NSL-90

Red Earth / Blue Earth

NSL-90 launched on the morning of Sunday, May 2, 2021. Matthew L. had some experiments to try. His 700g payload consisted of a single box with:

• • AP510 APRS tracker

  • TTGO T-beam LoRa tracker

  • Mobius Mini camera (70 degree field of view)

  • 808 #16 camera with its infrared-cut filter removed (120 degree field of view)

  • Various plant seeds experience high altitude radiation

An old 808 wide-angle camera had its infrared-blocking filter removed to help show some of the differences in springtime NC. Light below red, now allowed into the camera, would activate primarily the red and blue sensors. This gives the video a strange magenta hue and strong IR reflectors, like plants, will show up much brighter. A normal Mobius Mini camera, mounted along side as a "context camera", had a smaller field of view.

Tim W. and Paul L. assisted on this flight. A 600g cell was filled with H₂ to produce 2kg of neck lift.

This shows the Apex area from above with the "wide band" camera. A pseudo-near-infrared image can then be processed by taking the camera's sensitivity and Bayer filter into account. Young leaves of deciduous trees look different than evergreens.

Above are similar views from the two cameras. Water shows up especially dark using the "IR" camera.

The flight progressed as expected. At 14km altitude, the flight ascended through a cirrus cloud layer. A shower of tiny ice crystals are seen and heard on the video recordings. The chase crew continued down to Farmville, NC for recovery. As NSL-90 passed 20km, the balloon flew above the eastward jet stream. So the flight just spun in lazy circles as it ascended. Again on this flight, Habhub's ingest of APRS data seemed to be on a 10 minute delay.

The cell burst at 31141.5m (102,170ft).
The chase crew waited patiently near Maury, NC. But it was soon discovered that the flight was descending too fast. The balloon remains fouled the parachute. So Tim and Paul drove their cars west to the more densely forested area around Snow Hill, NC.

Ten minutes after touchdown, they arrived in the area and received a fix on the payload's resting place. It reported being 15m above ground level. Thankfully, Tim is excellent with a bow, arrow, and line. So after securing safe land access, the crew loaded up on bug spray and headed into the woods for retrieval.