Attendees learned that these students
were designing and flying BalloonSats
with photometers in an effort to
measure the intensity of sunlight as a
function of altitude. One of their
references for this project was an
article I wrote about LED-based
photometers for Nuts & Volts.
Next up was me. I presented
on near space STEM (science,
technology, engineering, and
mathematics). The audience learned
about two near space launches I did
for the Bellevue School District
(Washington) this spring and the data
I hoped to collect. As it turns out, I’m
still in the process of collecting data
from 114 students in two states.
I also described two BalloonSat
activities I’m designing for
implementation in Idaho. First are the
BalloonSat classes I’m preparing to
teach through community education
in both Boise and Twin Falls. The
classes will be similar to a robotics
class I taught through community
education this spring.
I also shared my plan to bring
additional STEM educational
opportunities to Idaho students
through the Idaho Space Grant
Consortium. This project doesn’t
bring BalloonSats and near space
activities directly to students. Instead,
it’s a program that shows teachers
how to incorporate BalloonSats into
their curriculum.
Our third presenter was Dr.
Matthew Nelson. He brought a
national educational ballooning
organization to our attention. Model
rocketry has NAR and Tripoli, while
model aircraft has AMA. At this time,
however, no national organization for
amateur near space explorers exists.
Dr. Nelson shared with us several
reasons why an educational
organization might be useful to
amateurs like us.
First was the possibility of
insurance for our activity, and
second was the voice it gave to us
during discussions about changes in
federal regulations affecting our
activity. As in years past, there was
some disagreement about the
importance of a national organization
to the amateur community.
After Dr. Nelson’s presentation,
we took a break for lunch and a
demonstration of the vacuum cannon
by your humble author. Vacuum
cannons are amazing for their
simplicity and capability.
A vacuum cannon is a PVC tube
containing a ping pong ball and is
sealed at both ends with Mylar film.
An inexpensive vacuum pump then
removes the air inside the PVC tube.
When the Mylar film located on the
end opposite the ping pong ball is
cut, air rushes in creating pressure on
one side of the ball. That pressure
generates a force of around
20 pounds that accelerates the
seven gram ping pong ball at over
100 gees.
The result of this acceleration is
that after a distance of five feet, the
ping pong ball breaks out of the
other Mylar film with a bang traveling
at approximately 300 miles per hour.
Even a low mass ping pong ball will
rip through an empty aluminum can
if it’s traveling that fast. Now, that’s
what I call a demonstration of the
power of a vacuum.
After lunch, Bill Brown from
Huntsville, AL gave a presentation on
long duration balloon flights and
telemetry modes. Both Bill and the
California Near Space Project are
known for their long duration balloon
flights. They have demonstrated
several times that a latex weather
balloon launched near evening and
with just enough lift to carry a small
payload can drift across the United
States and the Atlantic Ocean before
bursting.
Bill’s telemetry modes include
some that transmit at low radio
frequencies. These HF signals are
capable of traveling much farther
than the higher frequency signals that
most of our near space payloads use.
That increased range makes these
lower frequency modes ideal for long
duration flights.
Our next presenter was Michael
Willett of ARBONET (Amateur Radio
Ballooning Over North East Texas).
Like me, he is focusing a lot of his
effort on using BalloonSats as a tool
for STEM education in school.
Michael then shared his thoughts on
using solar power for near space
flights.
One limitation on long duration
flights is their power requirement. If
the balloon remains airborne long
enough, the batteries supplying
power to its payload are bound to
die. As Michael explained, using solar
power wisely is one way to get
around this limitation.
Jim Emmert gave the final
presentation. His topic was about an
amazing animal called the Tardigrade,
or water bear. These tiny one
millimeter-long creatures can survive
extreme conditions like intense cold,
high vacuum, and lethal doses of
radiation by entering into a state
called tun. It’s a hibernation state in
which the Tardigrade’s body dries
out. Jim’s students want to
experiment on Tardigrades by
launching them into near space.
The presentation portion of GPSL
closed with a weather report and
flight prediction given by
meteorologist Mark Conner of
NSTAR (Nebraska Stratospheric
Amateur Radio). There was concern
earlier in the week that we would
cancel the launch portion of the
conference because of the amount of
rain Pella was experiencing.
APPROACHING THE FINAL FRONTIER
Pella was settled in 1847 by 800 Dutch immigrants
looking for religious freedom. It's also the home of Wyatt
Earp — a gunfighter at the OK Corral. Every May, Pella holds
the Tulip Festival. Where else can you purchase a pair of
wooden shoes and go dancing in town?
September 2013 13
