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1. Picoballoon Launch 19: Midway Islands

   The SF-HAB group launched another picoballoon on December 11th, 2021, from the Berkeley Marina. The launch party was Martin W6MRR, Robert K6RGG, and Kazu AG6NS. This picoballoon used two clear Chinese party balloons with hydrogen gas for lift. Martin's custom electronics was used, with a WSPR transmitter that alternated 14 MHz (20 meters) and 10 MHz (30 meters).

   The aprs.fi callsign was W6MRR-22 using the WSPR to APRS bridge, and the WSPR callsign was W6MRR.

   

   This picoballoon floated between 9,900 and 11,100 meters (32.5k to 36.5k feet) for the duration of the flight, which is the perfect altitude for picoballoons. This is above most bad weather (rain and thunderstorms), but still low enough to be in the fast part of the jetstream.

   From Oakland, this picoballoon headed east at a pretty fast clip. In total, it traveled about 23,000 km (~17,000 miles) in 12 days, for an average speed of about 80 km/hr (~50 MPH).

   One interesting thing was that this balloon was not received on Dec 20th and 21st, when it ...

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2. Picoballoon Launch 18: Almost around the World!

   While the previous Lodi picoballoon was floating over Mexico City, we launched another picoballoon from the southeast corner of the Berkeley Marina on November 13th, 2021. The launch party was Martin W6MRR, Robert K6RGG, Kazu AG6NS, and myself KF6ZEO.

   

   The forecast for the morning was no wind, and when we arrived at 10am the winds felt pretty calm. But after assembling the picoballoon train, it was apparent that even the very light breeze was too strong. The two clear Chinese party balloons were bent over, threatening to scrape against the ground.

   We waited almost 30 minutes for the winds to die down enough to release the picoballoon. During a bit of a lull in the wind, we walked across the parking lot while slowly releasing the balloon, kind of an in-motion release. This worked pretty well, and liftoff was at 10:30am local time (1830 UTC).

   The tracker electronics were built by Martin W6MRR, and we used two clear Chinese party balloons with hydrogen for lift. The WSPR callsign was W6MRR, and the APRS callsign was W6MRR-21.

   W6MRR-21 Flight Results ...

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3. Picoballoon Launch 17: Lodi to Florida

   SF-HAB's Central Valley Division launched a picoballoon from Lodi, California, on Thursday November 11th, 2021. The launch party was David WB6TOU and Skip N6NFB. The tracker electronics used this time was a ZachTek WSPR Pico transmitter. Two Chinese party balloons were used for lift.

   

   

   The WSPR callsign for the balloon was N6NFB, and the APRS callsign was N6NFB-1.

   

   N6NFB-1 Flight Results

   Unfortunately, the tracker electronics did not power up on launch day, November 11th. We thought all was lost, but it awoke the next day in Maidenhead grid square DL58, which is ~1640 km (~885 mi) southeast of the launch location. The balloon was at an altitude between 9,900 and 11,100 meters (~32.4k to ~36.4k feet). Only 11 WSPR packets were received by the network on the second day.

   

   In total, only 29 packets from this picoballoon were received by the WSPR network, indicating that something was wrong with the transmitter or antenna. This balloon transmitted for 3 days total.

   The last packet received from this picoballoon on November 14th was in EL77, which is about ...

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4. Pacificon 2021 Picoballoon and Radiosonde Presentation

   David WB6TOU, Martin W6MRR, and myself gave a presentation at the Pacificon, which is the annual ARRL Pacific Division ham radio conference held in San Ramon in the fall. Our presentation was titled "Picoballooning in the Bay Area: High Altitude Balloons, Picoballoons, and Radiosondes." Download the slides here.

   We also used this opportunity to launch the new SF-HAB website, which is a collection of how-tos, resources, and blog posts about our ballooning activities.

   The first third of the presentation was David talking about balloon mechanics, including how to prestrech, fill, measure, and release SBS-13 and cheap Aliexpress picoballoons. David launched two SBS-13 picoballoons from the Central Valley in winter 2021, one of which went 2.5 times around the world.

   

   The second third was Martin talking about picoballoon electronics. He discussed using APRS and WSPR for publishing telemetryon the internet. Martin designed and built a custom tracker for all of the picoballoon launches we have done from the Berkeley Marina.

   The last third of the presentation was yours truly talking about radiosondes. I gave a brief overview of their purpose ...

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5. October 2021 Picoballoon Activities: Launches 12 thru 16

   In the beginning of October 2021, we had a flurry of launches from the Berkeley Marina. In the span of two weeks, we launched five balloons. All of the picoballoons woke up after launch, which means that we are getting better at building, testing, and launching picoballoons. But unfortunately, only one of them survived the first night and woke up the next day. We can't achieve our goal of going around the world if the picoballoons only last for one day!

