Missions‎ > ‎

NSL-79 ATW-1

Around-the-World #1 (ATW-1)      Project Helios

David (Alex) W. has been flying weather balloons with his father Tim for years.  This past November, Alex made a friendly wager with his friend, that Alex could send a balloon around the world before their upcoming high school graduation.
  Alex's wager

Alex code named his first attempt of his Project Helios, Around-The-World #1 (ATW-1)

NSL-78 was a brief test of this flight's hardware, a LightAPRS-W tracker.  This is a solar-powered computer, GPS, and two radio transmitters -- frequency adjusting 2m APRS, and long-range 20m WSPR.

     Tracker mounted to back side of solar panel

After NSL-78, the hardware was rebuilt and attached to a specially constructed, superpressure "pico" balloon.  A small amount of H2 was added to achieve just a few grams of free lift.  The system was launched from Cardinal Gibbons High School on the afternoon of January 29, 2020.

   Alex prepping for launch from Cardinal Gibbons High School

Powered exclusively by horizontally mounted solar panels, this balloon would only transmit from mid-morning to mid-afternoon.  A super capacitor buffered the power load for the LightAPRS-W board which would wake-up, gather GPS data, and then transmit tracking data on a specific schedule.  At specified times, the tracker would send out 20m WSPR packets.  These took considerable time to transmit and only contained basic information -- namely transmitted power and a 4-character Maidenhead Grid Square coordinate.  This gave the flight's location within 1° latitude by 2° longitude (70 mile x 100 mile rectangle).
In between WSPR packets, the transmitter would also send APRS packets.  APRS telemetry provided exact location, altitude, solar voltage, board temperature, speed, heading, and GPS coverage.  Different countries use different APRS frequencies in the 2m band, and a few countries prohibit it entirely.  The computer had to figure out, from its GPS location, what APRS frequency to use, if any.

From January 29th through February 8th, we tracked the payload daily as it made its way successfully around the world!

Flight notes

  Day 1 Initial flight projection

   Day 2 over the Atlantic via WSPR

   Day 3  APRS data shows nearing Ireland

   Day 4  Over Hungary and Romainia

   Day 5 APRS data over Turkey
   Note the strong winds across Middle East and China

   Day 6  Plotting WSPR locations over Afghanistan

   Day 7  Daylight over China

   APRS telemetry still looking good

  Day 8  Morning wake-up off the coast of Japan

   Day 9 Pacific between Hawaii and Dutch Harbor

  Day 10 Approaching North America
   Prediction for the following three days

   Day 11 Wyoming and Colorado
  Will it miss Colorado storms?

   Day 12  Completed first trip around the world !

12 Feb, 2020:  Flight has since continued on to England and then down to Morocco and over to Egypt.
17 Feb 2020:  Flight has come ashore in North America again.  Currently floating over Mexico