Mark was able to give us good
news during his briefing; we had a
rain-free window suitable for
launching on Saturday morning. We
then finished Friday by preparing
near spacecraft and attending a
June 15, 2013
Saturday morning took
place in a parking lot at
NearSys launched four
balloons Saturday — a
record for the number of
launches by a single
person or organization.
Launching that many
balloons meant I spent a
lot of time running from one balloon
to another preparing them for filling.
However, once the balloon filling
began, I tended to stay with each
balloon until it was launched. I want
to thank Mark Conner (N9XTN), Bill
Brown (WB8ELK), Keith Kaiser
(WA0TJT), Mike Moody (KD0MEQ),
and Pete Lilja (KC0GPB) for sharing
balloons and hydrogen with me.
The four NearSys flights reached
altitudes of 67,000, 87,000, 93,000,
and 103,000 feet. I programmed
three of the missions to collect data
and would like to share some of
those results with you.
Figure 1 is a good example of
atmospheric temperature change. It
illustrates how the location of the
troposphere, stratosphere, and the
boundary between them — the
tropopause — are defined by their
Initially, the temperature of the
air decreases as the balloon climbs
14 September 2013
FIGURE 2. This data was collected using a
Honeywell HIH-4000 relative humidity sensor.
Like the LM335, it produces a voltage
proportional to the relative humidity.
FIGURE 3. One of the best cosmic ray sensors
I have found is the Aware Electronics RM- 60.
It runs off of five volts and produces a five volt
pulse when it detects a passing cosmic ray. The
PICAXE's COUNT command collected the data
displayed in this chart.
FIGURE 4. A GPS receiver can be a sensor of sorts.
Two pieces of data coming out of it are the speed and
altitude to the GPS receiver. Since the GPS is firmly
attached to the balloon and the balloon is a captive
to the wind, the GPS indicates the speed and
direction of the wind.
The flight path of the four NearSys missions is shown in this
closer to Pella. Both GPS trackers used on NearSys 13E failed
during its flight which is why its flight path ends early in descent.
It wasn't difficult to recover the flight, however, as one of the
trackers managed to spit out a position report at an
altitude of 5,000 feet.
FIGURE 1. The sensor used in this experiment is
an LM335 temperature sensor. It behaves like a
temperature-controlled zener diode and produces
a voltage proportional to its temperature. Its
output voltage was digitized using the eight-bit
ADC command found in a PICAXE.