James Flaten Associate Director of the MN Space Grant Aerospace Engineering and Mechanics (AEM) Department University of Minnesota – Twin Cities

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?

Video clip of a recent launch from St. Peter, MN – June 5, 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.)?

1500 gram helium- filled latex weather balloon (AKA sounding balloon) 8-foot parachute Shroud lines and shroud ring Rockettes payload with mirror boom and cable up to sensor pack in the balloon above. Stratostar tracking package (GPS and ham radio #1) Stratostar tracking package (GPS and ham radio #2) Random Guys pay- load with Geiger counter experiment. BBBC payload with look-up video and audio recorder. Team Sweetness payload with look- down camera and filter wheel. 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.

Troposphere – up to 12 km (planes fly here) (weather happens here) Stratosphere – up to 50 km (balloons reach here) (includes the ozone layer) Mesosphere – up to 80 km Thermosphere – above 80 km (satellites fly here) The 4 layers of the atmosphere. 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 Where do HAB missions go and what is “near-space” like?

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) G enuine consumables (balloon, helium, batteries, mileage) – a bout $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 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. Resistive heater. Digital still camera. BASIC Stamp I Flight computer To record temp. & pressure in the balloon.

Thick styrofoam box construction. Mirrors on boom so camera can look out, up, and down. Cable running to sensor pack to be inserted in balloon.

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

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 1/30 th 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. Spaceflight with Ballooning Freshman Sem. Summer Ballooning Teams Technical Elective & Sr. Design Ballooning with pre-college groups High-power Rocketry Freshman Sem. Uninhabited Aerial Vehicles 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