   All of these picoballoons used the same custom electronics designed and built by Martin W6MRR. Two cheap Aliexpress 36-inch clear plastic balloons were used, with around 6 grams of free lift.

   Picoballoon Launch 12: K6RGG-11

   On Thursday, Sept 30th, we launched just after noon local time (1900 UTC). The launch party was Martin W6MRR and Robert K6RGG. The tracker turned on about an hour later at 2022 UTC.

   

   This picoballoon was interesting because the tracker alternated transmitting WSPR beacons on 20 meters (14 MHz) and 30 meters (10 MHz). The antenna was the standard 20m dipole, not tuned for ...

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6. Picoballoon Launch 11: The Intermittent Picoballoon

   We launched again on Monday, September 20th, 2021, from our usual spot in the Berkeley Marina. The launch party was Martin W6MRR and Robert K6RGG, and the launch time was a bit later than usual at 11:30am Pacific time (1830 UTC). The picoballoon did not wake up on launch day. After our previous halfway around the world picoballoon, we were a bit dismayed to have another failed launch.

   

   But the following day it woke up! The picoballoon was meandering out in the Pacific Ocean in gridsquare CL79, somewhere between 9,900 and 11,100 meters (32.5k to 36.5k feet). While this is higher than most of our previous picoballoons, our ideal altitude is above 11,100 meters, which is higher than most bad weather but still in the jetstream.

   Something was definitely wrong with the tracker, because on Tuesday Sept 21st we only received a total of 7 packets from KFS and KPH (pdf). These two stations have have huge antennas right on the California coast near San Francisco, with excellent receivers. I ran a Hysplit prediction ...

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7. Picoballoon Launch 10: Halfway Around the World!

   At the beginning of Week 3 of Launch 10, we were getting excited that this balloon might circumnavigate the globe. The prediction made from the middle of Egypt showed strong winds would take the balloon to the West Coast within 5 days, maybe even crossing the -122 degree longitude line of our launch site before heading back out to sea.

   

   Flight Results

   Unfortunately, the picoballoon only survived two more days in the Middle East. In a situation eerily similar to W6MRR-17, a single packet was received from the ground in southwest Uzbekistan near the Turkmenistan border. The altitude reported was less than 900 meters (encoded in the WSPR power field as 0 dBm or 1 mW). Maybe the tracker was stuck in a tree, or just laying on the ground, we will never know. The single packet from the ground was received by Jari Perkiömäki OH6BG in Finland, approximately 3,700 km away.

   

   This picoballoon made it all the way from gridsquare CM87 to MN10. The center of MN10 is 63 degrees East longitude, which means that the balloon traveled ...

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8. Picoballoon Launch 10: First Two Weeks

   After the previous three picoballoons did not turn on, we were really struggling to launch another. Was it worth it to build trackers, inflate balloons, and get up early to launch a balloon that never turned on? Luckily, we powered thru and launched another picoballoon on Saturday, Sept 4th, 2021, from our usual spot in the Berkeley Marina.

   The team met at 9am, which is a bit later than usual. It was still very cloudy, so the actual launch didn't happen until 9:50am Pacific time (1650 UTC). The launch party was Martin W6MRR, Rob NZ6J, and Robert K6RGG.

   

   

   The tracker was released in full sunlight without getting wet in the bay.

   Predictions

   Running HYSPLIT predictions on the morning of the launch, the trajectory of the balloon was really dependent on what altitude the balloon finally reached. Lower altitudes, such as the red line at 9,000 meters, showed the balloon spinning in circles around the western United States. If we could reach 10,000 meters, the balloon had a good chance of reaching the Atlantic Ocean within 3 days ...

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9. Picoballoon Launch 9

   With the lessons learned from the failed previous launch, we decided to launch again the next weekend, August 28th, 2021. The launch party was Martin W6MRR, Justin, Robert K6RGG, and myself KF6ZEO. We launched again from the northwest corner of the Berkeley Marina.

   Our major lesson learned from the previous launch failure was there should be no fog or clouds at the launch site. Fog or clouds can condense on the balloon surface or tracker electronics, weighing down the picoballoon so it falls out of the sky. In addition, any winds or downdrafts associated with clouds can push the balloon into the ground.

   This morning there was no fog or clouds, but the smoke from the Caldor and Dixie fires meant the sun was a beautiful burnt orange color as I was heading to the launch site. You could barely see San Francisco from the Berkeley Marina.

   

   The winds felt very calm when we were ready to launch, and there was no wind ripples on the surface of the bay. But looks can be deceiving, and the very light breeze ...

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