Great Plains Super Launch 2015
Paul Verhage - Transatlantic attempts
Paul Verhage opened the session with a talk on a transatlantic attempt, six Washington student launches, four for Idaho, and a workshop for teachers about BalloonSats.
The transatlantic, latex flight launched with three ounces of lift in the late afternoon. It used a tinytrack. Using lead weights for balance, it drifted all night. Electronic tracking shut down reportedly from the cold. Cameras were too cold to operate, but interestingly, the GoPro continued to work. Paul explained how it may be the metal casing that allows GoPro cameras to withstand conditions even outside the payload. We later tried this with our GPSL2015 flight, and got good results to at least our maximum altitude of ~314,000ft / 3440 m. Also, apparently it is a known issue with the Canon cameras that they can interfere with radio. Simply covering it with aluminum foil should fix the problem. This launch got good media coverage. Paul also suggested protecting the latex from degradation with a covering like mylar or metal coating. The best time to access the strongest winds is during the end of November to the end of March. Mark Connor, a meteorologist, helps predict weather to determine when to launch. Paul discussed the balloons needed for these sorts of flights. Ideal sizes like the 4K-6k gram balloons are in the $400 dollar range, but one can use as low as a 1000g balloon. There is data somewhere to show how the smaller balloons do not allow for superpressure. From my research, much of the pressure calculations come from the expertise of Joe Mayenshein, Mike Manes, and Jerry Gable.
Paul mentioned his Idaho schools launch with the Cascade Science Class.
Paul described how 4th graders helped design the experiment to test if rubber bands could hold down hatches during flights. It worked. Good ideas can come from many places, especially while teaching.
He then explained the UNO Aerospace Education Workshop for teachers. By making teachers build it, they become comfortable with HABs and can then be ready to take them into their classrooms. He also described the goals of his conferences: to aquaint teachers with the existence and benefits of BalloonSats. Only $170 consumables. Gas may be available for free for many schools. Some schools block out an entire Friday for a flight day. Overall, this gives students STEM experience and allows them to travel where they cannot go in person.
I was excited to hear about the “Near Space Explorer,” a journal for publishing student work with HABs.
Future projects included: The “Near Space Explorer,” PICAXE electronics/programming trainer, CubeSat trainer, expanded BalloonSat kits, and BalloonSats without Borders (like Doctors without Borders, but with HABs).
Mel Whitten, Digital Video Broadcasting
Mul Whitten gave a first-class talk about digital video broadcasting (DVB) that was impressive and informative. He briefly gave background on the history of advances in file compression formats that have ultimately led to DVB. DVB was introduced in the UK in 1998, and while the USA has its own TV standard, HAMs prefer DVB over ATSC for its preferred transmission over narrow, robust bands and its low cost. ATSC is 5-10x more costly than DVB. Another issue is ATSC is patented, and each HDTV pays ~$50 to use it. DVB is opensource. Uses of DVB include digital signage or super local broadcasting.
Did you know MPEG stands for Motion Picture Expert Group and it uses prediction with movement compensation? This means, MPEG takes groups of pictures to estimate and reduce data required for each individual picture. Elementary streams are then further compressed.
DVB uses forward error correction to correct for noise bursts, but the more you add, the more latency. In other words, you wait longer from the time the image is recorded until you see it on the screen. The advantage here is that compared to analog, with digital video broadcasting, one can control this latency.
Some ideas I had never heard of: COFDM (coded orthogonal frequency division multiplexing) and guard intervals.
Then he elaborated on how to get on the air with DVB. He mentioned a great Taiwanese design house: ITE. Their product has API available to code your own stuff.
For a USB modulator/demodulator, see the HIDES UT-100B. It doesn’t get much easier. Broadcasting at 1080p HD.264.
Get a camera, like the HiDes DC-103, with 1080p, it weighs only a few ounces and is ~2in cubed. It only runs a few milliwats. It has a programmable frequency and uses an embedded linux OS.
So in review, a PC with Win7 or 8 is a given, add camera like DC-103, a transmitter/reciever like the UT100 dongle and a Yagi antennae. He also talked about other “wheel antennae.”
He uses a OE7DBH amplifier, or use Mitsubishi mosfit brick.
Some HAMs will use analog video to get to the P2 level and then switch to digital.
There is also a system called BATC which is a digipeater that allows for DVB, sort of like the UStream for HAM operators.
Bill Brown, Pico Balloons
Bill Brown talked next about Pico Balloons, and Leo Bodnar (M0XER), a cold-temperature lipo pack that can be ordered custom, for a price.
He talked about Alan Adamson’s peach-2 build, an open source radio with code available on github. It is totally powered by solar. For solar power use in general, look at PowerFilm. He discussed how to get materials for highpressure balloons; a Japanese company makes a nice material but they sell it in minimal quantities of 1000 sq. ft rolls. Mylar can be purchased from balloonsdirect.com.
He described the WSPRnet, a Weak Signal Propagation Reporter Network, and its possibilities for pico balloons.
He described Ron in California’s mass-flow reader. An expensive item that allows for precise balloon filling. He described the need for a pressure release valve with specs like a flat, plastic drinking straw.
He then showed off his Iridium satellite-based tracking system. He mentioned the Tracker9 available from radiobro, but I have had a hard time finding more information on this.
For radio direction finding, he mentioned two transmitters: the SquawkBox T-hunt and the MicroHunt T-hunt.
Phil Bunch, Radio Direction Finding
Phil Bunch gave a nice introduction to radio direction finding. Later, he helped us look for Carlton Corbitt’s payload and our balloon.
Atom, RoboMo Drones
Atom from RoboMo gave an really great talk on drones in general. We talked about how drones could help with the balloon recovery, but I was most excited about seeing his live demo and the discussion about what tech is currently available under $2k. I was impressed how he pulled the drone out of the air.
Bill Coby, Digital Photography
Finally, Bill Coby provided an introductory talk on digital photography. While trying to compress an entire semester of study into one short talk, Bill talked about apertures, the rule of thirds, separating the flash from your camera to reduce red eye, focus, filling your image with the important stuff, and much more. I wish we could have worked on some images from HAB flights together. He showed us videos he helped script and talked a little about some of the great experiences photography has afforded him over a long career.