James Flaten
Associate Director of the MN Space Grant
Aerospace Engineering and Mechanics (AEM) Department
University of Minnesota – Twin Cities
flaten@aem.umn.edu
http://www.aem.umn.edu/people/faculty/flaten/AEM1905BallooningSampleDocuments/
Abstract/Conclusions
 High-altitude ballooning (HAB) can offer an genuine,
hands-on spacecraft build-and-fly experience to
undergraduates, including freshmen, in a time-limited
and money-limited context.
 Freshman seminar class participants are very engaged
and gain experience with the engineering design cycle.
Teams generate significant oral and written documents.
 Challenges associated with conducting a class balloon
launch are substantial but surmountable.
 Early (exceptional) hands-on engineering experiences
like this can entice new students to study STEM and
motivate potential majors to stick with STEM studies.
Outline
 What is high-altitude ballooning (HAB)? FAQs
 AEM 1905: “Spaceflight with Ballooning” (Freshman
Seminar)
 The utility of HAB in broader educational contexts
FAQ about high-altitude ballooning (HAB)
 What does HAB look like (launch, recovery, etc.)?
 Where do HAB missions go and what is “near-space” like?
 Who is involved in HAB and why?
 How is HAB regulated and what does it cost (approx)?
 How can you learn to fly HAB missions?
What does HAB look like (launch, recovery, etc.)?
Video clip of a recent launch from St. Peter, MN – June 5, 2013
800-gram latex weather balloon (AKA sounding balloon)
About 4-lb payload – flight went to 84,846 ft.
(This was a “small” launch – more typically we fly
1500-gram balloons and 12-lb payload stacks.)
What does HAB look like (launch, recovery, etc.)?
What does HAB look like (launch, recovery, etc.)?
Rockettes payload
with mirror boom
and cable up to
sensor pack in
the balloon above.
1500 gram heliumfilled latex weather
balloon (AKA sounding
balloon)
8-foot parachute
Random Guys payload with Geiger
counter experiment.
Shroud lines and
shroud ring
BBBC payload with
look-up video and
audio recorder.
Stratostar tracking
package (GPS and
ham radio #1)
Team Sweetness
payload with lookdown camera and
filter wheel.
Stratostar tracking
package (GPS and
ham radio #2)
What does HAB look like (launch, recovery, etc.)?
Where do HAB missions go and what is “near-space” like?
HAB missions are tracked/chased using GPS/radio systems.
They drift 30 – 80 miles (or more) during ~2 hours in flight.
Where do HAB missions go and what is “near-space” like?
The 4 layers of
the atmosphere.
Thermosphere – above 80 km
(satellites fly here)
Mesosphere – up to 80 km
Stratosphere – up to 50 km
(balloons reach here)
(includes the ozone layer)
Troposphere – up to 12 km
(planes fly here)
(weather happens here)
Where do HAB missions go and what is “near-space” like?
“Near-space” (the stratosphere)
 Looks similar to outer space
 blackness of space
 limited depth of the atmosphere
 curvature of the Earth visible (barely)
 Feels similar to outer space
 low pressure
 low temperature (part way up)
 elevated (cosmic) radiation levels
Who is involved in HAB and why?
 The weather service
 Balloon data is collected daily and used for making weather forecasts
 Space enthusiasts (especially ham radio operators)
 For fun – cannot resist participating in an “amateur space program”
 Schools (I work with undergraduates (all levels) and pre-college
teachers and their students; grad student research also doable)



This activity motivates students and encourages them to think seriously
about outer space (one of the goals of Space Grant).
This is much cheaper than actually going into outer space (using rockets),
but has many of the same engineering challenges.
You can do real experiments in the near-space environment: remote
sensing, atmospheric studies, space hardware demonstrations, etc…
How is HAB regulated and what does it cost (approx)?
 HAB is regulated by the FAA under the rules called “FAR 101”
 In general you do not need FAA permission if you stay under 12 lb for
total payload weight (6 lb max per package) and operate safely (e.g.
don’t launch near airports, land well clear of metropolitan areas, etc.)
 Approximate costs:



GPS tracking equipment (flight and ground equipment) – a couple
thousand dollars (or more), plus laptop(s)
Science components – a few hundred dollars per payload (but these
items are reusable)
Genuine consumables (balloon, helium, batteries, mileage) – about
$500 per flight, on average
How can you learn to fly HAB missions?
 Attend a ballooning workshop and/or collaborate with an
existing ballooning group.




