect the first time. That's something we found out quickly in our first launch. Apart from our landing predictions being totally blown out of the water and our payload landing 2 hours late and 30 miles away from where it should have, the camera only recorded footage up to 75,000 feet because the batteries ran out. So we want to make another launch that we can be completely satisfied with. Apart from the desire to get everything near-perfect, we also want to do things a little different, maybe add some scientific equipment or more cameras, so long as we stay under the 4 lb limit. But we'll discuss that later.

What will be different?

The biggest difference will be the telemetry. Instead of a cell phone with inconsistent coverage and limited operating area, we'll be using a pair of FRS radios (462-467 MHz) with a 40 mile range that will transmit little bursts of data containing GPS coordinates. The coordinates will be supplied by a serial GPS unit feeding data into a circuit board which translates the data into APRS format. This data is sent over the radio in packets about every minute, and the receiving radio plugs into a computer's sound card. A program then finally translates the sound data into readable GPS coordinates. We'll go into more detail in a later post. The second biggest difference is the size of balloon we're using. Instead of an 800g balloon like the one we used last launch, we're going to use either a 1000g or a 1200g balloon. We'll also need more helium than last launch, and hopefully the price won't have gone up too high (yes, there is a helium shortage). We also haven't decided on a location yet, but since the radios only require line-of-sight we could theoretically launch anywhere there is unrestricted airspace. I wonder if we'd get in trouble launching it across crater lake...

How much will it cost?

The launch we did last summer cost us around $460, and this year we're estimating the cost to be around $400. Half of that price is in expendables like helium and the balloon. We could stop there and do the launch at that price, but as I've mentioned before we are going to purchase telemetry equipment. This will cost the other $200. These estimates are a little high, but that is about the max we are planning to spend. 

Well that's about all I have for now, later I'll go into more detail about how exactly the telemetry works, and update you on the status of this next mission. As always, thanks for reading and check back with us often. You can email us at nearspace13@gmail.com if you have questions or want to donate to or sponsor our launch. 

 

Video and Pictures Now Available!

Hey you! See those tabs on the top that say "pictures" and "video"? click them. That's where I keep the pictures and video. Yep, pretty simple.