Solar Eclipse Ballooning with a Multiband Tracking Subsystem for Undergraduate Research Experience

This paper discusses an on-going research project that offers an undergraduate research platform in electrical and computer engineering (ECE), especially for high-altitude ballooning in near space, that attracts and engages students in undergraduate research early on, and improves their overall learning experience at college. We first briefly describe an existing ballooning system designed for the 2017 solar eclipse project, and then provide details of the subsystems of our own payload that integrates three different modes of communication technologies to enhance tracking capability of the balloon system. Combined with the Iridium-based balloon tracking, our multiband tracking system can be a useful tool for tracking of high-altitude ballooning systems and provide a platform of undergraduate research for further enhancements or modifications, ultimately contributing to improving the student learning experience. 1. Overview of the Project The Eclipse Ballooning Project 2017 [1] is a nationwide effort to facilitate and coordinate highaltitude balloon flights across the August 21, 2017 total eclipse path, sending live video and images from near space to a designated website. While video and images of a total solar eclipse (SE) from near space are fascinating and rare, collection of them has never been done live in a network of coverage across a continent [2]. For the facilitation of high-altitude ballooning by university/ college teams with varying levels of experience, a baseline system developed by the national project office has been provided to all teams in July 2016 but also with opportunities of further enhancing/ complementing the baseline system [3]. The baseline system consists of a ground station and four standard payloads for still image, video, Iridium-based tracking, and cut-down, respectively. As one of the teams from the commonwealth of Pennsylvania, an undergraduate project team at the University will launch a high-altitude ballooning system (HABS) for the August 21, 2017 solar eclipse from a pre-selected location in Kentucky as part of the nationwide coordination of colleges and universities to capture the entirety of the eclipses across the United States. In addition to the baseline system, our team has been developing an additional tracking system that utilizes three different modes of communication technologies, hereafter referred to as the multiband tracking subsystem (MTS), to ensure recovery of the HABS in Kentucky’s mountainous terrain. The three communication technologies that comprise the MTS include a 900 MHz RF system, an Automatic Packet Reporting System (APRS) operating at ~150 MHz, and a cellphone-based tracking system operating at ~2 GHz. The MTS also utilizes a Global Positioning System (GPS) receiver and a micro-controller unit (MCU). The payload’s real-time position will be acquired by the GPS receiver, and the MCU will convert the raw GPS data into a set of formatted strings of positioning information. These strings will then be transmitted to the ground where each subsystem’s receiving end will map and track the payload with real-time location-mapping software developed by the team utilizing Google Maps. The project team consists of eight undergraduate students, mostly ECE majors but including a science major, and two faculty advisors from the ECE and Physics departments. All students participate in this project as an extracurricular activity and do not receive any course credit toward completion of the ECE or science curriculum. For the remainder of this paper, we 1) present a brief description of the baseline system, as well as detailed descriptions of the MTS of our SE ballooning system, 2) identify key technical knowledge required for a successful design of the subsystems in reference to specific ECE course content, 3) present how the extracurricular research activities are administered to keep students motivated and engaged in the project, and 4) present and discuss assessment results on how these extracurricular project activities contribute to improving the student learning experience and thus student learning outcomes defined by ABET. 2. High-Altitude Ballooning System for Solar Eclipse 2.1. Brief Description of the Baseline System Figure 1 shows the functional diagram of the entire solar eclipse ballooning system. It consists of a balloon system, a baseline ground station, and an MTS mobile station. The balloon system consists of five payloads which include four baseline payloads for still image, video, Iridium, and cut-down of the baseline system. The fifth payload, MTS-Tx is an additional payload for a 3-mode tracking subsystem which will be further described along with its counterpart in the MTS mobile station in the subsequent sections. Although the balloon payloads operate on batteries, the ground station requires AC power. As such, a portable generator may be required to supply power to all components of the baseline ground station if the ground station is placed far from any source of AC power. On the other hand, the AC power to the MTS mobile station will be supplied from a