Payload-building
Handling weather balloons
GPS tracking (with ham radios)
Recovery techniques
 Advice – try to find someone who
already has ballooning equipment
to fly your payloads at first, before
deciding to sink in real money (for
the GPS tracking equipment).
AEM 1905 “Spaceflight with Ballooning” class
(Freshman Seminar)
 Taught 4 fall semesters in a row (2008 – 2011)
 Capped at 20 students – must be incoming freshmen
 No prerequisites – students backgrounds varied widely
 Worth 2 credits (but is the work of 3 credits!)
 Generic credit – not required by any specific major
 Not an explicit recruiting tool for aerospace/engineering,
but participants gain a better appreciation of spaceflight
& of STEM fields (at least)
AEM 1905 “Spaceflight with Ballooning” class
(Freshman Seminar)
 The payload project plus the HAB flight (all-day field
trip) are central to the course (in addition to talking
regularly about freshman issues/succeeding in college)
 Student teams did a series of 3 oral design reviews plus
submitted 3 revisions of written documentation about
their payload. Sample reports, plus other curricular
materials, are posted at
http://www.aem.umn.edu/people/faculty/flaten/AEM1905BallooningSam
pleDocuments/
AEM 1905 “Spaceflight with Ballooning” class
(Freshman Seminar)
Each team needed to build a payload shell and outfit it:





Cannot exceed 2 lb yet is insulating and physically strong
enough to let interior science components survive the flight
Solder a resistive heater and computer/sensor pack (from a kit)
Log temperature (inside & outside), pressure, and rel. humidity
Carry a camera and do a science investigation with the photos
Do one more “unique science experiment” (instr. permission)
HOBO data logger
To record temp. in
box, in balloon,&
outside.
BASIC Stamp I
Flight computer
To record temp.
& pressure in the
balloon.
Resistive heater.
Digital still camera.
Thick styrofoam
box construction.
Cable running to
sensor pack to be
inserted in balloon.
Mirrors on boom so camera
can look out, up, and down.
Photo 60 – just before release
Photo 69 – about 5,500 feet
Photo 115 – about 37,000 feet
Photo 174 – about 77,000 feet
Photo 192 – just after burst, about 85,000 feet
Photo 248 – nearing touchdown, under 500 feet
Pressure vs Time
1000
800
Pressure (millibar)
600
400
Series1
200
0
-20
0
-200
20
40
60
80
Time (minutes)
100
120
140
160
180
Frames from BBBBC video camera watching balloon.
The initial balloon diameter is about 10 feet.
73 minutes into the flight at about 89,000 feet.
The balloon is now about 30 feet in diameter.
Notice balloon starting to tear from
the bottom of the video frame.
In 1/30th of a second (one frame on the video)
the entire balloon is destroyed.
How this class fits in to AEM Dept. and MnSGC offerings:
It has spurred more hands-on options, especially for freshmen.
Summer
Ballooning
Teams
Uninhabited
Aerial Vehicles
Freshman Sem.
Technical
Elective &
Sr. Design
Spaceflight with
Ballooning
Freshman Sem.
Ballooning with
pre-college groups
High-power
Rocketry
Freshman Sem.
Closing Comments
 Each year students report changing majors toward STEM
due to the influence of this class and several from each
class have stuck around to do extracurricular ballooning.
 Challenges often center around the logistics of getting the
whole class off-campus for a full day (a weekend day) late
in the semester for a weather-dependent event. Do make
contingency plans for the possibility of not being able to
fly or not successfully recovering the payloads (rare).
 Learning to do balloon launches is non-trivial so perhaps
learn to do that before considering offering such a class.
 Funding comes from the U of MN’s CSE Dean’s office and
from the MN Space Grant Consortium. Thanks!
Abstract/Conclusions
 High-altitude ballooning (HAB) can offer an genuine,
hands-on spacecraft build-and-fly experience to
undergraduates, including freshmen, in a time-limited
and money-limited context.
 Freshman seminar class participants are very engaged
and gain experience with the engineering design cycle.
Teams generate significant oral and written documents.
 Challenges associated with conducting a class balloon
launch are substantial but surmountable.
 Early (exceptional) hands-on engineering experiences
like this can entice new students to study STEM and
motivate potential majors to stick with STEM studies.
James Flaten
Associate Director of the MN Space Grant
Aerospace Engineering and Mechanics (AEM) Department
University of Minnesota – Twin Cities
flaten@aem.umn.edu
http://www.aem.umn.edu/people/faculty/flaten/AEM1905BallooningSampleDocuments/