2009 Issue

25 dollars. Additional flights costs are determined by expendables (batteries, helium, and the flight balloon) as well as transportation costs, which taken together are typically below $500 per flight. For example, the HARBOR flight system con- tains a Command and Telemetry System (CATS) built with a Garmin GPS 15LW chip receiver and antenna coupled to a Microtrak 8000 2-meter FM transmitter. CATS also controls a modified Nikon CoolPix digital camera. These are as- sembled with some custom-built timing circuitry and project Members of the recovery team enjoy their success. The addition of the parachute, ham anten- nas, payload boxes, custom box bags, line, and custom-built cut down system brings the total to $1500. This leaves room in the budget for instru- ments to characterize the payload environment, including a Pace scientific XR440 Pocket Logger with multiple pressure and temperature sensors. The entire base flight system, including instru- ments, boxes, and parachute, weighs less than 8.0 lbs. Given the modest cost, it is a useful exercise (and usually necessary) to build under a tight budget. This provides a realistic experience for students involved in the design process. They must determine which systems must be redundant, where they can splurge on off-the- shelf components, and when to save money by making their own custom components. Of course, if money is no object, the sky is the limit. Improvements can include a custom panoramic camera, an infrared camera, several additional sensors to determine the orientation of the stack during flight, and video capabilities. This is a primary advantage of high altitude ballooning: since the payload is recoverable, additional im- provements are relatively inexpensive and rarely require amajor re-design of the flight system. The HARBOR teamhas several extensions to our basic design underdevelopment, in the testing phase, or ready for the next flight season. It’s quick The total flight duration is from one to four hours, governed by the ascent rate and burst height of the balloon. Even including time for HARBOR team members release the flight stack. setup and recovery, flight operations can be completed in a day. Provided the recovery was successful and more expendables are on hand, the flight turnaround is nearly immediate. This combination of short flight duration and rapid turnaround provides for an accelerated design cycle, encouraging students to design, fly, modify, and fly again. This rapid turn-around also makes the high altitude balloon platform perfect for “guest payloads”. These can be parts or instruments that need to be tested in a real-world, extreme environment, or payloads provided by school or community groups interested in sending items to near-space. It’s accessible Since the flight line duties include basic opera- tions (such as holding the balloon or stabilizing the stack), new team members with developing skills can participate in the excitement of a launch with limited knowledge. As such, the flight team can involve new university students, younger students through school outreach programs, and local participants in the launch. And, since flight tracks are captured online, the progress of the flight can be monitored remotely. Community outreach is an automatic outcome of the flight experience. In our case, one call to Duchesne Mayor Clint Park resulted in several dozen participants and spectators from the com- munity. The extensive flight preparations of laying out the flight stack, readying the equipment, and filling the balloon always sparks interest. In fact, the HARBOR teamperiodically holds test fills and tethered launches with the express purpose of attracting a crowd. Perhaps most importantly, the activity is specifically allowed by the FAA, governed by Flight image from 79,000 feet. continued on page 35