A balloon launched on May 20 by “Amateur Radio Roundtable” web show host Tom Medlin, W5KUB, and team has begun its third circumnavigation of Earth. The balloon, at 43,000 – 45,000 feet, completed its second trip around the globe on June 19. It crossed the Atlantic ocean “in record time” at a speed of about 170 MPH, the balloon website reported this week.
The balloon, identified as W5KUB-18, carries APRS and WSPR amateur radio payloads. As of the afternoon of June 23, it was heading over Uzbekistan at over 100 MPH.
As the balloon website states, the mission and goal are to launch a high-altitude balloon for long-duration and multiple trips around the world. The balloon, an SBS-13, is capable of flying up to 45,000 feet. “It will be filled with hydrogen to obtain higher altitude,” the website explains. “It will be solar powered only (no batteries, so it will only transmit during daylight). We will receive tracking every 10 minutes via WSPR on HF [14.0971 MHz].” Tracking transmissions will be turned off over the UK, Yemen, and North Korea due to regulations. The homebrew tracking transmitter runs just 10 mW but, Medlin told ARRL, it’s being heard as far away as 9,000 miles.
“The entire tracker with GPS and processor is only 2 grams,” Medlin said. “That’s about the weight of a penny. The entire payload is only 15 grams total.” The current effort is the group’s 9th attempt to circumnavigate the globe.
Medlin says the balloon project has broadened his horizons. “You have to do a lot of specific engineering and measurements down to the 0.1 gram to fly one,” he told ARRL. “You also become a weatherman, watching all the NOAA websites, winds at different altitudes, storms, etc. Storms will bring you down,” Medlin said. With the float altitude set at 44,000 feet, he expects to be able to fly above most storms. “You also become very well-versed in geography as it flies,” he added.
Medlin’s livestreamed “Amateur Radio Roundtable” (promotional) goes live on Tuesdays at 9 PM Eastern Time and accepts calls from viewers. The show is simulcast on HF at 5,130 kHz. He has operated a live cam at Dayton Hamvention® for several years.
“It’s been a great experience, and hams around the world are having a great time,” Medlin attested. “I even issue them a certificate for being part of the experience. Many young people are watching and getting involved, and teachers who teach STEM are contacting me to get information and help. We are having fun.”