Near Space
However, I do not
110000
recommend you do this,
as I may have been 100000
lucky.
90000
I like to solder the
wires of the telephone 80000
cable to a straight male 70000
header with 0.1” between
centers. This type of 60000
header is available from 50000
Jameco as part number
Altitude (feet)
109575. I tin each wire 40000
and then slide thin heat 30000
shrink tubing over it.
Next, I tin the short 20000
pins in the header and 10000
press a tinned wire in contact with a header pin and 0
0
heat them with a soldering iron.
The solder on the
wire and the header pin
melts and fuses the wire to the pin.
After it cools, I slide the heat shrink
over the soldered connection and
shrink the tubing. Afterward, I can
plug the RM- 60 into the BOE’s breadboard or my flight computer, like I
would a servo.
I use the following code to
determine the counts per minute
from the RM- 60. My code is written
for the BS2pe, so you will need to
modify the count time if you use a
different flavor of BASIC Stamp. On
my flight computer, I store the
results into a RAM Pack B. If you are
sending up an RM- 60 with your BOE,
then you can store the results in the
EEPROM of the Stamp. After recovery, you can download the results of
the flight.
100
200
300
400 500
Flux (cpm)
600
700
800
900
Figure 4. Cosmic ray flux.
gm
radiation
CON
VAR
0
WORD
Geiger_Counter:
COUNT gm,34843,radiation
DEBUG DEC radiation
ray showers. There really are fewer
cosmic rays to detect, but each
detection on average contains more
energy.
Had this flight occurred shortly
after a solar flare, the cosmic ray flux
most likely would have continued
increasing above 62,000 feet. If the
mission had taken place closer to the
geomagnetic poles, the increase in
cosmic ray flux would have climbed
more rapidly.
So, get out there and start using
the RM- 60. For $150.00, it’s a great
little Geiger counter. I do not work for
Aware Electronics and I don’t receive
compensation from them. I’m just a
satisfied customer. Let me know how
your Geiger counter experiments
turn out. Remember that you can
contact the amateur near space
group closest to you and arrange for
them to carry your experiment into
near space.
Onwards and Upwards,
Your Near Space Guide NV
This code assumes the RM- 60 is
connected to P0 and counts the
number of pulses from the RM- 60 for
10 seconds. Since I have so many
other experiments onboard my near
spacecraft, my flight computer can
SEPTEMBER 2004
only afford to count cosmic rays for
10 seconds at a time. After recovery,
I download the results from the
Geiger counter into a spreadsheet
and multiply the results by six to get
the cosmic ray flux in units of counts
per minute.
In your experiments, you should
count cosmic rays at a fixed interval.
Use the APRS data from your near
spacecraft to determine the altitude
at each measurement. When you
combine the cosmic ray count with
the altitude in a spreadsheet, you
generate a chart like the one in Figure
4. It shows data that was recorded
and collected at the Great Plains
Super Launch on July 3, 2004. My
near spacecraft weighed nine pounds
and made an altitude of 104,571 feet
on a 1,500 gram balloon with 15
pounds of lift.
This chart is typical of what my
near spacecraft measure. The flux
increases with increasing altitude, as
Viktor Hess would be familiar with.
The cosmic ray flux increases until
an altitude of 62,000 feet is reached.
Higher than that, the cosmic ray flux
decreases. t appears that the drop in
cosmic ray flux occurs because the
near spacecraft enters a region
where there are primary cosmic rays
that have not yet produced cosmic
Resources
Parallax — www.parallax.com
Aware Electronics — www.aw-el.com
Jameco — www.jameco.com
OnSet — http://onsetcomp.com
101